I keep losing pressure in my tires, and among other things, I'm looking at the valves in the tubes. It's an old mountain bike with 26 inch tires. Can I use Presta tubes on rims drilled for Schrader valves? I know the valve will be smaller than the hole and could cause issues there, but has anyone had success (or failures) with this?
As you mentioned, one of the primary differences between a Presta and Schrader valves are the diameters--with Schrader valves being slightly larger--and therefore the valve holes on bicycle rims are drilled to suit one size or another.
Your foremost concern with using a Presta valve in a rim drilled for a Shrader valve shouldn't be 'movement' of the valve stem, as geoffc suggested, but rather a 'hernia' of the tube through the excess space at high pressure, leading to a blowout.
Most mountain bike tires sit at a low pressure, therefore you will probably get away with it, however, there is a very inexpensive adapter, sometimes called a 'valve grommet', which is made out of rubber or metal and serves to make the valve hole small enough for a Presta valve to fit snugly. It will also not come loose under high pressure, unlike geoffc's 'old tire' solution.
5The tension nut that comes with presta tubes does that job pretty well. Apr 22, 2011 at 18:13
imho, MTB rims with presta valves plus the grommet are the best of both world. you will never get a flat because of valve steam pinching.– gcbMay 1, 2015 at 22:17
1The nut won't really protect you against the "hernia" since it sits above the rim and the tube could get extruded up into the space around the valve stem. Once it was there the nut would keep the tube from going further, but it could (would) getting pinched between the rim and the valve stem. That seems to be asking for a puncture in a hard to fix place.– dluJul 20, 2015 at 23:11
Yes you can. Many presta tubes come with a grommet to allow you to use presta valve tubes in a wheel drilled for schraeder valves.
I do this all the time, basically use the presta nut on the inner side to avoid the tube getting "pinched" in the extra space, then if you can find another presta nut, screw that one to the outside where it's supposed to be. Works like a charm.
I have not tried it, but consider, once the tube is inflated, the pressure will hold the valve stem pretty much in place. The concern would be if the edge is rough enough that it would cut into the tube that protrudes.
Consider cutting an old tire and wrap the base of the stem with some old tube material and you would probably be fine.
As others have mentioned, there's ways to do it. I'd just recommend not doing it. I have more pressure loss problems with my Presta bikes than I do the Schrader equipped ones. Strikes me as a downgrade rather than an upgrade. The only advantage I find to the Presta is the size, which will let you run narrower wheels/tires.
It should work fine if the Presta tube is meant to inflate as large as a MTB tire is supposed to be. I'd tape the valve to increase it's size.
Back when I rode a road bike hybrid, I always used presta tubes with schraeder rims. I can't say it worked 100% of the time, but I only had an issue once. And that was across a couple years.
So, what was the issue? May 9, 2013 at 18:00
2As Dustin mentioned, it was an issue with the tube pushing through the hole around the valve stem. I'm back on the same bike now and I have a small rubber piece that wraps around the stem and prevents the tube from going through. Jun 6, 2013 at 14:58
I have done it and it worked fine. Another alternative is to drill the correct size hole in the opposite side of the wheel - thus you can run presta or schrader in the same rim.
I inherited the wheels set up this way. The person explained his reasoning that he preferred to just pump up the tire after a flat rather than changing tubes or patching. My questions about puncturing the newly inflated tires immediately after got me a dim look since it sounded like he didn't bother to do any triage to remove the cause of the flats...
4This solution is great if you find yourself often switching tubes & tires, but be careful! If you drill directly through the seam of the rim, it may greatly reduce the integrity of the wheel. Additionally, make sure you use a 'boot'--a piece of cardboard or plastic--to cover the unused hole, and prevent the tube from blowing. Aug 25, 2010 at 20:07
How are two holes worse than one?– TimAug 25, 2010 at 20:40
5A bicycle rim is a long, straight piece of metal that's bent into a circle and joined together; therefore, there is a welded 'seam' at some point along the rim, which is sometimes a weak point. Typically, it is directly opposite the valve hole, so if you were to drill a hole on the weld, you could weaken it even more. Aug 27, 2010 at 15:48
On my hybrid I have a schrader valve on the front wheel (the tube hasn't had a flat yet so I've not changed the inner) and a presta valve on the back. The nut that holds the presta valve to the rim seems to prevent any "hernia" from occurring, although occasionally I burst a rear tube when pumping it up too vigorously (it appears to "hernia" through the hole slightly and causes a burst around the base of the valve). I always tighten the nut after inflation.
The reason for the presta valve on the back is that the size of inner tube I use only comes in presta valve versions at Halfords which is where, through pure force of habit, I end up buying replacement inner tubes.
I've been using a Presta valve in my front schrader rim since I picked up tubes last, because they were out of schraders in my rim size. Haven't had any problems yet, knock on wood.
I have used both types of valves in tubes. In my view the presta is strictly for narrow rims. I prefer schrader valves my self for several reasons:
- the schrader valve tubes will hold high pressure the same as the presta.
- They are easier to fill
- they are easier to check the pressure using standard pressure guages found anywhere.
I say this based on more than fourty years of repairing and riding bicycles.
However, if you prefer presta then I can say that a presta valve in a schrader rim is usually no problem.