Dumb Michelin innertube question (2020)

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I was about to install a new Michelin inner tube and noticed on the new valve stem there were two nuts and a dimpled washer. I didn't think both nuts went on the outside and the dimple was obviously meant to go against the rim, so where does the extra nut go (no jokes please). And I'm doing front and rear so I looked at the other one and there were two nuts there. There must be some reason I thought and, in all innocense, I went to the web. I was surprised to find discussions about this! Some put both nuts outside and others put one nut inside. The majority put one of the nuts inside. Since the dimpled washer fit nicely against the opening for the valve stem, no problem, but that left the one nut up against the innertube. How could that be ok? Unless the two nuts on the valve stem sandwich the dimpled washer and the rim tightly and the tube at the valve stem is thus held away from rubbing against the nut. Why all this wondering? I don't want a flat 20 miles from home.
 
I have seen this style before. I also found it odd. My guess/conclusion was one of the nuts screws down on the dimpled washer, compressing the inner tube, and holding the valve stem in the tube. The second nut goes on the outside of the rim. This puts one nut against the inside of the rim and it seemed like a clunky design.
 

 
From a BSA site



I sent my questions, as written at the beginning of this post, by email to Michelin UK in Stoke-on-Trent. I received the following reply from Tony Charlton, Technical Manager at Michelin.

"The inner tube is installed with the conical washer sitting between the inner tube and wheel rim. On a road bike the first lock nut should then be run down to lightly touch the rim, and then backed off by half a turn. The second lock nut is run down until it meets the first one, then the two nuts should be locked together by using spanners to rotate them in opposite directions.

For off road inner tubes being used at low tyre pressures there is a possibility of tyre creep, and the inner tube could be pulled around slightly with the tyre. If the inner tube is bolted to the rim the valve can be ripped out. If the lock nuts are raised further towards the valve cap then inner tube has some leeway to move before this happens. Any movement is thus obvious as the valve stem will no longer be straight and pointing at the centre of the hub, but will be pulled round at an angle by the tyre and can then be seen and corrected."



Dumb Michelin innertube question (2020)
 
Kommando is correct. Pretty sure there is a picture on the box, I believe the last Airstop I installed had that picture.
 
From a BSA site



I sent my questions, as written at the beginning of this post, by email to Michelin UK in Stoke-on-Trent. I received the following reply from Tony Charlton, Technical Manager at Michelin.

"The inner tube is installed with the conical washer sitting between the inner tube and wheel rim. On a road bike the first lock nut should then be run down to lightly touch the rim, and then backed off by half a turn. The second lock nut is run down until it meets the first one, then the two nuts should be locked together by using spanners to rotate them in opposite directions.

For off road inner tubes being used at low tyre pressures there is a possibility of tyre creep, and the inner tube could be pulled around slightly with the tyre. If the inner tube is bolted to the rim the valve can be ripped out. If the lock nuts are raised further towards the valve cap then inner tube has some leeway to move before this happens. Any movement is thus obvious as the valve stem will no longer be straight and pointing at the centre of the hub, but will be pulled round at an angle by the tyre and can then be seen and corrected."



Dumb Michelin innertube question (2020)
Makes sense -- now. Though holding the valve stem like that only makes it less obvious that the tube is being rotated. Maybe if it got sucked around there would be a catastrophic failure. Anyway, now hoping for Indian summer days.
 
Although the recommended gap of backing off 1 full turn for a road bike is a lot less than the recommended gap for an off road bike the valve stem will still slightly lean to one side if the inner creeps and the valve stem has some leeway before being ripped off.
 
That picture only shows the washer and nuts on the stem. Look at the angle of what looks just like the tube at the base. NOT the rim with stem poking out. And doesn't that look like the washer just below the nuts on the stem? Shouldn't the washer be pictured on the inside? Oh, you could make the argument either way. I wasn't sure, so I asked. I was not sure that picture didn't just represent a depiction of what you would find in the box. Too vague. Did not seem like an instructional diagram. Even now that I know, the image does not serve well.
 
That picture only shows the washer and nuts on the stem. Look at the angle of what looks just like the tube at the base. NOT the rim with stem poking out. And doesn't that look like the washer just below the nuts on the stem? Shouldn't the washer be pictured on the inside? Oh, you could make the argument either way. I wasn't sure, so I asked. I was not sure that picture didn't just represent a depiction of what you would find in the box. Too vague. Did not seem like an instructional diagram. Even now that I know, the image does not serve well.


Just showing what's on the box isn't "what's in kommandos picture". There's obviously no rim depicted.

I've always fitted the valve with one nut against the washer so one nut inside the rim and the other on the outside with no problems and will likely continue doing so.
 
Dumb Michelin innertube question (2020)
Can‘t load complete pic because of file size. Guess Jerry needs for fix this.
 
I have always been confused by this as well. Installed a tube on my TC 100 Suzuki with the washer on the inside. The washer wore a hole in the tube. Perhaps the rim shape caused the washer to protrude further than normal from the inside but I haven't installed another with the washer on the inside. YMMV.
 
I have always been confused by this as well. Installed a tube on my TC 100 Suzuki with the washer on the inside. The washer wore a hole in the tube. Perhaps the rim shape caused the washer to protrude further than normal from the inside but I haven't installed another with the washer on the inside. YMMV.
That bothered me too. So I put the small conical washer Under the new rubber rim strip. Who knows, who knows. Maybe the dimpled washer was supposed to go point end toward the tube. Someone might say, "such a fuss," but 20 miles down the road with a flat?
 
That bothered me too. So I put the small conical washer Under the new rubber rim strip. Who knows, who knows. Maybe the dimpled washer was supposed to go point end toward the tube. Someone might say, "such a fuss," but 20 miles down the road with a flat?
Yeah I thought about turning it over but that didn't seem right either. Also wondered if it was for use on a rim with a larger valve stem hole but I've never seen one with a larger hole. Just decided to leave it out. Doesn't seem to be a problem. A flat on the little Suzuki isn't so bad but I really don't want one on the Norton. Been there, done that.
 
Yeah I thought about turning it over but that didn't seem right either. Also wondered if it was for use on a rim with a larger valve stem hole but I've never seen one with a larger hole. Just decided to leave it out. Doesn't seem to be a problem. A flat on the little Suzuki isn't so bad but I really don't want one on the Norton. Been there, done that.
I cannot see changing the inner tube by the side of the road. And if you've ruined the tube around the valve stem, you're not just pulling it out a little to patch it, you're replacing it.
 
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