Tube sizing?

h34e0f Posts: 370
edited September 2012 in Road beginners
Could someone explain the size difference between 700 x 18-23c and 700 x 25-32c please? Also, that are the differences in Presta and Presta long? Is it just personal preference? I have one of each at the moment (what the bike came with) and can't really tell the difference.

I mean, obviously you want to match a 700 x 23C tyre to a 700 x 18-23c tube, but what are the differences in the sizes?


  • Salsa
    Salsa Posts: 753
    It's the width of the tube, an 18-25 would be for a tyre between those sizes (average racing bike tyre). The 25/32 is for wider/deeper touring/hybrid tyres.
    Presta long valves (62mm) tend not to be threaded and are designed for deeper aero rims, whereas normal 42mm threaded ones are for normal rims. You can use longs in normal rims though, might have trouble getting the pump head on the shorter one with a deep aero rim though.
  • MichaelW
    MichaelW Posts: 2,164
    Pumping can apply sideways forces to the valve. A presta long in a normal rim can provide a lot of leverage and make the valve more vulnerable to damage. Not a problem if you use CO2 or track pumps, only with smaller hand pumps.