Tubular rim glue ???

[Zog The Undenia]

[email protected] wrote:

> There is no market for them. That's the reason they have
> not been further developed and why so few are made.

It's admittedly a small market, but they're still strongly
recommended on the track (although not mandatory). As a
very occasional track rider who always has to use the loan
bikes, I've never actually looked to see what type they're
using. I spend long enough trying to find one with a
vaguely straight wheel.

 

[Tom Sherman]

Carl Fogel wrote:

> A Muzi <[email protected]> wrote in message
> news:<[email protected]>...
>
>>>A Muzi wrote:
>>>
>>>>...Just not here, a thousand miles from a mountain.
>>
>>Tom Sherman wrote:
>>
>>>I guess that the "Ocooch Mountains" do not really count
>>>as mountains. They do give flatland cyclists quite a
>>>workout, however.
>>
>>Very figurative. At least within a day's ride, you can't
>>melt tub glue on a hill by braking.
>>
>>(and haven't been to that mountain, either)
>
>
> Dear Andrew,
>
> I hadn't even heard of Wisconsin's answer to the Andes:
>
> www.trails.com/explore/Tcatalog_trail.asp?TrailID=BGM006-
> 038
>
> "Here's a tour to take on once you've gotten your
> climbing legs in shape. You'll have to tackle four steep,
> 400-foot cli..."
>
> I look forward to "Andrew Muzi's Tour of the Ocooch" page.
>
> Carl Fogel

Dear Carl,

I used to live in Richland Center and I have most likely
ridden the "four steep, 400-foot cli..." on the Peugeot P-8
[1] I purchased from Andrew Muzi back in the Dark Ages.
While 400-ft of elevation gain may not sound like much to a
Coloradan, it becomes quite challenging when the climb is
less than a mile long. I did not find the hills too bad at
the time, since I was 14 years old and had a body fat
percentage that many in the UCI peleton would have been
jealous of (sadly this is no longer the case).

[1] Regrettably destroyed by a stop sign running truck.

Tom Sherman - Quad Cities (Illinois Side)

 

[Carl Fogel]

"David L. Johnson" <[email protected]> wrote in message news:<[email protected]>...
> On Mon, 08 Mar 2004 12:38:56 -0800, Carl Fogel wrote:
>
> > So here's a truly ignorant question: compared to silk or
> > cotton, would Kevlar be better, worse, the same, or
> > impossible?
>
> Well, there are some synthetic-fiber tubulars available.
> The first ones were nylon, and had to be so small to begin
> with (since the thread stretched) that they were damn near
> impossible to put on. I have tried some modern ones, but
> I am not sure what the fibers were; probably a lot of
> polyester, but maybe some aramid (kevlar) as well. I would
> imagine kevlar would be pretty good, since it does not
> stretch and is very strong, but I don't know how it is
> used for tubular tires.

Dear David,

Good lord, I hadn't thought of nylon!

I always get muddled with Kevlar. I keep reading that Kevlar-
bead tires are stretchier, but that's compared to steel-wire
bead. So when you say that Kevlar doesn't stretch, are you
comparing it not to steel, but to cotton and silk?

Carl Fogel

 

[Jobst Brandt]

Carl Fogel writes:

> So here's a truly ignorant question: compared to silk or
> cotton, would Kevlar be better, worse, the same, or
> impossible?

No. Kevlar has high losses and does not adhere well to inter-
ply casing elastomers. This was first discovered with Kevlar
belts to prevent flats. If the belt is thick enough to do
much good, the tire performs like a slug. That is why Kevlar
belts don't do much good, they being made so thin to leave
some life in the tire.

Silk has far more strength than cotton because the filaments
are many times longer that the longest filament in a cotton
boll. Cotton relies partly on filament overlap and friction
to give its thread tensile strength. Silk can do that with
far fewer filaments because they are so long. Thin casings
that could hold high pressure were two important features of
silk tires, and of course the resulting weight. These tires
were truly paper thin.

Jobst Brandt [email protected]

 

[Jp]

"David L. Johnson" <[email protected]> wrote in message news:<[email protected]>...
> On Sat, 06 Mar 2004 09:23:55 -0800, JP wrote:
>
>
> >> No, that would not follow at all. The sharper edge of
> >> the clincher rim is real, and is the reason you need to
> >> be careful about inflation pressure with clinchers.
> >
> > In other words, you have to keep the tires pumped up to
> > a very high pressure to keep them seated so the tube
> > does not have a chance to come in contact with this
> > sharp edge.
>
> No, that is not how a snake bite works. A snake bite is
> when the tube is pinched between the two layers of the
> tire, one contacting the road, the other just past the
> bead. If the tire came unseated, the tube would pop with a
> rather loud report.

Maybe but I'm not entirely unconvinced that there could not
be a pinch between the bead and some spot in the interior of
the rim, as the bead is suddenly forced away from the hook
on the flange toward the base of the rim. I don't ride
clinchers so I have no personal experience about it, nor
have I read about how pinch flat are supposed to happen. You
are probably basing your knowledge on high speed photography
that someone has done to investigate the phenomenon.

Nevertheless, tubulars can be ridden at almost any pressure
without risk of pinch flats, unlike equivalent width
clinchers which have a pretty narrow inflation range.

JP

 

[Carl Fogel]

[email protected] wrote in message news:<[email protected]>...
> Carl Fogel writes:
>
> > So here's a truly ignorant question: compared to silk or
> > cotton, would Kevlar be better, worse, the same, or
> > impossible?
>
> No. Kevlar has high losses and does not adhere well to inter-
> ply casing elastomers. This was first discovered with
> Kevlar belts to prevent flats. If the belt is thick enough
> to do much good, the tire performs like a slug. That is
> why Kevlar belts don't do much good, they being made so
> thin to leave some life in the tire.
>
> Silk has far more strength than cotton because the
> filaments are many times longer that the longest filament
> in a cotton boll. Cotton relies partly on filament overlap
> and friction to give its thread tensile strength. Silk can
> do that with far fewer filaments because they are so long.
> Thin casings that could hold high pressure were two
> important features of silk tires, and of course the
> resulting weight. These tires were truly paper thin.
>
> Jobst Brandt [email protected]

Dear Jobst,

Another excellent explanation!

I take it that the strength of silk allows its paper-thin
construction, which in turn reduces rolling resistance--not
much left to deform.

Thanks,

Carl Fogel