I fitted a set of recommended Kumho tyres to the 850 R exactly 12 months ago, MOT time cometh so I removed the wheels to clean everything and the back of the Volans etc etc... to my surprise and the tyres have needed pumping up regularly..like every 10 days or so to maintain pressures. They have all got cracks on the inside, nothing shows on the outside at all but the inside is nasty.. So I returned them.. Oh the pain!..Well you have to buy 4 new tyres and we send these back to the distributor and he makes allowance for the tread used and issues a credit for the remainder...Hmmmm...
It seems that Kumho had a recall for exactly this problem back in 2012..so its back...I've gone for UniRoyals this time.
He did try to convince me that because they had been losing pressure I'd done the damage myself by so doing and the damage was caused by the tyre rubbing against the rim...I sort of pointed out that perhaps the cracking would have appeared on both front and back if that was the case.. he grudgingly agreed..So the moral is IF you have Kumho's have a looksee on the inside walls