Bizzare Tire Wear



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Tony

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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" <[email protected]> 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, [email protected] (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"------------------
__________306.350.357.38>>[email protected]__________
 
"The Lawyer" <[email protected]> wrote in message
news:[email protected]...
> >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"------------------
__________306.350.357.38>>[email protected]__________
 
In article <[email protected]>, [email protected] 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" <ns_dkerber@ns_ids.net> wrote in message
news:[email protected]...
> In article <[email protected]>, [email protected] 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
<ns_dkerber@ns_ids.net> wrote:

>In article <[email protected]>, [email protected] 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
 
On 16 Feb 2004 04:31:42 -0800, [email protected] (Tony) may have
said:

>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?

If you ride on the big rear cog or small front cog a lot, I'd look at the possibility of lateral
chain slap, possibly due to a stiff pivot on the rear der. This is just a guess, but that's where
I'd start. Also, look for a front der cable end that might be rubbing on the tire. beyond that,
you've got a real puzzler...and I wouldn't give better than one in 20 odds of my suggestions being
the cause.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.
 
Rick Onanian <[email protected]> wrote in message news:<[email protected]>...
> On 16 Feb 2004 04:31:42 -0800, [email protected] (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.

actually, one of my friend was riding his mountainbike always with highly _overinflated_ tires (like
6 bars instead of 4 as in its specs) when he was riding on paved roads. His tires started to produce
such lines on the sides (the pattern of the threads that form the base of rubber compound) after a
month or two. i believe underinflated tires would have other, more eye-catching symptoms like
excessive wear of the tread.

but the problem definitely has to do something with inflation.

one hint: if you're inflating your tires at gas stations, beware that usually gas station pressure
meters are not at all correct! the biggest difference I measured was 8 bar (shown at the gas
station) vs 5 bar measured with a trusty piece of equipment.

Frank www.plitkorn.com
 
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