Inner tube question.

[EckyH]

if the inner tube is on the inside with no road surface contact, then how does that effect performance?

Think of the inner tube as just more rubber on the inside of the tyre. More energy is necessary to deform the additional rubber. An aggravating factor is the movement between the inner tube and the tyre. Depending on the circumstances like friction coefficient between these two sorts of rubber it can require even more energy.

E.

 

[ebikeerwidnes]

Think of the inner tube as just more rubber on the inside of the tyre. More energy is necessary to deform the additional rubber. An aggravating factor is the movement between the inner tube and the tyre. Depending on the circumstances like friction coefficient between these two sorts of rubber it can require even more energy.

E.

Anyone know any figures on that

Asking because a "major difference" for a "proper racing bike" on a training run
might be a "nothing important" for a hybrid out for a tootle in the country

 

[EckyH]

Anyone know any figures on that

Jarno Bierman knows: https://www.bicyclerollingresistance.com/specials/cx-gravel-tubes-vs-tubeless
There are the absolute values of an - imho - average inner tube, in terms of quality, rubber thickness, price, weight etc.

Iirc the rolling resistance is linear proportional with speed. Therefore the values in the article can be easily extrapolated to other speeds.

Asking because a "major difference" for a "proper racing bike" on a training run
might be a "nothing important" for a hybrid out for a tootle in the country.

Exactly.

E.

PS: In my opinion his conclusion has to be understand solely in that kind of comparisons he made: A tubeless tyre with and the self-same tyre without an inner tube. This conclusion has no specific validity for any other combination of a - unfortunately only hypothetical - high end tube type tyre with a high end latex or TPU inner tube.

 

[midlandsgrimpeur]

I thought it was cycling law that if you have a drop off in performance you blame it on everything else except yourself! And you changed BOTH tubes! I'd take that as a win win, lol.

I have a mate I cycle with and I am a fair bit fitter. For the first six months, every time we went cycling he genuinely couldn't work out why he struggled to keep up, he had every excuse under the sun; bike problems, not enough breakfast, dehydrated, too warm, too cold. Eventually the penny dropped and he said "you're just on another level to me aren't you?" 😂