Problems inflating presta tyres on my new Focus Variado.

LordSplodge

I may just being doing something real stupid here.

I got a Focus Variado from Wiggle yesterday and put it all together no problem but I cannot for the life of me figure out the presta valve. I also got a Joe Blow Max II from Wiggle.

I managed to get about 85 psi in the tyres but then the pump pops off the vale. Also it gets almost impossible to pump any hgher.

Is there an idiots guide on how to attach your pump to a presta vale or is it so obvious that I am just being a dumb blonde?

Cracking bike but it is a world away from my trusty steed, a 2006 GT Avalance 1.0 disc.

Smokin Joe

Are you closing the locking lever on the pump head after you have pushed it onto the valve?

alfablue

Unscrew the top of the valve, give the pin a dab with your finger to release some air (the valves can be sticky and not let air in unless you do this).

Insert pump head fully, while holding it down turn the switch on the pump head upwards, in line with the valve.

Pump.

If it blows off (and it shouldn't) you can put a strap (like a luggage strap or pedal strap) around the rim and pump head - I have to do this on my aged Specialized pump as the rubber in the head has worn out. But I wouldn't expect this on a new pump, so I think it may be you are just pumping into the pump tube not the inner tube because the valve is not properly unlocked or released, as above.

Jez mon

Sounds like you aren't unscrewing the presta valve before pumping.

Smokin Joe

He must be unscrewing the valve to get 85psi in.

STEFANOS4784

Yeh, sounds like a dodgy pump to me, ask for an exchange, or see if you can use some-one elses to see wether that makes a difference :?

synchronicity

Smokin Joe wrote:

He must be unscrewing the valve to get 85psi in.

Maybe he's just got 85psi in the pump hose. I pump up so many tyres, I've done that before. :oops:

whyamihere

I've just put 110psi into the hose of my Joe Blow without it blowing off (I reckon the grip on my threaded valve was too great) so it's definitely possible.

LordSplodge

I don't think it is the pump as it pumps both my wife's and my MTB slicks up to 65 psi no problems at all.

Oh and I did loosen the valve!

The problem I have is getting the damn thing connected. I'll follow the advice of this thread and have another bash!

avoidingmyphd

i'm afraid a pump doing 65 psi in a mtb tyre is no guide in this situation. I'm not saying it's the pump, just that your 65psi story doesn't rule it out I'm afraid.

I've had pumps that were fine at that pressure, and a joke any higher. (a low end decathlon track pump for starters)

LordSplodge

I managed to get 100psi in once I figured out the correct way of mounting the pump head. Still seams to be a lot more fiddly than the MTB style valve.

Cheers for all the advice. Scared me stiff pumping the tyres to that pressure, after all years of putting 40psi in tyres has told me that 100psi will make a loud bang!

Zendog1

I think the wheels you have are relatively deep section and this means not a lot of valve poking out for the pump to grip on if you have "standard" tubes. I have the same problem with my Shimano 561's.

If you take the lock nut off before attaching the pump it helps but still fiddly or you can get long valve tubes (Conti do them - cost more naturally).

carl_p

I also have a Joe Blow and I have to let a good blast of air out of the tyre before I can inflate to 120 psi. I find that unless I do this the pump handle will not go down at all and it takes a bit of fiddling around before I get a correct reading of the tyre pressure and am able to reinflate.

How far should I be unscrewing the top, all the way as far as it will go, or just a little?

I think zendog has called it correctly actually about deep section wheels.

doog442

Could be the valve itself. I had the same problem with the inner tubes that came with my spesh tricross. Just couldnt get a decent fit using my track pump and it was really hacking me off.

Ive just fitted some road tyres and got some new schwalbe tubes and have no problem with these valves, fit like a glove with no air escape and Im using a £10 Tesco pump

For the sake of £5 or £6 may be worth giving it a try.

LordSplodge

doog442 wrote:

For the sake of £5 or £6 may be worth giving it a try.

I need to get some inner tubes anyway as I am cursed by the Puncture Faerie all the while on my MTB and I don't think she will forgive me just because I have a new bike.

Carl_P: I have also found that letting a bit of air out of the tyre helps. Not sure why but after a good session trying different things that seems to help. Glad I got up to 100 thouhg as it didn't fell right going out with the minimum psi yesterday.

Zendog: Not sure what you mean by deepdish, I am new to the road side of things. To me it looks like a reasonable amount of valve sticks out, are RS10's deep then?

Thanks for the support guys!

the_hundredth_idiot

Bumping this one back up a bit!

I've just bought a track pump for the presta valves on my new bike (always used Schrader before). So far, not especially impressed. It does pump up the tyres but with what seems like an enormous amount of air escaping from the pump (to the extent my wife paused the TV and asked me sarcastically when I'd be finished as she couldn't hear anything*). The gauge also flips about a bit rather than steady at the current pressure.

What am I doing wrong? It should be so simple and I'm reasonably mechanically minded. Take off dust cap, unscrew lock-nut on presta valve, put pump head over valve, push down and flip up lever. Or is this just one of those things with presta (i.e. Schrader has a little spring which stops air escaping, presta doesn't)?

THI

* Yes, I was in the sitting room with my bike propped against the sofa she's usually so fastidious so no idea why she's tolerating that.

