Pre-1987 (Eroica Compliant)

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

Speed - the number of cogs on the freewheel.

Range - the number of teeth on the smalles and largest cogs, this gives you an indication of how hard or easy the gearing will be, the lower the number the harder the gears. The tooth count of the cogs inbetween are usually evenly spaced, ie: a 6 speed 14-24 freewheel would likely have cog sizes 14, 16, 18, 20, 22 & 24.

Threading - this needs to match the thread of your rear hub. ISO is the modern standard and is almost exactly the same as older English/British and Italian thread, allowing you to mix and match between these thread types as long as it's not going to be under extreme force, in which case it's best to stick to an exact match. Hubs with a French thread must be used with a French threaded freewheel.

Stack Height - the total height (or width if you're looking at it when installed) of the freewheel, this is measured from the base (back of the largest cog) to the top (front of the smallest cog).

Chain width - this is mainly relevant for singlespeed and some older 3 or 4 speed freewheels - if this is ⅛” then you must use a ⅛” chain, but most freewheels (especially multiple speed ones) will use a standard 3/32” chain.

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

Chainset Type - the number of chainrings the derailleur was designed to work with. ‘Double’ derailleurs are actually capable of working on ‘triple’ chainsets but they may struggle when shifting, especially if there’s a big step down from the middle to inner ring, so it’s better to match these correctly.

Frame Fixing - the way the derailleur fixes to the frame, if you have a tab on your frame to mount the derailleur to you need braze-on. If there’s no tab then you require a clamp-on type (also referred to as band-on or clip-on), these come in different sizes to match the diameter of your seat tube.

Pull Type - the direction of which the cable needs to ‘pull’ the mech in order to shift. If your cable runs up to the derailleur from the bottom bracket area then you need bottom pull, if your cable comes down from above you need top pull. Some later derailleurs can be used for either setups, these are referred to as dual pull.

Designated Speed (9 Speed & Above) - the speed of the chain that the mech was designed to be used with. This only becomes relevant for mechs marketed as 9 speed or above when chains became narrower, as the derailleur cage plates became marginally narrower too. We refer to it as ‘designated’ speed as technically you can use (almost) any derailleur with any chain, however if you want optimum performance it’s best to stay close to the manufacturers recommendations.

Indexing System (Shimano Only) - this is only applicable when using Shimano shifters that have an indexed left shifter such as STI or Rapidfire. For the indexing to work correctly when using these shifters the derailleur and shifters must be of the same type, so Shimano drop bar shifters need to be matched with a Shimano ‘road’ derailleur, and Shimano flat bar shifters must be used with Shimano ‘MTB’ derailleurs.

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

Thread Type - this must match the bottom bracket thread on your frame. The 3 common thread types on classic and vintage bikes are English (also known as British or ISO), Italian & French, and are usually (not always!) found on frames built in their respective countries. If you're replacing a bottom bracket the cups should have the thread type stamped on one of them, if not there are a couple of things to look at; bottom bracket shell width (English & French = 68 mm, Italian = 70 mm) & drive side cup thread direction (English = left, Italian & French = right). The only curveball to watch out for here, although pretty uncommon, are Swiss threads (also found on some French frames, Motobecanes being one) which will have the same shell width & thread direction as an English thread frame but the actual thread pitch will be different. If none of the above matches what you have, there are a few lesser known varieties that will require some further research.

Axle Length - your crankset dictates the axle length you need and the recommendation should be used to avoid issues with chainline. If you're replacing a bottom bracket that works perfectly then this can be matched, otherwise you'll need to check the manufacturers spec, a good resource for older bikes is Velobase.

Axle Type - you can tell which type of axle you need by looking at the shape of the bottom bracket hole in your crankset. For square tapers, the ISO introduced a standard for European makers in the early 90s, JIS then did the same in Asia. Before then it was not so simple, and although there is a degree of interchangeability, the best way to make sure you have the right axle is to stick to the same brand from the same era, ideally the proprietary model.

