[Transwave]

I am optimizing my old rigid mtb for gravel use (instead of buying a gravel bike) and decided to replace my chunky 2.6 tires to Race King RaceSport 29x2.2 to save weight and reduce rolling resistance. Do you think i should replace my Sentry rims (i32mm) with Arch (i26mm)? The case for replacing the rims is that Arch are 100g lighter compared to Sentry. Is the reduction of weight worth the effort of swapping rims? I generally like wide rims but perhaps i will get better performance (besides reduced weight) since i am mounting significantly smaller tires..

 

[mikesee]

Depends on your terrain. You'll likely notice the change in rolling resistance more than the weight loss.

 

[Transwave]

Depends on your terrain. You'll likely notice the change in rolling resistance more than the weight loss.

Which rim will give the lowest rolling resistance? How does it depend on the terrain?

 

[mikesee]

Which rim will give the lowest rolling resistance? How does it depend on the terrain?

If you're on flat but twisty trail, where the bike is being leaned back and forth often, you might not notice any difference in rim width.

If you're riding straight roads for hours at a stretch, the rim width delta will be more apparent.

A wider rim gives any given tire a more square profile. More square means more rubber on the ground, which means more rolling resistance, which means more energy out to maintain the same speed.

 

[Transwave]

I've mounted the tires. It is 54mm wide on Arch, 56,5mm wide on Sentry at the same pressure. It looks like the tire has a more accurate shape on the 26mm rim and it is closer to manufacturers recommendation. Perhaps i will do the swapping after all...

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