Road Tire Liners ?

Magnusfarce said:

I've used a set of Tuffies in my old road bike tires for about ten years,
and have had virtually no problems with flats. I don't really mind the
added weight. I want to put some on the new road bike I'm getting and am
wondering what the current recommended versions are.

- Magnusfarce

Dear Magnus,

It isn't so much the added weight as the extra rolling
resistance that many people consider a drawback. Basically,
you're riding on an added layer of soggy plastic and
constantly deforming it. It doesn't spring back well, which
is why tires aren't made of plastic.

If the new bike and the old bike use roughly the same tires,
and you're happy with the old bike, you might try just
putting your old liners in the new bike's tires.

Tuffy strips are solid plastic and give better protection
against things like small thorns than woven Kevlar liners,
which are now sometimes incorporated in tires--pointy stuff
pierces anything woven.

If you're expecting lots of flats from glass or sharp rock
chips, you might look into a set of tires with built-in
Kevlar.

Here's a link to a number of comments from users:

http://www.roadbikereview.com/wheels/rim-strip/SBS%20MR.%20TUFFYS/PRD_97410_2507crx.aspx

(I note with civic pride a comment from a disgruntled
touring rider who purchased his liners in "Peublo, CO" to
stop thorns.)

And there's the obvious www.mrtuffy.com, but it seems to be
having internet hiccups.

If you like 'em, buy the suggested width. Their chief
competitor seems to be SpinSkins. If you keep the old bike,
you might try running one bike for a while without them to
see whether they're really needed after ten years. You might
be lucky enough to be riding now where flats are rare.

Good luck,

Carl Fogel

Magnusfarce said:

I've used a set of Tuffies in my old road bike tires for about ten years,
and have had virtually no problems with flats. I don't really mind the
added weight. I want to put some on the new road bike I'm getting and am
wondering what the current recommended versions are.

- Magnusfarce

why not just buy puncture resistant tires??? i've had awesome ZERO
puncture results this winter with kevlar belted hutchinsons whereas
others have punctured once or twice per rain ride.

Quoted message said:

It isn't so much the added weight as the extra rolling
resistance that many people consider a drawback.

True so far.

Quoted message said:

Basically,
you're riding on an added layer of soggy plastic and
constantly deforming it. It doesn't spring back well, which
is why tires aren't made of plastic.

I believe the second part is incorrect. Polyurethane (the plastic
Mr. Tuffy's are made of) can have very good rebound. It is true
that adding any material to a tire should increase hysteresis losses
but polyurethane is one of the better choices of materials.

Polyurethane pneumatic tires have been tried. The material has a lot
of very promisng properties but wet traction was the biggest problem.
Ever try to roller skate on wet roads?

Getting back to the subject at hand. I'd never put Mr. Tuffys on a
bicycle I use recreationally but I've used them on my commuter bike
and went years between flats. When I'm using my bike for
transportation avoiding flats is more important than rolling
resistance.

Bruce Jackson said:

Quoted message said:

It isn't so much the added weight as the extra rolling
resistance that many people consider a drawback.

True so far.

Quoted message said:

Basically,
you're riding on an added layer of soggy plastic and
constantly deforming it. It doesn't spring back well, which
is why tires aren't made of plastic.

I believe the second part is incorrect. Polyurethane (the plastic
Mr. Tuffy's are made of) can have very good rebound. It is true
that adding any material to a tire should increase hysteresis losses
but polyurethane is one of the better choices of materials.

Polyurethane pneumatic tires have been tried. The material has a lot
of very promisng properties but wet traction was the biggest problem.
Ever try to roller skate on wet roads?

Getting back to the subject at hand. I'd never put Mr. Tuffys on a
bicycle I use recreationally but I've used them on my commuter bike
and went years between flats. When I'm using my bike for
transportation avoiding flats is more important than rolling
resistance.

Dear Bruce,

D'oh! You may well be right.

I blathered without thinking of anything except rolled-up
Mr. Tuffy polyurethane liners, which are soggy. But that's
probably more the flexible, loosely-packed layers--a similar
long thin strip of tire rubber rolled-up would probably be
much soggier than a real tire.

Now I have to go and look around for rolling resistance of
polyurethane versus tire rubber.

Luckily, my main point survives even my material ignorance
in that any extra layer of material will increase rolling
resistance.

Carl Fogel

<[email hidden]> wrote: (clip) any extra layer of material will
increase rolling resistance.
^^^^^^^^^^^^^^
I'm not sure that is true, either. Try to visualize the effect of a metal
hoop between the tube and tire. That might actually DECREASE the amount
that the tread squirms. That's probably why steel-belted radial auto tires
produce better gas mileage. I realize that this is becoming an academic
argument, but then, you seem to be an academic kind of guy.

Leo Lichtman said:

<[email hidden]> wrote: (clip) any extra layer of material will
increase rolling resistance.
^^^^^^^^^^^^^^
I'm not sure that is true, either. Try to visualize the effect of a metal
hoop between the tube and tire. That might actually DECREASE the amount
that the tread squirms. That's probably why steel-belted radial auto tires
produce better gas mileage. I realize that this is becoming an academic
argument, but then, you seem to be an academic kind of guy.

Dear Leo,

Hmmm . . . I'm intrigued, but how would an interior metal
tire liner reduce the hysteresis of the rubber?

It would just press against the inside of the tire, like the
inner tube pressing against it.

You could be right, but I have a vague notion that it's the
radial (versus cross) ply design that accounts for less
rolling resistance in car tires.

Luckily, we have a number of posters who know lots about
such things, so they may explain whether it's the steel in
the belts or the radial construction.

