23mm on 17mm internal diameter rims?

Discuss light weight issues concerning road bikes & parts.
Hexsense
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by Hexsense

vejnemojnen wrote:
Calnago wrote:Yes, a 23mm clincher on a 17mm internal width rim will be very similar to a 25mm clincher on a 15mm internal width rim.
.

Nope. It'll be much better.

what exactly do we want from wider tire/rim ?
If it is rolling resistance, both are about equal as wider rim also reduce rolling resistance, same as wider tire size.
If it is handling you are right.
If it is comfort, wider actual tire might be cushier as the tire shape is more springy.
If it is aero, wider rim and narrow tire clearly win, no question!
If it is pinch flat protection on a big bump then nope. 25c tire on 15mm rim is still even taller than 23c tire on 19mm rim (but narrower). Thus in this area, bigger tire size still win.
Image

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Beaver
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by Beaver

On a 21C rim (which should be 28mm wide at least) you can mount tires from 23 to 28mm without issues. Pick 23mm tires for perfect roads or if you can do 35+km/h on average for best aero, 28mm will be a couch, 25mm is a great compromise.

https://www.youtube.com/watch?v=Py9Loc8xjoo
https://www.youtube.com/watch?v=aX7SCWlcix4

I'm 70kg and have very rough roads. A 25mm 4000S II with 4/4.5bar reduces road buzz to a minimum and rolls very well. Cornering is better than 23mm on 17C.

Only problem: you need a not to old road bike with 28mm tire clearance...

by Weenie


Marin
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by Marin

Beaver you need to get decent tires or noone will take you evangelizing seriously ;O)

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Calnago
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by Calnago

Ha... Continental surely does get slammed on this forum. But for checking out tire clearances with rims and frames, they probably sit taller than any other clincher I've seen, and rim width does make a difference in how tall a tire sits as well. So when I do some testing, I usually like to use the Contis as a benchmark for clearance experiments. Plus, they are probably the most popular tires (4000Sii) in the area I live in. Tubular Veloflex are nice for sure, but the reality is that very few people in the real world (WW, for the most part, is not the real world), actually run tubulars on a daily basis. I don't run anything else now, and for the winter I really like the Continental Competition most of all, as I think they grip really well in the wet and I just like the dotted tread. The downside is how difficult they are to mount and require tons of stretching. And I would never use one as a spare for fear I'd never be able to get it on the rim out on the road in the cold if I flatted. My go to spare is a Veloflex Carbon 23mm.
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Hexsense
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by Hexsense

Beaver wrote:On a 21C rim (which should be 28mm wide at least) you can mount tires from 23 to 28mm without issues. Pick 23mm tires for perfect roads or if you can do 35+km/h on average for best aero, 28mm will be a couch, 25mm is a great compromise.

Hi, Beaver.
I have a gift for you. I finished my front wheel replacement with 21mm inner width rim.
This is Continental GP4000sII size 23c on it. which transformed into 27.39mm wide and ~23.5mm (somewhere between 23 and 24) tall giant monster. I think it'll be easier to you to explain to people that it's fine and good to mount narrow tire on the wide rim when you have a picture. Note that in the photo it show the label which says 23mm and also a calipers that wrote 27.39mm.
DSC_1744s.jpg

It ride supremely well and not too far off from Vittoria Corsa G+ 25c on the same rim. which is 29.3mm wide and 23mm tall (wider but not as tall). Now as Vittoria 25c is not as tall as Continental 23c. I wonder which one will actually perform better on not perfect road with many potholes.

gsecco
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by gsecco

I also thank everybody for the comments. I was wondering about that because Fulcrum 17C specifications says that the rim is for 25-28mm.

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Beaver
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by Beaver

gsecco wrote:I also thank everybody for the comments. I was wondering about that because Fulcrum 17C specifications says that the rim is for 25-28mm.


It's of course possible, but tire performance will be better if you don't use more than 23mm tires.

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Beaver
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by Beaver

Hexsense wrote:
Beaver wrote:On a 21C rim (which should be 28mm wide at least) you can mount tires from 23 to 28mm without issues. Pick 23mm tires for perfect roads or if you can do 35+km/h on average for best aero, 28mm will be a couch, 25mm is a great compromise.

Hi, Beaver.
I have a gift for you. I finished my front wheel replacement with 21mm inner width rim.
This is Continental GP4000sII size 23c on it. which transformed into 27.39mm wide and ~23.5mm (somewhere between 23 and 24) tall giant monster. I think it'll be easier to you to explain to people that it's fine and good to mount narrow tire on the wide rim when you have a picture. Note that in the photo it show the label which says 23mm and also a calipers that wrote 27.39mm.
DSC_1744s.jpg
It ride supremely well and not too far off from Vittoria Corsa G+ 25c on the same rim. which is 29.3mm wide and 23mm tall (wider but not as tall). Now as Vittoria 25c is not as tall as Continental 23c. I wonder which one will actually perform better on not perfect road with many potholes.


