# 35c wheels on a 23-32c rim? Is this OK?



## armstrong (Jul 9, 2013)

Hi folks

This puzzles me a bit. Bought a hybrid recently from a not-so-LBS (90 min drive from where I live). Very happy with the purchase. 2013 Rocky Mountain Metro 30.

Anyways - I'm pretty sure everything I got on the bike is "stock" as per the manufacturer's specifications (Rocky Mountain Metro 30 (Canada) - Bike Depot and Broadway Cycle. Bicycle stores in Toronto and Thornhill Ontario. Specialized Scott Marin, Gt Mountain and Road bikes). 

The funny thing is this: The rims are WTB (according to the link, they are presumably Freedom Ryder 21 - the bike is not beside me now) and they have a sticker on them saying the recommend tire size is from 23c - 32c. But the tires on them are Kenda Kwest 35c (consistent with the link above).

Q: Is there a "problem" with using 35c on a rim that recommends only 23-32c? If not, is there anything I should be careful with? (e.g. don't inflate to full PSI or something like that?) Do any of you find it odd that the stock components they put on the bike aren't "recommended" for each other?? Anyways - photo here with a little passenger.

Thanks in advance.


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## PJ352 (Dec 5, 2007)

I did a quick search on that wheelset and couldn't find the rim width (21" is my guess). To know for sure, you could measure the width, but I think you're fine.

Here's a link to a chart with width considerations:
Tire Sizing Systems


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## Kerry Irons (Feb 25, 2002)

PJ352 said:


> I did a quick search on that wheelset and couldn't find the rim width (21" is my guess). To know for sure, you could measure the width, but I think you're fine.


I think you mean the width is 21 mm, not 21". Agree that 35mm tires should not be an issue.


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## PJ352 (Dec 5, 2007)

Kerry Irons said:


> I think you mean the width is 21 mm, not 21". Agree that 35mm tires should not be an issue.


And you would be correct in that assumption. :wink5:


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## armstrong (Jul 9, 2013)

Ok. Here's the photo of the sticker. So it's actually a 15c, and the recommended tire widths are 23c - 32c, which I think is funny cause it comes stock with 35c wheels. Your link even has the same recommended tire widths.

So anyways - my wife's hybrid has 16c wheels with 28c tires. What I'll do is swap tires with her (so my bike will have 15c with 28c and hers will have 16c with 35c). Hopefully that'll be an adequate fix.


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## JCavilia (Sep 12, 2005)

armstrong said:


> Ok. Here's the photo of the sticker. So it's actually a 15c, and the recommended tire widths are 23c - 32c, which I think is funny cause it comes stock with 35c wheels. Your link even has the same recommended tire widths.
> 
> So anyways - my wife's hybrid has 16c wheels with 28c tires. What I'll do is swap tires with her (so my bike will have 15c with 28c and hers will have 16c with 35c). Hopefully that'll be an adequate fix.


I don't know if you need a "fix". That label is a recommendation, not a hard rule, and actual tire widths vary from their nominal sizes. Your 35 mm tire may be only 31mm wide. If the tire seems to be seated well all around, and it stays in place when inflated to the pressure you want, and it rides okay, it's fine. If you hadn't read the fine print you'd never think anything is wrong.

If you're going to be the one carrying the kid on the seat, you should have the bigger tires, so you can run lower pressures for more comfort and still avoid pinch flats. So I would not recommend the switch you are considering. Especially if you are heavier than your wife.

BTW, your questions will be less confusing if you use the proper terms consistently. The metal hoop is the "rim". The assembly made up of rim, spokes and hub is a "wheel." And the rubber thing is a "tire" (not a "wheel").


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## armstrong (Jul 9, 2013)

The tires look very oversized for the rim. The rim looks to be basically the same size/width as the rim on my road bike, which has 23c tires. I think if I took a cross-section of the rim/tire, it would kinda look like a Super Mario mushroom.

Suppose I keep things the way they are - should I keep tire pressures a bit lower than max so as not to put too much stress on the rim? Or is this irrelevant?


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## PJ352 (Dec 5, 2007)

armstrong said:


> The tires look very oversized for the rim. The rim looks to be basically the same size/width as the rim on my road bike, which has 23c tires. I think if I took a cross-section of the rim/tire, it would kinda look like a Super Mario mushroom.
> 
> Suppose I keep things the way they are - should I keep tire pressures a bit lower than max so as not to put too much stress on the rim? Or is this irrelevant?


I think you're overthinking this. If you look at the chart, a 15mm width rim can run a 23 to 32c tire, with a footnote that states: 

Note: This chart may err a bit on the side of caution. Many cyclists exceed the recommended widths with no problem. 

If you haven't experienced any problem, I'd leave things as is.

As far as what pressures to run, tire size, construction and total rider weight are what dictate a starting point, tailoring from there based on riding style and road conditions.

Here's a chart that should get you started. Use the second one.

Bicycle tire pressure calculator


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## AndrwSwitch (May 28, 2009)

Mountain bikers routinely use tires that are three times the width of the rim, or more.

If it bothers you, don't buy hybrids.


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## JCavilia (Sep 12, 2005)

> should I keep tire pressures a bit lower than max so as not to put too much stress on the rim? Or is this irrelevant?


Tire pressures should hardly ever be max, but it has nothing to do with the wide tire putting stress on the rim (which it won't).

I repeat. If the tire stays on properly when you ride, and feels okay cornering, it's fine. Forget you ever saw that label.


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