Dumb Question: How do you inflate to desired pressure w/ valve extenders?

Jun 15, 11 10:36

Post #1 of 30 (17738 views)

I'm sure this will open me to endless ridicule, but I'm using a wheel (Jet 9 fwiw) w/ valve extender for the first time. By the nature of how the valve extender works (ie, it requires constant pressure from the pump to stay open), I find it almost impossible to pump to specific pressure w/ any precision.

I must be a dumb-ass, because this seems kind of fundamental.

Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [rrkid] [ In reply to ]

Jun 15, 11 10:47

Post #2 of 30 (17711 views)

I use a paperclip to break the stiction of the valve before attaching the pump, then just pump as per normal.

Even on a standard wheel w/o extenders, the presta valve closes due to the tire pressure between strokes.

Assuming you have a good seal on the valve with the pump head, the pressure gauge should read the tube pressure accurately.

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Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [rrkid] [ In reply to ]

Jun 15, 11 10:55

Post #3 of 30 (17696 views)

if you have the valve extender on loosely and air is leaking out it'll be a pain in the ass ... try adding teflon tape to the threads of the tube when attaching the valve extender and that will seal things up nicely - and allow you to more accurately gauge the pressure.

Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [TomNYC] [ In reply to ]

Jun 15, 11 10:58

Post #4 of 30 (17680 views)

TomNYC wrote:

if you have the valve extender on loosely and air is leaking out it'll be a pain in the ass ... try adding teflon tape to the threads of the tube when attaching the valve extender and that will seal things up nicely - and allow you to more accurately gauge the pressure.

Yeah, I got tape on their... it just doesn't seem to seal back up while I have the pump on, and obviously once the pump is off, well... but maybe it's the seal, I'll tinker with it. Pain in the ass is the operative phrase, thus far.

Speaking of tape - HED recommends buying another extender and pre-installing on your spare tube. Do you do this?

Why doesn't anyone make a valve extender with valve core? Seems like you could get removable core tubes and it would seal better and be easier to use...

Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [rrkid] [ In reply to ]

Jun 15, 11 11:01

Post #5 of 30 (17668 views)

rrkid wrote:

Why doesn't anyone make a valve extender with valve core? Seems like you could get removable core tubes and it would seal better and be easier to use...

Check Vittoria website. Others too...

http://www.vittoria.com/product/accessories/

Last edited by: Brushman: Jun 15, 11 11:05

Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [rrkid] [ In reply to ]

Jun 15, 11 11:04

Post #6 of 30 (17654 views)

there are valve extenders made for tubes with removable valve cores ... do a little internet shopping and you'll find them. I don't currently use them b/c the polyurethane tubes i'm using don't have removable cores.

i typically do pre-install an extender on my tube for a race.

Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [rrkid] [ In reply to ]

Jun 15, 11 11:09

Post #7 of 30 (17632 views)

Is it a Zipp extender? They are not compatible with my pump, but work fine with a friend's. Also, they do make cored extenders (Topeak maybe).

Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [rrkid] [ In reply to ]

Jun 15, 11 11:17

Post #8 of 30 (17599 views)

This place sells tubes with removable valve cores and Tufo valve extenders. With this setup you will have a much more reliable pump interface as well as ability to tighten the screw. Just remember to carry a normal extender in your flat repair kit to use in case you need to use a non-rcv tube.

http://www.worldclasscycles.com/...s_adhesives_cart.htm

Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [rrkid] [ In reply to ]

Jun 15, 11 11:29

Post #9 of 30 (17573 views)

Zipp valve extenders don't work well.

Big thumbs up for Topeak's valve extender - it allows you to inflate (i.e get a stable psi reading) and close off the actual tube's valve just like "normal". You can leave it in place permanently but I typically remove it after inflation - that must save a whopping .001 grams of aero drag ;-)

Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [Brushman] [ In reply to ]

Jun 15, 11 12:30

Post #10 of 30 (17484 views)

Brushman wrote:

rrkid wrote:

Why doesn't anyone make a valve extender with valve core? Seems like you could get removable core tubes and it would seal better and be easier to use...

Check Vittoria website. Others too...

http://www.vittoria.com/product/accessories/

Yep - PBK has the Vittorias (which look really well designed), and the Topeaks as well (not as sexy but 25% of the price).

As a peripherally related aside, I noticed that almost all the latex tubes around are unthreaded, which obviously makes for problems for most folks w/ extenders.

Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [rrkid] [ In reply to ]

Jun 15, 11 12:36

Post #11 of 30 (17468 views)

Vittoria extenders work nicely.

Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [JimMoss] [ In reply to ]

Jun 15, 11 12:44

Post #12 of 30 (17447 views)

I may be encountering the same deal on my Zipp extenders. Basically the pump head isn't locking on the extender air tight and it letting the pumped air escape out around it. I tried pumping up my new flashpoints yesterday and it was a huge pain in the ass.

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Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [rrkid] [ In reply to ]

Jun 15, 11 13:16

Post #13 of 30 (17400 views)

Not sure anyone answered your second question.. yes, if your wheels need valve extenders, "pre-treat" your spare with a valve extender.. will save you time if you have to change it.

