GP400s sides splitting

instinct

Hi all,

Recently my GP4000s tyres are starting split on the sidewalls. There is about 1700k on them and I always keep them at 120 PSI as recommend.

Perhaps I'm running too much pressure ? I am surprised how badly they are wearing as I was expecting a bit more mileage.

But I like them so much I want another set. They roll really well and grip is great (in the dry) but I am reluctant to purchase another set as they are not the cheapest.

Is there anything else worth considering that is a bit more hard wearing ?

Riding is mostly 25k commutes with the odd spin over typical NCD road surfaces.

Thomasofmel

I recently bought GP4000 tyres from Chain reaction after reading all the positive feedback on them - as above, I had pressures of 120 PSI on both tyres. After few hundred km the sides split on the front tyre. I was extremely disappointed - went to the local bike shop, who already knew that continental tyres have weak sides and were a bad purchase. Replaced both tyres with Panasonic Panaracer ones - great profile and a good tyre.

thebionicdude

Interesting. The same happened to me about five times. I bought them all at once, so I just thought maybe it was a dodgy batch. I was considering sending them back to Conti as the wear marks clearly show they weren't worn at all. I haven't gotten around to it yet though, they are just hanging up out of mind in the garage. Like you I really like the tyre, so I really don't want to switch if I don't have to. I never had problems before last year and like you I was running higher pressure then too.

120psi is not the recommended pressure, 110 is. 120psi is max acceptable pressure. I tend to roll around Leinster on 100psi on the front and 105psi on the rear to remove the road-chatter. I'd have a bit more for racing if it's on main roads and if I'm in France, well then I'll go 120.

It will be interesting to learn if others have had similar problems since it's a popular tyre.

8kvscdpglqnyr4

I've been riding GP4000s for a number of years now and have not had that problem. I've heard a couple of friends mention it but it's never happened to me.
They're on all my wheel sets: I ride + race more than 1,000km per month on them.

robertxxx

Lads is it not the brake pads that are causing this?

Check the to see if there is an edge on the top of the brake pad which rides over the rim when pulling the brake, it happened to me and it has caused a split on the side wall, but I caught it in time before it got worse.

07Lapierre

GP4000 S are fitted to my 3 bikes....they are excellent.

Pablo Rubio

used to love the GP4000 S but had a good few side wall failures so stopped using them myself.

ABEasy

robertxxx wrote: »

Lads is it not the brake pads that are causing this?

Check the to see if there is an edge on the top of the brake pad which rides over the rim when pulling the brake, it happened to me and it has caused a split on the side wall, but I caught it in time before it got worse.

Exactly what happened to my tyre, lesson learnt keep an eye on brakes now when cleaning chain, etc.

thebionicdude

robertxxx wrote: »

Lads is it not the brake pads that are causing this?

I don't think so. That would just score a line around the circumference of the sidewall, no? This is just a split that leads to a small hole and a bulging tube. No obvious reason for it but obviously tyres take an awful pounding thereby exposing any flaws.

I'll buy again. As other posters, say, they are great and I have had lots of them without any problems before a spate from tyres all bought at once. Hence the suspicion of a temporary glitch in the manufacturing process but it is interesting to learn how other people are getting on with them.

Thanks!

route66

thebionicdude wrote: »

I don't think so. That would just score a line around the circumference of the sidewall, no? This is just a split that leads to a small hole and a bulging tube. No obvious reason for it but obviously tyres take an awful pounding thereby exposing any flaws.

I'll buy again. As other posters, say, they are great and I have had lots of them without any problems before a spate from tyres all bought at once. Hence the suspicion of a temporary glitch in the manufacturing process but it is interesting to learn how other people are getting on with them.

Thanks!

It's this lady's fault:

Dermot Illogical

Thomasofmel wrote: »

Replaced both tyres with Panasonic Panaracer ones - great profile and a good tyre.

I had a couple of sets of panaracer closer and found them weak enough. They puncture and tear with ease. I wouldn't trust them for anything other than pootling around to the shops.

instinct

robertxxx wrote: »

Lads is it not the brake pads that are causing this?

Check the to see if there is an edge on the top of the brake pad which rides over the rim when pulling the brake, it happened to me and it has caused a split on the side wall, but I caught it in time before it got worse.

Thanks for all the replys. I did read about misaligned brakes on the net and have checked mine and quite sure its not the problem. But there is very little clearance in there so who knows what goes on under load. Need to take a closer look.

Reduced PSI to 100 for the time being. Bike actually felt a bit smoother this morning which was nice

doozerie

I've not seen such problems with my GP400S's or those on my wife's bikes. I have one set on a bike for 3 years, but relatively low mileage over that period, another set on a "winter" bike with reasonable mileage for the last year or so. My wife has quite a bit of mileage clocked up on the ones on her road bike over the last few months too, and she has the 25mm version on her commuter (but only for a couple of months now). I imagine that tyre pressure does play a part, both my wife and I use 100psi on the back and about 90 to 95psi on the front.

Before the Continentals I used Michelin Krylion Carbons on one bike and when I bought them I found a lot of online discussion about quality issues with them (the Krylions). The suggestion at the time was that Michelin had moved production outside of France and that what had been a consistently reliable tyre before that suddenly became very unreliable. If I remember rightly the sidewalls were the main problem area. Whether the speculation about the cause was accurate or not the problem seemed to be reported a lot for a year or more, and then faded away so it seemed like the problem had been resolved. I have a vague memory of Michelin making a statement to the effect that they'd made a change in their manufacturing process to deal with the issue, and certainly I had no problems at all with my Krylions which I bought after this had blown over. This might have no relevance to the issue people are experiencing with their Continentals but it might make the possibility of essentially a bad batch seem more plausible.