Dumb dumb dumb...in Italy with my wife and all my wheels are for Presta...we buy my wife a Trek hybrid with 700cc wheels and I didn't check and of course, the wheels are schraider....in Italy, it seems impossible to get a schraider tube...I got a couple presta tubes as spares and then realized the wheels on my wife's bike are schraider...in a 'pinch', would a presta valve work 'to get you home' or will the tube just extrude out the schraider hole, get 'pinched' and pop on the rough edges of the hole??? Thanks!!

Any bike shop should have adapters for just this circumstance--they're "collars" that fit into the Schrader-drilled rim, with an inner diameter the size of a Presta valvestem.

Any bike shop should have adapters for just this circumstance--they're "collars" that fit into the Schrader-drilled rim, with an inner diameter the size of a Presta valvestem.

Never thought of that...but unfortunately, I am finding these little things that you can just run to a store and get in 10 minutes in the states end up in a weekend adventure overseas...

Any bike shop should have adapters for just this circumstance--they're "collars" that fit into the Schrader-drilled rim, with an inner diameter the size of a Presta valvestem.

This item may not be readily available in Italy. I think the OP's best bet is to lay down a couple of extra layers of rim tape over the valve hole. A hardware or eletrical supply shop may have some "stress relievers" that would fit, but matching sizes would just be coincidental.

If you use presta valves in schrader rims, please don't do it for long. It'll probably get you home, but eventually the tube will rupture at the base of the valve stem. I'd say, if you got a flat, go ahead & use it. If you plan on touring Italy with it, plan on getting soem new tubes along the way.

A hardware or eletrical supply shop may have some "stress relievers" that would fit, but matching sizes would just be coincidental.

That was the first thing that came to my mind.

Tape in several layers works, but my suggestion would be to punch a hole in the tape so the edges won't fray. Maybe a better idea would be to find a rubber washer the correct size, lay that between a couple layers of tape, and put THAT on the inside of the rim. The washer would keep the valve away from the edges of the hole, and support the tube so that it does not push into the hole under pressure.

You don't have a problem. A couple of my older bikes' rims are drilled for Schrader, and I've run nothing but presta tubes as long as I can remember. It used to be standard on mountain bikes, when they were "American" and drilled for tubes you could buy in the supermarket. Just center the valve in the hole and forget it.

You don't have a problem. A couple of my older bikes' rims are drilled for Schrader, and I've run nothing but presta tubes as long as I can remember. It used to be standard on mountain bikes, when they were "American" and drilled for tubes you could buy in the supermarket. Just center the valve in the hole and forget it.

Between my wife, one of my sons, and me we have 6 bikes with 700 C wheels. 2 have rims driller for Schrader valves. I use presta valves in the Schrader rims and have not had a problem. I do use threaded stems and center the stem in the hole, then tighten down the nut. makes pumps and spare tubes a lot easier when they are all presta.