I don’t want to cause you unnecessary alarm, sa, but have you checked the date stamp on your ‘new’ tyres? I tried to buy Roadrunners a couple of years back and was told they were no longer in production and that the Roadrider was the replacement cover. Avon only list the Roadrunner on their web site
http://www.avon-tyres.co.uk/motorcycle. I hate to think that you have bought tyres already a couple of years old, if the MoT regs change as they threatened a while back that any tyre over 5 (or was it 8 ?) years old would be a failure it could affect your wallet badly.