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

Fixing Type - if you have small mounts on either side of the frame’s down tube you need braze-on shifters, if there are no mounts you’ll need clamp-on (sometimes referred to as band-on). Some 'aero' frames have mounts fixed to the top of the down tube, for these frames you require top mount shifters for the correct boss type (see below).

Shift Type - friction shifters don't click into gear when you change, when they do click it's referred to as indexed shifting. For this to work correctly you must use the same system as your rear derailleur, if you're using friction levers you can mix and match. You don't need to worry about the front derailleur as left downtube shifters aren't indexed.

Speed - the number of cogs at the back the right shifter is designed to be used with. This is important with indexed shifting but with friction shifters you can in theory run any shifters with any speed setup, although the right lever will need to be pulled back further to shift into the larger cogs.

Shifter Boss Type - the shape of the mount (for braze-on fixings only). Campagnolo / ISO is standard and easily identified by the flat sections on either side, usually combined with a square base for the backing stop plates to fit. There are also Shimano ones with a keyhole shaped base and much less common French ones that are round with no flat sections.

Boss Thread Size - M5 (5 mm) is standard for Campagnolo / ISO bosses, but Shimano bosses will often have M4.5 (4.5 mm) threads and the French bosses would likely have 5 x 1 mm threads.

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

Fixing Type - if you have small mounts on either side of the frame’s down tube you need braze-on shifters, if there are no mounts you’ll need clamp-on (sometimes referred to as band-on). Some 'aero' frames have mounts fixed to the top of the down tube, for these frames you require top mount shifters for the correct boss type (see below).

Shift Type - friction shifters don't click into gear when you change, when they do click it's referred to as indexed shifting. For this to work correctly you must use the same system as your rear derailleur, if you're using friction levers you can mix and match. You don't need to worry about the front derailleur as left downtube shifters aren't indexed.

Speed - the number of cogs at the back the right shifter is designed to be used with. This is important with indexed shifting but with friction shifters you can in theory run any shifters with any speed setup, although the right lever will need to be pulled back further to shift into the larger cogs.

Shifter Boss Type - the shape of the mount (for braze-on fixings only). Campagnolo / ISO is standard and easily identified by the flat sections on either side, usually combined with a square base for the backing stop plates to fit. There are also Shimano ones with a keyhole shaped base and much less common French ones that are round with no flat sections.

Boss Thread Size - M5 (5 mm) is standard for Campagnolo / ISO bosses, but Shimano bosses will often have M4.5 (4.5 mm) threads and the French bosses would likely have 5 x 1 mm threads.

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

Chainset Type - the number of chainrings the derailleur was designed to work with. ‘Double’ derailleurs are actually capable of working on ‘triple’ chainsets but they may struggle when shifting, especially if there’s a big step down from the middle to inner ring, so it’s better to match these correctly.

Frame Fixing - the way the derailleur fixes to the frame, if you have a tab on your frame to mount the derailleur to you need braze-on. If there’s no tab then you require a clamp-on type (also referred to as band-on or clip-on), these come in different sizes to match the diameter of your seat tube.

Pull Type - the direction of which the cable needs to ‘pull’ the mech in order to shift. If your cable runs up to the derailleur from the bottom bracket area then you need bottom pull, if your cable comes down from above you need top pull. Some later derailleurs can be used for either setups, these are referred to as dual pull.

Designated Speed (9 Speed & Above) - the speed of the chain that the mech was designed to be used with. This only becomes relevant for mechs marketed as 9 speed or above when chains became narrower, as the derailleur cage plates became marginally narrower too. We refer to it as ‘designated’ speed as technically you can use (almost) any derailleur with any chain, however if you want optimum performance it’s best to stay close to the manufacturers recommendations.

Indexing System (Shimano Only) - this is only applicable when using Shimano shifters that have an indexed left shifter such as STI or Rapidfire. For the indexing to work correctly when using these shifters the derailleur and shifters must be of the same type, so Shimano drop bar shifters need to be matched with a Shimano ‘road’ derailleur, and Shimano flat bar shifters must be used with Shimano ‘MTB’ derailleurs.

