Bizzare Tire Wear

Hello, have a question that is puzzling me and I hope someone can
help.

I have a 99 Specialized StumpJumper Comp. I commute to work in
Michigan, about 2.75 miles each way. It is cold out but the sidewalks
are usually clear, maybe ride a little ice and packed snow at
intersections.

My question is my rear tires are getting these weird diagonal lines on
the sidewalls where the tire just seems to be thinning out. This
first happened on a Hutchinson Alligator. I only noticed it when a
few of these wearing out bands got so bad that the tube was actually
bulging out. So, I switched it out for a Specialized Dirt Master comp
which is on a different rim. Now I am noticing the same wear pattern
on this second tire.

It is multiple diagonal lines that run almost the entire sidewall.
They are spaced less than an inch apart and it just looks like it is
wearing out. I thought at first it must be rubbing but I can't see
anywhere that the tire doesn't clear the frame and the brake pads
aren't far enough out to cause it. It is not abrasion from rocks or
whatever because I am riding only on the sidewalks and roads, and only
very occasionaly these aren't cleared of snow. Is it the cold?
Haven't had any problems with the front tire though, still has the
Hutchinson on it and no problems.

Any Ideas?

Thanks,
Tony

"Tony" wrote in message
Hello, have a question that is puzzling me and I hope someone can
help.
............ rear tires are getting these weird diagonal lines on
the sidewalls where the tire just seems to be thinning out. ....

Any Ideas?

Thanks,
Tony

I have had this happen also. It comes from not keeping enough pressure in
your tire. When you go over small bumps or road obstacles watch your rear
tire where it meets the road. The tire folds in on itself creating a pattern
of diagonal lines across the sidewall of your tire. Do you get multiple
pinch flats? Try pumping tires up to spec (use a gage) before every ride. I
keep my rear tire at ~45psi, Maybe it's a little overkill but, I weigh 83Kg
never get pinch flats and my rims stay true.

On 16 Feb 2004 04:31:42 -0800, (Tony) wrote:
It is multiple diagonal lines that run almost the entire sidewall.
They are spaced less than an inch apart and it just looks like it is
wearing out. I thought at first it must be rubbing but I can't see
anywhere that the tire doesn't clear the frame and the brake pads
aren't far enough out to cause it. It is not abrasion from rocks or
whatever because I am riding only on the sidewalks and roads, and only
very occasionaly these aren't cleared of snow. Is it the cold?
Haven't had any problems with the front tire though, still has the
Hutchinson on it and no problems.

Any Ideas?

Are you keeping it inflated well, near or at it's maximum rated
pressure? Do you weigh a lot?

Sounds like what would happen to a terribly underinflated tire if
you rode on it for too long and were lucky enough not to have to
replace the tube daily.

Maybe terribly beat up bearings would allow the wheel to rub the
frame when weight is on it, but not when you spin it by hand. Try
looking down while you ride.
--
Rick Onanian

Try looking down while you ride.

Do NOT do that. It is a basic mistake. In traffic it can get you
killed.

Instead try running the bicycle by hand, preferably on a stand, or if
you don't have that option lift it by the seat tube and work the cranks.

If you can't see the problem your brakes are probably out, this is
most likely brake pad maladjustment, remember that the brake pads
have an entry geometry with respect to the rim.

--

_______________________ALL AMIGA IN MY MIND_______________________
------------------"Buddy Holly, the Texas Elvis"------------------
in.edu__________

"The Lawyer" wrote in message
...
Try looking down while you ride.

Do NOT do that. It is a basic mistake. In traffic it can get you
killed.

I would hope that no one would look down at their rear wheel while crossing
rush hour traffic. I do believe there are times when you can look at your
back wheel though.

I would hope that no one would look down at their rear wheel while
crossing rush hour traffic. I do believe there are times when you
can look at your back wheel though.

Fair enough. Let me tell you a story, though.

Oh my God, not really.

I was riding along on Pennsylvania Avenue and I was riding quick
on my Peugeot, not skipping any beats and this was about five years
ago. A gaggle of bicycle cops were figuring out how to ride in the
midst of this, they were staring at their feet.

