Mountain Biking - Drilling Rim to fit a Schrader Valve.

Has anyone done this? Any special precautions? I have a Schrader front and a Presta rear. The rear is an Alex DP-20. I don't want to have to carry two spare tubes and I like the connivence of being able to air up a Schrader at a gas station or with my air compressor in my Jeep.

Just run presta, you shouldn't be using an air compressor to fill up the tires on your bike if it doesn't have the bit designed to handle filling a bicycle tube. That bit has a built in pressure gauge so you don't accidently overfill your tires, thus blowing them off the rim and possibly screwing up the bead on the tire.

It's either get presta tubes and use an adapter and get the special bit for bicycle tubes/wheels, or get presta tubes and get a floor or hand pump with a smart head that takes either presta or Schrader.

I want to run Schraders and I am set in my ways. Air compressor works way faster and more convenient I run big tires 2.5s so I am not worried about over filling them as I have never had a problem with it. My tire pressure gauge does Schrader. My front is already a Schrader. I just want to know if anyone has done it and if there are any special considerations I need to take.

Take your time using a succession of bits. Don't try to do it in one drilling because the bit will often have the tendency to catch the aluminum and rip it causing an irregular sized hole.

In lieu of a conventional twist bit, which will have that tendency to grab into the soft aluminum, I prefer to use a step bit: http://www.dpiclearcoat.com/shop/images/16501.jpg

Not drill the hole crooked, being that if you do drill it out crooked, the rim is pretty much ruined, after that, if it's drilled out, you have to go in with a small round file to smoothen out the burrs, if you don't, you will get flat after flat, after flat.

Schrader is an outdated design that may work good for car purposes, but should go the way of the woods valve in regards to bicycle tubes.

+1. I would agree with Smashy on going with Presta, though. There's no way or reason you could get me to go with Schrader. Also, he is right about how careful you need to be.

This will alow you to use a compressor on a presta valve. Won't help with the 2 different tubes issue.
http://www.nashbar.com/profile.cfm?category=600097&subcategory=60001057&brand=&sku=14931&storetype=&estoreid=&pagename=Shop%20by%20Subcat%3A%20Tube%20Accessories

Is The only way to measure the pressure in a presta valve tube is to have a pump that has a pressure gauge on it? I havent been able to find an equivalent of this (http://www.kneedraggers.com/image_storage/b/9b/b9ba1297537cb196dec9fcbd2c92beda_rough.jpg) for measuring tire pressure on a presta tube. Its kindve annoying because I have a nice pump it just doesnt have a pressure guage on it.

Is The only way to measure the pressure in a presta valve tube is to have a pump that has a pressure gauge on it? I havent been able to find an equivalent of this (http://www.kneedraggers.com/image_storage/b/9b/b9ba1297537cb196dec9fcbd2c92beda_rough.jpg) for measuring tire pressure on a presta tube. Its kindve annoying because I have a nice pump it just doesnt have a pressure guage on it.

The Topeak Road Morph has a built in gauge and is compact in size. I really like it. http://www.deanwoods.com.au/store/images/topeak_roadmorph.jpg

Im a dumbass and I bought the mountain version... It doesnt have one.

Is The only way to measure the pressure in a presta valve tube is to have a pump that has a pressure gauge on it? I havent been able to find an equivalent of this (http://www.kneedraggers.com/image_storage/b/9b/b9ba1297537cb196dec9fcbd2c92beda_rough.jpg) for measuring tire pressure on a presta tube. Its kindve annoying because I have a nice pump it just doesnt have a pressure guage on it.

a great guage
http://www.pricepoint.com/detail/16081-245_SETBT7-2-Accessories-37-Pumps/Beto-Digital-Air-Pressure-Gauge.htm

as far as presta or schreader.. I have one bike with each kind, both work fine.. the presta I like when I have a flat because you can start filling it with your mouth before slapping co2 in it..

I've never used a gauge when riding MTB, just learned the get a feel for relative pressure, no biggie.

Thanks for the link, DirtP.

The Topeak Road Morph has a built in gauge and is compact in size. I really like it. http://www.deanwoods.com.au/store/images/topeak_roadmorph.jpg

OO, my mini morph has that kind of guage on it. But I could not figure out how to read it.
It just looks like this

|3 60 4|
|2 30 3|
|_____|

Or somthing like that.
How do you read it?

Without going down and digging it out, I think it has both PSI and BAR markings on it. Got it for my GF's roadbike and haven't actually had to use it in a while :thumb: Geez, is it THAT hard to figure out?:)

Without going down and digging it out, I think it has both PSI and BAR markings on it. Got it for my GF's roadbike and haven't actually had to use it in a while :thumb: Geez, is it THAT hard to figure out?:)

IM guessing the "30" is PSI, but its weird cause the most ive seen it go is 25, maybe 30 psi. Which doesnt make sense because I made my tube tire hard as rock .

