Bicycle Mechanics - My new wheel is presta...

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View Full Version : My new wheel is presta...


Mithrandir
08-23-11, 09:53 AM
So I got a new rear wheel yesterday, after waiting 3 weeks to have it built. Only I completely forgot to check/specify that I would prefer a schrader valve hole. So of course I get it, and it's presta.

Not that I have any problems with presta, I've just always used schrader and my front wheel is schrader. So now I have a dilemma. The wheel is absolutely great, already put it on and used it (bought a presta tube), but my tube situation is a bit awkward, because I don't want to have to carry around one presta and one schrader tube at all times.

The way I see it, there are two possible solutions:

1) Get the new wheel hole drilled to fit schrader
2) Find one of those grommet things and just use presta on both wheels from now on.


1 seems like it could damage the wheel. I'm not really keen on making a permanent change to something like this at the moment, so 2 seems like a more realistic solution. However I know nothing about grommets. Are they all compatible with all rims? I've seen plastic, rubber, and metal ones on the internet. Would this one work? http://www.amazon.com/Pyramid-Sunlite-Bicycle-Rim-Grommet/dp/B000AO9QX8/ref=sr_1_1?s=sporting-goods&ie=UTF8&qid=1314114635&sr=1-1

I asked the LBS for one when I was there but I think I wasn't clear or they misunderstood me, they dropped a presta-to-schrader pump adapter into my parts bag instead of a grommet (my fault for not paying close enough attention). I'm heading back on Friday for a bike fit so I'll ask them again, but just in case they really don't have anything I'd like to be prepared to order one online.

Any suggestions?

Thanks!


HillRider
08-23-11, 10:02 AM
Do #2. Decent quality Presta tubes are much easier to find and you could weaken a narrow rim by drilling out the valve hole to Schrader size. Any of the grommets will work including the ones you referenced. I'm sure your LBS has what you need but requires a better explanation of what you are looking for.

lubes17319
08-23-11, 10:16 AM
http://img.alibaba.com/wsphoto/v0/352323041/Free-Shipping-NEW-Bicycle-Tube-Presta-Valve-Stem-Schrader-Adapter-Cap.summ.jpg


tcarl
08-23-11, 10:19 AM
Back in the late 1970's/early 80's I bought a pair of Wolber Super Champion 27" touring rims that had Schrader valve holes. In the mid '80's I converted them to Presta using the rubber grommets. I still have both rims and am still using the original grommets and everything is still working fine. That's what I'd recommend. Installing the grommets is a bit of a nuisance, but patiently work with it, take your time and you'll get it. I think I've (carefully) used a small screw driver to help pry them in. Also, the presta valve stem fits very tightly in the grommets so I have to rather slowly and gently "force" the stem in or out of the grommet whenever installing or removing the tire/tube.

dsbrantjr
08-23-11, 10:42 AM
Mithrandir: If the wheel was offered with either Schrader or Presta drillings, it would seem that the manufacturer feels that the larger Schrader hole would not excessively weaken the wheel. However, carrying a Presta tube and a grommet would be easier and lighter than 2 tubes. I'd go the Presta route if you are reluctant to drill the wheel. Don't forget that you will need a Presta-capable pump head or the adapter pictured above.

fietsbob
08-23-11, 10:45 AM
Enlarge the hole .. a tapered reamer will do.
but thin rims don't work as well with S/V
because the stem is thicker.
less rim is left.

Change the rear to another P/V , there are sleeves to fill the extra
size difference of the hole..

rydabent
08-23-11, 11:40 AM
My Rans bike came with rims drilled for shrader stems, but it also came with the aluminium gromets for the presta tubes it came with. They work fine, and I really like the presta valves.

Btw while I have read about people drilling out presta hole rims I think it is kinda crude and dumb to do so.

motobecane69
08-23-11, 01:01 PM
1. just stick a presta in the front. you don't need no stinking grommet mang. or just use the presta to shrader adaptor. I love those things. I use it on my commuter bike because the 35c tires only need 85psi and thats how high my lbs compressor goes to. The other thing I like about those adaptors is that I can leave the presta valve open and screw that on. then i don't have to unscrew it, open the valve, screw it on, fill it, unscrew, close the valve, screw it back on.

fietsbob
08-23-11, 01:09 PM
Mavic makes the best adapter, I've seen, it snaps in place , and stays there.
until removed..
http://www.sjscycles.co.uk/mavic-rim-valve-hole-drilling-converter-insert-schraeder-to-presta-prod3335/

Al1943
08-23-11, 07:48 PM
Get the grommet.