tyres and springs

[Bluebottle]

I have a 1600xflow, live axle 7, can anybody tell me what spring rates I should be using and what tyre pressures are optimal (Michelin Pilots 195.55x15)...many thanks

[philwaters]

I have a 96 Classic L/A and upgraded the springs to 310lb on the front and 115lb on the rear and have been really happy with this. I have not changed the ARB from the wimpy little thing but it is on my ever increasing list.

Depending on what you are going from you may need to have adjustable heights to compensate and get back the ride height as the stiffer springs will not sag so much. However, if you speak to a few places, you might be able to find someone that can tell you what spring length you need to avoid this ???

Tyre pressure depend on what you are using the car for more. I have just lower my 185-60/13 from 22/23 to 16 psi all round and the difference is imense! I now have more grip and much more pradicatable breakaway when having fun. I would suggest lowering in stages and finding whats right for you. Between 16 and 20 would be a good starting point.

 

Phil Waters

The car in front must be less in control teeth.gif

[Nigel Riches]

Bluebottle, from the Caterham build manual, the tyre pressure for 15" wheels is 18psi, so Phils response of 16psi is perhaps a little low, perhaps it was a gauge error, but if it feels good for you, do it. Can't help on the springs other than to say I replaced mine with Caterham p/n 79601 dedion 09/88>07/91 at the front, and Caterham p/n 77815 live axle competition at the rear with new shocks to suit, all for road going use, and difference is amazing, much better ride, not nearly so much bump thump, so the old x-flow 7 is much nicer to drive now, unfortunately I don't know the spring rates, no doubt one of the learned society will be able to inform you.

Regards Nigel.

[hubcap]

Hi there,

 

I think the part numbers Nigel refers to are the same as the springs I fitted to my 7, from memory these are 50% stiffer than standard i.e. approx 220lb/in front and 120lb/in rear. They seem to work pretty well, the handling is much better and with the dampers set on soft still quite comfortable on the road. I have just uprated the front suspension by fitting the extra top front link (as the scholarship cars) with a 5/8" arb in place of the standard 3/8" item. Not had a chance to test it yet! Anyone else had experience of this?

 

As far as tyre pressures go, 19-20 psi (cold) seems about right on 185/70 13" 021R's.

 

 

 

Hubcap

[Pierre Gillet]

I am now at 16 psi (cold) on my 021Rs 185 60 14. Even wear, more comfortable, and equivalent handling on the road.

 

Pierre