Best Rim Inner Width for XC

[irideti]

I've been running 2.25 tires on my hardtail for decades but might try 2.40 in the future. What's the optimal inner width for these tires? I just had spokes cut off on my old wheelset since the rear Stans Crest Mk3 have crack around nipples. These rims have 23mm inner with. I'm planning to reuse those lovely CK hubs. My wheel builder told me to get a wider inner since wider 'pinches' tire less for more optimal shape. Should I go for 24, 25 or even wider inner?

I know this forum loves BTLOS but I'm still debating between BTLOS and Lightbicycle.

[Buzz Killington]

30mm

[dddd]

Are you regularly testing the limits of your current setup's pinching tendencies?

If not, then the width change might be little more than theoretical and debatable.

Do you ride in low-traction regions having hard-pack surfaces covered with loose soil? I do myself, and for my riding I prefer a wider rim to spread out the tread cap flatter, since I can't lean aggressively on the slippery surfaces.
At low pressure, the flatter tread cap gets pulled under the rim (in a favorable way) under cornering loads and off-camber surfaces anyway.

At some point, a much-wider rim will increase pinching tendencies (from my own limited experience using very wide rims with 2.3 and 2.4" tires), but you seem to be homing in on a narrower range of much narrower rim widths than I've used.

Carbon rims will allow you to increase rim width and depth at little cost in added weight, so some modest increase in rim width makes sense to me.

For XC racing, take note of what other XC riders are using in your geographical area.

[yarbsr02]

2nd vote for 30mm

[EB]

28 to 30mm.

[Jaybee]

My XC bike has a set of 25mm wide alloy rims and some 30mm carbons. Maybe placebo, but for the same tires in widths from 2.25 to 2.4, the sidewall support through corners and grip feels much more secure on the wider rims. The 25s are fine and I can't remember the last time I pinched, but the 30s are just more fun.

[catchourbreath]

29mm ID on 2.4s riding NYC area trails feels pretty supported and haven't had any problems

[irideti]

Is 2.25 tire going be much wider on 30mm inner? Or a non-issue for MTB since tire is already much wider than the rim. I'm concerning about clearance.

[Rev Bob Dobbs]

29-30mm. I write 29mm because Enve M5’s (which I ride and race) spec as 29mm. With that said, 30mm historically is my preferred width. However, I don’t think 1mm makes a difference.

[Hilltopperny]

I'm running 27 id on my cross country bikes with 2.25-2.4" tires with no regrets! They feel great for their intended purpose with zero wheel flop when aired down and set up tubeless.

Sent from my Pixel 6a using Tapatalk

[nspace]

Same with experience 27mm here. A set of WeAreOne Faction 29er rims and 2.35” Schwalbes. It’s a fantastic setup and great warranty should I need it.

[KonaSS]

I ride 30s. Think anything in the 27-30 range works well.

[Applesauce]

Originally Posted by nspace

Same with experience 27mm here. A set of WeAreOne Faction 29er rims and 2.35” Schwalbes. It’s a fantastic setup and great warranty should I need it.

I run Factions on both my “big” bike and my XC race bike. They’re simply the best, and from the best manufacturer. I’ve ridden wider (and lord knows, we’ve all ridden narrower), and I don’t like how it squares off a tire. This is especially true on tires with minimal side knobs, like XC racing tires. Maybe less of an issue on the free ride tires most folks seem to run these days.

OP, if you’re considering carbon - and I would only be considering carbon - I would only consider rims with a lifetime “warranty” (actually a replacement policy, I would call it). I can’t remember the last time I pinched a tire on my XC bike, but I can definitely remember the last time I cracked a rim, or hit the rim hard enough to destroy aluminum.

[nspace]

Originally Posted by Applesauce

I run Factions on both my “big” bike and my XC race bike. They’re simply the best, and from the best manufacturer. I’ve ridden wider (and lord knows, we’ve all ridden narrower), and I don’t like how it squares off a tire. This is especially true on tires with minimal side knobs, like XC racing tires. Maybe less of an issue on the free ride tires most folks seem to run these days.

OP, if you’re considering carbon - and I would only be considering carbon - I would only consider rims with a lifetime “warranty” (actually a replacement policy, I would call it). I can’t remember the last time I pinched a tire on my XC bike, but I can definitely remember the last time I cracked a rim, or hit the rim hard enough to destroy aluminum.

+1 to the warranty and the tire profile! Keep an eye out for any promos around the holdidays. This is when I bought my rims, and got them for $340 CAD ($244 usd) each. I wish I bought another set.

[eri]

I ride 2.35 to 2.6 on light bicycle ‘930s’ that have 30mm internal width. The 2.35 (maxxis dhf exo) are much more controlled.than the same tire on a 24mm internal width tire. I’d no idea how unnatural the narrow rimmed wheel behaved.

The other thing wide carbon rims allow is an asymmetrical spoke bed. Spoke length and tension were just about perfect left to right with that rim (and ck hubs.)

I’m skeptical about the value of lifetime rims. The ones I’ve seen don’t include rebuilding. Aluminum rims dent and ‘wear out’ but I’ve never broken a carbon rim so I’m happy to just stay in the lower price end of the market.