When you go to see these chaps: http://www.centregravity.co.uk one of the first things they do is check the current durometer of your tyres. Old tyres are hard tyres, and if you have a miss-match across the same axle it will cause handling oddities.
And if it's good enough for Chris and his team it's good enough for me, so I'd buy a cheap durometer checker and find out if my tyres were within the desired range.
When you go to see these chaps: http://www.centregravity.co.uk one of the first things they do is check the current durometer of your tyres. Old tyres are hard tyres, and if you have a miss-match across the same axle it will cause handling oddities.
And if it's good enough for Chris and his team it's good enough for me, so I'd buy a cheap durometer checker and find out if my tyres were within the desired range.