Mountain Bike Reviews Forum banner
1 - 8 of 8 Posts

1,642 Posts
Crests aren't much narrower than the flows, I run 2.5's on flows.
I would guess you chose crests for the low weight, you probably wouldn't run 2.5's?
Just guessing caus you ain't telling what you want??

9,334 Posts
qkenuf4u said:
cool thanks folks.. im not a bicycle guru in the slightest so i have no clue about those measurements.....
for tire width selection, what's important is the ISO size, which has the bead seat diameter (BSD) and the internal width of the bead. for a 26" rim the BSD will always be 559 (it's millimeters, but the ISO size doesn't usually include "mm"). for a 29er rim it will be 622.
the internal width measurement will also be in millimeters. for the stan's crest it is 21mm.
the size is usually on the rim decal and is written 21-559 (this is the ISO size for your rim). there are variations in how manufacturers write it, though.

here's an example of a rim sticker that has the ISO size. you can see it in the bottom right corner:

(what's funny is that's a 29er rim... woops! :eek:)

in general, the narrowest tire you want to run is the ISO size + 5-10mm, which is why I recommended a minimum width of 28mm. 25.4mm=1", so a 28mm tire is equivalent 1.1", though typically only fatter tires are referred to by the english measurement (hence 2.0, 2.2, etc.) a tire's ISO size, however, will usually be reported in millimeters and written similarly to the rim size, so a 26" racing ralph 2.25 will be ISO 559x57. Schwalbe writes it 57-559.
the fattest tire you can run is more of a grey area. some rim/wheel manufacturers have recommended tire widths, but people seem to push that envelope with sucess pretty regularly. if your tires are matched to your rims in terms of intended use (XC, DH, etc.) you're usually going to be OK, though if you put a huge tire on a very narrow rim, you are going to be more susceptible to squirm.
if you really want to get into it, sheldon's article pretty much covers everything, including a bunch of historical and non-mountain-biking related stuff.
hope that helps. :thumbsup:
1 - 8 of 8 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.