Reference
Compatibility and sizing references for bike parts — freehub bodies, bottom brackets, axles and more. Each page is a straight-answer chart you can check before you buy.
Shimano GRX Compatibility: 11-Speed, 12-Speed and Upgrade Paths
GRX series numbers track tier, not speed count, which is where most mistakes start. This reference covers the 10, 11 and 12-speed generations, the 2.5mm chainline offset that separates GRX from road...
Tubeless Valves, Tape and Sealant: What Size and How Much
Short answer: tape width is internal rim width plus about 5mm. Valve length is rim depth plus at least 15mm. Sealant is 30 to 60ml per road tyre, 60 to 90ml for...
Wheel and Hub Compatibility: Spokes, Spacing and Rim Depth
Short answer: a wheel fits your bike if five things match: hub spacing, axle type, freehub type, rotor mount and rim size. Hub spacing is the one people get wrong. Modern road...
Bicycle Torque Specifications by Component
Short answer: most small clamp bolts on a bike want 5 to 6Nm, most large drivetrain interfaces want 35 to 50Nm, and disc rotor bolts want 2 to 4Nm. Those three bands...
Crank Length and Chainring Compatibility
Two different 110mm bolt patterns that fit nothing in common, the minimum ring size your crank allows, which spindle standard matches which bottom bracket, and why shorter cranks have become the default...
Brake Compatibility: Mounts, Fluids and Upgrades
Flat mount, post mount and which adapters genuinely exist. Why the old rule that Shimano means mineral oil and SRAM means DOT no longer holds, what happens when the two are mixed,...
Saddle Width and Sit Bone Sizing: Getting It Right
Measure your sit bones, then match the saddle's stated range rather than adding a fixed number to it. Real ranges by model, the Selle Italia S and L numbering decoded, and why...
Seatpost Diameters and Setback: What Fits Your Frame?
Seatpost sizes are separated by fractions of a millimetre and there is no near enough. Common diameters, why clamp size is a different number entirely, setback as a fit choice, dropper post...
Cassette and Gear Ratios: What Fits and What to Choose
What 11-32T actually means, how to work out your easiest gear as a single comparable number, the freehub and derailleur limits that decide what you can fit, and which ratios suit short...
Handlebar and Stem Sizing: What Fits Your Bike?
Clamp diameters, steerer sizes, and the width measurement trap that makes a Deda 42 roughly a 40 from any other brand. Choosing stem length and bar width, what integrated cockpits lock you...
FLR Cycling Shoe Size Chart: Finding Your Size
FLR road, triathlon, MTB and gravel shoes share one conversion scale. The full chart from EU 38 to 49 with foot length in centimetres, how to measure under load, and the five...
Brake Pad Compatibility: Which Pads Fit Your Bike?
Disc pads are shaped to a caliper, not a bike brand. Pad shapes by caliper family, organic versus sintered, the resin-only rotor warning, and why fitting alloy rim pads to carbon rims...
Cycling Helmet Size Chart: Sizing by Head Circumference
Helmet sizes are not standardised between brands. A 54cm head is a Small in five brands and a Medium in three others. Head circumference charts for every brand we stock, plus the...
Bicycle Chain Compatibility: Which Chain Fits Your Drivetrain?
Chain speed is chain width. The full width chart, where brands can safely be mixed, why 12-speed broke the old rules, quick link reusability by speed, and how to cut a chain...
Pedal and Cleat Compatibility: Which Cleats Fit Your Pedals?
Cleats are specific to a pedal system, not a shoe brand. Bolt patterns, why SPD-SL and Look Keo cannot be mixed, float colours explained, the SH51 and SH56 difference, and when a...
Tyre and Rim Width Compatibility: What Fits Your Wheels
Tyre width must fall between 1.4 and 2.5 times the internal rim width. The full chart, hookless pressure and width limits, ETRTO markings, and why fitted width differs from the sidewall number.
Disc Rotor Standards: Centerlock, 6-Bolt, Sizes and Adapters
Three questions get confused here: how the rotor attaches to the hub, how big it is, and how the calliper attaches to the frame. Full tables for 6-bolt and Centerlock, rotor sizes,...
Bike Frame Size Chart: Sizing by Height and Inseam
Height gives you a starting range, inseam narrows it, and neither settles it. Charts for road, gravel and MTB, how to measure inseam properly, why a 56cm from one brand isn't a...
Thru-Axle and Quick Release Sizing: Which Axle Fits Your Bike?
An axle needs three numbers: diameter, hub width and thread pitch. Full tables for front and rear standards from QR through 12x142 and Boost, why two 12x142 frames can need different axles,...
Bottom Bracket Standards: Which Bottom Bracket Fits Your Frame?
Which bottom bracket fits your frame? You need two things: the shell standard and your crank's spindle. Full tables for BSA, Italian, T47, BB86, BB30, PF30, BB386EVO and BBRight, matched against Shimano...
Freehub and Cassette Compatibility: Which Cassette Fits Your Wheel?
Which cassettes fit your wheel? Full compatibility tables for Shimano HG, 11-speed road, Micro Spline, SRAM XD and XDR, and Campagnolo — how to identify what you have, when you need a...
