Which size of tires for which width of the rims?

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TonyM
Posts: 3376
Joined: Thu Jan 22, 2015 4:11 pm

by TonyM

Hi,

There are so many claims from all the different wheel manufacturers that I am slowly getting confused... :(
As far as I understand from all the wheel manufacturers and their marketing claims:

- 17C rims: best when the tire measures 23 to 25mm on the rim, so usually for 23mm tires
- 18C rims: best when the tire measures between 25 and 28 mm on the rim, so usually for 25mm tires
- 19C rims: best when the tire measures 28mm or more on the rim, so usually for 28mm tires

Do I understand it right?

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charlieboy52000
Posts: 111
Joined: Wed Jan 08, 2014 5:43 am

by charlieboy52000

Here take a look
Www.betterbybicycle.com/2014/04/a-simpl ... heels.html



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robertbb
Posts: 2180
Joined: Thu Jul 23, 2009 3:35 am

by robertbb

For both aero and handling, you want the *actual measured width of the tyre* (when inflated to the appropriate PSI for your bodyweight) to be as close as possible to the *actual measured width of the brake track*. This will result in least drag *and* a tyre that doesn't flop as you corner.

For comfort, you simply want the widest tyre that will fit on your rim (and work with your frame).

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TonyM
Posts: 3376
Joined: Thu Jan 22, 2015 4:11 pm

by TonyM

robertbb wrote:For both aero and handling, you want the *actual measured width of the tyre* (when inflated to the appropriate PSI for your bodyweight) to be as close as possible to the *actual measured width of the brake track*. This will result in least drag *and* a tyre that doesn't flop as you corner.

For comfort, you simply want the widest tyre that will fit on your rim (and work with your frame).


Thanks! :thumbup:

Looking at some wheels manufacturers and their statement concerning the optimal tires for their rims, it indeed works when I understand the tire size as the actual measured width of the tire on the rim as you wrote.

Incidentally I realize that sometimes the inner width is the same for different wheels in a segment (like for example DT Swiss ARC wheels) but the outer width is different depending in the rim heigh. Maybe the dimension of the outer rim given by the manufacturer is at the maximum point of the rim and not at the brake track.

Marin
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Joined: Wed Jan 22, 2014 11:48 am
Location: Vienna Austria

by Marin

The reality looks like this:

15c rims: You can use 23m, 25mm, 28mm and other sizes.
16c rims: You can use 23m, 25mm, 28mm and other sizes.
17c rims: You can use 23m, 25mm, 28mm and other sizes.
18c rims: You can use 23m, 25mm, 28mm and other sizes.
19c rims: You can use 23m, 25mm, 28mm and other sizes.

You also won't notice much of a difference in ride, feel, or aerodynamics.

I ride 24mm Turbo Cottons on 15c / 23mm wide rims as my race wheels.
I ride 23mm Veloflex Masters on 18c / 25mm wide rims as my training wheels.
I ride 30mm Grand Bois tires on 18c / 25mm wide rims as my road / gravel wheels.
I ride 35mm Compass tires on 19c / 24mm wide rims for gravel.

All combos work really well. Aero is good enough for a great result in a recent TT on the race wheel. Don't overthink this, get the best tires you want to afford and don't get super narrow rims, that's it.

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