I have a mavic wheelset that has Schrader sized holes and uses a grommet to step down the hole to presta sized.
Has anyone had any joy getting this to work tubeless?
If yes, I assume running the grommet under the rim tape and just pushing valve through?
The valves WTB and Superstar sell work well- they have a huge conical base that’ll often (probably not always- depends on shape) seal a schrader hole just as well as a presta. I wouldn’t use the grommet at all but you might want to find one of the lockrings with the adaptor step
Another approach I used, before I found those, was possibly mental but it worked- I filled the hole with chemical metal then redrilled it for presta. That was for a rim that’d been horribly drilled out by some idiot, but it’d work for factory too.
Could you not just cut up a Schrader rude and use the valve from that? You’ve probably got lots lying around. I find the spout of the Stan’s bottle fits perfectly in a Schrader valve with the core removed. And they get gunned up less than Presta valves.
Thanks both. Good to know.
I’d just assumed only presta had removable cores – been years since I looked at a Schrader, but if they’re removable too that would eliminate any possible gap.
No issues having no lock nut then?
I’ve bodged a tubeless set up with a schrader rim/presta valve using a grommet before and it worked, as you say cover with rim tape and make a presta size hole, the sealant will fill any gaps. Even easier if your valve has a rubber o ring seal