Bicycle Mechanics - difficulty inflating presta valve tubes

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sers
11-15-05, 11:47 PM
Let me preface this by saying this is the first time I've dealt with presta valves...

Today I picked up a Park Tool Home Mechanic Floor Pump. I then attempted to inflate my tires. I placed the pump head on the (unthreaded) valve, and locked it according to the directions on their website. My tires are supposed to be inflated to 100-130 psi. When I got up to about 90 psi, the pump head slid off. I attempted it again, making sure it was firmly seated and locked - when I got up to about 110 psi, it slid off again.

What could I be doing incorrectly? Is there an art to getting the pump head to stay on?


mike
11-16-05, 02:40 AM
Did you loosen the nut on the air-release pin before you started to pump?

mike
11-16-05, 02:43 AM
Yes, Presta valves can be funny that way.

Push the valve as deep into the pump head as possible. You might have to hold the pump head while you pump. If you start with a flat tire, you sometimes have to support the back of the valve by pushing on the tire behind where the valve is.

Good luck. You'll get it.


oboeguy
11-16-05, 06:23 AM
My Joe Blow Pro pump stopped working properly. I recently emailed the manufacturer and they said that the pump head may have been damaged by pushing Presta valves too far into the pump.

Al1943
11-16-05, 11:57 AM
My Joe Blow Pro pump stopped working properly. I recently emailed the manufacturer and they said that the pump head may have been damaged by pushing Presta valves too far into the pump.

Hummm- I've always pushed mine all the way in.

spinerguy
11-16-05, 12:29 PM
Let me preface this by saying this is the first time I've dealt with presta valves...

What could I be doing incorrectly? Is there an art to getting the pump head to stay on?

The lever in this model must be down at the time of insertion, once the valve is fully introduced lift the locking lever up to prevent the problem that's ocurring to you.
If you are doing it already it may be a defective head.

spinerguy
11-16-05, 12:33 PM
Yes, Presta valves can be funny that way.

If you start with a flat tire, you sometimes have to support the back of the valve by pushing on the tire behind where the valve is.



That's why I don't get rid of the little valve retainer nut.
;)

DieselDan
11-16-05, 04:53 PM
Park's Home Mechainc Floor Pump is crap. Go get a Topeak or Silica.

sers
11-16-05, 08:20 PM
Park's Home Mechainc Floor Pump is crap. Go get a Topeak or Silica.

why is it crap?

bitingduck
11-16-05, 11:11 PM
With a silca (or other pump with a small diameter) you can pump with one hand while holding the chuck with the other and still get high pressure.

DieselDan
11-17-05, 09:31 PM
why is it crap?
Mine broke. The one my friend bought broke. Several were sent back by my LBS because the head would not stay on the valve. The replacment I got broke a hose that was difficult to replace. Then the head broke on the replacement. I got a Topeak Joe Blow Sprint and haven't had a problem yet.

cascade168
11-17-05, 11:03 PM
Mine broke. The one my friend bought broke. Several were sent back by my LBS because the head would not stay on the valve. The replacment I got broke a hose that was difficult to replace. Then the head broke on the replacement. I got a Topeak Joe Blow Sprint and haven't had a problem yet.


You should take this up with Park Tool. They are pretty serious - and pretty good - about customer service. A friend of mine had a Park Pro floor pump that got recalled (I forget why, but it was a pretty big recall). They just sent him a new pump. Now he has two Park Pro floor pumps that both work perfectly. Save your receipts.

cascade168
11-17-05, 11:13 PM
What could I be doing incorrectly? Is there an art to getting the pump head to stay on?


Lever should be down (parallel to the hose). Unscrew the little valve head on the tube all the way. Tap it to make sure it unseats and reseats - you should hear a little puff of compressed air. Now push the pump head on as far as it will go and pull up the lever so that it's in line with the valve stem on the tube. Pump your tire up to the desired pressure. Push the lever back so it's parallel to the hose again. Pull the pump head off the valve stem. When you do this you will hear a big puff of compressed air - this is the stored up pressure in the pump itself, not the tire. Now, screw the little valve head on the presta stem down and you are done.

Repeat this many times and you will learn to love presta valves and the very nice floor pump you have ;-) It takes some practice, but once you get the hang of it you'll love it. It ain't rocket science, but it does take a little getting used to. Good luck ;-)

infieldfly
11-18-05, 07:29 AM
I too had a problem with high pressure and an unthreaded stem. Try degreaser and/or rough it up with sandpaper, there is probably nothing wrong with your pump.

Jenniemw
12-10-05, 01:20 PM
I too am a newbie to Presta valves. I am having real trouble pumping my tyres and just need some basic advice. I've been riding a mountain bike for years and now having switched to a road bike, am simply doing something wrong... can anyone give me a quick idots run down, or have a link to some a-z tips?

buttbybrooks
12-10-05, 01:54 PM
After thirty years of pumping up presta valves I decided I didn't care for it so I bought a $99 air compressor from Lowes and scharader adaptors for my presta valves. Now I just give a short blast to my road bike and away I go.

I still use a hand pump when installing new tubes but the compressor worked out great.

royalflash
12-10-05, 02:00 PM
Let me preface this by saying this is the first time I've dealt with presta valves...

Today I picked up a Park Tool Home Mechanic Floor Pump. I then attempted to inflate my tires. I placed the pump head on the (unthreaded) valve, and locked it according to the directions on their website. My tires are supposed to be inflated to 100-130 psi. When I got up to about 90 psi, the pump head slid off. I attempted it again, making sure it was firmly seated and locked - when I got up to about 110 psi, it slid off again.

What could I be doing incorrectly? Is there an art to getting the pump head to stay on?

you just have to hold the pump head on and pump one-handed- some Presta valves are better at gripping the pump head than others (I think the quality of the thread varies)

beyondthesun
01-06-06, 12:19 AM
can you use a regualar gas station air pump to pump up the tires with presta valves, or does the pump need to be set up for presta vavles onle and not schader? i'm new to them as well and i went to the station to get some air in em before i left for a ride, and had no idea what i was doing.

royalflash
01-06-06, 12:54 AM
can you use a regualar gas station air pump to pump up the tires with presta valves, or does the pump need to be set up for presta vavles onle and not schader? i'm new to them as well and i went to the station to get some air in em before i left for a ride, and had no idea what i was doing.

yes but you need to get a little adapter first from your LBS that screws on the presta valve head. It is probably better though to buy a proper Presta floor pump rather than using a gas staton pump if you can.

lrzipris
01-06-06, 05:47 AM
sers, you should have no problem pumping tires to 130, as most floor pumps are rated (ie, state that they can go up to) for about 160. And you should not have to hold the pump on the valve while you finish the job. If your pump keeps blowing off, my conjecture (and this is purely speculation) is that there's something wrong with the locking device.

If you belong to a club or ride with other cyclists, can you borrow other kinds of floor pumps and see if you have the same problem with them? Isolate the problem and possible sources....

Jenniemw, it's hard to respond to your post because you don't say what kind of problems you have. Generally, you unscrew the the air release pin (as Mike said in post #2), push it down once or twice, insert the pump head and lock it, then start pumping. It may take a stroke or two for the air pressure to build up enough to push the pin in and actually get to the tube.

When you reach the desired pressure, simply reverse the process, being careful not to wrench the pump head off so violently that you risk causing a leak at the valve stem. With frames pumps, support the valve stem while inflating the tube so you don't damage it and again risk a leak. Incidentally, if you keep that small nut on the valve stem itself, don't tighten it too much--it's really only useful for holding the valve of an uniflated tube in place so you can get the pump head on; it serves no other function, and many people discard them.