Has anyone done this? Any special precautions? I have a Schrader front and a Presta rear. The rear is an Alex DP-20. I don't want to have to carry two spare tubes and I like the connivence of being able to air up a Schrader at a gas station or with my air compressor in my Jeep.

Drilling is feasible, at least with some rims. I'm not sure about yours. It will make it weaker to some degree, though.

A simpler, less likely to screw up your rim option would be a presta to schrader adapter, available for a couple bucks at your lbs. Works with air compressors, pressure gauges, and gas station nozzles. To avoid the hassle of two different tube types, I'd run a presta tube in the Schrader rim too, with a rubber grommet to snug and seal it.

Is The only way to measure the pressure in a presta valve tube is to have a pump that has a pressure gauge on it? I havent been able to find an equivalent of this (http://www.kneedraggers.com/image_storage/b/9b/b9ba1297537cb196dec9fcbd2c92beda_rough.jpg) for measuring tire pressure on a presta tube. Its kindve annoying because I have a nice pump it just doesnt have a pressure guage on it.I'd never trust one of those to measure the pressure in a bike tire.

I use an electric pump, but its got a built in gauge, and it also has an auto shutoff thing on it. Preset the pressue and it will shut off.
I use an adapter for my presta tubes

Drilling your rims could, potentially weaken them.

Well. I've been hunting the web and reading replies and have decided to go Presta in front with the little rubber thing and keep the Presta in the rear but have the Presta to Schrader adaptors with both of them. I don't want to wreck my rim if I screw up drilling i as I just dropped money on a new frame and don't want to buy more parts any time soon. But I think if I get a new rear wheel I will get it with a Schrader hole already in it.

just buy that gauge I posted above, one of the most useful things I have bought. the one I got is accurate at least with my other schreder guages. I expected it to be junk for that price, but it's not.

Snerff.. Iv'e drilled several rims now and not had a problem yet. Moreover Iv'e done it without a jig. All I would suggest is that as Kenhill3 said use a succession of bits. That is, dont just ram a shrader valve sized bit in there, work up to that size, last time I used two bits, that did the job nicely. Also remove any burrs , I use a round file and gently work the burrs off. If your not too concerned with appearances just use some emery cloth. Any hole reduces the strength of a rim, going from presta sized to shrader sized doesn't mean it will suddenly explode just because you drilled it and not the manufacturer.

Edit: you want a good gauge? buy a Michelin. A good tyre shop or motorcyle shop (BMW) will have one.

What's the big deal about different valves anyway? I don't really see an advantage or disadvantage to either...

All my bikes have schrader valves......one day when I grow up I'll be a real biker and run presta.:fred:

I'm sure I'll grow up one day................ Naaah meybe not.

Totally off topic, but my XC bike is back from Kalgoorlie cyclops.

Whoop.

Im a dumbass and I bought the mountain version... It doesnt have one.

It should...or at least the new ones do. I just bought one and it has a gauge.

I've drilled 'em. No problem. Just use care and de-burr. Schrader vs Presta? Your choice. Both work. If Schrader was as bad as some say why do all cars use 'em?

Im a dumbass and I bought the mountain version... It doesnt have one.

I have both and I feel strongly that the mountain version is much better for the bigger tires (I think it shoves more air through and the road shoves the air to a higher pressure easyer, but I may be wrong).

I have both and I feel strongly that the mountain version is much better for the bigger tires (I think it shoves more air through and the road shoves the air to a higher pressure easyer, but I may be wrong).

You are correct sir.

A tapered hand reamer (http://www.bikeparts.com/productinfo/Tapered-Hand-Reamer-35-to-20mm-taper-for-enlarging-Presta-valve-holes-to-Schrader-46026-15455.html) is the best tool for the job. Safer than drilling.

http://www.bikeparts.com/pimage/BPC301961.jpg

A tapered hand reamer (http://www.bikeparts.com/productinfo/Tapered-Hand-Reamer-35-to-20mm-taper-for-enlarging-Presta-valve-holes-to-Schrader-46026-15455.html) is the best tool for the job. Safer than drilling.

http://www.bikeparts.com/pimage/BPC301961.jpg

You are absolutely correct. I totally forgot about these. Thanks.

All my bikes have schrader valves......one day when I grow up I'll be a real biker and run presta.:fred:

Schrader on the Kona. We should start a gang. The Schrader Gang.

A tapered hand reamer (http://www.bikeparts.com/productinfo/Tapered-Hand-Reamer-35-to-20mm-taper-for-enlarging-Presta-valve-holes-to-Schrader-46026-15455.html) is the best tool for the job. Safer than drilling.

http://www.bikeparts.com/pimage/BPC301961.jpg



I used this to effectively widen the opening to fit a Schrader valve on a Presta rim. Like others have said... no problem.

Schrader on the Kona. We should start a gang. The Schrader Gang.

Yeah! The TGMBSVG. That's how we roll.

Yeah! The TGMBSVG. That's how we roll.

Awesome. I've always wanted to be a part of something.