Topic: Tire inner tube, valve stem with conical washer + 2 nuts - How to fit the rim?

[PeWe]

I had to find out how the inner tube has to be fitted since it has 1 conical washer and 2 nuts.
Washer look to fit the rims curved part
These can be set in different ways but one method must be better by design.

I have read about these ways of mounting the inner tube
1. Washer only on stem, rim, 2 nuts on outside locking each other with a small distance from rim to allow stem to move when tire grip the tube if pressure is too low

2. Washer on stem + nut, rim, 1 nut on outside tightened against rim ( This method to not allow washer to fall off when mounting the tube and not allowing stem to go inwards outwards filing the hole in the rim)

3. Washer on stem, rim, nut on outside only when mounting tire, leave off when inflated.

I have done as many others, method 2. But method 1 seems to be the preferred way.
Here from another thread  with claimed information from Michelin. Same brand of tube I have used.
http://forum.arielownersmcc.co.uk/viewtopic.php?t=3880&start=10#p25405

If the tire has correct pressure, no worries of either way as it seems. Problem with too low pressure and/or wrong tire mounting lube causing the tire to rotate during acceleration or braking.

- How do you do it?    I have seen this to be discussed on several forums, almost like a good slippery thread.

[Yamahawk]

I would do it #1 way, without any room left, and snug the 1st nut up after tube is in rim, then lock the 1st nut with the 2nd one. You really don't want the tube to spin at all, no matter the pressure of air in the tire. If the inevitable happens, and your tube loses air, there isn't much you can do to prevent tube damage if you aren't aware of it. Normally, the rear tire will give a sign by wallowing or swerving from side to side, front tire will want to wash out.
Charlie

[ekpent]

 Just did a couple of tires very recently and did the #1.

[PeWe]

I have 3 wheels with new tires. K2 build and spare rear for quick wheel change on my K6.
I'll try no.1 next time.
Maybe I'll get "problem" keeping the washer in place on stem not falling off when getting the tube valve stem thru the hole while crushing my fingers by the tire

[754]

I would do it #1 way, without any room left, and snug the 1st nut up after tube is in rim, then lock the 1st nut with the 2nd one. You really don't want the tube to spin at all, no matter the pressure of air in the tire. If the inevitable happens, and your tube loses air, there isn't much you can do to prevent tube damage if you aren't aware of it. Normally, the rear tire will give a sign by wallowing or swerving from side to side, front tire will want to wash out.
Charlie

If you give it a bit of slack, you can tell if the tire moves on rim, or more important, whether tube is lined up to the hole. Nothing like adding stress to the tube to cause premature failure.
 If you don't  do the above  you get no warning or chance to correct..any misalignment or slipping.

[markreimer]

#1!!

I ripped a valve stem out of my tube last year when it slipped, I had the nuts tightened down. Now I leave it a bit slack and double nut.


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[przjohn]

#2 and don’t tighten the outside nut down. Leave it loose so thet if the tire moves on the rim it does not break the stem out of the tube.

[pjlogue]

Just curious if anybody has experienced a tire slip on a rim on anything other than a real flat tire.  Perhaps during burnouts it may slip if the tire pressure is very low but I can't see slipping of a tire on a rim if there is any sort of pressure in the tire.  Even at 5 psi there is hundreds of pounds of force pushing the tire against the rim walls.  Unless a tire was mounted with grease or oil I can't see it happening. 

Just curious.

-P.

[754]

Some tires fit /grip tighter than others,

At 15 psi, on a bike with struts, they can slip.. I run 4 sheetmetal screws into the bead, both sides.

[jgger]

We used to run 2 rim/bead locks on our dirt bikes and would leave the nuts off of the stem completely.  And yes with 2 rim locks my 250  Montesa  would  slip the tire once in a while. This was on Acront rims.

I have also seen Frank's sheet metal screw trick used,  but I never wanted to drill my rim.You need to be very careful about the length of screws you use!

[markreimer]

When mine ripped I hadn’t checked pressure in a long time. It was a dirt bike tire, lower pressure to start. Jumped on the bike, hit the gas and boom instant flat


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[754]

 I bet you woukd have done something about if you saw the stem tilted 10 or 15 degrees... early warning..

[markreimer]

Never thought to check these things before that happened. Now I always check!


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[PGF550F]

I always use option #1 for all the reasons already mentioned but I have never experienced a tire slipping on the rim. Likely not riding it hard enough. 

[PeWe]

I have old memories of a vulcanized stem, no nuts at all. 
This seems to be extra important on dirt bikes and similar.

I check when mounting the inner tube that the stem is pointing up thru the hole by 90 degrees with no stress making it point different to start with. Also important that I can push the stem inwards min 10mm when tire is mounted, before inflating it,  to ensure the tire is not resting on the tube

I pump the tire with double pressure (5 BAR) and deflate it completely and repeat same again to be sure that tire has seated correctly. Then around 2.5 BAR.

I'm not worried about method 2 since I have read about guys ensuring that is OK when they have done that professinally during decades. But better to do it the "best" way or "less chance to get problem" way according to method 1, (tube- washer - rim - doble nuts a bit up on the stem)
This will easier make water to get access to the inside and rim will rust? 
- Seal the stem/rim hole?

