moman

My old tyre had a small presta valve which broke. So i want to put in a new car valve type of inner tubing so its also easier to pump. As i am sure you know its a lot wider so I have been told to simply drill through widening the hole. What size do I need and do you have any tips? Thanks

RonH

Not all rims are made for drilling. Can you post a picture or do you know what type rim you have?
Why do you think schrader valves are easier to pump?

prathmann

An 11/32" drill bit should work ok. Or you could use a reaming tool to enlarge the hole. The latter method is less likely to create metal shavings that could end up stuck inside the rim. If you do drill it out, make sure you smooth the edges of the hole so there aren't any sharp spots that could cut the valve stem.

Velo Dog

I wondered the same thing...my first few bikes, probably like most people's in the '70s, had schraders. I was surprised when I switched to prestas and didn't have to fight that spring.

Louis

If the rim is narrow like most road bike rims are, widening the valve hole could significantly weaken the rim at that point. With a wider rim it could be a non-issue.

I concur with the other posters; converting to Schrader is not an upgrade.

Retro Grouch 

If you're using an air compressor it's so much faster and easier to inflate a Schrader that it isn't even close.

Booger1

11/32 drill,chamfer the holes,done.

I've drilled every rim I've owned in 40 years,big or small,no problems.

No carbon rim drilling please.

prathmann

Your pump head should have had a little nub to depress the pin in the Schrader valve thus eliminating any need to "fight that spring." I do remember the first frame pump I got from the local Schwinn dealer in 1970. It was designed for Schrader valves but I quickly discovered that it didn't work well at all since it was missing the little nub. Went back to the Schwinn dealer and we discovered that about half the pumps in his inventory were also missing the nub. Exchanged mine for one with the nub and it worked fine.

Both valve types should be equally easy to pump using a decent hand or floor pump - most of which accommodate both Presta and Schrader. But if you have a compressor which only works with Schrader then that's certainly still easier - and more convenient than having to mess with a Presta to Schrader adapter.

spinnaker

The big question is why go through all that trouble and taking the chance you will ruin the rim. Or worse weaken it little enough so you won't notice at first abd then have a catastrophic failure. Just buy a freaking presta inner tube!