DowneasTTer

I'm new to the 650b sized rim. My wife's Canyon Roadlite came with 650b x 30 tires. I plan on replacing them with pro one tubeless when they wear out. But, in the mean time I would like to have some kind of puncture repair on the road (currently using the well it'll never happen to us plan). Anyway all of the tubes I can find in 650B seem to be 40 mm or bigger for mountain bikes. Any idea if the 40mm would be ok with the 30mm tires or any idea of where to search to find 30mm ones. Thanks for any help you guys can provide.

ThermionicScott 

I'm seeing a few out there. Can't figure out how to directly link this one, but BikeTiresDirect sells a "27.5 x 1.25/1.5" tube here that would be perfect: https://www.biketiresdirect.com/prod...sta-valve-tube

DowneasTTer

Thanks for the link. I give them a try.

DowneasTTer

In searching the internet (ya I know about how true some of the statements on the internet can be) I found a couple of places that said in a pinch a 700 tube will work in a 650 (27.5) tire. But not the other way around. Any truth to that statement? If so I only need to carry one size tube as a spare as my Roadlite has 700 series wheetset and my wife's xs has the 650B wheel set.

ThermionicScott 

It *can* work, and early in the 650B revival, people often needed to make do with 700C or 26" tubes. It's not ideal since you're jamming a larger-circumference tube into a smaller-circumference rim, causing it to wrinkle and fold in places. Harder to keep it from pinching.

Best to carry a spare tube in each size. Heck, I've gotten in the habit of carrying an extra 700C tube on my 650B bike, as someone around me will eventually need it.

DowneasTTer

Thanks again. I guess that's the best until these tires wear out and then back to tubeless for me.