did low pressures kill my conti tires

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Geoff
Posts: 5395
Joined: Sat Dec 13, 2003 2:25 am
Location: Canada

by Geoff

60 is not low enough to cause that problem for large-volume tires. I routinely ride tires that low when there is ice and snow down. I would expect that your issue is an installation problem.

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avispa
Posts: 262
Joined: Tue Mar 11, 2008 2:36 am

by avispa

I was on Conti 4 season and 4000S for a while and had this issue with threads peeling off the side walls or near the beads...

I’m now trying Pirelli PZero 4s and for a month have been very happy.... any of you have an opinion on these tires?

By the way, is there a tire post/topic here at WW?

Svetty
Posts: 539
Joined: Thu Mar 26, 2009 11:06 pm
Location: Yorkshire - God's Own Country

by Svetty

When I used to ride GP4000s the reason I had to retire the tyres was usually when they started shedding threads from the bead area.
I now use Veloflex or Vittoria clinchers and have no further problems with this issue......

JoO
Posts: 439
Joined: Thu May 04, 2017 7:30 am

by JoO

I switched to vittoria corsa G 25 mm on 21 C rims on the nice bike.
Tire gets 28 m wide but not as tall as the GP 4000.
It is about the maximum height my canyon can take.
Very happy with the way it rides compared to the conti's.

Still running 60 PSI.

The next bike will have to take 28 mm vittoria's.

L3X
Posts: 348
Joined: Wed Feb 25, 2009 8:39 pm

by L3X

In my experience it's very possible for a small wobble to appear because of low pressures. I've had various sidewall tears in both road and MTB tires and I do run pretty low pressures usually. I'm guessing before the sidewall actually tears there will be damage done that creates the small wobble described.

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mpulsiv
Posts: 1384
Joined: Mon Mar 24, 2014 9:17 pm

by mpulsiv

Here you go https://youtu.be/fOwhbUd6lvM. Is this what some of you experienced?
~1000 miles on both tires (28mm GP4000s) both were inflated to 60 psi from day one. This tire has so much volume (e.g. ~30.5mm wide and 29mm tall) in contrast to competition. It defeats the purpose of running it higher than 60 psi. Might as well go back to 25mm, if you are going to run at higher than 60 psi.

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JoO
Posts: 439
Joined: Thu May 04, 2017 7:30 am

by JoO

The wobble in the video is exactly what I have.

I am aware of the TOUR test (i have a subscription)
Although I now am more critical towards their testing criteria:
-the rolling resistance test does not correspond with real world riding (see Silca and Compass blog)
-the rating of stifness (higher being always better) does seam meaningless (see Compass blog and cycling tips podcast with Jan Heine and James Huang)
-chain lube test did not correspond with friction facts test
...

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mpulsiv
Posts: 1384
Joined: Mon Mar 24, 2014 9:17 pm

by mpulsiv

JoO wrote:
Thu Aug 16, 2018 10:55 am
The wobble in the video is exactly what I have.

I am aware of the TOUR test (i have a subscription)
Although I now am more critical towards their testing criteria:
-the rolling resistance test does not correspond with real world riding (see Silca and Compass blog)
-the rating of stifness (higher being always better) does seam meaningless (see Compass blog and cycling tips podcast with Jan Heine and James Huang)
-chain lube test did not correspond with friction facts test
...
What do you think the root cause of the wobble? I’m going to reach out to Continental and demand warranty replacement before I recycle it.
I’m not concerned about rolling resistance because this is not my race tire. The sole purpose of it is to run at lower pressure.
Racing is a three-dimensional high-speed chess game, involving hundreds of pieces on the board.

:arrow: CBA = Chronic Bike Addiction
:arrow: OCD = Obsessive Cycling Disorder

JoO
Posts: 439
Joined: Thu May 04, 2017 7:30 am

by JoO

mpulsiv wrote:
Thu Aug 16, 2018 4:26 pm
JoO wrote:
Thu Aug 16, 2018 10:55 am
The wobble in the video is exactly what I have.

I am aware of the TOUR test (i have a subscription)
Although I now am more critical towards their testing criteria:
-the rolling resistance test does not correspond with real world riding (see Silca and Compass blog)
-the rating of stifness (higher being always better) does seam meaningless (see Compass blog and cycling tips podcast with Jan Heine and James Huang)
-chain lube test did not correspond with friction facts test
...
What do you think the root cause of the wobble? I’m going to reach out to Continental and demand warranty replacement before I recycle it.
I’m not concerned about rolling resistance because this is not my race tire. The sole purpose of it is to run at lower pressure.
cause = failed sidewalls
reason for that? =>not suitable for very low pressures?

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mpulsiv
Posts: 1384
Joined: Mon Mar 24, 2014 9:17 pm

by mpulsiv

Quite dissapointed that sidewall went kaput at 60 psi. It would be acceptable at 40 psi with 100 kg rider but we are talking about only 60 psi with 71 kg rider with such a short life span.

If you don't agree with Tour test methodology, take a look at results from DT Swiss. 28mm tire is a better choice but running 28mm tire at 6 bar (87 psi) is absolutely crazy! Tire manufacturers need to realize that majority of cyclists are not American football players, we don't weight 100 kg :roll:

Image
Racing is a three-dimensional high-speed chess game, involving hundreds of pieces on the board.

:arrow: CBA = Chronic Bike Addiction
:arrow: OCD = Obsessive Cycling Disorder

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