[jlh3rd]

The owner’s manual of my 75 550 f states to tighten the valve stem retaining nut , not nuts. The Honda expert I get info from also says that the bikes came from japan with one nut on the valve stem,then inserted into the rim....the shaped washer and then the remaining nut is put on the valve stem outside the rim and tightened.
Also, the AMCA  judges will deduct points for a “double nutted” valve stem in judging a Japanese bike.
     This being said, I’ve seen numerous publications showing double nutted valve stems.......
Your choice....I go with experts most of the time...

[PeWe]

CB750 shop manual show 2 nuts on the outside. That part of manual written for CB750 K0 wich was long time ago.

This is an interesting subject and it is discussed a lot in various motorcycle forums.
I trust Michelin as a tube manufacturer in this matter. They must have got complaints about defect tubes and therefore written about it, the thread with link I referred to earlier.
Anyway, interesting information and something to consider when replacing the tire.  Search the subject and read the various reasons of why doing the different alternatives.

[jlh3rd]

Gives me a headache...

[crazypj]

I use nuts on road bikes (even if they aint too fast) and no nut on dirt bikes so valve stem can move around, it's no fun trying to race on a flat even if you are in muddy conditions
Never tighten nuts right down though, it can stress the stem to tube connection, finger tight plus one flat should be more than adequate. The theory, as I remember it from  1950's Dunlop film, is road racers can be going quick enough for valve stem to centrifuge inside tyre and cause failure, 'scramblers' going slower with lower pressure are more likely to get tyre creep so allowing valve to move is safer and provides visual indication that they need 'fixing'

[przjohn]

I don’t understand why you would double lock nut a stem to the rim? Is the stem going somewhere? Tire pressure, even low pressure will keep the stem pushed fully out. Most dirt bikers don’t even run a nut and those tires are running less than half the pressure of street bikes. What purpose does locking the nuts serve?

[754]

It holds them in place 3/8 of an inch up.
 And seeing as they are locked together  it stops people from running up to you saying the nut is falling off, even though the cap would stop it..

[PeWe]

OK, I updated 4 of my wheels today with a 2:nd nut on the outside, both nuts about 5-6 mm up on the stem locking each other. (I had 4 spare nuts from used tubes)
I tightened the rim hole-stem with a thin stripe of vulcanizing tape I strapped around the stem close to the hole. The inner tube valve stem can flex now. 
A thin rubber washer wider than the metal washer sitting tight on the stem can be an upgrade. It will keep the washer in place when mounting the tube and seal the hole. A piece of an old tube with punched hole for stem... I'll save an old tube for that.

[crazypj]

LOL, stuff is way better now than it was 40~50 yrs ago and we take more care making sure it's 'safe'.
I think it's really because we are more fragile, at 19 you know your 'immortal'

[PeWe]

We can keep us informed thanks to Internet. I'm sure the off road / dirt bike guys  have known this for decades.

[754]

The worst part today is price of a tube... you can buy a used tubeless mag for two or three times the price of a Conti or Pirelli tube..

[PeWe]

Yes, the price of the tube add some. The spoked wheels look very nice though and an important part of the bike.
I have so far always replaced tube with the tire. Maybe possible to change tube every 2:nd rear tire?  If it will survive the removal of the old tire stucked into the rim

[crazypj]

I replace tubes when they need it. If you use talc  (baby powder) inside tyre and on tube it's possible to get several uses. The tyre and tube will move around, sometimes independently of each other during normal use so tube will actually 'wear out'. If any of the mould marks are worn or damaged, tube is 'done for' as it will still 'move around' but could get too tin to hold air

[PeWe]

Good to know. I remember some tires had talc inside when new.
A tube inside a rear tire that worn out at around 3000 miles must be ready for one more round.

[jgger]

You can also air up the tube off the rim and the weak/worn spots will bulge out.

[PeWe]

Another good thing to look for when reusing the tube.
Check the shape and if it bubbles in water, it can have been pinched when bending the tire side off.

We can continue this thread about which talc is the best? Baby powder or Babe powder?

More interesting stuff about talcum powder (White powder sold on the street might be an alternative?)
https://draxe.com/talcum-powder/
https://www.drugwatch.com/talcum-powder/
https://www.cancer.org/cancer/cancer-causes/talcum-powder-and-cancer.html

[Yamahawk]

Another good thing to look for when reusing the tube.
Check the shape and if it bubbles in water, it can have been pinched when bending the tire side off.

We can continue this thread about which talc is the best? Baby powder or Babe powder?

More interesting stuff about talcum powder (White powder sold on the street might be an alternative?)
https://draxe.com/talcum-powder/
https://www.drugwatch.com/talcum-powder/
https://www.cancer.org/cancer/cancer-causes/talcum-powder-and-cancer.html

GoldBond Medicated talc, in case your rims get a little rash...
Charlie

[PeWe]

http://www.goldbond.com/blog/product/medicated-baby-powder/
That's corn starch.
Potato starch might be another one?

How it will react with moisture can be the guide. I have used corn starch and potato starch in the kitchen to make sauce and stews thicker.

[crazypj]

This is going into the realm of 'Pythonesque'   

[PeWe]

Pythonesque means really fun as the English lads could make it with their flying circus....right? 

[crazypj]

Yep. I'm always quite surprised that 'America' finds 1970's British humor 'current'