Pre-1987 (Eroica Compliant)

Cable Routing - non-aero means the cables come out at the top of the brake levers, meaning the cables are on show. With aero levers the cable comes out of a small hole by the handlebar, allowing the cables to be hidden under the handlebar tape.

Bar Clamp Size - this should be close to the outside diameter of your handlebars at the point the brake levers will be fitted. This will rarely present a problem with drop bars as 23.8 mm is standard, and a 24.2 mm clamp will fit just fine as they do have a little adjustment in them. There are some older sizes to watch out for but these will be noticeably different.

Cable Routing - non-aero means the cables come out at the top of the brake levers, meaning the cables are on show. With aero levers the cable comes out of a small hole by the handlebar, allowing the cables to be hidden under the handlebar tape.

Bar Clamp Size - this should be close to the outside diameter of your handlebars at the point the brake levers will be fitted. This will rarely present a problem with drop bars as 23.8 mm is standard, and a 24.2 mm clamp will fit just fine as they do have a little adjustment in them. There are some older sizes to watch out for but these will be noticeably different.

Cable Routing - non-aero means the cables come out at the top of the brake levers, meaning the cables are on show. With aero levers the cable comes out of a small hole by the handlebar, allowing the cables to be hidden under the handlebar tape.

Bar Clamp Size - this should be close to the outside diameter of your handlebars at the point the brake levers will be fitted. This will rarely present a problem with drop bars as 23.8 mm is standard, and a 24.2 mm clamp will fit just fine as they do have a little adjustment in them. There are some older sizes to watch out for but these will be noticeably different.

Drilling - the number of holes for the spokes.

Rim Size - the sizing given by the manufacturer, these can be confusing so we also give the ISO diameter too for clarification.

ISO Diameter - the diameter of the rim at the point where the tyre is seated (bead seat diameter). This is a universal measurement, often displayed on tyres as 28-622 or similar, 28 referring to the tyre width and 622 being the ISO diameter in millimetres.

Valve Type - presta valves are the thin ones and Schraeder are the fatter ones. Schraeder valve holes will also accept the older Dunlop/Woods type valves.

Rim Width (OD) - the width of the rim, measured from the outside of one wall to the other.

Rim Height - the overall height of the rim, measured to the highest point of the rim’s profile.

Pit to Pit - this measurement is taken from the centre of one armpit to the other, across the chest with the jersey laid flat.

Top to Bottom - this will always be from the very top of the collar to the very bottom hem, we provide measurements for both the front and back, always taken with the jersey laid flat.

Shoulder Seam to Sleeve End - this measurement is taken from the shoulder seam down to the very end of the sleeve on the outside.

Across Neck - for consistency on all neck shapes we gather the front and back together and lay them flat, then measure across the stitching (as shown in the supporting photos).

Across Sleeve End - measured across the sleeve end, laid flat.

Pit to Pit - this measurement is taken from the centre of one armpit to the other, across the chest with the jersey laid flat.

Top to Bottom - this will always be from the very top of the collar to the very bottom hem, we provide measurements for both the front and back, always taken with the jersey laid flat.

Shoulder Seam to Sleeve End - this measurement is taken from the shoulder seam down to the very end of the sleeve on the outside.

Across Neck - for consistency on all neck shapes we gather the front and back together and lay them flat, then measure across the stitching (as shown in the supporting photos).

Across Sleeve End - measured across the sleeve end, laid flat.

Chainring Count - the number of chainrings the crank was designed to fit. Fixed gear track bikes, single-speeds and some geared bikes use a single chainring, road bikes commonly use a double (two rings) and most touring bikes and mountain bikes will use a triple chainset (three rings).

BCD - stands for Bolt Circle Diameter (sometimes referred to as PCD - Pitch Circle Diameter), and this needs to match the BCD of your chainring(s). To calculate this, measure the distance in millimeters from the centre of any chainring bolt hole to the centre of an adjacent one and multiply it by 1.709 (you’ll likely need to round the resulting number up or down a little to get your BCD measurement).

Crank Arm Length - this is measured from the absolute centre of the bottom bracket hole to the centre of the hole for the pedal.

Pedal Threads - the pattern of the thread that your pedals screw into, this is usually stamped on the pedals themselves and most bikes use a standard thread of 9/16” x 20 tpi. The exceptions being older French bikes, bikes with cheaper one-piece type chainsets and Shimano’s Dyna Drive system (easily identifiable as the pedal holes are about an inch wide!).

Bottom Bracket Type - ‘square taper’, as the name suggests have a square shaped axle that slots into the crank and ‘cottered’ axles are round and secured by pins - pretty much every bike up until the 1990s would use one of these, cottered being the much earlier system. Since then, different manufacturers have introduced their own systems that are not interchangeable so you must use a crank that matches.

Drilling - the number of holes for the spokes.

Rim Size - the sizing given by the manufacturer, these can be confusing so we also give the ISO diameter too for clarification.

