My son emailed and asked if he could put 32s on Mavic Open Pro rims. I had tried to do this about 6 months ago for a neighbor, and had no success with Gatorskins. The tire kept blowing off the rim when approaching the correct pressure. Any of you have an experience with a different tire that was successful?

There was a thread about this in the Mechanic's forum here:
https://www.bikeforums.net/showthread...c-Open-Pro-Rim

In it a user named blandin posted this:

From the Mavic Web site.

Tire dimensions and maximum inflation pressure

TIRE SIZE MAXIMUM PRESSURE

mm bars psi

19 10.00 146.00

23 9.50 138.00

25 9.00 131.00

28 8.00 117.00

Hope that helps!
-Bob

The Mavic site does not recommend anything larger than 28. However, Cyclocross riders have been installing 32's for a long time without any problem.

What model in the 32 size tire is being considered?

He hasn't picked one yet and was asking me for recommendations.

I have absolutely no experience with this newer stuff but generally tend towards wire beads since the '80s.

A guy in town that I ride with runs 35's panaracers on his open pros. I asked him a few years ago because they looked bigger than the 32's I had on my open sports, same size rim. Never had a problem.

I have folding bead Michelin 32mm Pilots on my Cross Check with Mavic Open Pro rims. Looks completely normal. Max pressure for the tire is 80 psi I think and I typically run 65 psi or so. That is more than enough pressure. I started out running 85 on them but that was just more than needed, not for the rim but for the tire. The Pilots are fat for their size, I could have been happy with the 30mm. But I love the ride of the 32mm. In any case, no worries, they are fine on the Open Pro rims, rock solid mount up.

LC

https://sheldonbrown.com/tire-sizing.html

Scroll down to the admittedly very conservative width compatibility chart. Also note that tires w/ 28mm callout sizes can vary considerably in width from brand to brand. I currently run 700Cx28mm Contis on the Bianchi, which cannot accommodate 700Cx28mm Specialized Armadillos.

That pressure chart up there is misleading, I think. It may be possible to run, say, 28s at 117psi--probably is, if Mavic says so--but why would you do it? It obviates the reasons for using larger tires.
FWIW, I run 35mm Paselas at 75 psi with no problems.

I've run 37mm (nominal, actually measure 34mm) Conti Contacts on Mavic CXP-33 rims with absolutely no worries. Open Pros are a tiny bit wider than CXP-33, so I can't see why there should be a problem.

Hi,

At the "correct" pressure for 32mm tires they should not blow off the rim.

For fatter tires on skinny rims maximum psi is not a good idea.
Optimum psi is a good idea, search on "tire drop and pressure",
though a guesstimate for 32mm is 60psi rear and 50 psi front.

rgds, sreten.

A member of the "tyres should be hard enough, and too hard
serves no useful purpose" school of thought. The fatter the
tyre the lower the pressure that is hard enough, hence
fatter tyres are more comfortable at optimum pressure.

I am running 60 psi in Vittoria Randonneur Hyper 35 with Open pro's without a problem.

Thanks, folks. The issue was that we were trying to run them at full pressure. Backed it off to 85 lbs. and all was fine. He did a 40 mile ride yesterday and a 30 mile ride this morning with no issues.

BTW, you all make me look really smart. He said to me, "Dad even if you don't know the answer, you know where to go to find it." Once again, thanks!

Just wanted to add my experience: also ~35mm Conti Travel Contacts on OPs for a year with no problems whatsoever. I ran them between 40 and 75psi. With a 32mm tire and a lighter rider, you're probably fine with 60-75psi. No need to run them at 100+ psi and anyway at that point you really negate the main benefit of larger tires: extra shock absorption.

Hi,

85 psi is still a lot for 32mm. Front should be 10% to 15% lower than the rear.

https://www.bikequarterly.com/images/TireDrop.pdf

32mm and 85psi rear is about right for a bike + rider = 200 lbs. ~ 70psi front.

rgds, sreten.

He's 210 lbs. all of it muscle.

210 lbs is a lot but 32 tires are wide. Check the tire manufacturers website and I would be surprised if they recommend more than 85 or 90 lbs max. What you want to do is ride with minimal rolling resistance and too much air pressure increases that.

Edit: Here's a good article on tire inflation. Check the chart near the bottom. So with a 250lb rider plus bike weight, 75 lbs of pressure is about right (of course this varies by tire manufacturer)

https://bccclub.org/documents/Tireinflation.pdf

As noted by others, Michelin website says 28mm is the maximum recommended size for Open Pros. However, lots of cyclists run larger tires on OPs with no problems. I've run Ritchey CrossMax Pro 32s with no problem as well as Rivendell Jack Browns, which measure 34mm wide on my OPs. Here's a photo of my Ritchey cross bike with 34mm Jack Browns on OP rims.

Bontrager, when in Santa Cruz, rolled down MA 40s to 26" then put MTB tires on, when no one sold super-light MTB rims.

became a Trek Corp Brand name ..