Originally Posted by Pleiades

Tyre rubber does tend to get harder during storage and consequently less "grippy". In the UK you are not allowed to supply "new" tyres over six years old. In fact most of the big tyre manufacturers instruct retailers to send stock back if it's been on the shelf for two years. How old are the tyres? Your bike might be a 2010 model, but often Yamaha would bulk buy tyres to cut costs, so they could be older still?

Be interesting to find out how old they actually are. Have a look on the sidewall for the date moulding. The first two digits show the week and the second two digits show the actual year - Eg: 1411 means it was manufactured in the 14th week of 2011.



Might be worth pushing your dealer to give you a fresh set if they are very old or miss-behaving badly? Or at least give you a generous discount on a new pair. Got nothing to lose - Those that don't ask, don't get!