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Re: Wide Rims and Tires: Real Measurements

Posted: Thu Apr 06, 2017 2:24 am
by Matt28NJ
dmp wrote:Stans 340 rims, Michelin Pro4 Service Course @ 85psi = 24.9mm
Stans 340's, Michelin Power Race @85psi = 24.9mm. Both measured with a Mituyoto dial caliper.


Thanks... but you might want to tell us what the original tire size is... :?

Re: Wide Rims and Tires: Real Measurements

Posted: Thu Apr 06, 2017 2:24 am
by Weenie

Re: Wide Rims and Tires: Real Measurements

Posted: Thu Apr 06, 2017 3:34 am
by dmp
Matt28NJ wrote:
dmp wrote:Stans 340 rims, Michelin Pro4 Service Course @ 85psi = 24.9mm
Stans 340's, Michelin Power Race @85psi = 24.9mm. Both measured with a Mituyoto dial caliper.


Thanks... but you might want to tell us what the original tire size is... :?

Oops! They are both 23

Re: Wide Rims and Tires: Real Measurements

Posted: Thu May 25, 2017 4:45 am
by Hexsense
Light Bicycle 46mm deep, 21mm internal width.
Continental GP4000sII 23c 85psi -> 27.39mm ~24.5mm tall (not that i actually ride this high pressure, this is only for first mounting seat).
Also, it is 27.12mm wide at 65psi, latex tube.
Vittoria Corsa G+ 25c 85psi -> 29.9mm at first then go down to 29.3mm later and stay that way (so stable state is 29.3 i think). Interestingly this is only ~23mm tall which is less tall than Conti 23c. Perhaps it grow sideway too much on wide rim vs Conti to the point that it is wider but not as tall?
DSC_1744s.jpg

Re: Wide Rims and Tires: Real Measurements

Posted: Fri May 26, 2017 12:13 pm
by Beaver
mpulsiv wrote:
boots2000 wrote:Really?- In my experience the GP4000 II 700x28mm ride like butter. Fast too. Just need a bike with much clearance for them to work.

I have been using Schwable one clincher 700x28- It was ok. Runs big too but not as big as the Conti GP4K.

Just put on a set of Vittoria G+ 700x28- definitely smaller than the Schwable it replaced.

Marin wrote:Yes, I have 25 and 28mm G+. The 28 is just under 1mm wider than the 25.

The 25s are roughly 27mm, the 28s are true 28mm. The weight is also very close BTW.

Conti GP4000s 28s are probably the fattest 28s you can find, mine came out to 31mm. Plus the ride is awful, glad I got rid of them.


As of March 2017, there are no carbon or aluminum race frames (rim caliper) on the market that will clear 28m Continental GP 4000S II. This tire is 29mm tall and 31mm wide http://www.bicyclerollingresistance.com ... i-23-25-28

Your only option is Trek Domane 2017 model disc or steel/titanium frame, either rim caliper or disc.


Felt FR, Orbea Orca '17 and Ridley Fenix SL should also be possible.

Re: Wide Rims and Tires: Real Measurements

Posted: Fri May 26, 2017 12:34 pm
by Marin
Beaver wrote:Felt FR, Orbea Orca '17 and Ridley Fenix SL should also be possible.


Interesting, but how will they clear 31mm tires with short drop brakes?

Re: Wide Rims and Tires: Real Measurements

Posted: Fri May 26, 2017 2:36 pm
by matejS
I can confirm Schwable S One 30mm (on 20mm inner width rims they measure 30mm) can fit Ridley Fenix SL. There is a bit of a struggle with the breaks, but with a proper brake adjustments and slight squeeze of the tire when putting on/off they work.

Re: Wide Rims and Tires: Real Measurements

Posted: Fri May 26, 2017 7:45 pm
by Beaver
Marin wrote:
Beaver wrote:Felt FR, Orbea Orca '17 and Ridley Fenix SL should also be possible.


Interesting, but how will they clear 31mm tires with short drop brakes?


What about the new Shimano brakes? That looks like a lot of clearance:

Image

And with the new frames the brake mount location is higher.

Re: Wide Rims and Tires: Real Measurements

Posted: Fri May 26, 2017 9:03 pm
by Marin
I just checked, the new DA brakes have 2mm more reach than the old ones, 51 vs. 49mm. Only helps if frames and forks are designed to take advantage of the longer brakes of course.

Re: Wide Rims and Tires: Real Measurements

Posted: Sat May 27, 2017 8:14 am
by Beaver
Marin wrote:I just checked, the new DA brakes have 2mm more reach than the old ones, 51 vs. 49mm. Only helps if frames and forks are designed to take advantage of the longer brakes of course.


Helium SLX with 25mm Ultrasport on Fulcrum 5:

Image

Orca:

Image

Re: Wide Rims and Tires: Real Measurements

Posted: Sat May 27, 2017 12:29 pm
by Marin
nice

Re: Wide Rims and Tires: Real Measurements

Posted: Thu Aug 31, 2017 3:32 am
by misterq
so for those running say 23s on the wider rims such as what I am looking at is 18 inner and 25 outer. Are you running bigger volume latex tubes? I use the vittoria ones and guessing for the gp4000s 23s which should measure over 25 I could or should run the 25/28 latex

Re: Wide Rims and Tires: Real Measurements

Posted: Thu Aug 31, 2017 7:42 pm
by TSJ
Here's a question as it relates to tire pressure:

Are you guys running pressures based on actual inflated tire size or based on the manufacture size?

A 23 tire equals 25+ on wide rims....does that mean that I should be inflating my 23 tires based on the ideal pressure for a 25 tire? or 25 tire based on a 28 etc....

Re: Wide Rims and Tires: Real Measurements

Posted: Fri Sep 01, 2017 8:30 pm
by Beaver
You won't need larger tubes, as the tire gets mainly wider than higher. It's more volume but not that much.

One may start e.g. with a 25mm tire on a 21C rim (real 28mm wide) with the pressure you would use with a 28mm tire, but you could possibly even go lower...

Re: Wide Rims and Tires: Real Measurements

Posted: Fri Sep 01, 2017 9:27 pm
by Hexsense
misterq wrote:so for those running say 23s on the wider rims such as what I am looking at is 18 inner and 25 outer. Are you running bigger volume latex tubes? I use the vittoria ones and guessing for the gp4000s 23s which should measure over 25 I could or should run the 25/28 latex

Latex can stretch 7.5 times.
Butyl can stretch 1.5 times.

So, no. unless your tube is very undersized to save weight from the start, i'll be more than fine.

Re: Wide Rims and Tires: Real Measurements

Posted: Fri Sep 01, 2017 9:27 pm
by Weenie

Re: Wide Rims and Tires: Real Measurements

Posted: Sat Sep 02, 2017 3:40 am
by TobinHatesYou
TSJ wrote:Here's a question as it relates to tire pressure:

Are you guys running pressures based on actual inflated tire size or based on the manufacture size?

A 23 tire equals 25+ on wide rims....does that mean that I should be inflating my 23 tires based on the ideal pressure for a 25 tire? or 25 tire based on a 28 etc....


You should be inflating your tires based on volume and not printed widths. If your "23mm" tire is actually 25mm when inflated on your rims, then use lower pressures than if they actually inflated to 23mm. The rim interface forces on a 25mm tire at 90psi are greater than that of a 23mm tire at the same PSI.