Do I need a new tire?

David Crist said:

My front tire has developed a series of cracks where the side wall
starts to round over to the running surface. Should I replace this
tire? What causes this? Overinflation? Underinflation? I've got
less than 1000 miles on this tire. Is there a rule of thumb related
to mileage and tire replacement?

Yes, but ho many years parked in daylight does this tire have. If the
rubber is cracked, get new tires and ride them until they wear through
to the cords, but ride them. That shouldn't take years.

Quoted message said:

I hate changing flats. Is a Kevlar tire the way to go?

It doesn't matter what kind of casings they have if you age them
forever. They all rot in time. It's the rubber that dies.

Jobst Brandt

David Crist <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

My front tire has developed a series of cracks where the side wall
starts to round over to the running surface. Should I replace this
tire? What causes this? Overinflation? Underinflation? I've got
less than 1000 miles on this tire. Is there a rule of thumb related
to mileage and tire replacement?

How many months has the tire been on your bike? If more than 1 year, it
could be dry rot.

David Crist said:

Quoted message said:

My front tire has developed a series of cracks where the side wall
starts to round over to the running surface. Should I replace this
tire? What causes this? Overinflation? Underinflation?

More likely underinflation, leading to excessive flex of the sidewalls.

Quoted message said:

Quoted message said:

I've got
less than 1000 miles on this tire. Is there a rule of thumb related
to mileage and tire replacement?

Cracks in the rubber are harmless. The rubber is not a structural part
of the tire.

See: http://sheldonbrown.com/tires

An anonymous poster said:

How many months has the tire been on your bike? If more than 1 year, it
could be dry rot.

Nope. Tires are not subject to dry rot. They are not made of wood.

Sheldon "Old Myths Die Hard" Brown
Newtonville, Massachusetts
+---------------------------------------------------------+
| It is good to learn from your mistakes; |
| It is better to learn from the mistakes of others. |
+---------------------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

Ozone will kill a tire very fast.

Ken

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

Quoted message said:

My front tire has developed a series of cracks where the side wall
starts to round over to the running surface. Should I replace this
tire? What causes this? Overinflation? Underinflation? I've got
less than 1000 miles on this tire. Is there a rule of thumb related
to mileage and tire replacement?

I hate changing flats. Is a Kevlar tire the way to go?

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

Quoted message said:

My front tire has developed a series of cracks where the side wall
starts to round over to the running surface. Should I replace this
tire?

Pump it up to maybe 20% over rated maximum, if no bulges develop in an hour, the
tire's still ok to use, but deflate to rated maximum before riding.

Quoted message said:

What causes this? Overinflation? Underinflation?

Riding on an underinflated tire will cause cracks.

Quoted message said:

I hate changing flats. Is a Kevlar tire the way to go?

I found them very vulnerable to thorns 20 years ago. A teflon innertube liner
goes far to eliminate flats, and they're so much fun to mount. Be more careful,
because with the liner in place, there's about three times the likelihood of the
innertube getting out between the tire and the rim. Inflate to 40 psi,
completely deflate, massage the tire-tube-liner-rim assembly, and reinflate to
half, three quarters, and full pressure, letting the assembly sit for a half
hour between increases, and inspect carefully and frequently for that bulge near
the rim. Let the whole thing set overnight before riding on it. This seems to
eliminate the noisy blowouts caused by the tube popping out between the tire and
the rim for me.