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rockraven00

2 nuts on tube stem

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new tube had 2 nuts.

old tube had 2 also, I put one against the cap but the old one was on the inside of the rim, Is this correct? I thought the little beveled thing on tube was supposed to go against the inside of the rim, not the extra nut...

What?

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one nut on the inside of the rim, the other nut on the outside. That is correct. It is so the nut on the outside can be tighted without pulling the valve out of the tube.

Having given you the correct answer..... if you use a rim lock, the outside nut on the tube is not needed. I do not use the outside nut. I have a rubber grommet on the outside that seals the valve opening and forgo the nut.

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YOung, why is that metal tapered washer in there then, just to shap to the tube to prevent nut pressure digging into the tube?

I might then think if there is no need for the outer nut with a rimlock, then the inner nut can also go.

I do what I read and usually use the outer nut to tighten against the cap, might help lock it in place.

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The tube moves around a tiny bit inside the tire as the tire sidewalls flex. The inside and outside nuts prevent the valve stem from sliding in and out the rim’s valve stem hole during tire flex. This is why the valve stem is metal. A rubber valve stem would quickly wear through by rubbing on the rim hole.

It is common for the valve stem to run in and out a ¼ inch or so while riding. The valve stem junction is the weakest part of the tube. The in and out flexing hastens the failure of the tube at the junction area. If the stem is locked in place with the nuts, it will not move in and out, thus hopefully lengthening the life of the tube.

Your wondering why I do not use the outside nut? Fair enough question. I enjoy working on my bikes and change tires myself. New tire, new tube. The tires and tubes do not stay on my bikes long enough to wear out. Fixing a flat on the side of the trail is easier without the nut.

The metal bevel on the valve stem is there to protect the stem junction.

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do what works for you, but there shouldn't be a nut on the inside. Doing so often will have the stem deflect one way or the other and is pushing the stem inward on the tube more than needed.

The curved piece is all that is needed on the inside of the rim to protect the tube and well.. it's CURVED for a reason.. to fit in that part of the rim as designed, spin a nut on the stem a few threads to mount your tire so it doesn't pull through during mounting. Once mounted (and after ya have set the bead), spin the 1st nut to the rim lightly, and use the 2nd to lock the 2 nuts together.. Be SURE your putting the valve stem in the BIG hole of the rim, and the rim lock in the small hole. The big hole allows for minor movement of the stem without damage or if the tube should move a tad, the small hole for the rim lock keeps the rim lock in place.. exactly what it should do..

Blow the tube up 1 time.. but then deflate before you go crazy with psi to pop the beads, doing this helps work out kinks in the tube if you have some. (and is exactly what is on the box directions of some tubes). Don't over torque the rim lock nut as you will strip the treads. I like the TUSK ones and some others that have a 2-3x larger rim lock nut.

EDIT: i just changed a front and rear for this weeks harescramble, and i have only 1 nut on my rims.. inside is the half moon thing that protects the stem, then outside i have a rubber boot thing that will move a bit, and keeps water/mud outa the stem hole. I then lightly tighten 1 stem nut down on that boot to keep it from riding up the stem , then the valve cap.. 👍

Edited by MELK-MAN
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Posted (edited)

I have always left the inner nut inside the wheel and the outer nut tighten to the outside of the rim, reading for the first time today that you are not supposed to tighten the outer nut and reading many more opinions, I had to verify what the manufacturer does. 

Looking at this video at 6:17 shows I do it right.

https://www.youtube.com/watch?v=-DjwJgr4jiQ

Edited by Ronen Festinger

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Leave valve stem loose/ hardly tightened down so it can move a little with acceleration/braking or else you will rip the stem or tear it, letting air out and flat city.

 

Joe

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Yep, if you tighten down the outer nut you will never know if the tire is starting to slip on the rim.  If it does, you will see the valve stem at an angle.  If you tighten the nut, your first indication that the tire slipped will be a flat tire after the valve stem ripped out of the tire.  Personally, I run the outer nut up against the valve stem cap.

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Funny enough just went through this with TTR 110 which doesn't have a bead lock.

First time tire was off and tube out was to patch two holes and one nut was over conical washer inside rim and this is how it came from dealership brand new.

I think when tire starts to move it will strip outer nut as I found and stem will cock and rip tube.

Going to put some witness marks on rim and tire cause I'm curious how much movement is involved during rides?

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2 hours ago, Gflo said:

Yep, if you tighten down the outer nut you will never know if the tire is starting to slip on the rim.  If it does, you will see the valve stem at an angle.  If you tighten the nut, your first indication that the tire slipped will be a flat tire after the valve stem ripped out of the tire.  Personally, I run the outer nut up against the valve stem cap.

I've been doing that since my first trip to Baja.....

👩‍🌾

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5 hours ago, markdgregory said:

Perplexed as well.  But here is a reference that adds a different perspective.

Look at TR4 / TR6

https://www.tireinnertube.com/content/11-valve-stem-types

 

 

Interesting. Never seen a factory new wheel with both nuts and washer on outside, as described. Always has washer and nut inside, maybe a nut outside.

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Continental and Michelin both say no nuts inside, both nuts go outside and thread up to the cap. One acts as a locknut

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5 hours ago, azmaxxed said:

Continental and Michelin both say no nuts inside, both nuts go outside and thread up to the cap. One acts as a locknut

I've always wondered that...it seems to sit better with no nut...but I always left one inside.

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8 hours ago, azmaxxed said:

Continental and Michelin both say no nuts inside, both nuts go outside and thread up to the cap. One acts as a locknut

Links?

From My understanding the first nut clamps the stem in place in the tube with the washer. A leftover from the old days when you could replace valve stems in tubes. The second is unnecessary, it just tightens the stem to the rim where needed.

I would question why the motorcycle manufacturers would go against the recommended fitting practice too.

I asked around a few of the importers down here and no-one could give Me an answer.

Edited by DEATH_INC.

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I believe this was quoted from ADV rider, the guy contacted both tire manufacturers and they said the same thing. The stem needs to float or it will rip sooner or later, I use no nuts but those silicone seals that slide over the stem.

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