Bicycle Mechanics - Prest valve lock nuts and valve covers

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mcavana
08-22-04, 08:04 AM
The guy at my local bike shop says i don't need to use either the plastic valve covers or the lock nuts on my presta valves. he says the only reason the tubes come with the plastic valve covers is so when they are folded up in your bag, the vavle stem does not damage the tube. He says he does not use the lock nuts because they can stress the tube at the base of the stem, they make a stem that is not lined up correctly with hole in rim look straight and ultimately they don't do anything good except hold the stem out when filling.

What are your thoughts? this isn't a big deal, but it would be nice to not have to screw those nuts on if not necessary (i do have long stems, takes some time) It would also be nice if i didn't have to get down on my hands and knees and look for the stupid plastic valve covers every time i drop one (happens at least 2 times when i change tire... used to hold it with my teeth until one day i couphed and ate one!!)


sydney
08-22-04, 08:07 AM
The guy at my local bike shop says i don't need to use either the plastic valve covers or the lock nuts on my presta valves. he says the only reason the tubes come with the plastic valve covers is so when they are folded up in your bag, the vavle stem does not damage the tube. He says he does not use the lock nuts because they can stress the tube at the base of the stem, they make a stem that is not lined up correctly with hole in rim look straight and ultimately they don't do anything good except hold the stem out when filling.

What are your thoughts? this isn't a big deal, but it would be nice to not have to screw those nuts on if not necessary (i do have long stems, takes some time) It would also be nice if i didn't have to get down on my hands and knees and look for the stupid plastic valve covers every time i drop one (happens at least 2 times when i change tire... used to hold it with my teeth until one day i couphed and ate one!!) The LBS guy is absolutely right.

mcavana
08-22-04, 09:39 AM
hooray!!!


Fat Hack
08-22-04, 09:41 AM
agree

Raiyn
08-22-04, 11:09 AM
Exactly right

prestonjb
08-22-04, 01:27 PM
It's not required and I don't use them. What are they for?

1) helps hold the stem up so it is easier to get the pump head on.
2) Keeps the MUCK and dirt from getting into the valve area and thus cloging the valve open...

Stressing the tube? Nope that would be if you overtighten the nut.

John E
08-22-04, 07:22 PM
I agree. The cap can press against the valve stem projection, causing a slow air leak. The nut, if put on before the tube is inflated, will make you more likely to pinch the tube between the tyre bead and the rim. Save (a little) rotating weight and (a little) time during puncture repairs!

Grampy™
08-22-04, 09:07 PM
Uh, oh..... forum member all agree on something......

Raiyn
08-22-04, 10:53 PM
Uh, oh..... forum member all agree on something......
RUN FOR IT!!!!

Heh

sakarias
08-22-04, 11:30 PM
Hmmm. I guess I'm out voted, but I use the caps. I want to keep grit (in our rainy climate) out of the valve seat. I had to toss a schrader valve tube, years and yearsago, that leaked, perhaps from grit getting into the valve seat.

I use the rings when inflating a deflated tube. Helps get the pump on. I run the ring a ways down the valve shaft, then push on the pump. After I finish pumping, usually, I run it down the rest of the way, but not tight, and leave it there.

I have never lost air from using the cap. I have never damaged a tube by using the ring. I am not concerned about the tiny extra weight.

I have never lost a cap. My wife loses them frequently.

So, one small contrary view. (Guess you don't have to run for cover?!)

As always, "your mileage may vary."

Ed Holland
08-23-04, 02:53 AM
Well Mcavana, I think the guy at your bike shop is wrong!

I use the valve cap, it keeps all the grit and grime out of the tube's valve mechanism - this is particularly worthwhile if one ever rides in wet weather or dirty conditions. It certainly can't do any harm, unless you're eating a lot of them ;). The locking ring is much less important - as evidenced by many tubes which are made without threading on the valve stem.

Its your choice at the end of the day though :)

Cheers,

Ed

Mzungu
08-23-04, 02:59 AM
There is a case to use the lock.

I agree the ring can cause problems while riding . The exception is during roadside inflation, it helps keep the valve secure when you are using a frame pump and it rocks back and forth and you are tired. With out the lock there is more stress while inflating with frame pump.

bkrownd
08-23-04, 03:24 AM
The last presta tube that I bought doesn't even have any threads for a locking nut.

EyeBike2
08-24-04, 01:57 AM
Man I agree. For using a hand pump on the side of a trail, those lock nuts make things much easier.

khuon
08-24-04, 03:20 AM
You also need to be careful if using the lockring. If you tighten it down too much and inflate, there is a chance that as the tube expands in the rim and tries to tug at the ring, the entire stemcore will pop out. I've had this happen before. Use the ring to get things started and at about 15 to 20 PSI or when it seems everything has gotten form and seated, either loosen it or take it off altogether before continuing to inflate. If you want to keep it on then make sure it's just finger-snug after the tube is fully inflated.

I admit that I keep my lockrings on my tubes that have them. I also keep the valve covers for no specific reason. I have found that tubes without full threading and thus without lockrings are better in that they don't degrade the seals in my pumps as quickly so I've started buying those instead.

tbick
08-24-04, 08:59 AM
Uh, oh..... forum member all agree on something......


I'll save the day,,,,no we don't .

You should use the lock nut but not the cover....no wait...you should use the cover but not the lock nut......oh crap...now I'm really confused

RainmanP
08-24-04, 10:25 AM
Hmm, well, I've been using both all this time. I may rethink the nut, but I will continue using the cap. I just don't see how it can be good to get grit and crud in around that valve seat.

a2psyklnut
08-24-04, 10:27 AM
The Gary Fisher Rep had these yellow fish stem covers, so I use them!!!!

Here little fishy....Here little fishy......

L8R

froze
08-26-04, 12:17 AM
I agree with Sak. I use the nut just to make it easier to inflate the tire...but you could do the same thing by pressing in on the tire where the valve is to force the valve up out of the hole; that's how I usually do it anyway, it's just easier the other way. The nut will not stress the tube IF you don't overtighten it, just finger snug itand your fine. Now you could make an argument about the nuts weight, but it's not going to kill you-if it does then your too weak to be on a bike anyway!!!

The plastic cover will not allow the air to leak out if on too tight, reason being...you have the valve nut tightened. The plastic cover does prevent dirt and water from getting into the rather fragil valve and screwing it up later when you need it to work. And what the heck does the little plastic cover weigh? I doubt if 2 combine weigh over a gram-I can't even feel the weight in my hand!!!

So gee, what to do? I would rather go without the nut and keep the cover if I had to choose between one or the other; but since I don't race, nor am I a weight weenie, I use both.

SanDiegoSteve
08-26-04, 04:08 PM
Anyone else get an annoying rattle without the nut? I had a tube with a threadless stem. After about 12 months, it started to rattle a lot. I used it as a que to change it.
The replacement had a nut, so I put it on. I didn't like the rattle.