planning a wheelbuild and I’m not sure what is the ideal range for internal rim width given my tire choice and type of riding.

Tires are Panaracer Gravel King SK 27.5 x 1.9”. Will be running them tubeless at lower pressure. Disc brake with 12mm thru axles. On a bike used for mixed surface rides, with a focus on gravel (gravel is relatively small, roads have some small pot holes).

I come at this from a different perspective. I’m far more concerned about mass...especially roatating mass...than about width. I choose the lightest rims I can find and don’t worry about how the tires are going to fit. Tires change, mass doesn’t. I regularly run 55+mm tires on 17mm rims without experiencing any downsides. The most important factor is the weight that I have to push. The wheels on this bike are build with XC-717 and Velocity Veloheats, both of which are 17mm.

DSCN1197 by Stuart Black, on Flickr

IMG_1975 by Stuart Black, on Flickr

I haven’t used 25mm rims for 2.125” and larger tires in nearly 30 years and haven’t discovered any downsides yet. The bike corners fine, climbs well and is rugged. It also happens to have nice light wheels on it.

I regularly ride at speeds higher than 25mph on knobbed mountain bike tires. I’ve never felt any kind of looseness in corners.

I haven’t experienced any kind of “folding over” in corners over the 25+ years I’ve been running wide tires on narrow rims. And, as I pointed out, that’s with konbbed tires. Even on pavement, I’ve never had any kind of problem. Nor on rocks or hard pack. The “folding over” thing is a friend of a friend of a friend of someone’s mother’s second cousin’s godson’s nanny’s brother myth.

And, just too be clear, I’m a big guy who rides and corners aggressively. If anyone were going to fold over a tire, I’d be that guy.

It’s so amusing that you can use so little information to jump to such wrong conclusions. First, if you “putzing” around on fire roads usually means much faster speeds than riding single track. Secondly, if you can’t stop with v-brakes, it’s your skills that are lacking and need the crutch of “superior” disc brakes.

By the way, Mavic XC-717 as well as other similar rims in their line are aimed at cross country riders and used by professionals who aren’t “putzing” around.

+1
seems we’ve gotten off topic, but I agree nonetheless.
And as far as the comment a whole ‘nother person made about never rolling a beaded tire off a rim I’d say stay within the tire manufacturers recommendations. If you put a big fat tire on a skinny little rim, a person is going to drop the pressure for bouncy roads, then their in a turn and rolling a tire off a rim. And as the Brits say - then Bobs your uncle. Believe it or don’t the engineers working on this stuff are putting some thought and math into these sizings and pressure limits.

This is in-line with my experience on the road. When I went from 16mm To 21mm ID rims on my road/gravel bike, I was able to run the identical tire lower in the front without feeling it squirm under hard cornering on pavement.

Many people report the same thing with mtb tires, though I have never had the chance to test the same tire on 2 significantly different width rims. This may not be an issue if one runs higher pressures, but as people chase the lowest pressures they can get away with, tires squirming in corners or off camber scenarios is one of the limitinng factors. I know for me it is on the front end of my FS bike. And rim width (along with sidewall construction) effects this.

Rim width also effects the tread profile. With a narrow rim, you get a rounder profile and need to lean the bike over more to get the side knobs to connect. With a wider rim, you have a more square profile, and the knobs hook up with less lean. Too wide, and you start having intermediate or side knobs hooking up too soon (or all the time) and it just slows you down.

Peronally, if I were building a new set of wheels for what the OP is describing, I would go with something like 23mm ID. Maybe even a little wider..