Anyone experienced Conti 25mm GP4000s II tire wall failure?
prhymeate
Posts: 795
I had the original ones, no problems. A month ago my II's split and I had a puncture...well, 3 punctures over the distance of about 500 metres because I couldn't figure out what was causing them. I replaced the tyre with a new one and then today the same thing happened. Small slit in the tire wall about 1cm long and an inner tube that has two small holes at the same spot.
Have I just had bad luck, am I doing something wrong, or is this a known problem?
I only have about 7/800 miles on the new tyres. For what it's worth, I'm using cont inner-tubes, they are on Mavic Ksyrium Elite wheels and the tyre is about 95psi. Both times this has happened is just after topping up the air in my tyres.
Have I just had bad luck, am I doing something wrong, or is this a known problem?
I only have about 7/800 miles on the new tyres. For what it's worth, I'm using cont inner-tubes, they are on Mavic Ksyrium Elite wheels and the tyre is about 95psi. Both times this has happened is just after topping up the air in my tyres.
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If you take the tyre back to the store they may send it to Conti for assessment.
This said, if it's happened twice I would take a look at your wheels carefully as the issue could be with them.0 -
If you take the tyre back to the store they may send it to Conti for assessment.
This said, if it's happened twice I would take a look at your wheels carefully as the issue could be with them.
I might do that, but I just put on the spare tyre gp4000s II from my old pair, pumped it up, wheeled the bike into the kitchen and it popped with such force it blew the fridge magnets off the fridge.
I'm guessing it's a wheel thing but I'm not sure what, I've run my finger round it and can't notice anything strange.0 -
The post might be a bit confusing now. I've had three failures, one a month ago and two today. This is a picture of the first one from today which looks the same as the one from a month ago.
This is the second one from today.
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What pump are you using? Are you sure you were only inflating to 95psi??
Was the tyre definitely seated properly in the rim?0 -
What pump are you using? Are you sure you were only inflating to 95psi??
Was the tyre definitely seated properly in the rim?
The pump is a halfords track pump, I've been using it for years with no problem. I actually inflated this one to slightly below 90 to be on the safe side. As far as I was aware they were seated fine.0 -
I've always used conti gps4000s and have had a recent spate (3 or 4 tyres) of sidewall failures which I've put down to being unlucky with some rather large stones... Can't ever remember having the same problem with the predecessor to the 4000 II...0
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That first picture looks very suspiciously as though your brake pad is misaligned and it's touching above the top of the brake track and rubbing on the tyre. You can see a deep groove in the lower sidewall where the pad has rubbed away and eventually it's gone all the way through the carcass where your finger is. If you compare to the other side of this tyre you should see the beading bit of the tyre should NOT have a deep groove in it like that, the bead moulding of the tyre is pronounced but the rubber surface has a smooth radius finish.
The second one is a proper sidewall failure and given the knick in the surface rubber, I'd put it down to bad luck with road debris rather than a manufacturing defect. I've got some Continental GP4000S IIs and haven't had a problem at all with them in ~5000 km. Before those I had two sets of Schwalbe Ultremo ZXs and had three (genuine) sidewall failures out of the four tyres in about the same distance, so in my experience the GP4000s IIs are a lot tougher.0 -
Couple of guys in my club have had this recently as well.0
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Do yourself a favour and stop using conti tyres that said ive never had a failure like that but that aside the ride quality is terrible, I'd go vittoira rubino pro tech or above.
I rode conti for 5 years all different makes and models road and MTB and mostly had no issues but once I switched to a more supple tyre it transformed my ride comfort.
6 almost new 4000s hanging in my garage for the last 2 yearsRule #5 // Harden The Feck Up.
Rule #9 // If you are out riding in bad weather, it means you are a badass. Period.
Rule #12 // The correct number of bikes to own is n+1.
Rule #42 // A bike race shall never be preceded with a swim and/or followed by a run.0 -
Stopped using Conti tyres years ago due to weak sidewalls - second photo shows classic Conti sidewall cuts caused by sharp stones. Cut along the bead could be due to a burr on the inside edge of the rim?Make mine an Italian, with Campagnolo on the side..0
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Cheers for the replies everyone. I checked the rim of the wheel when I had the punctures and it seemed fine. I'll take a look at the position of the brakes when I get a chance later today. I do seem to remember breaking sounding a little different than usual just before my puncture.
The Vittoria Rubino Pro Tech tyres look pretty interesting, especially at half the price of the conti's. I'll have to give them a try next time.0 -
Not a GP4000s, but this was the front Conti Sport Contact that came on my PX London Road after about 2 weeks of use (only about 80 miles)
Switched to Vittoria Voyager Hypers which are a far nicer ride and not a sniff of a puncture in the last 600 miles0 -
Here are a couple of photos of my brake pad positions. I'm not workshop minded so to speak, but to me the position of the blocks against the rim looks about right, however the wear of the pads looks like that could be what's causing the problems? I'm guessing I should move them down a few mm. Seems strange though as I don't remember changing the position and I've been riding the bike for about 18 months.
