Rim Width and Tyre Width
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- whitestone
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Rim Width and Tyre Width
Is there a recommendation or formula that relates internal rim width to tyre width? Ideally I'd like a rim that will cope with tyres from 2.35" to 3". I realise that I might not get the best tyre profile at either end of the range.
Better weight than wisdom, a traveller cannot carry
Re: Rim Width and Tyre Width
I've used light bicycle 35 and 38mm rims with that sort of range.
Could go wider though. And no idea if there's a formula
Could go wider though. And no idea if there's a formula
Re: Rim Width and Tyre Width
If in doubt, ask Sheldon Brown:whitestone wrote:Is there a recommendation or formula that relates internal rim width to tyre width? Ideally I'd like a rim that will cope with tyres from 2.35" to 3". I realise that I might not get the best tyre profile at either end of the range.
https://www.sheldonbrown.com/tyre-sizing.html#width
(Doesn't seem to work well on a mobile device)
Re: Rim Width and Tyre Width
There are a few charts floating about / some articles. I'd personally say about 35mm for what you're looking for.
Edit - Depends on the tyre profile in reality though.
Edit - Depends on the tyre profile in reality though.
Last edited by Richard G on Thu Apr 27, 2017 8:45 pm, edited 2 times in total.
- Bearbonesnorm
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Re: Rim Width and Tyre Width
I'd say 30mm internal is as narrow as you really want to go. Fitting a 3" tyre to anything smaller and you're simply dragging a heavy tyre about for no real benefit.
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Re: Rim Width and Tyre Width
surly rabbit hole's are perfect IMO at 50mm
Hugo's might be a good lighter option.
Hugo's might be a good lighter option.
- whitestone
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Re: Rim Width and Tyre Width
I was thinking of building up a wheel with a dynamo hub. Given the likely cost I'd rather have a rim that could cope with both normal and plus sized tyres.
Looking at that chart on the Sheldon Brown site and a quick bit of work on the calculator it looks like a tyre width/rim width ratio of 1.75 is about right for the narrow end and 2.25 for the wide end. 2.35" is 60mm => 60/1.75 = 34.3mm, 3" is 75mm => 75/2.25 = 33.3 so Richard's 35mm looks about spot on, equally 30mm isn't too far away.
I think I'm right in saying that a narrow rim makes a given tyre have a very round profile whereas a wider rim gives it a squarer one.
Found an article on bikerumour where they've gone to various tyre manufacturers about this. They (Bikerumour) say this: "But, with some calculations of the ETRTO standards, we came up with a rough guideline suggesting your rim width should be between 32% to 70% of the tyre width."
Looking at that chart on the Sheldon Brown site and a quick bit of work on the calculator it looks like a tyre width/rim width ratio of 1.75 is about right for the narrow end and 2.25 for the wide end. 2.35" is 60mm => 60/1.75 = 34.3mm, 3" is 75mm => 75/2.25 = 33.3 so Richard's 35mm looks about spot on, equally 30mm isn't too far away.
I think I'm right in saying that a narrow rim makes a given tyre have a very round profile whereas a wider rim gives it a squarer one.
Found an article on bikerumour where they've gone to various tyre manufacturers about this. They (Bikerumour) say this: "But, with some calculations of the ETRTO standards, we came up with a rough guideline suggesting your rim width should be between 32% to 70% of the tyre width."
Better weight than wisdom, a traveller cannot carry
Re: Rim Width and Tyre Width
I rode a chronicle on a 35mm rim for the borders350 attempt the other year.
It was still a bit lightbulb shaped but ran it at 10psi no trouble.
I'd not build up a dynamo wheel until you've tried the semi plus thing though bob. It's an acquired taste, great small bump absorption but odd 'square' steering.
Can lend you a 35/38 with a chronicle on if you want to try it.
It was still a bit lightbulb shaped but ran it at 10psi no trouble.
I'd not build up a dynamo wheel until you've tried the semi plus thing though bob. It's an acquired taste, great small bump absorption but odd 'square' steering.
Can lend you a 35/38 with a chronicle on if you want to try it.
- whitestone
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Re: Rim Width and Tyre Width
I've got a set of the Alpkit Rumpus wheels with a WTB Bridger 3" on the front, these are 650B+ rather than 29+ so I do have some feel for the sizing but those are 45mm rims.
If a 35mm rim was fine with the narrower tyre then I'd go with that, with the Chronicle on clearance at CRC I could try it and go back to the Bontrager XR4 if I didn't get on with it.
If a 35mm rim was fine with the narrower tyre then I'd go with that, with the Chronicle on clearance at CRC I could try it and go back to the Bontrager XR4 if I didn't get on with it.
Better weight than wisdom, a traveller cannot carry
Re: Rim Width and Tyre Width
on my 29+ wheel i'm running a dually rim which i really rate - it's been good for me so far
think it's 45mm outside, 39mm internal
think it's 45mm outside, 39mm internal
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- In Reverse
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Re: Rim Width and Tyre Width
The Dually is perfect for that range of tyre width. I've run 2.35 Nobby Nics, 3" Dirt Wizards and various things in between.
Re: Rim Width and Tyre Width
DT Swiss are doing some wider rims.
I think they are up to 40mm internal the last time I looked.
I think they are up to 40mm internal the last time I looked.
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