They were not aware.

I have found it true that if you (not you personally) stare at your
feet when riding you are not in the moment or "heads up".

If that is a problem for you I suggest Effective Cycling.

Or a brain transplant.


--

_______________________ALL AMIGA IN MY MIND_______________________
------------------"Buddy Holly, the Texas Elvis"------------------
in.edu__________

In article , says...
Try looking down while you ride.

Do NOT do that. It is a basic mistake. In traffic it can get you
killed.

Talk about paranoid! If you can't hold a decent line for a few seconds
while looking down at your tires, you shouldn't be on the road at all.
Just pick a time where there's no imminent traffic danger.


Instead try running the bicycle by hand, preferably on a stand, or if
you don't have that option lift it by the seat tube and work the cranks.

Without weight on it, you might not see anything.

....

--
Dave Kerber
Fight spam: remove the ns_ from the return address before replying!

REAL programmers write self-modifying code.

"David Kerber" wrote in message
...
In article , says...
Try looking down while you ride.

Do NOT do that. It is a basic mistake. In traffic it can get you
killed.

Talk about paranoid! If you can't hold a decent line for a few seconds
while looking down at your tires, you shouldn't be on the road at all.
Just pick a time where there's no imminent traffic danger.


Thank you

On Mon, 16 Feb 2004 19:11:17 -0500, David Kerber
wrote:

In article , says...
Try looking down while you ride.

Do NOT do that. It is a basic mistake. In traffic it can get you
killed.

Talk about paranoid! If you can't hold a decent line for a few seconds
while looking down at your tires, you shouldn't be on the road at all.
Just pick a time where there's no imminent traffic danger.

....like a weekend empty parking lot.

Eric operates in DC, #2 traffic city in North America, at least at
peak hours. He's right to be paranoid--it keeps him alive.

his "don't look down" advice is sound. Hell, it helped me learn to
clip into my pedals those many moons ago.

-Luigi
www.livejournal.com/users/ouij
photos, rants, raves



Instead try running the bicycle by hand, preferably on a stand, or if
you don't have that option lift it by the seat tube and work the cranks.

Without weight on it, you might not see anything.

...

Tony wrote:

Hello, have a question that is puzzling me and I hope someone can
help.

I have a 99 Specialized StumpJumper Comp. I commute to work in
Michigan, about 2.75 miles each way. It is cold out but the sidewalks
are usually clear, maybe ride a little ice and packed snow at
intersections.

My question is my rear tires are getting these weird diagonal lines on
the sidewalls where the tire just seems to be thinning out. This
first happened on a Hutchinson Alligator. I only noticed it when a
few of these wearing out bands got so bad that the tube was actually
bulging out. So, I switched it out for a Specialized Dirt Master comp
which is on a different rim. Now I am noticing the same wear pattern
on this second tire.

It is multiple diagonal lines that run almost the entire sidewall.
They are spaced less than an inch apart and it just looks like it is
wearing out. I thought at first it must be rubbing but I can't see
anywhere that the tire doesn't clear the frame and the brake pads
aren't far enough out to cause it. It is not abrasion from rocks or
whatever because I am riding only on the sidewalks and roads, and only
very occasionaly these aren't cleared of snow. Is it the cold?
Haven't had any problems with the front tire though, still has the
Hutchinson on it and no problems.

That is a fairly common failure mode for a modern nylon
casing bias tire. With use, notably with wide tires at low
pressures, the fabric simply comes apart. Notice how your
tire bulges out at the bottom? A wide tire without enough
pressure does that to a much greater degree. Casing flex,
taken to an extreme, pulls the layers of nylon thread from
each other and more quickly when the latex has dried and
flaked from the sidewalls.

As always, replace when the casing first gets lumpy, that
is, before the fabric actually rends. And you'll get much
better cornering and control with higher (normal, as written
on the sidewall) pressures anyway, on any hard surface such
as a street.

It's true that you get a wider footprint in loose material,
sometimes to very good effect in snow or wet mud, but we'd
consider that a temporary condition for most bikes.


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