matton

So i've been riding 28c tires on my roadbike for some time and a friend of mine is still rocking old 23c on 13c rims(to my knowledge/ Rigida 18 from the 90s)on his roadbike. His tires a bassically toast now and as he, liking the more comfortable 28c on my bike, could get 28s from a friend for free, we were wondering if they would fit the rim.

Brake and frame clearance is not a problem, but to my knowldege 13c rims, if they are, are only supposed to fit up to 25C.

The question I have now is, if anybody has actually tried this setup and if it really does make alot of difference, as I think 15c rims can fit up to 33c tires.

I just wanted to ask if anybody actually has got experience with this before going on a trip and noticing some long way from home that it just doesn't work.

base2 

It's not that they won't fit. It's more of an issue of side-wall squirm. Side forces such as in initiating a turn will not have the necessary internal support & there is a risk of squirmy, unpredictable performance unless the tire pressure is higher than you probably would want.

I once had an issue with a 54mm wide tire on a rim that recommended on up to a 38mm maximum. It happened while carrying 10 pounds of dog-food in a front low-rider rack at about 20mph. You could see the tire rolling side to side as the rim bounced left to right in opposition. Needless to say, a case of the shimmies was not a welcome occurence. I dealt with it appropriatly & I slowed down for the rest of the trip home.

Similarly, low rear tire pressure is a major, major factor in speed wobble in motorcycles, as the driving wheel starts wanting to launch the bike at ever increasing angles other than straight forward. I doubt a bicyclist has problems with that kind of leg power, but nevertheless, I believe it adequetly illustrates my point.

1 or 2 widths bigger than the rim manufacturers recommendations will probably be ok. But, I wouldn't make a habit of being flagerant in disregard.

Though, I do seem to remember a Jan Heine article about balloon tires on skinny rims having a more progressive suspension action. So there is that.

Jan Heine says that your friend probably won't die.

HTupolev

The current rims on my '83 Miyata are Sun M13II with an internal width of 13mm, and I'm using Panaracer Pasela tires with a nominal width of 28mm on them. Actual inflated tire width for this rim/tire combo ended up being about 26mm.




They'll certainly fit in the sense that they'll successfully mount.
The old ETRTO tire/rim size chart recommends against it. But the chart is fairly conservative, and the caveats to putting a "too-wide" tire on a narrow rim are very soft limits: the wider the tire is relative to the rim, the more of a "lightbulb"-ish profile it inflates to, which means less lateral support and potentially squirmier behavior. To what degree this results in anything tangible depends on pretty much every factor imaginable.

The tire+rim combination that we're discussing isn't flying very close to the sun.
The pressures I typically run my setup at aren't super-high: often around 80r/70f with bike+rider weight of around 190lbs. I've put a few thousand miles on the bike in this configuration, through lots of both solo riding and spirited group rides, sometimes exceeding 45mph on descents. It's been fine.

canklecat

Wider tires will fit, but as described above, handling may suffer. Whether you notice depends on your terrain and how you ride.

My favorite inexpensive hybrid tires are Continental SpeedRides, nominally 700x42 but measure closer to 38. They were terrific on 622x19 rims. But those wheels were pretzeled when I was hit by a car so that bike now wears 622x14 rims. Handling definitely suffered a bit with the SpeedRides on narrower rims. It feels mushy and imprecise on fast curves, especially with imperfect pavement. And it feels bouncy, not supple. I switched to narrower Conti Sport Contact II in 700x32, but really dislike those tires -- they're very durable and puncture resistant, but the ride is harsh at normal pressure, and sluggish at reduced pressure. So I'll switch to 700x28 tires for now, and eventually get some proper wider rims for that hybrid. I'm considering switching to tubeless for that bike.

All of my road bikes have 622x13 or x14 rims, and only enough clearance for 700x25 in the back. With some 700x25 tires I can feel a slight loss of handling precision, but not so bad with good tires like Conti GP Classics. No problem with 700x23 tires. One of my older road bikes original came with 700x18 or 700x20 tires, but I doubt I'd ride those now even if they were available.

Iride01 

If it's between trying the bigger tire on the existing rim or buying a bigger rim, then I'd try the bigger tire on the narrow rim first. If after riding some at different pressures it feels squirrely on turns. Particularly downhill twisty turns. Then I'd either go back to a narrower tire or buy a wider rim.

It's what I did in my much younger days when taking stuff outside it's recommendations was something you had to do to be cool.

Gonzo Bob

I have some old wheels from a crashed 1984 Fuji that have Ukai 700x13C rims. The wheels are now in my commuter and I've run various 28mm tires on them without issues.

matton

I was just wondering if they may balloon out a bit and cause the bike to feel a bit weird when cornering.

Looks like it's safer to use them. At least it won't be fatal.

Iride01 

Might. But until you try you won't know.

Shouldn't be fatal, but if you throw all caution to the wind until you know the answer then it might be fatal or nearly so.

ThermionicScott 

People used 28+ mm tires on rims that narrow all the time decades ago. Only recently have we started to overthink it so much. Just put 'em on and ride your bike!

smashndash

My hybrid came with 13mm rims. I put a 2.1" mtb tire on the front. Tried driving to a trailhead and the exhaust from my car burned a hole in the sidewall. I stuck some bubblegum and a dollar bill between the (new) tube and sidewall and sent it, brah.

You will be fine.

HTupolev

Probably not that many people.

The stock rims on my '79 Fuji, which came with 28mm tires, had an internal width of about 17mm. That was not wide at the time: in that decade, a lot of the rims used on lower-end road bikes with 27 x 1 1/4 clinchers had internal widths of over 20mm.
On the '83 Miyata 710 I mentioned above, the 13mm-internal rims are not original. I don't remember the exact dimensions of the stock wheels, but the rims were definitely wider than the current ones.

The widespread adoption of super-narrow clincher rims happened alongside the widespread adoption of super-narrow clincher tires. When 13mm-internal rims became popular, 28mm clinchers were not in vogue.