1 Spare Tube to Fit 26, 27.5, AND 29?

[c_t_smith]

I have all three wheel sizes (29er XC bike and 27.5/26 trail bike) and was wondering if I could just keep a 650b tube in my camelback and be covered if I got a flat on any of the 3 wheel sizes. I know from experience that a 26" tube works fine in a 650b, but would a 650b fit in a 26 and 29? If I just carry one tube all the time I'll greatly increase my odds of having an acceptable size with me as opposed to remembering to switch out my spare for different rides.

Has anyone tried this?

[borbntm]

A 26" tube will work with all three wheel sizes in a pinch.

[shiggy]

I have all three wheel sizes (29er XC bike and 27.5/26 trail bike) and was wondering if I could just keep a 650b tube in my camelback and be covered if I got a flat on any of the 3 wheel sizes. I know from experience that a 26" tube works fine in a 650b, but would a 650b fit in a 26 and 29? If I just carry one tube all the time I'll greatly increase my odds of having an acceptable size with me as opposed to remembering to switch out my spare for different rides.

Has anyone tried this?

The 26" tube is easier. Tough to stuff the 650B into a 26" tire

[DeeEight]

Just run one tube in 26" that's the closest match to the widths of tires you run. A tube will more easily stretch in diameter than it does in width. I've seen 26er mtb tubes inflated big enough to drive a minivan thru (and it was working fine until the exhaust pipe touched the tube and detonated it). My usual test to check tubes for tiny flaws/leaks in fact is to inflate them to several meters in diameter and see how quickly they shrink.

[MagicCarpet]

Looks like a sealed deal on the 26" tube, but you can add me to the list. Be more careful of the width - that, as much as possible, has to be correct. I recomend Continental MTB26 as a quality tube.

[smethbet]

My usual test to check tubes for tiny flaws/leaks in fact is to inflate them to several meters in diameter and see how quickly they shrink.

[c_t_smith]

Thanks for all the replies. I'll keep a 26" tube in my pack and not worry about swapping it out when I ride the wagon wheels.

[jrm]

26" tubes on 29 and 27.5" wheels. They're the cheapest & lightest