ISO Diameter - the diameter of the rim at the point where the tyre is seated (bead seat diameter). This is a universal measurement, often displayed on tyres as 28-622 or similar, 28 referring to the tyre width and 622 being the ISO diameter in millimetres.

Valve Type - presta valves are the thin ones and Schraeder are the fatter ones. Schraeder valve holes will also accept the older Dunlop/Woods type valves.

Rim Width (OD) - the width of the rim, measured from the outside of one wall to the other.

Rim Height - the overall height of the rim, measured to the highest point of the rim’s profile.

Size - this is the manufacturer’s sizing and must match the size or your wheels. This can be confusing as tyres have had different sizing systems over the years, and there are many (sometimes conflicting) sizes available. For this reason it’s important to check the ISO diameter too for clarification, especially for 26” wheels.

Bike Type - the type of bike the tyres were designed to be used on. Road tyres will generally be narrow with minimal tread, touring tyres wider with a bit more grip in the tread, and cyclocross & MTB tyres wider still (especially the latter), with a much more pronounced tread pattern.

ISO Diameter - this relates to the diameter of the wheel rims at the point where the tyres are seated (bead seat diameter). This is a universal measurement, often displayed on tyres as 28-622 or similar, 28 referring to the tyre width and 622 being the ISO diameter in millimetres.

TPI - stands for threads per inch and refers to the thread count of the tyre casings. A high thread count usually means more supple and lighter tyres, this can be anything as high as 320 tpi. We can’t always provide this information however, as it’s not always possible to know for sure.

Drilling - the number of holes for the spokes.

Rim Size - the sizing given by the manufacturer, these can be confusing so we also give the ISO diameter too for clarification.

ISO Diameter - the diameter of the rim at the point where the tyre is seated (bead seat diameter). This is a universal measurement, often displayed on tyres as 28-622 or similar, 28 referring to the tyre width and 622 being the ISO diameter in millimetres.

Valve Type - presta valves are the thin ones and Schraeder are the fatter ones. Schraeder valve holes will also accept the older Dunlop/Woods type valves.

Rim Width (OD) - the width of the rim, measured from the outside of one wall to the other.

Rim Height - the overall height of the rim, measured to the highest point of the rim’s profile.

Valve Type - there are 3 types of valves; Presta are thin with a little knurled nut on the end, Schrader are wider (the same as you would find on a car), and the less common Woods (aka "Dunlop"). Pumps designed for Presta valves can be used on Woods valves. Some pumps use hose connectors, these are available for all valve types.

Pump Mount Type - 'peg fit' pumps require pump pegs or 'umbrella' clips to fit to the frame, 'frame fit 'pumps are designed with curved ends to mount between two tubes (although these often have holes for pegs too). If mounting directly you'll need the correct length to fit your frame, or a clip/peg to hold one end.

Mount Location - frame fit pumps usually mount to the seat tube with the ends compressed between the top and down tube, they can however be mounted on other tubes as long as there's something supporting the handle end. Some head tubes have a little nipple or a small enough gap for under top tube mounting (this can be replcated with a simple strap or cable tie), and of course pump pegs or clips can be fitted anywhere!

Length (Min-Max) - the length of the pump fully compressed and uncompressed, measured at the points of support. The space you to intend to mount the pump should be within 1 cm of the minimum or maximum length to allow the pump to be securely mounted and dismounted.

Shifting system - friction means your gear levers don't click when you change gear, when they do click it's referred to as indexed shifting. If you have indexed gear levers they must use the same system as the rear derailleur, if you're using friction levers you can mix and match.

*Speed - the number of cogs at the back the derailleur was designed to be used with. This is important with indexed shifting, but with friction shifters you can in theory run any rear mech with any number of cogs, but you are more likely to have issues running high numbers of cogs with mechs from earlier eras.

Max cog size - the amount of teeth on the largest cog of your freewheel/cassette can be no greater than this to work with this derailleur.

Chain wrap - subtract the size of your smallest rear cog from your biggest, then do the same with your chainrings, add the 2 numbers together and you have your chain wrap.

Chain width - generally speaking, derailleurs designed for more than 3 speed use will fit a standard 3/32'' chain, the exception being some Cyclo & Simplex models from around the mid 1900s.

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.

Seatpost Diameter - this needs to match the internal diameter of your frame’s seat tube closely, it should be possible to insert the seatpost without force but the fit should be tight enough so it doesn’t just drop in, with no play once inserted. If you have a post that fits the measurement should be stamped somewhere near the bottom, if not you’ll need to measure with a caliper or seatpost sizing tool as the sizes go up in 0.2 mm increments.

Length (Centre of Rails to Base) - measured from where the centre of the saddle rails will sit once installed, all the way to the bottom of the seatpost. Normally there’s a mark to tell you how much of the seatpost needs to be inserted in the frame, however this isn’t always the case so we’d recommend allowing a minimum of 6 cm.