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@ Ryan: That's clearly done by a rock or other road debris; any tyre would've likely been the same. Just bad luck. I've had a large thorn defeat a GP 4 Seasons by going through the sidewall; just a freak incident.
Any tyre with a reinforced sidewall is going to give a rubbish ride
Which reminds me I must give my tyres a good looking at after my Garmin arranged for me to do 4 miles of flinty farm track on the road bike on Monday.
To the OP: I'd agree that the pad wear suggests you've found the culprit. You really need to check brake block alignment with the brakes jammed on, as the brake block will move up as the caliper closes.
Could it be that the wheel has been removed / seated slightly differently in the dropouts at some point since the brakes were set up?0 -
To the OP: I'd agree that the pad wear suggests you've found the culprit. You really need to check brake block alignment with the brakes jammed on, as the brake block will move up as the caliper closes.
Could it be that the wheel has been removed / seated slightly differently in the dropouts at some point since the brakes were set up?
Good point, I'll have another quick look with the brakes on. I guess it is possible that it was seated slightly differently since being set up.
Thanks again for the help all. It seems obvious now, but I wouldn't have really thought to check the break pads rubbing against it.0 -
I had a problem with a weak spot in the wall of some GP4000s that I had bought from one of the online suppliers (Chain reaction from memory). It was pretty much between the bead and the tread and just a bulge about 10mm long and 5/6mm wide protriding by 3/4mm.
I noticed this on first inflation before even going for a ride. Contacted CR who, after I had sent some photos, replaced the whole order (ie two tyres not just the one with the problem). Great service from CR, but a PITA from Conti.Wilier Izoard XP0 -
Until I'd seen the brake block photo I thought the split near the bead looked like a fault with the tyre. Doesn't actually look like the sidewall has been abraded.
You may find when you check with the brakes on that the unevenly worn block isn't actually hitting the tyre yet...
So it might be worth trying for a warranty return via the retailer after all.0 -
That second photo is a dead giveaway, definitely a brake pad alignment issue. That massive lip on the top of the pad is what has chewed your tyres up. If you look at them, that abraded line above the bead will go all the way round the affected side and nothing at all on the other side.
I'd take the pad cartridges out and sand it down so that it's flat again and re-position the pads a bit lower. They might look as though they're in line, but as keef66 says, you really need to check with the brakes jammed on to account for the caliper arm movement.
I know it sucks to lose two tyres to a preventable issue, but I definitely wouldn't be reusing either of those.0 -
Yeah - check alignment with brakes on.
Definately, you can see the line on the tyre that the pointy part of the pad has worn, eventually getting thin enough that it split. The point bit is running over the edge of the wheel and is pointy because its not getting worn by the rim and is running in the well between rim and tyre - just where your tyre wear/split are. Not doubt at all...0 -
Yea, I don't plan on using either tyre again. I've realigned the brakes and have a spare 23mm gatorskin to use until I get a new tyre.0
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Because the brakes describe an upward arc when you pull on the lever, they will go higher onto the rim or tyre as the blocks wear down.
I think the GP4000SII on the front of my bike is coming up for 4500 miles and still looks OK. I just replaced the rear which was fitted at the same time; it was badly cut up and a puncture persuaded me it was probably time to swap, but the sidewalls were in reasonably good shape still.
The "problem" I've had with them is thin threads coming away from the bead, around the circumference of the tyre. A colleague and his son have had the same with theirs. I don't know the cause and it doesn't seem to affect performance.0 -
I used the GP 4000 II's on a trip to the Alps this summer.
All appeared to be OK throughout the trip, however, on returning to the UK I switched tyres to my summer Vittoria's. On taking the Conti's off I found the rubber around the bead had melted in 3 or 4 places. The tyres were being held on by mere threads and I was close to disaster had they popped on a descent.
Won't be going back.0 -
I used the GP 4000 II's on a trip to the Alps this summer.
All appeared to be OK throughout the trip, however, on returning to the UK I switched tyres to my summer Vittoria's. On taking the Conti's off I found the rubber around the bead had melted in 3 or 4 places. The tyres were being held on by mere threads and I was close to disaster had they popped on a descent.
Won't be going back.
Actually, that could be a good thing - that they designed them well enough with the threads to resist even searing heat, hot enough to melt rubber. If the rim really got that hot then surely it would have melted any tyre? I would say its possible you were lucky that the Conti's saved you, where other tyres may not...
I cant say for certain which of these two opposite conclusions is true but I would be surprised if Conti's used rubber with a significantly lower melting point than anyone else. I would be worried and looking for what was the cause which generated that much heat if I were you, not simply blaming the tyres.0 -
I used the GP 4000 II's on a trip to the Alps this summer.
All appeared to be OK throughout the trip, however, on returning to the UK I switched tyres to my summer Vittoria's. On taking the Conti's off I found the rubber around the bead had melted in 3 or 4 places. The tyres were being held on by mere threads and I was close to disaster had they popped on a descent.
Won't be going back.
Actually, that could be a good thing - that they designed them well enough with the threads to resist even searing heat, hot enough to melt rubber. If the rim really got that hot then surely it would have melted any tyre? I would say its possible you were lucky that the Conti's saved you, where other tyres may not...
