Rim Width

[RonS]

Hello all,
  The rim I used to build up my Rolloff wheel, a DT Swiss XR 425, has been damaged, causing a very annoying pulse while braking. The person who built it inspected it for defects and did his best to minimize the effects of the “bulge” (which was only a fraction of a mm on one side). I will be going for a good ride tomorrow to see how his repair worked, but there is a possibility that a new rim will be in order.

  The XR 425, at 17mm inside width, is at the low end of the ETRTO scale for use with 50mm tires. I would like to use a wider rim for the next build and would value your opinions. I normally use 50mm tires and likely will never go under 42mm. The rims I have easy access to purchase range from 19mm to a seriously wide (and heavy) 30mm. I am leaning toward a 25mm Velocity or Ambrosio rim.

  Is there an “ideal” width rim for use with a 50mm tire?

Ron

[mickeg]

In my case, when I am doing touring with my Sherpa on good quality pavement, I lean towards the narrower Schwalbe Marathon (the plain one) in 40mm width.  For more rough ground, I use the Schwalbe Dureme or Extreme in 50mm width.  Thus, I wanted a rim that would be narrow enough for 40 and wide enough for 50mm.  I have been really happy with a rim that is 21mm wide (inside width).  The rim, a Salsa Gordo, has been out of production for several years, so don't bother looking for it.

I do not know which chart you are using, but I like the one at the bottom of this page:
http://www.sheldonbrown.com/tire-sizing.html

That chart suggests that if you always will stick with 50mm tires, a 25mm rim like you are looking at is probably ideal.

[RonS]

Thanks, Mickeg.
I vaguely recall reading that article by Sheldon Brown but must have missed the part about rim to tire width ratio