Run Flat tires

"Lee Lindquist" schreef in bericht
...

I'd like to set up a bike for commuting.

Is there such a thing as run flat tires for bicycles?

Alternatively, is there something I can fill the tires with
that will turn into foam, or something, and achieve the
same effect?

Thanks.

--
- Lee

Modern bike tyres hardly ever go flat, especcialy when maintained properly
and replaced at appropriate time.


--
Posted by news://news.nb.nu

On Mon, 13 Dec 2004 12:39:48 -0500, Lee Lindquist wrote:


I'd like to set up a bike for commuting.

Is there such a thing as run flat tires for bicycles?

Not exactly, "Airless" tires and tire conversions exist, but they are
widely disparaged as being too stiff, too heavy, often too expensive,
and usually too difficult to install.

Alternatively, is there something I can fill the tires with
that will turn into foam, or something, and achieve the
same effect?

Technically, yes, a bike tire could be foam-filled. The equipment to
do this is not found in the bike market, however; visit an industrial
lift truck[1] tire specialist to see if it's possible in your area.
bear in mind that you will end up riding tires that are literally
about as hard as rocks; if you run over a cigarette butt, you'll be
able to tell if it was plain or filtered. As an alternative, I would
point you in the direction of the recent (and numerous) discussions
here over the merits of Slime, thorn-resistant tubes, and tire liners.
Each of those offer some protection against flats, and even if used
together, all three at the same time would still not make the ride as
harsh as an airless or foam-filled tire.



[1] "Industrial lift truck" is the fancy, five-dollar mouthful of
words used for what most folks call "forklifts". You might find
either classification in your local Yellow Pages.



--
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On Mon, 13 Dec 2004 12:39:48 -0500, Lee Lindquist wrote:

Is there such a thing as run flat tires for bicycles?

Possibly separate topic - how do the automotive run-flats work?

"Erik Freitag" wrote: (clip) how do the automotive run-flats work?
^^^^^^^^^^^^^^
I believe they rely on sidewalls that are stiff enough to hold the weight of
the car without collapsing completely. This idea, applied here, would
result in a pretty heavy tire.

Years ago I recall a tire that had a double wall, with a vent between the
inner and outer chambers. If the tire started to deflate, this vent was
supposed to close, allowing the tire to hold air in the inner chamber. The
design did not survive the test of time.

On Mon, 13 Dec 2004 12:43:20 -0800, Erik Freitag
wrote:

On Mon, 13 Dec 2004 12:39:48 -0500, Lee Lindquist wrote:

Is there such a thing as run flat tires for bicycles?

Possibly separate topic - how do the automotive run-flats work?

There are two types that I can recall. One uses an ultra-low-profile
tire and wheel assembly with a high-rigidity sidewall which will
permit the tire to continue to function when deflated. The other
relies on an inner structure to support the tread at an intermediate
point of pseudo-inflation. Both have speed restrictions, IIRC.

http://www.tirerack.com/tires/tirete...at/runflat.jsp

Neither tech holds much promise for bike tires in applications where
weight and ride quality are important factors.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

Werehatrack wrote:
On Mon, 13 Dec 2004 12:43:20 -0800, Erik Freitag
wrote:


On Mon, 13 Dec 2004 12:39:48 -0500, Lee Lindquist wrote:


Is there such a thing as run flat tires for bicycles?

Possibly separate topic - how do the automotive run-flats work?


There are two types that I can recall. One uses an ultra-low-profile
tire and wheel assembly with a high-rigidity sidewall which will
permit the tire to continue to function when deflated. The other
relies on an inner structure to support the tread at an intermediate
point of pseudo-inflation. Both have speed restrictions, IIRC.

http://www.tirerack.com/tires/tirete...at/runflat.jsp

Neither tech holds much promise for bike tires in applications where
weight and ride quality are important factors.

I'd think the second approach would have some potential for
commuter bikes. I've ridden for up to 6 miles on a totally
flat bike tire and it didn't result in any damage to either
the tire or the rim (even the tube was patchable), but the
ride felt very unstable at any speed over about 12 mph.
Shouldn't take much of an inner hard foam support to improve
the stability enough to make for a reasonable ride at slightly
reduced speed. The main technical issue I see is to allow
for easy mounting and demounting of the tire.

I don't see there being a sufficient demand for such a design
in the US, but possibly for the European and Asian markets.

Lee Lindquist wrote:

I'd like to set up a bike for commuting.

Is there such a thing as run flat tires for bicycles?

Alternatively, is there something I can fill the tires with
that will turn into foam, or something, and achieve the
same effect?

See
http://cmms.cat.com/cmms/servlet/cat.dcs.cmms.servlet.ImageServlet?imageid=C040803& imageType=2
for non-pneumatic wheels.

--
Tom Sherman - Rock Island County Illinois
Tetrahedral carbon lattices are not forever.

"Lee Lindquist" wrote in message ...

I'd like to set up a bike for commuting.

Is there such a thing as run flat tires for bicycles?

Alternatively, is there something I can fill the tires with
that will turn into foam, or something, and achieve the
same effect?

Slime, or tire liners will both give some puncture protection. The slower/heavier,
yet more reliable tradeoff there works pretty well for a commute bike.

Neither is perfect, but both work pretty well.

Not exactly, "Airless" tires and tire conversions exist, but they are
widely disparaged as being too stiff, too heavy, often too expensive,
and usually too difficult to install.


Unfortunately this _is_ what a lot of people say but the truth is that
most people _only_ say it _because_ they have read it in news groups
like this. In truth, most people do not have first hand knowledge of
Airless tires.

I, however, do and have found them to be super. When I'm riding to
work in the dark, in the rain, I want to be 100% sure that I don't get
a flat.

The fact that they weigh more and have about 1% more rolling
resistance, is of absolutely no consequence to me. I just want to get
to where I'm going and arrive on time.
Lewis.

***************************

wrote:

The fact that they weigh more and have about 1% more rolling
resistance, is of absolutely no consequence to me.

You dropped off a couple of zeros above. Not that it's of any
consequence.
--
terry morse Palo Alto, CA http://bike.terrymorse.com/