Results 1 to 3 of 3
  1. #1
    mtbr member
    Reputation:
    Join Date
    Feb 2008
    Posts
    313

    rim width and rear triangle on SL-R

    I'm considering replacing the 26" x 24.6mm Crest rims on a 2012 SL-R with 26" x 33mm LB carbon rims. Post [1] indicates a general rule of thumb for tire balloon dimension change with rim width change is approx. 1/3, which seems reasonable but I cannot confirm with present hardware.

    Given a Ground Control 2.3 as shown on the 24.6mm rim in Fig. 1 and using the guideline from Post [1], chainstay clearance should decrease from 6.3 mm to 4.2 mm, which seems borderline for acceptable clearance. I therefore wonder if anybody can confirm or improve upon this rule of thumb, specifically in the tire-to-chainstay dimension, before trying a set of rims shipped from LB?

    Also worth pondering is trying an upgraded 27.5 HD rear triangle on the SL-R with 27.5 LB carbon rims, which could be an interesting combination. With d-bug's observation (Post [2]) of BB height drop of maybe 1/8" and no HA change, taller 27.5 rims may hit a magic spot of maintaining very similar frame handling with a stiffer triangle and putative 27.5" rollover benefits. However Hans' recent comment (Post [3]) has merit, that a new triangle + links is expensive enough that perhaps I should just start over (Ripley). Essentially this all falls onto tire clearance as described above, thanks if you have any thoughts on this.


    References
    ---------------
    Post [1]: Having trouble choosing rim width...
    Post [2]: HD swingarm on a Mojo, here it is.
    Post [3]: HD retrofit swing arm for more 650B clearance



    rim width and rear triangle on SL-R-sl-r-tire-clearance-copy.jpg
    Figure 1. 26x2.3 Ground Control on Crest 24.6mm width rim (2012 SL-R).
    Last edited by ca_rider; 12-21-2013 at 06:30 PM.

  2. #2
    mtbr member
    Reputation:
    Join Date
    Jan 2005
    Posts
    877
    I have been running the LB Carbon 33 rims for (2) years on a Mojo SLR (with Ground Control 2.3 (which really measures more like a 2.2 tire). The id of the LB 33 rim is only 23 mm, a 2mm increase in width from the Crest (21)mm. The resulting increase in tire section width is negligible, however the lateral stiffness gained with the carbon rim is night and day better. So you should have no problems.

  3. #3
    mtbr member
    Reputation:
    Join Date
    Feb 2008
    Posts
    313
    Thanks for the helpful reply, I'll try 26"x33mm next. Also good point to consider the inner rim dimension instead of outer. Cheers.

Similar Threads

  1. 30mm rim width blur xcc triangle?
    By westin in forum 27.5 - 650b
    Replies: 3
    Last Post: 11-02-2012, 05:51 AM
  2. Does anybody else have this rear triangle?
    By mikkosan in forum Turner
    Replies: 5
    Last Post: 03-09-2012, 10:41 AM
  3. Rear Wheel Not Centered in Rear Triangle-EMD
    By mtnbikej in forum Niner Bikes
    Replies: 10
    Last Post: 12-20-2011, 01:42 PM
  4. Replies: 7
    Last Post: 07-05-2011, 08:01 PM
  5. FSR rear triangle
    By nodnelson in forum Specialized
    Replies: 4
    Last Post: 05-30-2011, 07:26 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •