ODonXO28

So I did my research and I do have how to measure sizes and what all numbers and whatnot mean, however something I'm having trouble locating is how much wider of a tire can I put on the existing rim. Current tire is a 32×622, how much wider can I go with the tire without happening to get new rims. Any help is greatly appreciated

FBinNY 

There are plenty of charts offering guidelines for tire width compared to the rims they're on.


Here's one There or others, and plenty of articles if you search bicycle tire and rim width chart or something similar.

Keep in mind that these are only guidelines, and there's plenty of fudge room on either side. As a general guide, overly wide tires tend to handle more poorly and tend to wallow in turns. Overly narrow tires sit low and increase the risk of pinch flats or rim dents.

SoCaled 

2nd piece of the puzzle is how wide/tall can fit in the frame/brakes, often the limiting factor.

grumpus

As a rough guide you can use a tyre that's 1.5 to 2.2 times the internal rim width, you'll have to remove the tyre (or at least deflate it) to measure the rim width. You'll also need to check that there's sufficient space for the wider tyre to not rub on the frame.

cyccommute 

Or 3+ times. All of my mountain bikes use narrow rims that measure at 17mm (0.7”) and are mounted with 2.2” to 2.3” (55mm+) tires. Even after thousands of miles and many years of riding, I’ve never experienced any kind of problem. My touring bike is fitted with 13mm wide rims and I use 37mm tires on it. The “guidelines” are extremely conservative. There’s a limit but I haven’t found it yet.

As mentioned above, the tire fit in the frame is more of a limiting factor than the width of the rim.

Steve B.

It’s not so much rim size determing tire size. The limiting issue if you choose to go larger is will it fit in the frame.

mpetry912 

@OP can you take a pic of the bike with the current tires installed

help us help you

/markp

Duragrouch

Besides rim and frame fit as noted, if a short-wheelbase road race bike, clearance to the front derailleur can be an issue with bigger than skinny race tires (ask me how I know). Same for brake clearance, if caliper brakes.

Also note: A bigger tire on the rear will change your gearing slightly (going to a slightly higher gear). A bigger tire on the front will alter your steering geometry slightly, but in a good direction, a taller tire will mean a bit longer trail/caster, which means the steering becomes a bit more "stable", like being able to ride no-handed, and the increase weight of the tire also has that effect. But the steering will feel a bit "heavier".

Also, a tire a lot wider than the rim, you may not be able to pull off and on the bike, while inflated. Most brakes open up for that, but sometimes that is limited on V-brakes by the pads hitting the inside of the seatstays or the front fork. (Ask me how I know.)

Iride01 

It's very likely that the tire will be rubbing the bike somewhere long before you ever got close to being oversize for the rim.

Welcome to BF.

Steve B.

This,^

Back in the early days of mt biking it was common to use lightweight rims that had the essential dimensions of road rims, thus 19mm or so. We shoved 2.5” tires on these at 35psi. The tires never rolled and it was obvious you could run a very wide tire on a pretty narrow rim and still can.

grumpus

Yes, conservative, but a good starting point if you're not sure what works with what. Back in the day we put 2 inch MTB tyres on 13 mm rims because that's what we had, but we weren't running low pressures and you can bet I got some nice wide rims as soon as they were available at reasonable cost. Wide tyres want low pressure, wide low pressure tyres on skinny rims equals disconcerting feeling in fast bends. I guess you get used to it, but I don't think it's optimal behaviour.

cyccommute 

Depends on how far back you go. My 1984 Miyata Ridge Runner came with 25mm (or wider) single walled rims. By the mid 90s, many high end rims were running around 17mm. I don’t ever recall seeing nor using mountain bike rims that were 13mm internal width. And the 25mm wide rims were certainly available during all that time.

Russ Roth

Agree that 13mm is narrower than what mtb rims actually came it but it isn't far off, I've got some NOS mavic 217 from the 90s, their external width is 19mm, internal is 15mm, now I wouldn't use them for a road bike, but their dimension was fairly average for a mtb rim in the 90s. The difference between a 2.1 tire on a 15mm internal vs a 25 or 27mm internal width on handling is just amazing. Widest rim I can think of for back then was the Rhino lite with a 22mm internal, which would have been nice but the rims were very heavy by the standards of the time and I didn't know anyone who rode them except as a durable commuter rim or for heavy riders. 25mm internal would surprise me but I don't think most people knew about them or generally used them and the idea of using a wide rim for tire profile wasn't something often pointed out. Although I'm not a convert to the whole 30c tires are the fastest and what everyone should ride view, I do now embrace the idea that wider rims make a difference and a tire can be too wide for a rim for the purpose of ride quality and handling.

Jeff Wills

In the late ‘80’s some ATBers were rolling down Mavic MA-2 and MA-40 rims from 622mm BSD to 559mm BSD. (If you start with a 36-hole 700C rim you end up with a 32-hole 26” rim.) 13.5mm internal width, 20mm outer. Eventually Mavic caught on and made them this way from the factory.
A while back I had several 26” Matrix brand aero rims that might have been narrower than the MA-40’s. I was going to use them for a speedy bike but never got there.

Duragrouch

Interesting. I wonder if said rolling machine could roll flat spots out of slightly bonked rims?