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

Speed - the number of cogs on the freewheel.

Range - the number of teeth on the smalles and largest cogs, this gives you an indication of how hard or easy the gearing will be, the lower the number the harder the gears. The tooth count of the cogs inbetween are usually evenly spaced, ie: a 6 speed 14-24 freewheel would likely have cog sizes 14, 16, 18, 20, 22 & 24.

Threading - this needs to match the thread of your rear hub. ISO is the modern standard and is almost exactly the same as older English/British and Italian thread, allowing you to mix and match between these thread types as long as it's not going to be under extreme force, in which case it's best to stick to an exact match. Hubs with a French thread must be used with a French threaded freewheel.

Stack Height - the total height (or width if you're looking at it when installed) of the freewheel, this is measured from the base (back of the largest cog) to the top (front of the smallest cog).

Cog width - this is mainly relevant for singlespeed and some older 3 or 4 speed freewheels - if this is ⅛” then you must use a ⅛” chain, but most freewheels (especially multiple speed ones) will use a standard 3/32” chain.

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 working days but larger items can often take a little longer to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import duties to pay upon receipt (even with the new post-Brexit trade deals, some countries may still charge you import VAT & clearance fees, so please bear this in mind when purchasing).

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

Speed - the number of cogs on the freewheel.

Range - the number of teeth on the smalles and largest cogs, this gives you an indication of how hard or easy the gearing will be, the lower the number the harder the gears. The tooth count of the cogs inbetween are usually evenly spaced, ie: a 6 speed 14-24 freewheel would likely have cog sizes 14, 16, 18, 20, 22 & 24.

Threading - this needs to match the thread of your rear hub. ISO is the modern standard and is almost exactly the same as older English/British and Italian thread, allowing you to mix and match between these thread types as long as it's not going to be under extreme force, in which case it's best to stick to an exact match. Hubs with a French thread must be used with a French threaded freewheel.

Stack Height - the total height (or width if you're looking at it when installed) of the freewheel, this is measured from the base (back of the largest cog) to the top (front of the smallest cog).

Cog width - this is mainly relevant for singlespeed and some older 3 or 4 speed freewheels - if this is ⅛” then you must use a ⅛” chain, but most freewheels (especially multiple speed ones) will use a standard 3/32” chain.

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

Speed - the number of cogs on the freewheel.

Range - the number of teeth on the smalles and largest cogs, this gives you an indication of how hard or easy the gearing will be, the lower the number the harder the gears. The tooth count of the cogs inbetween are usually evenly spaced, ie: a 6 speed 14-24 freewheel would likely have cog sizes 14, 16, 18, 20, 22 & 24.

Threading - this needs to match the thread of your rear hub. ISO is the modern standard and is almost exactly the same as older English/British and Italian thread, allowing you to mix and match between these thread types as long as it's not going to be under extreme force, in which case it's best to stick to an exact match. Hubs with a French thread must be used with a French threaded freewheel.

Stack Height - the total height (or width if you're looking at it when installed) of the freewheel, this is measured from the base (back of the largest cog) to the top (front of the smallest cog).

Chain width - this is mainly relevant for singlespeed and some older 3 or 4 speed freewheels - if this is ⅛” then you must use a ⅛” chain, but most freewheels (especially multiple speed ones) will use a standard 3/32” chain.

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

Speed - the number of cogs on the freewheel.

Range - the number of teeth on the smalles and largest cogs, this gives you an indication of how hard or easy the gearing will be, the lower the number the harder the gears. The tooth count of the cogs inbetween are usually evenly spaced, ie: a 6 speed 14-24 freewheel would likely have cog sizes 14, 16, 18, 20, 22 & 24.

Threading - this needs to match the thread of your rear hub. ISO is the modern standard and is almost exactly the same as older English/British and Italian thread, allowing you to mix and match between these thread types as long as it's not going to be under extreme force, in which case it's best to stick to an exact match. Hubs with a French thread must be used with a French threaded freewheel.

