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I have a Croix de Fer cross bike that I purchased for touring with luggage; for commuting to work, lighter touring and some mild offroad riding.

While it is nowhere stated officially, I can see on this review that the rims are 18mm wide: See the sticker

What range of tire width can I run? Saint Sheldon says 25-37mm for 17mm and 28-44mm for 19mm. And that it is on the safer side. What can I ride on this rim?

Also, the fact that the rims are for disc brakes and their lack of brake track makes them a tad shallower. Does that change anything to this consideration?

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    The manufacturer has a contact form on their website. I didn't see any specifications on the website for tire widths, but perhaps they would reply if you asked the directly.
    – Kibbee
    Commented Aug 26, 2013 at 23:56
  • I have no trouble running 35mm road tires on a 13mm rim. In fact, that's the way the bike came from the factory. Commented Aug 27, 2013 at 3:56
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    "mild offroad riding" and narrowest possible does not compute unless you like pinch flats and and excuse to buy new rims to boot. Most importantly why do you want narrow tires? Have you already got some, do you have a belief they are faster?
    – mattnz
    Commented Aug 27, 2013 at 4:07
  • @DanielRHicks: interesting... although that's "pushing" to the other side, but interesting.
    – Nic
    Commented Aug 27, 2013 at 6:09
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    @mattnz: I obviously don't mean to do my "mild offroad" with skinny tires. I am exploring my tyre options without purchasing a new wheel. And yes I've ridden skinny tires on a former bike and yes, they are faster. I don't mean to open here the debate skinny vs. fat tires. But the weight gain of skinny tires does help quite a lot (and yes I know, rolling resistance is higher at comparable pressures). No I mean to ride tires on the skinny side for light daily commuting (little or no luggage at all), 32-ish for touring, and 38-ish for winter commute and mild offroad...
    – Nic
    Commented Aug 27, 2013 at 6:16

2 Answers 2

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I think Sheldon's recommendations are a good rule of thumb - I might be wiling to go a tad narrower if I were truly compelled to do so, but that's all to be taken with a grain of salt. In terms of rim depth, it should play no part in your tire choice whatsoever as it has no bearing on how the tire will seat into the rim.

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  • So you think 25mm is a good minimum width? since 18 is between 17 and 19 and since he recommmends 25 as minimum for one and 28 for the other?
    – Nic
    Commented Aug 27, 2013 at 6:20
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    I would be willing to run it, but I don't always set the best example.
    – joelmdev
    Commented Aug 27, 2013 at 13:21
  • Going too narrow will compromise the tires performance to the extent that a better fitting wider tire will perform better. I don't believe dropping below 25 will give measurable benefits without rims that suit. 25 is probably OK, provided you are careful to maintain tire pressures.
    – mattnz
    Commented Aug 27, 2013 at 23:10
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The only 'theory' I can find is Steve Hed's, which is based on aerodynamic of wheels. See this article http://www.slowtwitch.com/Products/Things_that_Roll/Hed_Ardennes_Gets_Fatter_3559.html for example. While this sounds like it only make sense for road wheels, I can't find any theory against it on other type of wheels.

Looks like the best combination would be of the tyre to be as wide as the rim, so the tyre will 'look' straight to the air, e.g. 23 mm tyre on 23 mm rim. There are also tyres with 'lip' that should cover the gap between tyre and rim to make it even smoother. If you put 28 mm tyre on 23 mm rim, the tyre will create a bulge that will be visible to the air.

This also makes tyre selection rather limited because rim sizes don't vary much, e.g. 23 mm rims only available a few years ago. Currently, I'm still using 19 mm tyres on my 18 mm wide rims. I'd love to get 23 mm wheels so I can use 23 mm tyres first because it's better, second because it's hard to find 19 mm tyres.

On Sheldon's page he also mentioned that many cyclist exceeded the recommended widths on his page without any problem.

About the rim being disc brake rim, I don't think it makes any difference because even if the rim was shallower, the wheel diameter stays the same.

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  • Typically inner rim width are given. In this answer however, outer rim width are meant. The 18 mm wide rims likely have a nominal (inner) width of 13 mm. Would you please clarify this @imel96?
    – gschenk
    Commented Aug 26, 2017 at 8:22

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