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noob question about valves


ozgti's picture

By ozgti - Posted on 28 February 2012

Beginner noob question. Can I use a presta valve tube on a rim with an opening for a Schrader valve. also roughly much would an adaptor cost for my pump to use with a presta valve?

Thanks for any help

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Slowpup's picture

You run a slightly increased risk of tearing the valve out of the tube with the narrow presta valve in the schrader sized hole. Some tubes, and Mavic tubless valve adapters come with a nut that has a raised boss on one side. This fits neatly in the Schrader hole limiting the wobble.

Most frame pumps I've used already had the ability to swap from one type to the other. The rubber bit in the valve connector is reversible by unscrewing the retainer ring. One side is large hole the other small, and the one way valve fits differently to accomodate the change.

hawkeye's picture

^^^ what he said.

As a bit an extra precaution, my local bike shop gave me some rim tape offcuts that I just pushed a hole through with a Phillips screwdriver, and slipped over the Presta valve stem before fitting the tube to the Shrader rims I was running at the time.

Now of course I'm all tubeless except for my road wheels which are already Presta.

AdrianG's picture

Hi. There is a rim adaptor (adapter) that does the conversion for you; $1 each with $2 postage, on eBay. http://www.ebay.com.au/itm/Allow-Shrader-Rims-Ac....

Funny thing is; I came across this product (idea) for the first time ever yesterday, and today you post this! Smiling

Pete B's picture

My wheels came with the adapter in them but they're plastic, not rubber like the ebay ones seem to be. Should be able to get them from most LBS's.
Try this link for the pump adapter. These are available at the same price from any LBS.
http://item.mobileweb.ebay.com.au/viewitem?itemI...

Flynny's picture

First question would be why would you want to?

If you are not running high pressures or tubeless, presta valves are kinda more trouble than they are worth and it's far more common for people to drill out their presta rims to suit shcrader tubes.

That said you can run the prestas in your rim. Don't worry about stuffing stuff in the hole, if you have the nut nipped up finger tight you are not going to rim the valve out.

As for adapters, as others have stated more bicycle pumps will have an convertable head

otherwise the brass adapters will be around $2.50 ask your local bike shop for a "PCA"

AdrianG's picture

Ummmm. did you say some people drill out their Presta holes to take Schrader valves?

Isn't that like swapping out carbon components for steel ones because - well - steel's TOUGHER!

Heaven forbid we would encourage such sacrilege! It's like wearing lycra; it's the proper way to do it.

Skinny valves and skinny legs in tights! Smiling

Empy's picture

And guess which part of your rim is the weakest, then drill it out more.

That's an idea!

Empy's picture

Doh!

Flynny's picture

Weakest?

If adding an extra 1mm to the radius of the valve hole seriously compromises the strength of your rim I'd be worried about riding it in the first place.

Number of rims I've seen fail at the spoke holes (ie eyelets pulling through) = A few (Normally due to hacks over tightening the spokes)

Number of rims I've seen fail at the pin or weld = Lots (Normally due to a large impact)

Number of rims I've seen Fail at the valve hole (enlarged or not) = zero.

Small price to pay for most people to get a sturdier, easier to use valve which is less likely to break in a rush trail side pump up job.

AdrianG's picture

Hi ozgti. Like anything, the number of people you ask is the number of different answers you'll get.

It really does boil down to why you want to use different valves than the wheels were built for.

There's only one that I know; to be able to get your tyres pumped at a service station.

Good for the casual commuters maybe; they may be more casual about their riding - and their kit too - and they might let their tyres run pooped-out flat, and only ever top up when they cycle past a servo.

Thing is; we don't ride casual commutes, do we?. Tyre pressures are important, so we'll tend to want something handy; a pump at home (where you start riding) or on you (so you can pump where- and when- ever you need).

And any cycle pump will do prestas. Get a decent one - Lezyne! - and you're sorted!

So - in mho - just stick with what you have in terms of tubes. Smiling

Hope this helps.

Empy's picture

Have to admitt not for a long time. Modern rims are (mostly) prety strong, they usually fail at the point of impact.
So I guess that leaves the question which would be stronger if the valve hole was the point of impact?

Anyway I still don't see the advantage of schrader and you want presta for tubeless.

Empy's picture

Again, damn mobile device.

MarkkyMarkk's picture

If the only reason that you want to use the thicker schrader valves is to be able to use the compressor pumps at the service station - then you can just get an adaptor.

http://www.chainreactioncycles.com/Models.aspx?M...

I keep one of these permanently screwed onto one of my presta valves so I always have the choice of using whatever pump type is available.

ozgti's picture

Thanks for the comments guys. That rubber adaptor for the rim looks good. The main reason I was asking was that I ordered some tires from T7 and they are offering free tubes with each tire. For the size tube I need, they only have ones with a presta valve, hence my question.

Empy's picture

The valve with elect. tape it works fine. You can make the fit as firm as you like and it cushions the stem from tearing out.

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