Originally Posted by
jmm77
Anyone know if it is safe to move a RideNow tube from a larger tire after some use to a smaller one? In this case the gravel version (32-47C) from a 36c to a 34c tire. I thought I read somewhere this is a no no as the TPU cannot shrink back and can only be used in the same size or larger tire.
my view - if you're staying in a 700c - 622 diameter (or other same diameter move), and not going smaller, and the 'width' was within a few mm - even like going from 36 to 32 - I can't imagine how that would be a problem.
only reference I could find for TPU re-use was in this online article:
TPU Inner Tubes Part II: characteristics and market overview
Quote: " Re-using tubes: TPU Tubes can only be reused with tires of equal width or wider than the previous one (this has to do with the limited elasticity of the material)"
which was comprehensive, but also not a study, nor referencing evidence on many of the statements - focusing mainly on performance comparos and such...
so where did the 're-use statement evidence come from? manufacturer - CYA and also revenue booster?
I'd prolly think 2x before re-using a TPU in a 32mm, which was in a 45mm tire before... But I think this is a matter of degrees... 'Hand Grenade Close" should apply here.
I wouldn't lose sleep... especially at the pressures I run my tires...
Ride On
Yuri
EDIT: I'm actually thinking of going from 'Tubeless' to TPU on my MTB - I ride it so seldom now (when riding local I mostly use the gravel...) that paying attention to the Tubeless sealant re-charge is just another 'maintenance' thing... So when I forget, and the tire loses pressure and sealant gets dry... TPU will go on...
It's not like I do massive air or charge rock cliff faces for Mountain goat-like Gnar... I ride to survive.... LOL!