Tyre sizes

[Peter Cresswell]

Hi John,
Either of those tyre sizes will fit a Rostyle wheel ok, but the 185/70 x 14 might rub the outside of the tyre on the wheel arch when cornering hard. It seems that not all cars do this, but Heritage shelled cars might do it on one side or the other. Cars that have had lower rear wing repair panel might also do it - mine happens to rub on both sides when driving hard. You should remember that the left wheel will rub the left wheel arch when cornering to the left. This is because the axle moves to left (by as much as 2 inches) when cornering in that direction. Lowering the car ride height doesn't help either, but Poly bushes will help control the axle but might be a bit harsh on a road car. A thicker anti-roll bar might also help, and I am about to try this on my car. The 175/75 tyre is less likely to have this problem.
Both the 175/75 x 14 and 185/70 x 14 will much the same diameter as the standard 165 x 14.

[Laurie Kennard]

Hi - my first posting ..... as a non technical owner of a 1968 Roadster I am very confused by all the permutations for tyre sizes as I now need to replace mine. When I got the car 2 years ago it came with unusually large tyres - 195/65/R14 89H which are now starting to crack. I would like to go to narrower tyres to help with the steering, but can't decide from the above postings which size(s) would be suitable without changing anything further. The wheels are 14J Minator alloys.
Any specific advice on a size to change to and a good supplier of same would be appreciated. The car does less than 1000 miles a year so I don't want to spend the sort of money that it appears you can do with the specialist Longstone
thanks
Laurie