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Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [rrkid] [ In reply to ]

Jun 15, 11 13:21

Post #14 of 30 (17389 views)

The other issue you run into is if you attach the pump perpendicular to the rim, it may wiggle counterclockwise a little and create a gap between the threads. What you need to do is when you are attaching the pump that the head of the pump is as counter clockwise as it can go hitting the left spoke, so that once it is clamped on it can't turn counter clockwise anymore because it is resisted by hitting the adjacent spoke. If you do that and the o-ring is good on the pump head then you will have no issue.

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Last edited by: msuguy512: Jun 15, 11 13:21

Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [boilerup] [ In reply to ]

Jun 15, 11 13:21

Post #15 of 30 (17385 views)

I hate the Zipp extenders and having to use tape to provide a good seal. Also, just as others have encountered, some pumps work better with these extenders than others.

I have been using extenders from Bontrager. They do require you to take out the core, screw in the Bontrager extension, and then put the core into the Bontrager end. Its very easy to install and very easy to pump up. Only negative is you can only use Continental tubes with a removeable core. I keep a good supply.

Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [rrkid] [ In reply to ]

Jun 15, 11 13:30

Post #16 of 30 (17369 views)

Also be sure to use a butyl tube for your spare. CO2 and latex don't play well together.

I use the Topeak extender with a Vredestien removable core valve. Works great.

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Formerly DrD

Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [DrD] [ In reply to ]

Jun 15, 11 15:30

Post #17 of 30 (17292 views)

As a follow up question, how do you deflate with valve extenders? I have got HED Jet 60's & an up coming plane trip....

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Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [AlphaQ] [ In reply to ]

Jun 15, 11 15:39

Post #18 of 30 (17272 views)

With the Topeak and other similar extenders the valve is at the end so you deflate as you would normally on a regular valve. On the Zipp style extenders you can use a spare spoke or a thin allen wrench to push down the valve.

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Formerly DrD

Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [cth] [ In reply to ]

Jun 15, 11 16:28

Post #19 of 30 (17231 views)

Big thumbs up for Topeak's valve extender - it allows you to inflate (i.e get a stable psi reading) and close off the actual tube's valve just like "normal".

Why would you need to close the valve?

Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [rrkid] [ In reply to ]

Jun 15, 11 16:46

Post #20 of 30 (17213 views)

rrkid wrote:

I'm sure this will open me to endless ridicule, but I'm using a wheel (Jet 9 fwiw) w/ valve extender for the first time. By the nature of how the valve extender works (ie, it requires constant pressure from the pump to stay open), I find it almost impossible to pump to specific pressure w/ any precision.

I must be a dumb-ass, because this seems kind of fundamental.

Informative thread about this recently: http://forum.slowtwitch.com/...20extension;#3342198

the moral is, as : get tubes with removable cores (for latex, vittoria, but not michelin, or if you prefer racy butyl tubes conti supersonic are great). Then get extensions that you can reattach the core to, and then you can just use the valve like a regular one. Heaps of these type of extenders available. I use BBB, and these are fine, but conti, vittoria, etc, etc all make them. BBB make one that is 80mm long, so can turn a ~40mmm valve into a 120mm one and use it perfectly well even on a 1080 rim.

Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [DrD] [ In reply to ]

Jun 15, 11 17:57

Post #21 of 30 (17171 views)

Oh cool, I think I can handle this. Cheers for the answer.

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Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [jimatbeyond] [ In reply to ]

Jun 15, 11 19:35

Post #22 of 30 (17097 views)

I�ve been using the Topeaks with Michellin latex and I found if you didn�t close the valve there was more air leakage. So closing the valve is a nice thing to be able to do.
But to be honest I pump up the tires every time anyway as latex always leaks a bit.

Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [jmeyerle] [ In reply to ]

Jun 15, 11 20:27

Post #23 of 30 (17058 views)

jmeyerle wrote:

This place sells tubes with removable valve cores and Tufo valve extenders. With this setup you will have a much more reliable pump interface as well as ability to tighten the screw. Just remember to carry a normal extender in your flat repair kit to use in case you need to use a non-rcv tube.http://www.worldclasscycles.com/...s_adhesives_cart.htm[/quote[/url]]

Highlighted part very important. I DNF'ed my last HIM when I got my 2nd flat of the day and did not have a 2nd spare. A few people offered me tubes but none had removable cores and after standing on the side of the road for 25min I hitched a ride back.

Oh yeah and worldclasscycles has their own house brand of extenders for removable cores.

Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [jimatbeyond] [ In reply to ]

Jun 15, 11 23:21

Post #24 of 30 (17019 views)

jimatbeyond wrote:

Big thumbs up for Topeak's valve extender - it allows you to inflate (i.e get a stable psi reading) and close off the actual tube's valve just like "normal".

Why would you need to close the valve?

Good question...but it has always seemed just kind of odd (to me at least) to ride around with open valves. Hmmm, maybe the valves might not completely close and slowly leak some air out or even lose air in spurts when jostled by road bumps??? I don't think anybody would risk leaving a valve open with a shallow rim so why do it with deep rims - if you have the option to close it if you want?

Re: Dumb Question: How do you inflate to desired pressure w/ valve extenders? [cth] [ In reply to ]

Jun 16, 11 9:04

Post #25 of 30 (16920 views)

Air doesn't leak out of valves that aren't screwed closed.

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