H: Hubs, Wheels and Tyres Tyres

[oexing]

Has anybody ever seen a locknut for the valve cap on a car wheel ??? There are rubber seals in the caps that are perfectly shakeproof - anytime.
I wonder how many Gs are required to lift the internal one way valve at high speed for the cap to be a safety feature against sudden pressure loss ?? You typically see gradual pressure loss with certain inner tubes within several weeks so you will check tires periodically before each ride ? So I don´t see the cap as something extremely essential to safety.

Vic

 

[flxible]

For the latter half of my riding career I've subscribed to that theory (we're all looking for an edge) that natural rubber tubes do not tear when punctured, whereas synthetic tubes can. And thus far, knock on wood, the fairly low number of punctures I've had through the years have been limited to being just punctures, usually brought to my attention by a slow deterioration in handling that had me stopping to inspect. The one exception was recently, with a bike borrowed to run the USCRA MotoGiro last fall in Pennsylvania, which picked up a sheet rock screw in the rear that put a three inch tear in the synthetic tube and made for an abrupt, quite lively halt to proceedings. While anecdotal, it was enough to reinforce the use of the natural tubes. The trade-off has always been paying twice as much for a tube compared to synthetic, and the need monitor the pressure, usually topping up biweekly or so, but I consider that worthwhile as I'd probably not be checking my pressure regularly otherwise.

 

[Robert Watson]

Has anybody ever seen a locknut for the valve cap on a car wheel ??? There are rubber seals in the caps that are perfectly shakeproof - anytime.
I wonder how many Gs are required to lift the internal one way valve at high speed for the cap to be a safety feature against sudden pressure loss ?? You typically see gradual pressure loss with certain inner tubes within several weeks so you will check tires periodically before each ride ? So I don´t see the cap as something extremely essential to safety.

Vic

When did you last see a car tire with a tube in it?

I heard that the locknut under the cap came from the race crowd, especially those running high speeds on the banks at places like Daytona. No doubt it then became de rigeur for the cool wannabe racers. not unlike the current trend of tire shops to try and sell you nitrogen for your tires. I had a loooong talk with a Goodyear engineer several years ago about that. It was developed for the NASCAR crowd who talked about changing tires pressures in 1/4 psi increments. With plain air and a tiny bit of moisture and tires temps reaching past the boiling point, steam changed the pressure considerably. He did stress he knew of no circumstance where this would be applicable to street tires. Or even a stream liner running on the slat flats!!

 

[Cyborg]

I agree with you but we are all looking for some proof, Anyway of telling us how you came to think this.
Cheers Bill.

I am also a believer that the washer and one nut goes on the inside and the other left lose. I think it used to say that on the Continental site, but it's no longer there. Just for a giggle, I asked Bridgestone if they had any info in writing and this is the reply:

"Thank you for contacting Bridgestone Customer Service. I do apologize but we only handle the motorcycle tires here in this department. I would advise visiting this website to locate a dealer in your area that can further assist you: http://www.motorcycle-karttires.com/dealer.aspx

If you need anything else, please do not hesitate to reply back to this email, and I will help you in anyway that I can.

Thank you for being a Bridgestone customer, we do appreciate your business. Have a great night!"

Guess they have a separate department for tubes and they are all chained up in the basement with no form of communication to the outside world. Anyone else find that a dumb response or is it just me with my outlandish expectations?

 

[oexing]

Robert,
did I say anything about tubes in car wheels? Still cars have tire valves - but no locking nut for the caps, ever.
I just had a look at new Metzeler tubes on my shelf, no way was there a locknut or washer in the box. So if it is good enough for them so it is for me.
What purpose should the nut and washer on the inside of the rim have ? Only guess: You cannot pull out the valve by wildly turning the outer nut - but then that is only fixed fingertight at the knurled ring nut. And this is at best to fight centrifugal forces that would push the valve into the inner tube. The inner tube gets a load of 2 bar from air pressure so it will sit very snug at the rim inside. Maybe there is someone who could calculate how fast you´d have to go till the valve forces get higher than what the air inside the tube will stand and the outer nut has to take over.

Vic

 

[Peter Holmes]

You must have stockpiled the Made in Germany Metzeler inner tube a good few years ago, now all made in China, yes seriously, I imported a few boxes from the USA when I found them on the net thinking that I had found old stock, but sadly no, Made in China on the box, not cheap either! The German ones were the very best quality.

 

[greg brillus]

You can tell it's fare dunkum "Made in Germany" by the Messerschmitt part number................

 

[vibrac]

so my comments stand and I will continue do it as we used to do one nut outside and pray for proper rubber for our tubes

 

[Cyborg]

........

 

[oexing]

Hmm, when I think about the shape the inner nut forms to the rubber when it is inflated - I´d be worried about a likely cut by the washer´s edge then. I´d rather just keep the washer inside - that keeps things reasonably flush and flat - and would not add a nut inside the tire. That deformation of the tube by the high nut does not look right to me.

Vic