Mountain Bike Rims Explained: Width, Hookless & Carbon
Mountain Bike Rims Explained: Width, Hookless & Carbon
Mountain bike rims are one of the most overlooked parts of your bike. Internal width, rim depth, spoke count and whether they're hookless all change how your bike climbs, corners and holds up on rough terrain. Today, we're taking a closer look at our own carbon rim line — and showing you exactly how a 238 g 29er rim makes you faster up the climbs. Here's what mountain bike rims are all about.
How Do We Get a Rim Down to 238 g?
A rim looks simple from the outside — sidewalls, rim bed, spoke holes, and a valve hole — but a standard alloy rim still tips the scales at 400 g or more. Our XC-30 Flyweight? Just 238 g. That's lighter than a can of soda.
It isn't just about shaving the walls thinner. Carbon rims are built up layer by layer: carbon sheets are laid into a rim mold in specific orientations, then an internal bladder inflates them under heat and pressure. Engineers add material around the spoke holes where strength matters, and remove it between the spokes — strength where you need it, grams where you don't.
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Toray T700 / T800 / T1000: Why "Light" Doesn't Mean "Fragile"
Every rim in our range is built on genuine Toray carbon — T700, T800 and T1000. T700 brings toughness and impact resistance. T800 strikes the best balance of strength and weight. T1000 is Toray's highest-modulus grade in the T-series — lighter and stiffer — and it's the reason the XC-30 and XC-31 reach just 238–240 g.
Light doesn't mean fragile, though. Every rim passes the 100-joule professional impact test, the same safety standard pro-level bikes are built to. That's the confidence you get from a manufacturer with over 10 years of carbon rim engineering.
Picking the Right 29er for Your Riding
The number in the model name is the internal width in millimeters. All three are 29ers and work best with 2.3–2.4 mountain bike tires:
XC-30 (30 mm inner, from 238 g, 28 spokes) — our lightest entry point, built for XC racing and long XCM marathon rides. The 28-hole lacing keeps it lively without giving up stiffness.
XC-31 Disc (31 mm inner, from 240 g, 24 spokes) — lighter, wider, stronger, and our lightest rim at just 24 spokes. You won't notice the 2 g difference on the bike stand, but you'll feel it on the climb and the punchy corner exit.
Nexair XC-32 (32 mm inner, from 270 g, 24/28/32 spokes) — the widest of the three, with a 38 mm outer wall and 24 mm depth. The wider tire bed holds the tire better through corners, built for all-mountain riding and high-intensity XCO/XCM.
On depth: the XC-30 and XC-31 feature a 22mm profile, balancing aerodynamics and compliance. The Nexair XC-32 and 32er use a 24mm profile for added rigidity and high-speed stability.
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Hookless & Tubeless: Lighter, Fewer Flats
Every model is hookless and tubeless-ready. Without a bead hook, the rim is lighter and stiffer, the rounded outer shoulder cuts down on pinch flats, and the straight bed seals up cleanly with tubeless.
Our hookless rims have a maximum pressure rating of 35 psi, covering your typical trail tire pressure range of 26–35 psi. Always use hookless-compatible tires and never exceed the pressure limit. New to tubeless setups? Check out our guide to mountain bike tubeless setup and tire pressure.
Asymmetric Profile: Light but Not Flimsy
All four rims use a 2.8 mm asymmetric profile, with spoke holes offset ±7° to balance the uneven spoke tension that comes from a flanged hub. That lets the rear wheel build true at 120–130 kgf without twisting — meaning fewer broken spokes and less time truing wheels.
Choose your spoke count by rider weight: 24 spokes on the XC-31, 28 on the XC-30, and 24/28/32 options on the Nexair XC-32 and 32er. Flyweight versions suit riders up to 100 kg; Standard versions take you up to 130–135 kg.
The Lineup at a Glance
Model | Size | Inner width | Depth | Weight (Flyweight / Standard) | Holes |
XC-31 | 29er | 31 mm | 22 mm | 240 / 280 g | 24 |
XC-30 | 29er | 30 mm | 22 mm | 238 / 278 g | 28 |
Nexair XC-32 | 29er | 32 mm | 24 mm | 270 / 295 g | 24/28/32 |
32er | 32er | 30 mm | 24 mm | 330 / 350 g | 24/28/32 |
All models have an outer width of 35.6–38 mm and are recommended for 2.3–2.4 mountain bike tires.
Why ride Light Travel rims?
· Genuine Toray T700/T800/T1000 carbon
· 100 J impact certified
· factory-direct with over 10 years' experience
· custom laser-engraved logos and a choice of weaves and finishes.
Bottom line: for faster XC climbing, pick our XC-30 or XC-31 rims. If cornering stability is your priority and you’re working with a tighter budget, the Nexair XC-32 is the more cost-effective option. For 32-inch frames, go with our 32er rim. Customize your carbon rims today — reach out to us for current offers.
https://www.lighttravelcycling.com/carbon-wheels/discipline/xc-cross-country--rims-only
FAQ
Q: Will a 238 g rim be too fragile?
Not at all. The XC-30's 238 g comes from Toray T1000 carbon and a directional layup — it isn't thinner, it's smarter. The whole rim passes the 100 J impact test to pro-racing standards. It's built for XC; just don't send it into downhill bike-park laps.
Q: Flyweight or Standard — which fits my weight?
Flyweight is built for riders up to 100 kg. If you're heavier, or you ride hard, the Standard version takes up to 130–135 kg with extra stiffness and longevity.
Q: 29er or 32er?
Our range covers 29ers (XC-30 / XC-31 / Nexair XC-32) and a 32er. The 29er fits most mountain bikes; the 32er is built for larger frames that want extra rolling stability over rough ground.
Q: Can I get a custom logo or finish?
Yes. We offer laser-engraved logos, LT decals or your own custom artwork, with a choice of weaves (UD, 3K, 12K, Braided, Hexa-Comb) and finishes (matte, glossy, satin, paintless, coloured).
