Rims
Used MTB rims from UK sellers, in alloy and carbon for wheel builds and replacements. Match the internal width, spoke count and wheel size to your riding style and hub.
Why do rims wear out before the rest of the wheel?
The rim determines tyre profile, wheel stiffness, weight and durability, and it's the component most likely to need replacing on a wheelset: hubs last years and spokes rarely break, but rims take direct impacts and eventually dent, crack or wear out.
What internal rim width do I need?
Internal width, measured between the bead hooks or bead seats, determines how the tyre sits on the rim: wider rims spread the tyre for a squarer profile with better cornering support, while narrow rims give a rounder profile. As a guide, 25-28mm suits XC (2.0-2.3" tyres), 29-32mm trail and enduro (2.3-2.6"), and 33-35mm plus and gravity (2.5-2.8"). Running a tyre that's too narrow or too wide for the rim creates a poor tyre profile and can affect bead retention.
Alloy or carbon?
Alloy rims (6061 or 6069 aluminium) dent on hard impacts but don't catastrophically fail — a dented alloy rim is ugly but often still rideable, and they're cheaper and easier to true after impacts, which makes them the practical choice for aggressive riding on rocky terrain. Carbon rims are lighter (100-150g per rim), stiffer laterally and can be made wider without the same weight penalty, but carbon cracks instead of denting and a cracked carbon rim is scrap. For UK trail centres and enduro, alloy is the pragmatic choice; for XC racing and lighter trail riding, carbon makes a strong case.
28 or 32 spoke holes?
28-hole rims suit XC and trail — lighter, with adequate strength for most riders. 32-hole rims suit enduro, DH and heavier riders, where more spokes distribute the load and handle impacts better. The spoke count must match your hub — a 32-hole rim needs a 32-hole hub. Some rims are offset-drilled, with the spoke holes shifted to one side to help equalise spoke tension on the rear wheel, where the drive side spokes are significantly shorter than the non-drive side.
Is the rim tubeless ready?
Most modern rims are tubeless ready, meaning the rim bed is designed to seal with tubeless tape and hold a tubeless tyre bead securely. Hooked beads are the traditional design and work with all tyres; hookless (Stans and some carbon rims) are lighter but only compatible with tyres rated for hookless use, so check before buying. Some older rims aren't tubeless-compatible regardless of tape — if the rim bed has large spoke holes or an uneven channel, tubeless may not seal reliably and you'll be running tubes.