16" tyres

[Mike406]

hi Geoff

the current tyres are
Joyroad 185/175R16C steel belted radials

tyre pressures are 28 lbs/SQ "

tyres a probably 7-8 years old with very little usage

the rear shocks are new Koni and maybe I have them set too hard

the front were on the car when I bought it, so the may be 20-30 years old or in fact original from 1959

so if I go for new tyres radial should they be 175 0r 185

[Geoff Dowdle]

Mike ,

A test you can easily do to check the shockers (but not an accurate test , only an indication).
Bounce the car by pressing down in the bumper bars at each corner of the car .
If the body goes down a few inches and comes up quickly and bounces uncontrollably the shock absorbers probably need replacing .

The rear shocks being Koni should be adjustable . I you press down on the LH & RH side of the rear bumper bar you should not get much more movement than about an inch . Anything between 1/2 an inch to none , points to the Koni are set too hard.

I have Koni on one of my 400 and they are set quite soft .
The front shockers need to be set quite soft as the leaf spring is quite hard.
The rears should be set a little harder as the torsion bars are quite soft .

My GUESS is that the rear Koni could be adjusted way too hard.

I don't know the Joyroad tyres that are fitted but you should check and adjust the shock absorbers before you consider buying tyres.
I don't think your tyres are the cause of hard riding especially at 28psi

I inflate my 175/80 Austone Taxi tyres to about 35psi and the 400s ride smoothly.

Check with a tyre retailer for a recommendation of tyre size for the 406 with 4.5 wide rim.
As I mentioned in my earlier post the 175 is the ideal size and 185 will work OK but they are a little to wide .
Geoff

[David C]

Having driven my 403 on Vredstein Sport Classics for a bit I was happy enough to order a set for the 406 from Black circles to be fitted at a local garage.
It was only when I got there that I remembered that the Bristol wheels need a larger than standard valve if using tubeless tyres. One of the places I asked called them the "Land Rover ones". Another called them 415s. It seems these are not something most tyre fitters keep in stock so worth ordering ahead of time.
A lad from the garage made an anxious call to tell me that the tyres I ordered were a completely different size from those on the car. I don't think he had heard of crossplies.