Cyclocross - Confused n00b - Cross Tires on Road Rims?

I saw a lot of you guys run cross tires (30-35mm width) on road rims, by which i assume you mean 622x13-15c wheels. It doesn't seem to jive with Sheldon Brown's recommendation for optimal tire width over given rim size (1.45 - 2 times). So what's your experience, or am i missing something here?

There aren't that many wide road rims that have been specifically designed for wider cross tires. I think it's mostly because the use of tubular tires becomes more common as you get more serious about racing.

So the use of regular road rims has been out of necessity rather then choice... But really, it's not a big deal. I've ran 32-35mm tires on Open Pro's, which are 15mm I believe, and never had a problem.

Typical road rims run in the 19 to 20mm range. Not sure exactly what that translates to in terms of interior rim width, but if you look at the chart printed on Sheldon's site:
http://sheldonbrown.com/tire-sizing.html#width
you'll see 32mm tires are OK'd for all but the narrowest rims.

And Sheldon himself says, "This chart may err a bit on the side of caution. Many cyclists exceed the recommended widths with no problem."

You should see the size of some of the 29er tires that people happily use on Open Pro rims.

Also, generally speaking wider rims = heavier rims, and there's NOTHING worse than heavy rims. ;)

Appreciate the help, but in this chart, the width is for interior of the rim, not the outside. For a 19mm rim, the interior is 13-15mm, hence the 622x13c or 622x15c designation, I believe.


Typical road rims run in the 19 to 20mm range. Not sure exactly what that translates to in terms of interior rim width, but if you look at the chart printed on Sheldon's site:
http://sheldonbrown.com/tire-sizing.html#width
you'll see 32mm tires are OK'd for all but the narrowest rims.

And Sheldon himself says, "This chart may err a bit on the side of caution. Many cyclists exceed the recommended widths with no problem."

You should see the size of some of the 29er tires that people happily use on Open Pro rims.

Most road rim interior measures 13mm or 15mm, and the OP is 15mm. I can see why running 30-35mm tires may not be a stretch. But do you think a 30mm tire wall would do fine on a 13mm interior road rim?


There aren't that many wide road rims that have been specifically designed for wider cross tires. I think it's mostly because the use of tubular tires becomes more common as you get more serious about racing.

So the use of regular road rims has been out of necessity rather then choice... But really, it's not a big deal. I've ran 32-35mm tires on Open Pro's, which are 15mm I believe, and never had a problem.

*audible sigh*

We're trying to tell you that running cross tires on road rims works fine.

I ran Michelin Mud2s on Kysrium rims this year - I had one pinch flat when I hit a rock with about 25psi in the tires. I chalk that up to the low psi, not the rim width. Also, even when the tire deflated, it stayed on the wheel as I was going around an off camber turn.

I wouldn't sweat it.

My Kona Jake came with Alex AT-450 rims, which have a 13.5 mm interior width, and 700x35c Maxxis Locust CX tires. I've never had a problem with that. In fact, I recently mounted 29x1.6 Conti TownRides (which measure at about 40mm) on those rims. That's pushing things a bit, but it more or less worked.

Sheldon's table is anecdotal, a good starting point but subject to wide variation. A lot of other factors can come into play, including what pressures you intend to run, your weight, how you'll be riding and the quality of the tire and rim.

I have a fixed gear CrossCheck with CXP33 rims. I ran IRC Mythos 42s on it for two years (~2000 miles) on both road and trial. Bit of a clyde, generally ran them at about 80 psi. Never had an issue.

On the other hand, I ran some Schwalbe Marathons, either 38 or 40, on the same rim and had lots of issues with them blowing off

Thanks for the great info here. Being new to CX, I am looking ot start by probably commuting first and getting into real CX later. I had some Mavic Open Pros lying around (with 15mm interior rim width) and want to make sure 28-35mm tires width would be ok with them for my 165-lb weight. I am thinking about running them at higher pressure first, for mostly pavement and light trails with packed grass/dirt, with some Vittoria Randounneur Cross Pro 32mm tires.


Sheldon's table is anecdotal, a good starting point but subject to wide variation. A lot of other factors can come into play, including what pressures you intend to run, your weight, how you'll be riding and the quality of the tire and rim.

I have a fixed gear CrossCheck with CXP33 rims. I ran IRC Mythos 42s on it for two years (~2000 miles) on both road and trial. Bit of a clyde, generally ran them at about 80 psi. Never had an issue.

On the other hand, I ran some Schwalbe Marathons, either 38 or 40, on the same rim and had lots of issues with them blowing off