As for the academic nature of the topic, those are usually
the most interesting ones. As a practical matter, almost
anything with two wheels and pedals works surprisingly well.

Carl Fogel

<[email hidden]> wrote: Hmmm . . . I'm intrigued, but how would an
interior metal tire liner reduce the hysteresis of the rubber?
^^^^^^^^^^^^^^^
In a conventional setup, with no liner, the tread deflects until the
pressure x area is sufficient to support the load. Introducing a stiffener
between the tube and tire would spread the tire load onto a larger area of
the tube, resulting is less deflection. Less deflection--less hysteresis
loss. I see it as being equivalent to raising the tire pressure.

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Quoted message said:

On Thu, 14 Apr 2005 23:30:12 -0700, "Magnusfarce"
<[email hidden]> wrote:

And there's the obvious www.mrtuffy.com, but it seems to be
having internet hiccups.

Yeah the site seems to be having some sort of a break down. Do they make
them for older sized tires? i.e. 26x1&3/8?
Ken

Quoted message said:

But I suspect that top speed rolling down a hill will vary
from run to run depending more on the breeze than a tire
liner.

I test this over weeks of time and just notice the top speeds I can get
coasting down this hill. it's about as accurate as I can get in life.
I started testing tires for speed. this is on my bent. I went from a 85psi
1.5" rear tire to a specialized armadillo 1.5" at 100 psi and gained 2mph. the
front I went from a lower psi to 100 psi and gained another 1.5mph. but going
to a skinnier front wheel made no difference and going from the 1.5" to a 1"
120psi tire made no difference either for some weird reason.

--
Knight-Toolworks & Custom Planes
Custom made wooden planes at reasonable prices
See http://www.knight-toolworks.com For prices and ordering instructions.

Ken said:

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

On Thu, 14 Apr 2005 23:30:12 -0700, "Magnusfarce"
<[email hidden]> wrote:

And there's the obvious www.mrtuffy.com, but it seems to be
having internet hiccups.

Yeah the site seems to be having some sort of a break down. Do they make
them for older sized tires? i.e. 26x1&3/8?
Ken

Dear Ken,

Yes, the site still won't work for me.

And yes, Mr. Tuffy strips are available for 26 x 1&3/8:

http://www.bikepartsusa.com/product_info.phtml?p=01-82905

Here's a convenient table from the same site, giving the
sizes and color coding:

http://www.bikepartsusa.com/view.phtml?f_b=Mr+Tuffy

Carl Fogel

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Quoted message said:

Ken said:

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

On Thu, 14 Apr 2005 23:30:12 -0700, "Magnusfarce"
<[email hidden]> wrote:

And there's the obvious www.mrtuffy.com, but it seems to be
having internet hiccups.

Yeah the site seems to be having some sort of a break down. Do they make
them for older sized tires? i.e. 26x1&3/8?
Ken

Dear Ken,

Yes, the site still won't work for me.

And yes, Mr. Tuffy strips are available for 26 x 1&3/8:

http://www.bikepartsusa.com/product_info.phtml?p=01-82905

Here's a convenient table from the same site, giving the
sizes and color coding:

http://www.bikepartsusa.com/view.phtml?f_b=Mr+Tuffy

Carl Fogel

And if they are as good as some have claimed they would be worth the $10.00
plus shipping.
Ken

<[email hidden]> wrote: (clip)Physics suggests that in isolation it
should have improved things by reducing wind drag, but the chances of
isolating that small a single improvement from the simultaneous effects of
wind, temperature, barometric pressure, and so forth are small.(clip)
^^^^^^^^^^^^
Leo: This plays into the physics of testing for the effects of tire liners
by measuring very high downhill speed. Wind drag force goes up
approximately as the square of the speed, so at maximum downhill speed,
nothing else really matters. Rolling resistance is probably fairly constant
(I think), so it becomes insignificant compared to wind drag. Therefore, if
you are doing coasting tests to judge rolling resistance changes, I suggest
going to the other end of the scale. Find a gradient that produces a speed
of only a few MPH, and do the tests there. Wind drag will by relatively
small. Variations in rolling resistance should show up better in your top
speed.
^^^^^^^^^^^^^^^
Carl🙁clip)I often see such odd results when I'm expecting improvements (and
vice-versa). (clip)
^^^^^^^^^^^^^^
Leo: The reason for double-blind tests.

Quoted message said:

The good news is that your frustrating "for some weird
reason" results are a sign of good faith--it would be
suspicious if our crude real-life tests unfailingly showed
such tiny improvements. I sympathize, since I often see such
odd results when I'm expecting improvements (and
vice-versa). Nevertheless, it's fun to keep testing such
things in hopes of understanding them better.

lots of good info. this is more fun then anything else. I was surprised with the
first 2mph increase with only a PSI and different brand of tire. so silly me to
expect it going to smaller tired and higher pressure (G)
yes the temp and everything sure makes a difference. the only thing I have
going for me is that I won't have a tail wind. headwind sometimes but never a
tailwind.

--
Knight-Toolworks & Custom Planes
Custom made wooden planes at reasonable prices
See http://www.knight-toolworks.com For prices and ordering instructions.

Quoted message said:

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Quoted message said:

On Thu, 14 Apr 2005 23:30:12 -0700, "Magnusfarce"
<[email hidden]> wrote:
And there's the obvious www.mrtuffy.com, but it seems to be
having internet hiccups.

Ken said:

Yeah the site seems to be having some sort of a break down. Do they make
them for older sized tires? i.e. 26x1&3/8?

Rimliners are sold by width . Either overlap or cut for
various diameters

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971