Can you replace a Schrader tube with a Presta tube?

[thecaptn]

Hi People,
can anyone please tell me if there's a problem with puting a Presta valve through hole cut for a Schrader valve in a rim?
Pete

[pawnii]

No problem at all


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[Duck!]

Greater potential for blowing the valve out of the tube, as the narrower shaft doesn't sit snugly in the hole. Something to be particularly wary of if using a hand-pump, 'cos it will wobble the valve around a lot more and chafe on the rim.

[thecaptn]

Any idea if there's a plastic sleave availably to pack out the dead space around the stem?

[Duck!]

Quite probably. I know some rims do come with them.

[thecaptn]

Yes I'm sure I've seen them in rims on entry level bikes. I'll look about for some. I've an idea of what else I can do in the meantime. Thanks guys

[su-pista]

What you need is a threaded valve and a stepped valve nut. The indentation will seat in the rim. Should be able to find these at your lbs, just ask at the workshop if there is any about.

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[John Lewis]

Something similar to this.

http://www.amazon.com/Schrader-Presta-R ... B000XNZU1S" onclick="window.open(this.href);return false;

My velo uses presta valve but the hole in the rim is Schrader size. From the factory they have used cloth rim tape with a presta size hole. Has worked OK so far.

John

[LG]

Well my dodgy low tech addition is to cut a 1" square of a knackered inner tube, poke a hole in the middle, feed the presta stem through the hole and use this as protection against the larger schrader hole chafing the tube.

[Mulger bill]

Conti tubes come with the stepped nut, been using them in Schraeder rims since I built me Wanga hardtail.

[thecaptn]

Well my dodgy low tech addition is to cut a 1" square of a knackered inner tube, poke a hole in the middle, feed the presta stem through the hole and use this as protection against the larger schrader hole chafing the tube.

This was my plan too, dead inner tubes are an undervalued resource.

[thecaptn]

Conti tubes come with the stepped nut, been using them in Schraeder rims since I built me Wanga hardtail.

These are the tubes I'm ordering, they're only about $5 or so for a 29er tube from Wiggle at the moment

[il padrone]

You could use a suitably-sized flat washer but I would never rely on a bit of old tube. Best idea is to get the valve-hole insert.

[thecaptn]

Something similar to this.

http://www.amazon.com/Schrader-Presta-R ... B000XNZU1S" onclick="window.open(this.href);return false;

My velo uses presta valve but the hole in the rim is Schrader size. From the factory they have used cloth rim tape with a presta size hole. Has worked OK so far.

John

I'm thinking that I could rustle up a gromit this size maybe in my spares tardis tomorrow, thanks for the idea.

[WyvernRH]

I'm thinking that I could rustle up a gromit this size maybe in my spares tardis tomorrow, thanks for the idea.

Go down to your local Repco or other car spares place, one of the smaller sizes in the range of rubber cable gromits that they sell in packs will do the job.
Depending on the make they stock you may have to drill/ream out the inner hole a little to get an easy fit over the Presta stem.
Bunnings or other mega hardware stores sometimes have them as well.
Cheers
Richard

[il padrone]

Some tubes come already complete with an adaptor valve-stem locknut.





Otherwise, for the complete solution, you can buy the adaptor sleeve. Presta-schraeder stem-saver. BTW this adaptor really should be fitted from the inside of the rim, with the flange acting to stop the tube pushing out.

[Xplora]

What you need is a threaded valve and a stepped valve nut. The indentation will seat in the rim. Should be able to find these at your lbs, just ask at the workshop if there is any about.

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WOW I never knew that was the purpose of these things... I'm throwing the little things away right now, I don't need a "combo" valve adaptor LOL

[thecaptn]

Some tubes come already complete with an adaptor valve-stem locknut.





Otherwise, for the complete solution, you can buy the adaptor sleeve. Presta-schraeder stem-saver. BTW this adaptor really should be fitted from the inside of the rim, with the flange acting to stop the tube pushing out.

Hi Padre,
Can you tell me what holds these sleeves in? I imagine a drop of superglue would do the trick. I'll be near a Clarke Rubber on the weekend and will see if they have suitable grommets. The specific ones for sale on the interweb are stupidly priced, The cheapest I found were US $ 0.75 each and $28 delivery No wonder the Yanks are broke, idiots.

[il padrone]

The stem-savers sit on your valve stem and snug into the rim hole. This is pretty much enough to keep them in place, but then the flange (which should be on the inside) is held there by the pressure in your tube. I don't use any, but I believe they tend to stay in the rim when you take the valve stem out.

Avoid buying from the US. They think 'overseas' is Canada . Generally much cheaper to buy from UK (great post service) or Germany (slow post but lower prices and great range).

[thecaptn]

The stem-savers sit on your valve stem and snug into the rim hole. This is pretty much enough to keep them in place, but then the flange (which should be on the inside) is held there by the pressure in your tube. I don't use any, but I believe they tend to stay in the rim when you take the valve stem out.

Avoid buying from the US. They think 'overseas' is Canada . Generally much cheaper to buy from UK (great post service) or Germany (slow post but lower prices and great range).

Cool, thanks for the tip.
Pete