itspilsbury
Registered user
Hi,
Just finished servicing my wifes Harley XL883L ready for Morocco. Done everything except taking the front forks out to clean and re grease the head bearings (she wanted me to leave them alone until we get back!!! - worry wart!).
We changed the tyres from the original Harley ones when the bike had done 13K and put a set of Avon Venoms on which are recommended for the bike. They were far superior to the HD tyres improving the handling characteristics and her confidence tremendously. Anyway just checked both tyres over closely and found that the front one has cracks in the base of the grooves around the centre circumference of the tyre, the side grooves are perishing in the grooves. The tyre is only half worn with almost 4mm left in the centre. The cracks vary from a few mm to a couple of inches in length and are about 1mm - 2mm deep.
I rang the tyre supplier, "They don't make Venoms in that size any more, they do Cobras".
I rang Avon UK, and got put through a technician who said he was the tyre designer of both the Venom and the Cobra. He said usually it is not advisable to mix tyre models but the Cobra has been designed to run with the Venom.
What has caused this I asked ? GET THIS, the Harley handbook tyre pressures are wrong! He said the original Harley tyres have a very stiff sidewall and are stiff tyres, the Avon's are a much more flexible tyre and they recommend running them at a higher pressure! He says what has happened is the tyres have been run underinflated and therefore been flexing which has caused the cracks.
The Harley handbook says, - solo rider = front 30 rear 36 psi the AVON man he says NO! run them at solo rider = front 36 rear 39. (which is quite a difference up front). I have ridden the bike with the harder pressures today and it feels better to me as he suggests.
He said they try to get the message out to tyre suppliers, but hey !
This man was extreemly helfull.
I have ordered a new Cobra for the front.
I have told my local HD dealer and they didn't know this.
Any one else come accross this, or any comments?
Ian
Just finished servicing my wifes Harley XL883L ready for Morocco. Done everything except taking the front forks out to clean and re grease the head bearings (she wanted me to leave them alone until we get back!!! - worry wart!).
We changed the tyres from the original Harley ones when the bike had done 13K and put a set of Avon Venoms on which are recommended for the bike. They were far superior to the HD tyres improving the handling characteristics and her confidence tremendously. Anyway just checked both tyres over closely and found that the front one has cracks in the base of the grooves around the centre circumference of the tyre, the side grooves are perishing in the grooves. The tyre is only half worn with almost 4mm left in the centre. The cracks vary from a few mm to a couple of inches in length and are about 1mm - 2mm deep.
I rang the tyre supplier, "They don't make Venoms in that size any more, they do Cobras".
I rang Avon UK, and got put through a technician who said he was the tyre designer of both the Venom and the Cobra. He said usually it is not advisable to mix tyre models but the Cobra has been designed to run with the Venom.
What has caused this I asked ? GET THIS, the Harley handbook tyre pressures are wrong! He said the original Harley tyres have a very stiff sidewall and are stiff tyres, the Avon's are a much more flexible tyre and they recommend running them at a higher pressure! He says what has happened is the tyres have been run underinflated and therefore been flexing which has caused the cracks.
The Harley handbook says, - solo rider = front 30 rear 36 psi the AVON man he says NO! run them at solo rider = front 36 rear 39. (which is quite a difference up front). I have ridden the bike with the harder pressures today and it feels better to me as he suggests.
He said they try to get the message out to tyre suppliers, but hey !
This man was extreemly helfull.
I have ordered a new Cobra for the front.
I have told my local HD dealer and they didn't know this.
Any one else come accross this, or any comments?
Ian
