Original 13” diameter wheels for Midgets and Sprites come in three widths:
- 3.5J Original Steel wheel on Frogeye, Mk 2/3 Sprites, early Midget.
- 4J Wire wheel option throughout production.
- 4.5J Early and Late style Rostyle.
Tyres fitted were 5.20 Crossply and then 145 82 now 80 profile radials.
A common option is to use 155/80 or 155/70 series tyres, with Uniroyal Rain Expert being one of my favourites for everyday use. You can use 165/70 on the 4.5J rim which retains the same overall gearing as the original tyres.
Various alloy wheels are available for Spridgets with Minilite and Revolution being the most popular.
Widths suitable for roadgoing cars without wheel arch modifications are 5” or 5.5” and at a push 6” for round wheel arch cars.
Finding a tyre suitable for fast road and track day use is difficult, as bespoke track tyres such as Yokohama AO48, Toyo, Nankang etc tend to be compromised in wet grip, uncomfortable and tramline in everyday useage, although they grip well on smooth hot tarmac !.
If you can find them, Avon CR500 in 175/55 13 give excellent track performance, with very good wet weather grip. These were developed by Avon Racing to fit the original Caterham Superlite. So are a lightweight construction, with a reasonably compliant sidewall and rubber compound ideally suited for the weight of a Spridget. (Try BMTR or Caterham Cars for stock).