Just received a new inner tube through the post. It comes with two nuts on the valve stem instead of the traditional knurled ring.
Why two nuts? Does one nut go inside the wheel and the other used as the knurled ring? The tube has a conical washer at the bottom of the valve stem which I would expect to to fit nicely next to the wheel valve stem hole inside the wheel so why the second nut?
I don't know why they provide 2 but I would never fit a nut inside the wheel rim. In fact I usually run the outer nut up to the valve cap as that can give early indication of the tyre creeping. If it's tight down to the rim the first you know is when the tyre deflates rapidly....
While I always fit one nut tightened down onto the inner tube, and the other nut loosely screwed down onto the rim.
Quote from: V500 on 16 Jul, 2024, 17:50
While I always fit one nut tightened down onto the inner tube, and the other nut loosely screwed down onto the rim.
I don't understand 🤔 you tighten a nut on the tube then fit another loose nut.
The first nut clamps down on the valve stem/inner tube joint, while the second provides a loose location and visual indicator of tyre creep.
Simple eh, Bob?
I agree with that V500. Rubber glue doesn't bond well to steel, so a nut tightens the seal. Also if your tyres are correctly inflated, they should not creep.
That is why all off road wheels, that are run at low pressures, have two 'Security Bolts' fitted.
Yes I understand what your saying but years ago inner tubes didn't have this arrangement and don't recall having a problem with the valve stem/rubber joint. Still puzzled.
I seem to recall that they did have this arrangement, and there was sometimes also a "load-spreading plate" clamping down on the base of the valve stem area on the tube.
Quote from: V500 on 17 Jul, 2024, 09:16
The first nut clamps down on the valve stem/inner tube joint, while the second provides a loose location and visual indicator of tyre creep.
Simple eh, Bob?
So a nut goes on the valve stem between the rim and the tube. Then another nut goes on the stem outside of the rim. That's a new one on me I often don't even bother to use any stem nut since the day about thirty years ago when I was stuck in the rain with a flat and the lock nut had been enthusiastically tightened down by a spotty bloke at the tyre shop.
If factory had tightened one nut to the tube, it should probably be there. If two loose nuts I throw one away. Yet no problem. Of course nut a bit loose to see if tyre and tube has slipped on the rim.
Thanks Bill for enlightening me. Instead of being idol I should have Googled Michelin, and as you say, clearly shows your explanation.
With this arrangement it would indeed show tyre creep before disaster struck.
Hi,
Not all Michelin tubes come with two nuts.
Dave.
I saw those Michelin recommendations some years ago on the VMCC forum where the same debate was going on.
If Michelin say it it must be correct, but in a long (decades!) time of cars and bikes, I've never yet seen the locknuts placed as Michelin state. Further, some posters did a little impromptu visual survey at a show, and apparently no-one else did it that way either.
I guess not everyone got the memo.