Will it be ok to drill the valve hole bigger in a DT swiss XR 4.2D to take a schrader valve?
I use a round file.
Drilled my 5.1's 12 months ago with no ill effects.
Drilled my XR rims without issue.
should imagine it would be OK - but why would you want to ?
Also drilled my 420SL's and no probs.
Half way down Snowdon my mate gets a puncture. And he's forgotten his inner tubes. And he's the only one of us with Presta rims. So, we enlarged his orifices with small pieces of slate. Worked quite well.
4 years on drilled out 5.1
Drilled many a rim all are fine including 7 year old WTB speed disc rims 10mm drill bit low speed bit of oil.
Well there's a lesson, check you inner tubes before riding.
Also I don't think there will be any ill effects but why bother. Buy Presta tubes instead.
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Ok cheers guys