Broken Presta valves and correct way to pump tires

[cycloholichica]

I broke two Presta valve tips already. I looked it up and learned that I was pushing the valve tip too far into the pump head and was thereby weakening the tip each time I pumped. I am locking the pump head correctly.

Initially, I was NOT forcing the tip all the way into the pump but I did not feel I was getting much air in the tires this way. When I don't force the tip all the way into the pump head, I hear the air leaking and I have to practically use my full body weight to pump to the max psi.

Here are my suspected culprits.
Suspect No. 1: Cheap generic tubes
Both of the broken tips were from the tubes that came with my bike which have Deep V rims. The stem length is longer than a regular stem but shorter than a true extra-long stem. The tubes are generic ones and were made in Taiwan. (Not to diss Taiwan, since I am also made in Taiwan).

Suspect No. 2: Nashbar pump
I am using Nashbar's Big Red floor pump which has a dual head. I am not super strong but the amount of effort I have to expend to pump my tires seems unusually excessive. (Would a pump valve adapter be useful protect the Presta valve tip?)

Suspect No. 3: Me
Newbie who needs to learn the art of pumping tires?

One last thing. On a recent ride, I had a front flat and Charlie gave me one of his Specialized tubes with an extra-long stem. When I pump the front tire now, I do not have any problems. Pumps more easily and the valve tip doesn't seem as flimsy. Not sure if it's better designed or if it hasn't been weakened yet because it's still relatively new.

Any tips? (no pun intended)


-rachel

[ThE DoWnHiLL DeMoN]

by pressing the valve tips too far into the valve head, you're not only going to eventually going to break the valve, but you're also going to eventually damage the valve head on the pump. also, if you use threaded valves, you're going to eventually wear out the seal on the valve head washer too...

you only need to press the valve in far enough so it seals, which is just about the point you can't see it anymore, and that's it. then close the seal on the valve head, and pump up the tire, and you shouldn't hear anything leaking.

the main difference between budget pumps and more expensive pumps is that it usually takes less energy to pump up tires to a higher pressure with a more expensive pump. for example, pump up a set of tires to 120psi with a $30 Joe Blow Sport pump, then try to pump up the same tires with a $60 Park Tools PFP-4 Professional Floor Pump. the Park Tools pump makes it effortless, with barely any energy at all, while the Joe Blow makes it much harder to get to 120psi once you hit the 90psi mark. another difference between budget pumps and more expensive pumps is that the more expensive pumps usually have a nicer (and more accurate) gauge (that's usually closer to the handle to make it easier to see) and don't take as much effort to pump up tires to a higher pressure. the Park Tools pump i mentioned above is also rebuildable, so if you ever do damage the pump head or it eventually wears out, it can be replaced without having to purchase a completely new pump...

as far as the valves go, you don't need long valves unless you're running deep wheels. if you want a good tube, with non-threaded valves (so your pump head lasts longer) go with a pair of Michelin Air-Comp Ultra Light tubes.

http://www.excelsports.com/new.asp?page ... 1&minor=31

they go for a $5 each at Bike Junkie, on Broadway in Bethpage, which is down the road from where the club meets on weekends. if you're running Deep-V's, go with the longer 52mm valve stem, and if you're not the 36mm valve stem should be fine. it's best to go with the shortest that will work with your wheels...

[breaking away]

The main thing with pumping up tires i find no matter what pump you use make sure the presta valve is straight! If angled you will bend the valve and then it will breakoff!