Conti GP 4000S 11 "Review"
- Thread starter Wold Ranger
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Nervous now!
Wold Ranger
Old School Grand Master
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Re:
I've been having a good look at the two offending tyres, I have hung in the workshop and it's just too much of a coincidence, both "blow" holes are identical in shape and in exactly the same place at the junction between the tread and the start of the side wall. The one that went last year was on a dry day, in warm summer conditions, Sundays' event was on a flat straight downhill section of good road.
The side wall of the tyres, immediately next to the tread is extremely thin, less than 0.5mm, yet it becomes much thicker, towards the bead, which looks like a design or manufacturing fault.
If you dig around on the net, there is just too much evidence to indicate, too many failures of a very similar nature.
The other factor not commented on, is the sizing, 4mm oversized! That's huge, you can only assume this is to improve ride quality, but in reality is just plain wrong, also if you buy a tube for 23/25mm tyres, it will be over stressed in a tyre that comes up to over 27mm.
Loads more comments on the SAME fault/issue here too:
http://www.roadbikereview.com/cat/wheel ... px#reviews
I've been having a good look at the two offending tyres, I have hung in the workshop and it's just too much of a coincidence, both "blow" holes are identical in shape and in exactly the same place at the junction between the tread and the start of the side wall. The one that went last year was on a dry day, in warm summer conditions, Sundays' event was on a flat straight downhill section of good road.
The side wall of the tyres, immediately next to the tread is extremely thin, less than 0.5mm, yet it becomes much thicker, towards the bead, which looks like a design or manufacturing fault.
If you dig around on the net, there is just too much evidence to indicate, too many failures of a very similar nature.
The other factor not commented on, is the sizing, 4mm oversized! That's huge, you can only assume this is to improve ride quality, but in reality is just plain wrong, also if you buy a tube for 23/25mm tyres, it will be over stressed in a tyre that comes up to over 27mm.
Loads more comments on the SAME fault/issue here too:
http://www.roadbikereview.com/cat/wheel ... px#reviews
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last year fitted some Gatorskin tubular 25mm , and punctured the front after 2 days . the rear lasted a bit longer but was a pita when i got a puncture .
I use Tufo now .
I use Tufo now .
Wold Ranger
Old School Grand Master
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Spoken to a couple of LBS staff locally to me in two separate shops and they both concurred the same story with Conti' road tyres, regular side wall failures on group rides.
The story is that the tread area is very hard wearing and puncture proof and also very stiff, but the side walls are very thin, to save weight and offer a nice ride. Where the two junction, the non flexible tread butting up to the thin flexible side wall, causes a stress point and the canvas splits and hey presto "bang".
I really wouldn't want to trust these, other than on the very flattest and smoothest of roads.
Spoken to a couple of LBS staff locally to me in two separate shops and they both concurred the same story with Conti' road tyres, regular side wall failures on group rides.
The story is that the tread area is very hard wearing and puncture proof and also very stiff, but the side walls are very thin, to save weight and offer a nice ride. Where the two junction, the non flexible tread butting up to the thin flexible side wall, causes a stress point and the canvas splits and hey presto "bang".
I really wouldn't want to trust these, other than on the very flattest and smoothest of roads.
Thousands of cyclists use GP4000s without a problem. If you go looking on the internet for complaints about just about any product imaginable you will find them. If we believed them all we'd never buy anything. I trust Continental to make a good tyre over the opinion of an lbs who may or may not stock Conti.
Incidentally GP4000s are not bought by people looking for puncture resistance and to be hard wearing as you state. I don't even think Conti market them for those qualities. They are palpably soft to the touch compared to most tyres. They are not a winter training tyre although last year a Cat 1 clubmate of mine used them for a rainy week in Flanders in march without the slightest problem.
I suggest your issue is more to do with inappropriate tyre choice for winter riding, insufficient inflation as 90 psi isn't enough unless you are very light indeed, or even possible damage caused while fitting rather than any inherent fault
Incidentally GP4000s are not bought by people looking for puncture resistance and to be hard wearing as you state. I don't even think Conti market them for those qualities. They are palpably soft to the touch compared to most tyres. They are not a winter training tyre although last year a Cat 1 clubmate of mine used them for a rainy week in Flanders in march without the slightest problem.
I suggest your issue is more to do with inappropriate tyre choice for winter riding, insufficient inflation as 90 psi isn't enough unless you are very light indeed, or even possible damage caused while fitting rather than any inherent fault
D
Deleted member 24574
Over the years I have had blowouts on a range of tyres; these are lightweight tyres and if you catch a flint o the edge of a pot hole they will tear and blow.
GP4000 is not a winter tyre. It is a lightweight.
It is all part of using lightweight tyres; the OP is scaremongering IMHO... an engineer who make s such bold statements with a sample if 1 ...
FWIW I use Gatorskins for winter; Veloflex Master/Corsa for summer and Vittoria EVO CX / Conti Supersonic for racing ...
I have seen virtually no variance in sidewall failure between any of these ... It is luck of what you ride over.
GP4000 is not a winter tyre. It is a lightweight.
It is all part of using lightweight tyres; the OP is scaremongering IMHO... an engineer who make s such bold statements with a sample if 1 ...
FWIW I use Gatorskins for winter; Veloflex Master/Corsa for summer and Vittoria EVO CX / Conti Supersonic for racing ...
I have seen virtually no variance in sidewall failure between any of these ... It is luck of what you ride over.
D
Deleted member 24574
Re: Re:
I assume you know the dimension specified is the profile and not the width.
Wold Ranger":2orpsqem said:
I assume you know the dimension specified is the profile and not the width.