Here the first generation 4000S on HED Ardennes Plus (20.3C):

Image

:thumbup: What tire pressure do you run at what weight? I am 70kg and run f4.0/r4.5 bar with 25mm 4000S II on 21C rims (real width 28.5mm) - that feels a lot better on rough roads compared to 23mm tires on 17C rims. If the same low pressure is possible with a 23mm tire I would change, too. :)

Did you pick the Light Bicycle 21C rim? Meanwhile there are quite a few 21C/28mm wide options:

Light Bicycle RR36C02
Enve SES 3.4 (but quite heavy 475g and $$$)
NOX Falkor 36R
Venn Rev 507 TCC
Last edited by Beaver on Tue May 23, 2017 7:36 pm, edited 1 time in total.

Hexsense
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by Hexsense

Beaver wrote:Here on HED Ardennes Plus (20.3C):
:thumbup: What tire pressure do you run at what weight? I am 70kg and run f4.0/r4.5 bar with 25mm 4000S II on 21C rims (real width 28.5mm) - that feels a lot better on rough roads compared to 23mm tires on 17C rims. If the same low pressure is possible with a 23mm tire I would change, too. :)

Did you pick the Light Bicycle 21C rim? Meanwhile there are quite a few 21C/28mm wide options:

Light Bicycle RR36C02

I choose Light Bicycle 45mm for my front rim. Rear rim is still a 17mm inner width waiting for replacement later as it still serve me fine though.
That was on 85psi directly after mounting the rim (just to make sure the tire pop in securely at first). I only weight 68kg so i ride at 70psi on front wheel at the moment. I come from rim a lot narrower so 23c on this low pressure freak me out at first but it's clear that i can reduce it further so i'll slowly reduce pressure on every ride.

Are you sure your 25c Continental is only 28.5mm wide? That's only 1.2mm wider than my 23c. My Vittoria Corsa G+ 25c is 29.3mm wide but it interestingly has the less height than the 23c Conti. That maybe the only case i've seen Conti run narrower than Vittoria (but a lot taller i assume).

On my 17mm inner width rim. Conti 25c is both taller and wider than Vittoria 25c.

EDIT the typo number*
Last edited by Hexsense on Tue May 23, 2017 1:05 am, edited 1 time in total.

wwnick
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by wwnick

Hi Hexsense, what does the caliper say for the fingernail :lol:

Hexsense
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by Hexsense

wwnick wrote:Hi Hexsense, what does the caliper say for the fingernail :lol:

caliper doesn't say anything but my glove said it's time to cut my nails already.

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Beaver
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by Beaver

Hexsense wrote:
Beaver wrote:Here on HED Ardennes Plus (20.3C):
:thumbup: What tire pressure do you run at what weight? I am 70kg and run f4.0/r4.5 bar with 25mm 4000S II on 21C rims (real width 28.5mm) - that feels a lot better on rough roads compared to 23mm tires on 17C rims. If the same low pressure is possible with a 23mm tire I would change, too. :)

Did you pick the Light Bicycle 21C rim? Meanwhile there are quite a few 21C/28mm wide options:

Light Bicycle RR36C02

I choose Light Bicycle 45mm for my front rim. Rear rim is still a 17mm inner width waiting for replacement later as it still serve me fine though.
That was on 85psi directly after mounting the rim (just to make sure the tire pop in securely at first). I only weight 68kg so i ride at 70psi on front wheel at the moment. I come from rim a lot narrower so 23c on this low pressure freak me out at first but it's clear that i can reduce it further so i'll slowly reduce pressure on every ride.

Are you sure your 25c Continental is only 28.5mm wide? That's only 1.2mm wider than my 23c. My Vittoria Corsa G+ 25c is 29.3mm wide but it interestingly has the less height than the 23c Conti. That maybe the only case i've seen Conti run narrower than Vittoria (but a lot taller i assume).

On my 17mm inner width rim. Conti 25c is both taller and wider than Vittoria 25c.

EDIT the typo number*


What was the weight of the rim? 460g as stated? Only 20g more than the 36mm rim, maybe a better choice.

My rims are NOX S36R with 20.5mm inner width and I only run 58psi up front. :) Maybe that's why they are a little thinner.

Here it's 28.6mm on a 20.3C rim with 95psi:

viewtopic.php?f=3&t=136995&start=30#p1270126

But why the difference isn't 2mm? :noidea:

The main difference to 23mm tires on 17C rims is the heavily reduced road buzz on very rough tarmac (the one that even makes your car tires really loud). Bumps are softened a litte but not that much - for that "real" suspension is needed I guess (Speci Roubaix...).

I think I also have to try 23mm on my 20.5C - maybe they run very well with 60psi. :) The rim would also be wider than the tire then and offer best aerodynamics. ;)

Here you can see 23/25mm 4000S II on different rims: The height doesn't increase anymore from 17.8C to 20.7C.

Image

Hexsense
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Joined: Wed Dec 30, 2015 12:41 am

by Hexsense

it was 470g on my (cheap) scale.

Your picture doesn't really compare at the same pressure so that may be why it doesn't getting any taller.
Silca's graph shows tire getting slightly taller as the inner width increase (but not much at all, unlike width)
https://cdn.shopify.com/s/files/1/0309/ ... 7096805373

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