wider rims on same 23mm tires : lower pressure?

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Delorre
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by Delorre

For those that have switched to wider rims (23, 24 or 25mm wide) using their regular 23mm tires, have you lowered your tire pressures a little or not? A wider rim = a little more air volume, but after that....


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MNX1024
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by MNX1024

Yes, I went from 95/100 to 77/80 when I switched to wider rims.

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WMW
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by WMW

Delorre wrote:A wider rim = a little more air volume, but after that....


It's a very little more air volume. Maybe 5 psi would make sense.
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bm0p700f
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by bm0p700f

If your 23mm tyre now sits 25mm wide treat like a 25mm wide tyre forms that 100 psi instead of 110psi.

orange77
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Joined: Wed Mar 11, 2015 4:23 pm

by orange77

Hi,

Bringing this topic back up.

Anyone that has installed their 23mm tyres on a wide 25/26mm external 17/18mm internal rim, can give me real tyre wide data in mm?

I've have a 23mm Michelin PR4 Endurance on a 23mm external wide LB Rim with 24,16mm at 7bar. Will it "grow/wide" on a widder rim?

Thanks :thumbup:

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ms6073
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by ms6073

Switched to 25mm tires on our Zipp 303 Firecrest clinchers and the 17.25mm clincher bead width, paired with Vittoria Corsa G+ tires and and Michelin latex tubes, I measured them at ~27.1mm when inflated to 95 psi.
- Michael
"People should stop expecting normal from me... seriously, we all know it's never going to happen"

YogibearAl
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Joined: Thu Jun 02, 2016 6:25 pm

by YogibearAl

:D - I had the same question so I tried it based on stuff I already had.

My 38mm Chinese carbon Clinchers are 25mm external and 18mm internal width. I'm running Conti GP4000s II 23c which measures out at 25mm once inflated. I'm running them at 90-100psi. They run flush with the width of the wheel, which is said to be more aero. Running a 25C Conti GP4000s II brings that width out to 27+mm (tight fit on my frame). Running the 23c at 25mm 90 psi is actually quite comfortable I may even go lower but don't want to risk pinch flats.

I had the same 23c tires on some 15mm internal alloy rims and they measure out at 23mm running at 100-100psi. A little harsher ride.

At the same pressures in the carbon vs alloy its really hard to tell, with ride quality. The carbon wheels are so much stiffer with so much more feedback compared to my set of alloy wheels that its hard to make a comparison. Lower pressures definitely feels better on both wheels.

dfischer1
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by dfischer1

bm0p700f wrote:If your 23mm tyre now sits 25mm wide treat like a 25mm wide tyre forms that 100 psi instead of 110psi.


HED Belgium+ user here. This is what I do. I'm moving up to 25s next time I need to replace a tire -- looking forward to some smooooooth riding.

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dvdslw
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by dvdslw

I'm riding 23mm Schwalble Pro One's on Easton EC90sl's that are 28mm outside and 18mm inside, the 23mm tires measure 27mm aired up to 85/90psi. On a wide rim, the 23mm tire gives you the volume of a 25/27mm casing that allows you to run less air pressure which gives you that supple ride quality everyone seems to be looking for these days plus no weight penalty. Best of all worlds combined in one, just add tubeless and its amazing. Here's a pic of my EC90sl's & 23mm Pro One measured

Image

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