I cant say for certain which of these two opposite conclusions is true but I would be surprised if Conti's used rubber with a significantly lower melting point than anyone else. I would be worried and looking for what was the cause which generated that much heat if I were you, not simply blaming the tyres.
This.
As the old saying goes, "when you point one finger at your tyres, you're pointing three back at yourself".
Clinchers blowing off rims on alpine descents certainly isn't a new phenomenon and certainly isn't restricted to one brand of tyre, conti or otherwise. The cause is invariably people dragging their brakes for prolonged periods, possibly exacerbated by a high ambient temperature, so you might want to look at your technique rather than blithely assuming the tyres are to blame and that a different set will perform better. There's a good chance that the ones you replaced them with will perform even worse in this regard.
That's not even getting on to the topic of carbon wheels and road discs. If you tried descending whilst riding the brakes on either of those, you'll soon know about it!0 -
I gave up on GP4000s due to sidewall splits. Seems to be a common occurrence.0
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I used the GP 4000 II's on a trip to the Alps this summer.
All appeared to be OK throughout the trip, however, on returning to the UK I switched tyres to my summer Vittoria's. On taking the Conti's off I found the rubber around the bead had melted in 3 or 4 places. The tyres were being held on by mere threads and I was close to disaster had they popped on a descent.
Won't be going back.
Actually, that could be a good thing - that they designed them well enough with the threads to resist even searing heat, hot enough to melt rubber. If the rim really got that hot then surely it would have melted any tyre? I would say its possible you were lucky that the Conti's saved you, where other tyres may not...
I cant say for certain which of these two opposite conclusions is true but I would be surprised if Conti's used rubber with a significantly lower melting point than anyone else. I would be worried and looking for what was the cause which generated that much heat if I were you, not simply blaming the tyres.
This.
As the old saying goes, "when you point one finger at your tyres, you're pointing three back at yourself".
Clinchers blowing off rims on alpine descents certainly isn't a new phenomenon and certainly isn't restricted to one brand of tyre, conti or otherwise. The cause is invariably people dragging their brakes for prolonged periods, possibly exacerbated by a high ambient temperature, so you might want to look at your technique rather than blithely assuming the tyres are to blame and that a different set will perform better. There's a good chance that the ones you replaced them with will perform even worse in this regard.
That's not even getting on to the topic of carbon wheels and road discs. If you tried descending whilst riding the brakes on either of those, you'll soon know about it!
Had Schwalbe's that didn't melt on me on earlier trips. I know through experience my downhill technique has improved as well as my weight being significantly down on earlier visits to the mountains. There is a significant temperature delta when the rubber is neither liquid (i.e. fully melted) or as strong a it would be at lower temperatures. Within that band, the construction of the tyre and the bead encasement is critical. If sidewall slits are appearing more and people are experiencing problems with the bonding it would be a valid conclusion that Conti are making the sidewalls thinner/more delicate. That could be to reduce costs or to gain more supple tyre or other benefits but thereby it is a compromise and I for one, am not happy to trust their current position.0 -
Just to add some balance, and to tempt fate. I've never had any sidewall problems running GP4000, GP4000S, GP4000SII and GP 4-Seasons, for 10 years on a number of bikes. I have however had a failure with Schwalbe Ultremos - but only the one.
Not saying there isn't an issue with some batches of GP4000S tyres. There may well be. But I doubt it's a common occurence. More like an occasional one. For everybody on here who has experienced problems, there are probably hundreds out there that have not.0 -
... well, I was one of the 100s who had run them happily for years with no problem. Until Saturday... majestic sidewall blowout, at first I thought a gun had gone off close by but the instant deflation was a big clue.
2" rip, inner shredded, had to call the team car.
No sign of brakes rubbing - I'm always careful to keep them off the tyre - and the tyres were about 2 years old, certainly not under warranty but a bit disappointing as the first year they did very few miles, probably no more than about 3000 altogether.
Been very happy with them but maybe time to check on the competition.
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bompington wrote:... well, I was one of the 100s who had run them happily for years with no problem. Until Saturday... majestic sidewall blowout, at first I thought a gun had gone off close by but the instant deflation was a big clue.
2" rip, inner shredded, had to call the team car.
No sign of brakes rubbing - I'm always careful to keep them off the tyre - and the tyres were about 2 years old, certainly not under warranty but a bit disappointing as the first year they did very few miles, probably no more than about 3000 altogether.
Been very happy with them but maybe time to check on the competition.
TBH 3000 miles is a pretty good return for a tyre designed with racing in mind.
I seem to recall reading somewhere that Conti claim these tyres have a lifespan of approx 1500-2000miles.
Were the wear indicators still visible?
Even if the tyres are worn i still wouldn't expect a sidewall blow out though.0 -
Ive been using GP4000S for years. Only problem I had was one 'mare of a ride when I;d got complacent and got a puncture on.
Before and after that - no problems at all.
It does help if your own brake blocks aren't causing the problems though like the OP's were.0
