Mountain Bike Reviews Forum banner
1 - 6 of 6 Posts

·
Registered
Joined
·
27 Posts
Discussion Starter · #1 ·
I'm going to be building up a new wheelset with 26" light-bicycle AM rims. Right now I run a 2.35" Nevegal up front and every so often it will rub the fork. My fork is a Rockshox Recon 351 and the current rims are Bontrager Duster. If I go to the wider rim, will I run into more trouble with the rubbing? Thanks for the help!
 

·
Registered
Joined
·
6,613 Posts
The increased width of the rim will slightly increase the diameter of the tires. Usually whatever you increase the rim width by, the diameter will increase by 1/3 of that. So, increase rim width by 3mm, tire diameter increases by 1mm. This is just a rough estimate, some tires behave a bit differently.
 

·
Registered
Joined
·
6,613 Posts
It applies to the change in the inner width of the rim. If you think of the inner rim width as part of the circumference around the tire cross section, with the tire as the rest of the circumference, you're just increasing the circumference when you go wider on the rim. If you increase the circumference of a circle by "x", the diameter increases by x/Pi, or x/3.14. I just use a third for math in public.
 

·
Registered
Joined
·
27 Posts
Discussion Starter · #5 ·
Respect for MSU math... Being that the width of the tire is a fixed value and the base of it is stretched slightly wider on a wider rim, would the height of the tire then decrease? I'm just trying to figure out if I do a $1000 wheel build if it will work on my fork. Thanks for the help so far.
 

·
Registered
Joined
·
6,613 Posts
Different tires have slightly different structures in cross section. Some are more round, some more oval, but I'd expect the diameter to increase in every direction (which is what diameter does). So, if the side to side diameter increases, then the rim to top of tire diameter would increase as well. In cross section, it's just a circle, or close to it. I see what you are saying about the flat spot on the circle that would be the rim, but I don't think the height of the tire would get smaller until the side wall is nearer to vertical.
 
1 - 6 of 6 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top