planning to drill out my Rigida Grizzly rims to accommodate Schrader valves as i don't like Presta's. wondered if many others had done it and if there were any problems with regard compromising rim strength on heavy touring bike ?
thanks !
BikerWaser
Hi BikerWaser
I have drilled out 100's of rims!
(on motorcycle we drill and fit rim locks to stop tyres moving on rim) 1st off rim strength
you rim will
NOT be as strong after you drill your rim!
Big Hole less Meat Now drilling your rim to fit a Schrader valves!
1st you need a step drill bit.
Why? because when you use a standard drill bit into a Aluminium the hole can
(will not be) round, with a step drill bit the hole will be round
(and a little stronger).
2nd you need to drill your rim out too 8.5mm,
Why? some your tube can move about a little when your riding. Also some Schrader valves are rubber coated around the base and this is the size you need to fit them through your rim.
Now would it do it to my rims? No if it was to be cycle touring in the parts of the World that I can get presta valved cycle tubes
Yes if I'm off to say Africa again as there are very few presta valved tubes!
But Note that the Schrader valve tubes are Not made to a high standard! so your better off ordering replacement from overseas when your running low on spare tubes.
Here is a great read about cycle valves
http://sheldonbrown.com/brandt/presta-schrader.htmlI hope this is of help to you
PetePlease Note I have been a Motorcycle and Bicycle Mechanic for over 30 years! .