W5454

My track pump can be used for either presta or schrader valves by reversing the rubber thingy in the the connector that fits over the valve (the end screws off).If its set for schrader it won't grip a presta valve,so air will escape.

the_hundredth_idiot

Thanks, but it's not that as this pump head has two "holes" - one for presta and one for Schrader. I'm using the narrower one which I'm assuming is the presta one!

alfablue

Sorry if its obvious, but are you pushing the head fully home on the valve? It needs to be well in the rubber tube, then turn the lever.

the_hundredth_idiot

alfablue wrote:

Sorry if its obvious, but are you pushing the head fully home on the valve? It needs to be well in the rubber tube, then turn the lever.

Fair question and the answer is: to the metal.

I might borrow my neighbours again and see if I have the same problem using his. If so, might be a problem with the pump.

ColinJ

The Hundredth Idiot wrote:

What am I doing wrong? It should be so simple and I'm reasonably mechanically minded. Take off dust cap, unscrew lock-nut on presta valve, put pump head over valve, push down and flip up lever. Or is this just one of those things with presta (i.e. Schrader has a little spring which stops air escaping, presta doesn't)?

After you unscrew the valve, you need to press the end in to let some air out. When you try to do that you will probably notice that the valve was stuck and it takes quite a bit of a push to loosen it. More than your pump could have managed in fact. Once you've manually 'unstuck' the valve, reattach the pump and it should work properly when you try again.

PS

When you try pumping up a tyre with a valve stuck, it acts exactly the same as if you haven't unscrewed the end of the valve. As you use the pump, you'll feel an incredible amount of resistance, the pressure gauge reading will shoot up, but the tube won't inflate. All you are doing is raising the pressure in the pipe between the pump and the valve. Eventually you'll blow the pump head off the valve.

When you have unscrewed and loosened the valve as described above, you will still observe the same process mentioned in the previous paragraph, but when the pressure from the pump exceeds the pressure in the tube by an adequate margin, the valve will suddenly open (you'll hear a clicking sound when this happens), air will rush into the tube and you'll finally be getting somewhere!

philbamber

Solved it (thanks to advice on this thread)!

I was having this problem myself: I just couldn't get the tyre to inflate past about 85psi no matter what. Eventually, I managed to sort it by following these steps:

1. Make sure screw thread on presta valve is unscrewed (obviously);
2. Deflate the tyre a bit by tapping on the valve head several times. I even used a squirt of WD40 to make sure the valve isn't sticky and opens and closes properly. Get the tyre down to a low pressure.
3. Try reinflating the tyre. It'll be obvious if air's going into the tyre, rather than staying in the pump tube, because the tyre will get noticeably harder. Now that we know air's going in, just push on and go past the 85psi level and to full pressure.

Now to go for a ride.

bendertherobot

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19667741#p19667741]philbamber[/url] wrote:

Solved it (thanks to advice on this thread)!

I was having this problem myself: I just couldn't get the tyre to inflate past about 85psi no matter what. Eventually, I managed to sort it by following these steps:

1. Make sure screw thread on presta valve is unscrewed (obviously);
2. Deflate the tyre a bit by tapping on the valve head several times. I even used a squirt of WD40 to make sure the valve isn't sticky and opens and closes properly. Get the tyre down to a low pressure.
3. Try reinflating the tyre. It'll be obvious if air's going into the tyre, rather than staying in the pump tube, because the tyre will get noticeably harder. Now that we know air's going in, just push on and go past the 85psi level and to full pressure.

Now to go for a ride.

You may want to clean your rimes of WD40 before you do!

rafletcher

No, let him enter for the Darwin awards. WD-40 - Strewth!

jgsi

The J Blow can be a pain to inflate some valve heads.. Vittoria always needs the technique of valve at the top of the wheel.. holding onto it with one hand and inflating with the other.. hard work one handed but you can get there to top end pressures... 6 -7 - 8 bar if need be.
Smooth Michelin valves do seem to grip more.

fenix

I like that it took 7 years to solve.

Elfed

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19669516#p19669516]Fenix[/url] wrote:

I like that it took 7 years to solve.

Bike Radar award for greatest thread resurrection?

Sirius631

[url=http://www.bikeradar.com/forums/viewtopic.php?p=14969918#p14969918]LordSplodge[/url] wrote:

Is there an idiots guide on how to attach your pump to a presta vale (valve) or is it so obvious that I am just being a dumb blonde?

Sorry, I can't comment. You didn't actually tell us your hair colour. :P

keef66

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19670220#p19670220]Sirius631[/url] wrote:

[url=http://www.bikeradar.com/forums/viewtopic.php?p=14969918#p14969918]LordSplodge[/url] wrote:

Is there an idiots guide on how to attach your pump to a presta vale (valve) or is it so obvious that I am just being a dumb blonde?

Sorry, I can't comment. You didn't actually tell us your hair colour. :P

After 7 years there's a good chance he's either grey or bald

t4tomo

[url=http://www.bikeradar.com/forums/viewtopic.php?p=15010248#p15010248]The Hundredth Idiot[/url] wrote:

alfablue wrote:

Sorry if its obvious, but are you pushing the head fully home on the valve? It needs to be well in the rubber tube, then turn the lever.

Fair question and the answer is: to the metal.

I might borrow my neighbours again and see if I have the same problem using his. If so, might be a problem with the pump.

I think you need new wife.