Stack Height - the total height (or width if you're looking at it when installed) of the freewheel, this is measured from the base (back of the largest cog) to the top (front of the smallest cog).

Cog width - this is mainly relevant for singlespeed and some older 3 or 4 speed freewheels - if this is ⅛” then you must use a ⅛” chain, but most freewheels (especially multiple speed ones) will use a standard 3/32” chain.

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

Crank Bolt Type - 15 mm hex bolts used to be standard but some older TA, Stronglight and Zeus cranks used a larger 16 mm bolt, plus a few Japanese makers used a smaller 14 mm hex head. Allen key types were introduced in the 1980s and some are self-extracting, which means the crank removes itself when you undo the bolts.

Crank Bolt Thread - All square taper bottom brackets have a standard M8 x 1 mm thread, the only different thread types you’ll find on crank bolts are the much larger M12 & M15 bolts that are specifically for Octalink and ISIS bottom brackets.

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

Cable Type - brake and gear cables have different specifications and are not interchangeable.

Length (F/R) - it's important to check the cables are long enough for your setup. Some gear cables are designed for downtube gear levers only and there won't be enough cable to be used otherwise.

End Nipple Type - only relevant for brake cables. 'Pear' type cable ends step down in size to allow them to be used with drop bar levers normally found on road bikes, whereas flat bar levers usually require a 'barrel' end that sits in a similar shape slot within the brake levers.

End Diameter - for 'pear' type ends this is the diameter at its widest part, with barrel ends it's the diameter of the circular part.

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

Speed - the number of cogs on the freewheel.

Range - the number of teeth on the smalles and largest cogs, this gives you an indication of how hard or easy the gearing will be, the lower the number the harder the gears. The tooth count of the cogs inbetween are usually evenly spaced, ie: a 6 speed 14-24 freewheel would likely have cog sizes 14, 16, 18, 20, 22 & 24.

Threading - this needs to match the thread of your rear hub. ISO is the modern standard and is almost exactly the same as older English/British and Italian thread, allowing you to mix and match between these thread types as long as it's not going to be under extreme force, in which case it's best to stick to an exact match. Hubs with a French thread must be used with a French threaded freewheel.

Stack Height - the total height (or width if you're looking at it when installed) of the freewheel, this is measured from the base (back of the largest cog) to the top (front of the smallest cog).

Cog width - this is mainly relevant for singlespeed and some older 3 or 4 speed freewheels - if this is ⅛” then you must use a ⅛” chain, but most freewheels (especially multiple speed ones) will use a standard 3/32” chain.

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

Fixing Type - if you have small mounts on either side of the frame’s down tube you need braze-on shifters, if there are no mounts you’ll need clamp-on (sometimes referred to as band-on). Some 'aero' frames have mounts fixed to the top of the down tube, for these frames you require top mount shifters for the correct boss type (see below). There are also 'Clamp-Over' shifters that allow front & rear shifters to be used on a frame that only has a single braze-on.

Shift Type - friction shifters don't click into gear when you change, when they do click it's referred to as indexed shifting. For this to work correctly you must use the same system as your rear derailleur, if you're using friction levers you can mix and match. You don't need to worry about the front derailleur as left downtube shifters aren't indexed.

Speed - the number of cogs at the back the right shifter is designed to be used with. This is important with indexed shifting but with friction shifters you can in theory run any shifters with any speed setup, although the right lever will need to be pulled back further to shift into the larger cogs.

Shifter Boss Type - the shape of the mount (for braze-on fixings only). Campagnolo / ISO is standard and easily identified by the flat sections on either side, usually combined with a square base for the backing stop plates to fit. There are also Shimano ones with a keyhole shaped base and much less common French ones that are round with no flat sections.

Boss Thread Size - M5 (5 mm) is standard for Campagnolo / ISO bosses, but Shimano bosses will often have M4.5 (4.5 mm) threads and the French bosses would likely have 5 x 1 mm threads.

