Drilling Rims

hopesprings

Hello chaps,
Starting my first build at the moment, and I have some wtb speedisc rims. They are for presta valves and was wondering if it's safe to drill them to fit schraeder valves (stupid question probably).
I just prefer them and are on my other bike and don't want to buy a new track pump as I can spend the money on bits for the bike. Would have just done it probably but looks like a schraeder size hole would cut through the 'shoulder' on the rim.
Cheers

nicklouse

generally yes as long as you are not drilling into the walls of the rim.

narrow rims no. wider rims OK.

which Speed disc rims are they?

here you can see a possible issue

Deputy Dawg

You can drill them if the diameter of the schraeder valve hole will fit on the rim but it will make it a weaker.

If it were me, I'd just buy a presta to schraeder adapter for £1.99 & use the pump I already have.

hopesprings

nicklouse wrote:

generally yes as long as you are not drilling into the walls of the rim.

narrow rims no. wider rims OK.

which Speed disc rims are they?

here you can see a possible issue

Thanks for quick reply, they are 'all montain 20-559/537 ERD' I got them 2nd hand so don't have any other info, and no idea what those numbers mean.
The profile is broadly the same as in your picture although looking from tyre side of rim there doesn't seem to be the 'longitudonal gusset/brace' and the hole on the inner part of rim is larger, possibly schraeder size already

stubs

Use a new sharp 3/8th of an inch drill bit and check it wont drill out anything of the sloped part of the rim, after drilling make sure there are no sharp edges. I have done it to quite a few rims and never had a problem and I am a clumsy fat fuck. The strength of a rim is in the walls not the flat top otherwise drilling 33 or 37 holes in it would be a bad idea.

nicklouse

hopesprings wrote:

nicklouse wrote:

generally yes as long as you are not drilling into the walls of the rim.

narrow rims no. wider rims OK.

which Speed disc rims are they?

here you can see a possible issue

Thanks for quick reply, they are 'all montain 20-559/537 ERD' I got them 2nd hand so don't have any other info, and no idea what those numbers mean.
The profile is broadly the same as in your picture although looking from tyre side of rim there doesn't seem to be the 'longitudonal gusset/brace' and the hole on the inner part of rim is larger, possibly schraeder size already

tyre off and have a look on the inside. you do not want to be drilling into any of the supporting structure.

cooldad

Most track pumps adapt for both valve types, and by most I've not yet seen one that doesn't.

PashleyRider

Just run these if you are concerned about drilling. I used to use them and they were great, cheap enough to have a few spare and leave them on the bike.

http://www.ebay.co.uk/itm/NEW-PRESTA-TO-SCHRADER-VALVE-CONVERTER-BIKE-PUMP-ADAPTOR-ADAPTER-/380560312083?pt=UK_Sports_Leisure_Cycling_BikePumps_SR&var=&hash=item589b298713

hopesprings

stubs wrote:

Use a new sharp 3/8th of an inch drill bit and check it wont drill out anything of the sloped part of the rim, after drilling make sure there are no sharp edges. I have done it to quite a few rims and never had a problem and I am a clumsy fat fark. The strength of a rim is in the walls not the flat top otherwise drilling 33 or 37 holes in it would be a bad idea.

That's what I wanted to hear! Think it should be fine there's enough wiggle room. I've got the genny fired up and the Hilti out, I do love a bit of butchery!
3/8 though?? can you still buy that stuff? Always found imperial side too confusing and needlessly complicated, almost as if it's made up to punish the bad at fractions, is 3/8 the same 15/32x 11.5/64? Don't get me started on imperial thread and spanner sizes. So going 8mm then 9&round file.
Cheers

hopesprings

cooldad wrote:

Most track pumps adapt for both valve types, and by most I've not yet seen one that doesn't.

Well I'm abit of a cheapskate and my pump is cheap and only has one outlet, although never tried it on presta. I would have to buy new tubes too though :shock:

nicklouse

hopesprings wrote:

cooldad wrote:

Most track pumps adapt for both valve types, and by most I've not yet seen one that doesn't.

Well I'm abit of a cheapskate and my pump is cheap and only has one outlet, although never tried it on presta. I would have to buy new tubes too though :shock:

even with one outlet many will work on both sizes as is or just need the internals reversing.

stubs

hopesprings wrote:

stubs wrote:

Use a new sharp 3/8th of an inch drill bit and check it wont drill out anything of the sloped part of the rim, after drilling make sure there are no sharp edges. I have done it to quite a few rims and never had a problem and I am a clumsy fat fark. The strength of a rim is in the walls not the flat top otherwise drilling 33 or 37 holes in it would be a bad idea.

That's what I wanted to hear! Think it should be fine there's enough wiggle room. I've got the genny fired up and the Hilti out, I do love a bit of butchery!
3/8 though?? can you still buy that stuff? Always found imperial side too confusing and needlessly complicated, almost as if it's made up to punish the bad at fractions, is 3/8 the same 15/32x 11.5/64? Don't get me started on imperial thread and spanner sizes. So going 8mm then 9&round file.
Cheers

Yes you can still buy 3/8th drill bits they are 9.5mm diameter which is the correct size for a Schraeder valve hole. Its an old standard first used in about 1890 in the US iirc and as everyone in the US knows only godless commies and cheese eating surrender monkeys use metric. If your a bit nervous a size down and then file to fit is a good idea but dont make the hole too snug or the valve will rub. Treble check and then check again that your not going to go into the sloped part of the rim thats where you will screw everything up.

cooldad

A couple of new tubes seems like a far better option than random rim drilling. IMHO.

nicklouse

stubs wrote:

hopesprings wrote:

stubs wrote:

Use a new sharp 3/8th of an inch drill bit and check it wont drill out anything of the sloped part of the rim, after drilling make sure there are no sharp edges. I have done it to quite a few rims and never had a problem and I am a clumsy fat fark. The strength of a rim is in the walls not the flat top otherwise drilling 33 or 37 holes in it would be a bad idea.

That's what I wanted to hear! Think it should be fine there's enough wiggle room. I've got the genny fired up and the Hilti out, I do love a bit of butchery!
3/8 though?? can you still buy that stuff? Always found imperial side too confusing and needlessly complicated, almost as if it's made up to punish the bad at fractions, is 3/8 the same 15/32x 11.5/64? Don't get me started on imperial thread and spanner sizes. So going 8mm then 9&round file.
Cheers

Yes you can still buy 3/8th drill bits they are 9.5mm diameter which is the correct size for a Schraeder valve hole. Its an old standard first used in about 1890 in the US iirc and as everyone in the US knows only godless commies and cheese eating surrender monkeys use metric. If your a bit nervous a size down and then file to fit is a good idea but dont make the hole too snug or the valve will rub. Treble check and then check again that your not going to go into the sloped part of the rim thats where you will screw everything up.

Well 9.5mm is way too big.

the Schraeder threads are 7.7mm OD i normally use a 8.5mm drill which is fine for the full metal valves. it is also fine with most rubber based valves.

but again dont go drilling through any structure of the rim.

stubs

nicklouse wrote:

Well 9.5mm is way too big.

the Schraeder threads are 7.7mm OD i normally use a 8.5mm drill which is fine for the full metal valves. it is also fine with most rubber based valves.

but again dont go drilling through any structure of the rim.

Woops :oops: Just been and checked on a rim I drilled a couple of years ago. Your right its not a 3/8 its an 11/32 a touch too much beer down the Rugby club watching 6 nations I think.

hopesprings

Thanks for replies chaps. The urge for a diy quickfix passed and common sense has prevailed so ordered some tubes rather than risk facking my wheels!