I have a Cube Attain GTC (~1600 euro) I bought about 4 years ago. I have had no problem with tyres until I’d say the past 6 months when I started buying Continental 5000 Grand Prix Tyres. Firstly, I thought someone had slashed one of my tyres as there was a long blowout in the side wall of the tyre just above wire. Unbelievably I only noticed it until I went back to the bike after work to cycle home and that’s why I thought it strange. Anyway, Covid came in and I had to fix. I bought another Continental 5000 (from Halfords again) and as I was blowing up tyre it exploded in exactly the same way. Nowhere near 100 PSI. I thought fair enough. That was probably my fault as I tried to put in an anti-puncture strip inside the tyre which has worked really well in the back tyre (back tyre is a Continental Ultra Sport). So I removed the anti-puncture strip and bought another Continental 5000 Grand Prix tyre. I got about 1 mile down the road and the tyre exploded again. Same Issue. I then went and got the last Continental 5000 Grand Prix from Halfords (I know - you think I’d have learned, but everyone tells me they are a great race tyre. Now I have just walked home after only getting 5 miles. There is no metal sticking out of the side wall. There was no sign of a genuine puncture - and I do this journey a lot for work.
I cannot understand it. If it was a puncture like I’ve had in the past why in the hell does the tyre always explode just above the side rim. I put pressure to 100 PSI.
Can anyone help - is this a bad batch or am I doing something wrong?
I have to say I looked at it and it is close, but I didn’t think close enough. I’ll have to adjust and test. That can be only explanation. Stupid old me - should have looked beforehand. And…as you say…I’ll blame it on Trump
Just to add - I will be sticking with the standard Grand Sport Race SL 25c that came with bike if it happens again or the cheapo Continental Ultra Sport.
I had this myself with two separate GP5000’s. In the end I put it down bad luck based on friends’ good experiences and stuck with them. I did return the two failed tyres for a warranty claim though - and got three back… so
When you seat the tyre on the rim, are you able to do it with thumb/hand pressure alone or, do you need to use a tyre lever? If you’re using a lever, is it a plastic lever?
Just wondering if there’s even the slightest possibility that you could be compromising the wall of the tyre during the fit process.
Thought the same about the brake pad rubbing, but you should also hear or feel that. I’ve had that once, and it took a chunk out of the tyre really quickly.
this weekend Ive had to bin two conti gp4000s with less than 500miles on them.
The first sidewall just gave out, and Ive got chunks of ‘tread’ coming off the second the tread has come away from the carcass.
Personally Im done with Conti, used them for years but recently something seems to have happened with the manufacturing. They just seem really really weak.
A quick google seems other people having similar problems, esp with sidewalls.
So there was no rubbing noise when I was cycling or smell or rubber. The metal rim of the wheel was not bent or splintered in any way. No metal fragments, glass or any other intrusion. @PusherMan - yes it’s a plastic lever I use to seat tyre on the rim, but as you say that is another feasible reason as the tyres are incredibly tight. I use a hair dryer to slightly warm up before applying, but still very tight. If I was compromising the wall I would have thought the beads would have gone first. Maybe not.
OK - so I just went outside as this whole saga has been winding me up. Poor lighting in shed so got torch to look closer - I’m getting on so the eyesight is crap . I squeezed the brakes and realised the break is just over the rim and hence the brake has a rubber lip over the rim onto the tyre. See pic.
Just to add for anyone that stumbles on this is to remember that tyre can widen a small bit when weight is on also. This means that if the clearance to brakes is very tight, the extra width that comes when you sit on saddle can cause rub.
OK, I took a stab at a revised title, that hopefully covers the issue (note that I skimmed the thread to draw a conclusion, let me know if I am incorrect).