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

Chainset Type - the number of chainrings the derailleur was designed to work with. ‘Double’ derailleurs are actually capable of working on ‘triple’ chainsets but they may struggle when shifting, especially if there’s a big step down from the middle to inner ring, so it’s better to match these correctly.

Frame Fixing - the way the derailleur fixes to the frame, if you have a tab on your frame to mount the derailleur to you need braze-on. If there’s no tab then you require a clamp-on type (also referred to as band-on or clip-on), these come in different sizes to match the diameter of your seat tube.

Pull Type - the direction of which the cable needs to ‘pull’ the mech in order to shift. If your cable runs up to the derailleur from the bottom bracket area then you need bottom pull, if your cable comes down from above you need top pull. Some later derailleurs can be used for either setups, these are referred to as dual pull.

Designated Speed (9 Speed & Above) - the speed of the chain that the mech was designed to be used with. This only becomes relevant for mechs marketed as 9 speed or above when chains became narrower, as the derailleur cage plates became marginally narrower too. We refer to it as ‘designated’ speed as technically you can use (almost) any derailleur with any chain, however if you want optimum performance it’s best to stay close to the manufacturers recommendations.

Indexing System (Shimano Only) - this is only applicable when using Shimano shifters that have an indexed left shifter such as STI or Rapidfire. For the indexing to work correctly when using these shifters the derailleur and shifters must be of the same type, so Shimano drop bar shifters need to be matched with a Shimano ‘road’ derailleur, and Shimano flat bar shifters must be used with Shimano ‘MTB’ derailleurs.

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

Thread Type - this must match the bottom bracket thread on your frame. The 3 common thread types on classic and vintage bikes are English (also known as British or ISO), Italian & French, and are usually (not always!) found on frames built in their respective countries. If you're replacing a bottom bracket the cups should have the thread type stamped on one of them, if not there are a couple of things to look at; bottom bracket shell width (English & French = 68 mm, Italian = 70 mm) & drive side cup thread direction (English = left, Italian & French = right). The only curveball to watch out for here, although pretty uncommon, are Swiss threads (also found on some French frames, Motobecanes being one) which will have the same shell width & thread direction as an English thread frame but the actual thread pitch will be different. If none of the above matches what you have, there are a few lesser known varieties that will require some further research.

Axle Length - your crankset dictates the axle length you need and the recommendation should be used to avoid issues with chainline. If you're replacing a bottom bracket that works perfectly then this can be matched, otherwise you'll need to check the manufacturers spec, a good resource for older bikes is Velobase.

Axle Type - you can tell which type of axle you need by looking at the shape of the bottom bracket hole in your crankset. For square tapers, the ISO introduced a standard for European makers in the early 90s, JIS then did the same in Asia. Before then it was not so simple, and although there is a degree of interchangeability, the best way to make sure you have the right axle is to stick to the same brand from the same era, ideally the proprietary model.

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

Housing Type - brake and gear cables have different specifications and are generally not interchangeable, although older bikes with non-index shifting often used brake housing instead of gear. We'd still recommend using the dedicated front or rear derailleur cable housings for non-index setups whenever possible.

Casing Width - the outside diameter of the housing. Brake cable housing is a little wider in diameter than gear, this is to accommodate the slightly thicker inner cables.

Ferrule Size - if ferrules are included, this measurement is of the outside diameter at the widest part

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

Housing Type - brake and gear cables have different specifications and are generally not interchangeable, although older bikes with non-index shifting often used brake housing instead of gear. We'd still recommend using the dedicated front or rear derailleur cable housings for non-index setups whenever possible.

Casing Width - the outside diameter of the housing. Brake cable housing is a little wider in diameter than gear, this is to accommodate the slightly thicker inner cables.

Ferrule Size - if ferrules are included, this measurement is of the outside diameter at the widest part

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

Axle Type - for square tapers, the ISO introduced a standard for European makers in the early 90s, JIS then did the same in Asia. Before then it was not so simple, and although there is a degree of interchangeability, the best way to make sure you have the right axle is to stick to the same brand from the same era, ideally the proprietary model.

