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What size drill bit for presta rims to make them schrader?

Spunger

Git yer dumb questions here
Feb 19, 2003
2,258
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I looked everywhere and the last time I did this the holes came out way too big. I was told to use a 21/64 bit which isn't in any kit of drill bits I have. I'll go by Sears later and see if they have just that one single bit in a package.

But what size do most use? I have a set of singletracks that are presta drilled but I'd like them to be Schrader as I got a boatload of schrader tubes. It just seems like it'd be easier to do.

Any help would be great :)
 

dropmachine

Turbo Monkey
Sep 7, 2001
2,923
10
Your face.
I always just try to compare the tail of the bit to the valve, and drill away. If it doesnt' fit, go one size bigger. Takes 2 seconds to do, and you're done.

DOn't forget to deburr the edges.
 

nmjb

Monkey
Apr 26, 2005
217
0
Idyllwild, CA
I always just try to compare the tail of the bit to the valve, and drill away. If it doesnt' fit, go one size bigger. Takes 2 seconds to do, and you're done.

DOn't forget to deburr the edges.
I've done it this way a few times, it has always worked great.
 

Zutroy

Turbo Monkey
Dec 9, 2004
2,445
0
Ventura,CA
Becareful about getting metal flakes into the rim too, can be a pain in the rear to get them out, oiling it a far amount will help catch them.
 

Dartman

Old Bastard Mike
Feb 26, 2003
3,916
0
Richmond, VA
It's 21/64"s and you can get one at ACE hardware for about $2.

Didn't worry about metal flakes either. Just drilled 'em out and rode. No problems.

Mike
 

Spunger

Git yer dumb questions here
Feb 19, 2003
2,258
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805
Those step'drill bits are great for fabbing things up but for precise things nothing beats a normal size bit.

I'll just go check out sears and see what I can find :)
 

in the trees

Turbo Monkey
May 19, 2003
1,210
1
NH
I've always used an 11/32" bit and it works just fine. I got this info from a Nashbar catalog ages ago when I first started mtn. biking.

toby
 

dropmachine

Turbo Monkey
Sep 7, 2001
2,923
10
Your face.
This thread is funny. Its almost like "how many licks does it take to get to the middle of a Tootsie pop" but instead its "how many posts does it take to make a friggen hole bigger?"


Its a freakin hole in a rim.
 

Spunger

Git yer dumb questions here
Feb 19, 2003
2,258
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805
dropmachine.com said:
Its a freakin hole in a rim.
I know it is :) But I don't want some giant hole in my rim, it'd be nice to get close to the right size. I picked up a 21/64 bit which hopefully drills a hole just the right size. I asked because it's not like schrader valves have changed in size over the years.