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Re: tubeless

Posted: Fri Sep 02, 2011 7:33 am
by Ken in Oklahoma
vanzen@rockerboxer.com wrote: Jeopardy time: Why were mini compressors invented ?
That's easy! To compress Minis.

("Tell him what he won!")



Ken

Re: tubeless

Posted: Fri Sep 02, 2011 7:38 am
by Ken in Oklahoma
Major Softie wrote:I think his real point was that your engine be in proper tune so that it will idle on one cylinder.
Jean is a lady Major. :|



Ken

Re: tubeless

Posted: Fri Sep 02, 2011 8:53 am
by Roy Gavin
The tubeless cross spokes on my R100GS lost air suddenly a couple of times for no apparent reason, so I fitted modern extra heavy duty thick tubes. That brought the number of flats I have had in half a million miles to four---------.

I had heard the old wife's tale about tubes making tires run hotter so I kept a good check on the temp to see what actually happened

They ran cooler, I presume because the thick tubes conducted more heat from the tread round to the rim - air is a very poor conductor.

Re: tubeless

Posted: Fri Sep 02, 2011 11:31 am
by Deleted User 62
ME 109 wrote:
vanzen@rockerboxer.com wrote:
Jeopardy time: Why were mini compressors invented ?
Fish tanks and trials bikes?
Mini fridge?

Re: tubeless

Posted: Fri Sep 02, 2011 1:30 pm
by Major Softie
Ken in Oklahoma wrote:
Major Softie wrote:I think his real point was that your engine be in proper tune so that it will idle on one cylinder.
Jean is a lady Major. :|

Ken
Oops. And, I knew that too. :oops:

Re: tubeless

Posted: Fri Sep 02, 2011 2:09 pm
by DanielMc
vanzen@rockerboxer.com wrote:
Jeopardy time: Why were mini compressors invented ?
My very first airhead, a 77 R100/7 had (Fournier?) air suspension units with a neat little 12v compressor plumbed in. It lived under the seat and vibrated when in use. I never noticed especially but my passenger did...

Re: tubeless

Posted: Fri Sep 02, 2011 5:52 pm
by Jean
MS, you read that right. I have a good imagination, but "running down the road" on one cylinder while using the other to inflate a low tire stretches it.
Even a right-angle valve stem won't make THAT easy to do.
"lay the wire on the cylinder." (?) Maybe. My NGK caps have the contacts rather far up in the caps so I'd use a spare plug or bit of bolt to make SURE it's got a path to ground.

a sure path to ground

Posted: Sat Sep 03, 2011 12:53 am
by vanzen
Riding a flat-twin airhead with only one operating cylinder
is entirely feasible and, on occasion, may be the only recourse to continue down the road.
And actually, the idle will want to be re-adjusted to accommodate these most unusual circumstances ...

... but in the event of a flat, please use the pump
and when the tire is aired-up –
disconnect it and put it back under the seat or wherever.
Do not leave the engine-air pump connected,
reconnect the damn spark-plug, eh ?
... and then head on down the road.

imagination will be the key to creative thinking,
and essential to problem solving.
"Stretching it" will not be a bad thing ...
speaking to the imagination – but not the engine-air pump hose.

Re: tubeless

Posted: Sat Sep 03, 2011 1:19 am
by Major Softie
Roy Gavin wrote: I had heard the old wife's tale about tubes making tires run hotter so I kept a good check on the temp to see what actually happened

They ran cooler, I presume because the thick tubes conducted more heat from the tread round to the rim - air is a very poor conductor.
That "old wife's tale" is what the DOT, tire manufacturers, physicists, and engineers tell us. I'm not saying that you did not witness what you witnessed, nor can I explain it. I'm just saying you have a very funny definition of an "old wife's tale."

My WAG on your GS experience is that, if your measurements were actually accurate comparisons of identical riding situations, the higher heat generation warning with a tube relates to high speed operation that is unrelated to your use of your bike.

Re: tubeless

Posted: Sat Sep 03, 2011 9:08 am
by Roy Gavin
The tubeless tire in question had the notation on the side - "On tube type rims use a tube."
There was no mention of reduced speed rating.

Given that providing the speed rating on a tire is a mandatory requirement if fitting the tube reduced the speed rating then it would be mandatory to provide both ratings , but I have never seen a tire marked that way..

My recollection is that the the no tube ,err,theory originated when radial tires were introduced - the theory was that the flexible side walls would rub against the tube and heat the tube.

Over the years the story seems to have migrated to all tires, but I have never seen anything authoritative to back it up, and as I said, actual experimentation proves it doesn't happen, at least not with extra heavy thick tubes, and it would appear not with the tires that Metzler test and sell.