Tube Valve Length

Just wondered if anybody has trouble with this. I find that for some rims the required length is 80mm, The problem is quite a few tubes/tubs don't offer the option, and if you wish to fit extenders, the items have to have a removable valve. This option is not usually marked, so Contis for example are not extendable, but you only find out when you open the box! Ditto with Conti Giro tubs. I just wish there was a universal standard, like Vredestein.

no, just buy hetero clincher rims and ordinary tubes.

Do Mavic CXP 33 rims need extenders? They aren't that deep, are they?

Do Mavic CXP 33 rims need extenders? They aren't that deep, are they?

no they don't.

I wondered because I just bought a set.

How bold of you.

How bold of you.

I'd like to put a new slant on this.

Hellos. apologies if this will be considered off topic. just searched for some sort of valve discussion.

Q: I have a sks track pump at home, schraeder (sp?) attachment but with a presta adapter. you know the ones. http://bit.ly/m3h6F

The problem is that when i try to inflate using the adapter, the pokey middle bit that it meant to push down the valve head to allow me to pump air in when i push the thumb lock down, is not long enough to reach through the adapter to push down the valve head.

I have found one presta innertube so far that it works with, and that just has a really short valve. But I don't really want to have to replace all my inners jjst to use my pump.

Advice would be appreciated. Ridicule is thoroughly expected.

you fucking idiot!!!!!!!!!!!

;-)

there's no physical interaction between the pump and the valve for prestas. It's the forced air from the pump that opens the valve.

loosen the valve. tap it with your finger to let a burst of air out. Then seat the adapter. Then the pump.

I suspect the problem you are experiencing is from one of three things, in this order:

1. you aren't unscrewing the valve.
   
2. after unscrewing the valve, you aren't taping it in to let a burst of air out and unseat the thing so that the forced air can get in. they do get stuck.
   
3. your pump has both types of interfaces (presta and schrader) and there's an automatic relay in the head of it. Sometimes this relay gets stuck and doesn't let air out properly. Remove the pump from the tube and whack the head of it on your knee cap as hard as you can. Try again.
   
   

P.S. -- schrader valves DO need to have the valve physically opened.
p.p.s -- if your pump does have both types of interfaces, you don't need an adapter. a picture of your pump would help a tiny bit.

Ridicule is thoroughly expected.

Let the flaming commence...........

ah. excellent. i hadn't tapped the valves before pumping. thanks jersey.

i just switched from mtb to racer so hadn't used my pump for prestas until now.

ah. excellent. i hadn't tapped the valves before pumping. thanks jersey.

i just switched from mtb to racer so hadn't used my pump for prestas until now.

Must have been a shit mtb that ran Schraders...

Must have been a shit mtb that ran Schraders...

clearly you have no idea what you're spouting.

clearly you have no idea what you're spouting.

Clearly...

yep. i promise you that if you wander over to any of the big three, and check out their MTBs you'll see that as you progress from light weight XC bikes to more burly freeride and jump bikes youll find more and more schraders.

yep. i promise you that if you wander over to any of the big three, and check out their MTBs you'll see that as you progress from light weight XC bikes to more burly freeride and jump bikes youll find more and more schraders.

You OK with pumping those up?

Must have been a shit mtb that ran Schraders...

yeah it was okay, one of the hard-tail red bull set-ups from roseversand.de from a few years ago

http://www.roseversand.de/output/controller.aspx?cid=156&detail=400&detail2=671

it's actually pretty common for mtb to use schraders though.

You OK with pumping those up?

http://www.specialized.com/us/en/bc/SBCBkModel.jsp?sid=10Demo&eid=4346

theres a 5500 USD bike.

click specs