rear rim sizes

[d_alexand]

While pricing new rims (hoops only) I noticed some bikes have the option of 18" or 19" rear rims, and 2.15 or 2.50 widths...

1. Is there any benefit to using the 19x2.50 instead of the 19x2.15?

2. Does the rear wheel diameter change the way the bike handles? Or would the recommended tire for each size rim make them the same height (18 tire with taller side wall = 19 tire with lower profile)?

Just curious...

 

[BigRedAF]

Yes and Yes,

I'm away from my desk so memory says 2.15 is a 125/250F width and 2.5 is a 250/450F width.

The 18/19 diameter issue has been hashed out over the years by better riders than us and the 19 won. Reasons are better control in the whoops, less sidewall deflection and less weight.

 

[SpeedyManiac]

18" and 19" wheels have the same outer diameter with a tire mounted. The 18" tire has a taller sidewall to make up the difference. 18" tires are easier to change (with less chance of pinching a tube) but have more sidewall flex when riding. For offroad this is nice, but not for motocross.

 

[rmc_olderthandirt]

How does a larger wheel save weight?

Rod

 

[IndyMX]

Less rubber weight, I'd imagine.. as compared to a negligible amount of extra weight from the wheel.

 

[BigRedAF]

Aluminum is lighter than rubber.

 

[d_alexand]

gotcha

Thanks for the info.