Round 2 of getting absolutely nowhere with my Ridley CX build. Background, I’m running a set of 50mm carbon wheels on my road bike, I use the Continental Presta 60mm 700x18-25 Race 28 tubes, and the valve sticks ~10mm out of the wheel as you’d expect.
Tonight, I went to put CX tires on the wheels using the Conti Presta 60mm 700x25-35 Cross 28 tubes, but the f*cking valve is only 45mm long. It comes nowhere close to clear the carbon section.
WTF? I bought three of these tubes, all have a 45mm valve, but the box clearly says 60mm, just like the 18/25 tubes, and the 18/25 tubes are spot on 60mm.
The help bit is this, can I run the 18/25 tubes with 34mm CX tires? Or is this going to pose some sort of problem. I also don’t know where I’m going to get a CX tube 25/35 with true 60mm valves, I do NOT want to run extenders, especially in CX.
I would have thought that this could cause you some problems. The advice that I have always been given is to run within the recommended widths. I have run 28c with the narrow size for a year of commuting without issue, but perhaps 34 is too much? Paging Nikcee…
To be fair, I ran a 18/25 conti tube on my rear wheel, with 35c conti contacts for well over 9 months with no problems. No problems at all and the only reason its not in there anymore is because the new conti contacts I bought (32c) came with tubes.
Your tube wall will be thinner, thus more likely to puncture if the tyre is pierced/pinched. But as Lorday mentions nothing will fail catastrophically.
I’ve run 35s with 19-23mm tubes after punctures (and finished longer rides) as my spare tube happened to be that size and I’m still alive.
Alternately you could check your LBS and see if they can help (a friendly one might even swap the tube for the ‘right one’).
Out of interest… why don’t you want to run extenders?
I’ll run extenders if I can source some proper ones with a valve, the type where they screw on to a tube w/o a removable core I don’t like, especially if there is potential for the wheel to be dunked in mud and water. For this weekend I’ll just have to run the 60mm 18/25 tubes and hope for the best.
I think it is getting f*cked by Conti, their box says the product has a 60mm stem, when in reality it’s a 45mm. That’s poor on their part.