Axle Length (D) - your crankset dictates the axle length you need and the recommendation should be used to avoid issues with chainline. If you're replacing an axle that works perfectly then this can be matched, otherwise you'll need to check the manufacturers spec, a good resource for older bikes is Velobase.

Centre (B) - measured from the outside of the 'shoulders' of the bearing races, as seen in the diagram.

Drive Side (C) - the right side (with any logos etc on the axle facing you), your right crank and chainrings will mount to this side.

Non-Drive Side (A) - the left side, where the left crank arm will be mounted.

Shell Width - the width of the bottom bracket shell the axle was designed to fit, measured at its widest point.

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 working days but larger items can often take a little longer to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import duties to pay upon receipt (even with the new post-Brexit trade deals, some countries may still charge you import VAT & clearance fees, so please bear this in mind when purchasing).

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

Crank Bolt Type - 15 mm hex bolts used to be standard but some older TA, Stronglight and Zeus cranks used a larger 16 mm bolt, plus a few Japanese makers used a smaller 14 mm hex head. Allen key types were introduced in the 1980s and some are self-extracting, which means the crank removes itself when you undo the bolts.

Crank Bolt Thread - All square taper bottom brackets have a standard M8 x 1 mm thread, the only different thread types you’ll find on crank bolts are the much larger M12 & M15 bolts that are specifically for Octalink and ISIS bottom brackets.

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

Speed - the number of cogs on the freewheel.

Range - the number of teeth on the smalles and largest cogs, this gives you an indication of how hard or easy the gearing will be, the lower the number the harder the gears. The tooth count of the cogs inbetween are usually evenly spaced, ie: a 6 speed 14-24 freewheel would likely have cog sizes 14, 16, 18, 20, 22 & 24.

Threading - this needs to match the thread of your rear hub. ISO is the modern standard and is almost exactly the same as older English/British and Italian thread, allowing you to mix and match between these thread types as long as it's not going to be under extreme force, in which case it's best to stick to an exact match. Hubs with a French thread must be used with a French threaded freewheel.

Stack Height - the total height (or width if you're looking at it when installed) of the freewheel, this is measured from the base (back of the largest cog) to the top (front of the smallest cog).

Cog width - this is mainly relevant for singlespeed and some older 3 or 4 speed freewheels - if this is ⅛” then you must use a ⅛” chain, but most freewheels (especially multiple speed ones) will use a standard 3/32” chain.

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

Number of Cables - the number of cables the guide is designed to accept.

Guide Type - some setups require specific guides for the derailleurs to operate correctly. Tunnels simply act as a channel to guide the cable whereas stops create an end point for the cable housing, giving the cable the leverage it needs. Bar control stops are required when using handlebar shifters if your frame doesn't have any guides or braze-ons.

Tube Diameter - most steel (and early lugged aluminium) frames will have a down tube of 28.0 mm - 28.6 mm, this was standard for a long time but there are 'oversized' steel and aluminium tubes that have a diameter of 31.8, 34.9 and even 38.1 mm.

We've been safely sending orders around the world since 2010. There's a handy shipping calculator on the shopping cart page so you can see the cost of postage as soon as you've added it to your basket. Your order will be carefully packed and sent with tracking & insurance, we despatch most orders within 2-3 days but larger items and orders placed before the weekend can take an extra day or two to process.

We accept returns, please notify us within 14 days and ensure the item arrives back with us no later than 30 days after the order was received.

We don't charge VAT, however, if buying from outside of the UK please remember that there may be import fees to pay directly to the delivery company before receiving the order. Unfortunately we can’t advise on the exact costs as it varies from country to country, so please check your national rates before purchasing.

Crank Thread - 22 mm is the standard thread for almost all cotterless cranks, the only exceptions are some Stronglight cranks made up until the early 1980s, and Specialites T.A. Campagnolo produced some self-extracting crank bolts with covers that had a reverse thread.