OOOOOooooo, looking online at both of the above rims, I see they are double-socketed, oh that is so much stronger in fatigue, no wonder they were rolling those touring rims down. Yeah! I think I have one of the above wheels for my road bike deep in storage, after fatiguing 2 previous sets of rims, those double-socketed ones wear like iron. I've searched for same in a 20"/406 rim, but unable to find. Maybe some of the newer double-wall rims are extra thick at the spoke hole, but if I were taking a world tour, I might look for someone who could roll some rims down for me, although that may be too big a jump down in radius. I'd also see if Mavic would sent me sockets and rivets to modify their 406 rims, if they make 406. Looking online, yikes, all they list is 26", 29", and 27.5". What's the world coming to?! Dang-ol off-roaders. Ahh, here's some road rims... all lightweight race rims or carbon, none of the old tough touring rims.

cyccommute 

The key there is that “some” mountain bikers were resizing rims. The vast majority weren’t and the vast majority of rims were much wider than 13mm.

Duragrouch

I could be completely wrong, I don't do mountain bikes, nor know the history. But looking at the source rims that they rolled down to a smaller diameter, they may not have been doing that for the rim width, but rather due to the source rim toughness, and that width was the only one available; Both rims mentioned are double-sockets/eyelets, so tie the spoke into both inner and outer rim walls, so at least 50% reduction in stress, and actually more because the socket ("thimble") spreads the load over a vastly larger area then just a drilled hole for the spoke nipple. (IIRC, been a long time) Each 10% reduction in stress, doubles fatigue life, so (if true) 50% reduction is 2^5=32X increase in fatigue life, and in this case, most probably much greater. The sockets also inprove ultimate strength (immediate spoke pullout due to stress, not cracks over time). The downside of double-socketed is that the steel thimbles add a lot of rim weight, and rotating inertia. Those rims wear like you wouldn't believe. I don't see them on Mavic's website, probably been gone for many years now. A darned shame.

cyccommute 

Keith Bontrager started cutting down and rerolling rims in 1984. I’ve not heard of any one else doing it but there may have been. Some of the reason for doing so was to make a lighter wheel and perhaps a bit stronger. Rims for mountain bikes of that era tended to be single wall, balloon tire rims which weren’t the strongest nor lightest wheels around. The Mavic MA-2 was a rim that he could cut down and it had a double walled, box construction. Mavic responded with the MA-40 which was the same rim but in a 559mm size.

grumpus

There's no need for a ring roller, just remove a few spokes and whack the rim with a rubber mallet. I used to do that fairly often, it worked better on cheap (soft) rims.

FBinNY 

You need to have a sense of history. Mountain biking started out with a couple of guys riding 26" coaster brake balloon tire bikes of the period down mountain trails. There were no bikes or components made for that, so when they got tired of having to push those coaster brake bikes back up, and wanted better they had to improvise.

Duragrouch

Oh I totally get it. I'm assuming they may have been "smarter than the average bear". The double wall made the rim stronger in bending, like for rolling over a big rock at speed (rim "bottom"). But the double socket/eyelet design, also made them way stronger in terms of spoke stress at the rim (rim "top"). Maybe both features came automatically on double-wall rims of the era, I don't know, that was before I got serious in biking (and still never in mountain). I do recall reading somewhere that Weinmann "double concave" rims were so strong, that someone running into something, would bend the fork before bending the rim, but that may apply to most or all double-wall rims. Ah, found a pic, these were concave on the outside at the spoke holes, not convex:

Duragrouch

Oh yes. Even with my VERY minimal knowledge of mountain biking, I knew that to be true. Those folks were pioneers. I think a long time ago, I read an article about that time, and the people who advanced things, but I cannot recall info now.

I will also say, that after becoming an engineer, I shudder at the things I did long before, like taking a large flange aluminum french hub with a badly bent over flange, and just straightening it, and building it up on a wheel and riding it. I was poor, and ignorant, using parts I found in the trash.

FBinNY 

Why shudder? It worked out OK, didn't it.

It's very easy to start overthinking stuff. With experience you learn that very often "good enough" actually is good enough.

Duragrouch

Maybe, probably helped by the tangential spoking I used. I was clever about straighting it, first bending back in a vice, then using 3 steel dowels, 2 in one vise jaw and 1 in the other, to correct small localized lateral bends. That said, based on decades of experience later in engineering...

Steel, maybe. But aluminum doesn't respond as well to large yields and then being bent back. And this particular hub flange was bent over a LOT, the bike had been in a crash, that's why in the trash. And it's a safety critical application, with possibly, "non-graceful degradation mode", meaning possibly catastrophic failure with no warning. Let's just say I got lucky. "Don't believe that it won't happen, just because it hasn't happened, yet." - Jackson Browne, I forget which song.

A single wall aluminum rim, after a hard pothole, the sidewall was slightly bent, I had no concerns about carefully bending it back straight, it was a small amount of yield, and, under both road and spoke loads, the rim, which constitutes a beam in bending, the outside is loaded in compression, less likely to fail in fatigue versus tension.

I've straightened aluminum racks.

An aluminum handlebar that had a big bend... I would be hesitant to just straighten it, I'd replace. But then again, I'm not as poor as I used to be. In the third world, that would get straightened, and might be fine, just not worth the risk to me, knowing what I know now.