Getting the right tube first time
Two numbers decide whether a tube fits, and both are easy to check before you come in.
The width range
Every tube is made for a span of tyre widths — 700x20-25, 700x25-32, 700x32-47. Your tyre width is printed on its sidewall. Pick the range it falls inside. A tube stretched beyond its range is thin and puncture-prone; one stuffed into a tyre far narrower than it wants to be folds on itself and pinches.
The valve length
This is the one people get wrong. The valve has to clear the depth of your rim with enough thread left to fit a pump head. A shallow box-section rim is fine on 42mm. A mid-depth rim wants 60mm. Deep carbon aero wheels need 80mm.
If the pump will not seat properly, or you are wrestling with a valve extender, the tube is too short for the rim.
Tubes are not obsolete
Tubeless gets most of the attention, and for good reason on mountain bike and gravel setups. But a tube is simple, cheap, needs no maintenance between punctures and fixes at the roadside in minutes with cold hands.
Plenty of good bikes should stay on tubes: commuters, winter trainers, and any bike that gets ridden without much thought given to it. And every tubeless rider should still carry a tube, because it is the get-home fix when a cut is too big for sealant to close.
Common questions
Presta or Schrader?
Almost every road, gravel and modern mountain bike uses Presta — the slim valve with the little lock nut on top. Schrader is the fatter car-type valve, mostly found on entry-level and older bikes. Look at the hole in your rim.
What else should I carry?
A tube, tyre levers and a way to put air back in. Come and see us at the shop if you want a hand putting a saddle pack together.
