Tyre size and inner tubes - i just don't get it

[272BHP]

Why are Wheel/Tyre/Tube size so unfathomable?

Just bought some Schwalbe Marathons 700x32 and got the recommended Schwalbe inner tubes as well. 700x28

They are not even a close fit; the inner tubes are way bigger in circumference and no matter how I try they seem about 3 inches too big .

Luckily I found one Specialised spare inner tube 700x28-38 that fits perfectly. But I am still about a £10 pound down and have 2 useless inner tubes.

[uncinqsix]

That's odd. I'm running those tubes on my commuter (with 32c gatorskins), and they're absolutely fine for size. Maybe a dud batch?

[anonymous-user]

272BHP said:

Why are Wheel/Tyre/Tube size so unfathomable?

Just bought some Schwalbe Marathons 700x32 and got the recommended Schwalbe inner tubes as well. 700x28

They are not even a close fit; the inner tubes are way bigger in circumference and no matter how I try they seem about 3 inches too big .

Luckily I found one Specialised spare inner tube 700x28-38 that fits perfectly. But I am still about a £10 pound down and have 2 useless inner tubes.

Just cram the tube in, once the tyres are hooked on and blown up, it won't matter

[272BHP]

Isn't there a big danger of pinching doing that? the last time I changed a tyre I managed to pinch the inner tube and caused a blow out as I was pumping the tyre past 70psi -

The cat is still traumatised.

[JustinF]

You're only likely to cause a pinch when mounting if tube gets caught between tyre and rim, a couple of pumps of air should prevent.

[272BHP]

Ok rammed it in and pumped the tyre up to 80psi. Took it out for 5 mins earlier and seems ok. Hopefully I'm good now - thanks for all the help!

[gazza285]

I bought a load of Continental Race 28s, in the size of 20-25, I use these in all my 700c wheels, which have tyres from 23 to 35 wide. Never had a problem.