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Wide Tyres on Narrow Rims

by Brooksy1882
Fri, Jan 29, 2021 15:57
7

Hi All,
Looking on my standard bike I appear to have Alex Rims Etrto 622 x17.

Would I be right with this marking, my rim width is 17mm?

Currently I have 25mm tyres but with recent wintery weather (and punctures) contemplating getting 28mm Reyes before later in year buying a new wheelset.

If my rims are 17mm and i do buy 28mm tyres this will create a 'light bulb' affect Right? Is that not sensible/beneficial to ride this way?

Right now until spring summer arrives I'm probably more interested in no punctures and a little more grip on the roads I assume the 28mm would give me?

If you're new please join in and if you have questions pop them below and the forum regulars will answer as best we can.

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6 comments

Avatar
NickJP | 3 years ago
0 likes

My touring bike has been running 37-38mm tyres on Mavic MA2 rims for the past 25 or 30 years, and those rims are only about 13mm internal width. Early MTB rims were cut down MA2s, and ran 2" tyres without problem. You'll be fine for whatever size of tyre will fit in your frame.

Avatar
Balthazar | 3 years ago
3 likes

Going from this chart at Rene Herse:

https://www.renehersecycles.com/wp-content/uploads/2020/09/ETRTO-Tire-Ri...

17mm rims are fine for up to 55mm tyres (at least). I can't find the original ETRTO specs in a moment, but I trust Jan Heine on this sort of thing...

This is a newish worry, with aero or aesthetics at its heart. You'll be fine with 28's.

Avatar
ktache | 3 years ago
1 like

i have been running up to 2.1 inch tyres on my wonderful 26 inch Mavic 717s for several decades.

It has never ever been much of a problem.

Avatar
Dnnnnnn | 3 years ago
1 like

Sheldon says Yes.
https://sheldonbrown.com/tire-sizing.html#width

Re: punctures, which tyres you use is much more relevant than whether they're 25mm or 28mm. There's a recurring article here which has about a zillion comments on it, everyone offering their tuppenceworth on the best options.

Avatar
Simon E | 3 years ago
2 likes

Yes, ETRTO will specify the internal width.

A 28mm or 30mm tyre will be fine on 17mm internal rim. I'm not sure you'll get noticeably more grip but you might get a little more comfort from slightly lower pressures. It will have a slight 'light bulb' appearance but that's not an issue. 32mm ought to be fine but I'd not like to say for certain.

Puncture resistance is determined mainly by what the manufacturer puts under the tread. It's invariably a tradeoff between comfort and protection, since the puncture belt makes the tyre (and sidewall if added there) stiffer and less compliant, regardless of pressure.

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hawkinspeter | 3 years ago
3 likes

The main issue with a bulbous tyre is the aerodynamics, but that's only likely to be relevant if you are running deep rims. Personally, I find that there's more benefit from the extra comfort and better rolling resistance of 28mms on our bumpy British roads.

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