Just sharing our experience with these Bridgestone KA4 tyres. We are new to karting but out of the 4 full sets we have bought so far 4 have had this issue where a chunk of the tyre hasn’t properly moulded together (1 front, 3 rears). That’s an issue with 25% of the tyres.
The issue doesn’t seem to show itself until the tyres have done 40-50 laps (or a clubbie) but it means we can no longer use the tyre for practice.
I work in product development and engineering and if we were to product a product with a 25% failure rate that would be a fairly monumental disaster.
Is it unreasonable to expect Bridgestone to provide a tyre that can do more than 1 clubbie or is it expected that the tyres wouldn’t be used for more than that?
Just seeing if anyone else is having this issue and what they think about it?
Not exactly a tyre failure, although I wouldn't be overly happy with a tyre delaminating like that.
I have seen quite a few tyres do that over the years - generally rear tyres. Mostly it occurs under braking, as this causes more stress on the surface of the tyre than occurs during acceleration.
I have found that reversing the rotational direction of the tyre seems to cure the problem.
If you are worried about the arrow on the sidewall, it rarely matters which way the tyre is mounted.
Had quite a few do this also. There was a bad batch late last year and after speaking to PFG they where happy to replace them via your local dealer. They generally delaminate in line with barcode.
I have had a few do this in the middle fo the year, less so recently. One really bad one, I took back to DPE and they exchanged it for a new tyre. For this rest, we kept using them and they did not get any worse and lasted a good 200+ laps.
Yes, just noticed that now. Definitely a consistent fault then.
Paul Knowles said:
They generally delaminate in line with barcode.