Tubes
Used MTB inner tubes from UK sellers, in butyl and latex, with 26", 27.5" and 29" sizes and Presta or Schrader valves. Keep a spare in your pack even if you run tubeless — a tube is the fastest trailside fix for a slashed tyre.
Do I still need tubes if I run tubeless?
Every tubeless rider should carry one: when a sidewall slash is too big for sealant to plug, a tube gets you home. Plenty of bikes still run tubed setups, where tubes are the everyday consumable alongside tyres.
What size tube fits my tyre?
Tubes are labelled by wheel size and tyre width range, such as 29 x 2.0-2.4. The wheel size must match exactly — a 27.5" tube won't seat properly in a 29" tyre. The width range is more flexible because tubes stretch, so a tube rated 2.0-2.4" will work in a 2.5" tyre at a push, though it'll be thinner and more puncture-prone at the stretch; buy tubes that match the midpoint of your tyre width for the best fit.
Presta or Schrader?
Presta (thin, threaded, with a locknut at the top) is standard on mountain bikes with modern rims, while Schrader (car-tyre style, wider) is still found on budget bikes and some older rims. Your rim's valve hole determines which you need — Presta valves fit Schrader holes with an adapter ring, but Schrader valves won't fit through a Presta-drilled rim. If you're buying tubes for an emergency spare, match the valve to your rim.
Butyl, latex or lightweight?
Standard butyl tubes are cheap, durable and hold air well, losing about 1-2 PSI per day. Lightweight butyl tubes (Maxxis Ultralight, Continental Race) save 30-50g per tube by using thinner rubber — fine for XC, but more puncture-prone for trail use. Latex tubes are the lightest option with the lowest rolling resistance, but they lose air overnight and cost significantly more. For a trailside emergency spare, standard butyl is the right choice — you want reliability, not weight savings, when you're fixing a flat mid-ride.
What should I carry to fix a flat?
A folded inner tube, tyre lever and mini-pump or CO2 inflator should be in your pack on every ride, even if you run tubeless. When sealant can't fix a cut, remove the tubeless valve, stuff the tube in and reinflate — a five-minute fix versus a long walk home. CO2 inflators are faster but single-use, while a mini-pump is heavier and works every time. Tubes also turn up in the wider wheels and tyres listings.