Which Springs?

[James7]

I've had my 1.6K 7 for about 10 months and find the suspension is a bit firm on bumpy roads. You certainly notice imperfections in the road and on very bumpy roads it really bounces up and down. Only mildly bumpy sections of road can have the rear wheels lifting and the wheels spinning up. Sometimes I end up having to back off and go a fair bit slower than otherwise might in a regular car.

 

The car is a 2004 Ex Academy with narrow track front suspension and came with the standard Bilstein M0 dampers with adjustable platforms. The springs had however been changed to the Caterham Race Eibach items. I believe that these are 250lbs/in front and 215 lbs/in rear, whereas the standard items are 150 lbs/in front with progressive rear springs (from 0 - 95 mm: 110lbs/in, the next 87.5 mm: 130 lbs/in and the remainder: 200 lbs/in). The car has a front ARB with red bushes. There is a rear ARB which is using the rearmost mountings. I use the car mainly on the road but have done a couple of trackdays and anticipate that I’ll continue to do a few trackdays a year and might look to try my hand at sprinting/hillclimbing at some point in the future.

 

I understand that these springs may be under damped with the standard Bilsteins. I don’t want to change the dampers, though and I suspect the springs may be too firm for the road in any case. I’m considering the following options (in no particular order) and would appreciate any comments/further suggestions on what might achieve a good ride/handling compromise on both road and track.

 

1. Fit standard Caterham springs front and rear (rears progressive);

2. Keep the Race fronts and fit standard progressive rears;

3. Keep the Race fronts and fit Caterham 21 progressive rear springs(Part 24076 - 30% stiffer than standard progressives);

4. Fit 170lbs/in fronts (Part 75517) and Caterham 21 progressive rear springs.

 

Many thanks.

 

James

[Bricol]

Where are you James?

 

My 2001 car is on standard springs and dampers if you want a comparison?

 

Bri

[James7]

That would be very kind thanks Bri. I’m in Leeds, how about you?

 

James

[Mark Gregory]

Option 1: Standard Caterham front & rear.

You can adjust the handling a bit by changing the rear ARB.

[Richard Price]

Stanard sprigs and dampers, with ared front ARB works really well

I'd get rid of the rear ARB.

I've tried with and without my rear ARB seveal times, but allways ended up dissconnecting it, and now I've removed it completely.

 

 

[Stationary M25 Traveller]

Ditched my rear ARB. Found when cornering on a bumpy road that when one wheel lifted, the ARB lifted the other, so the car hopped sideways. Much better since I removed it. Only takes 15 minutes.

[Mankee]

Interesting to hear your views about using race springs with standard MO dampers. I would have thought that upping the spring rate so much without uprating the damping might be the root cause of your skittishness? On the road at least. How do they feel on the track? As my car is track-only, so my needs will be different to yours.

 

If you wanted a set of standard 150lb front and progressive rears to try out, then I might well be interested in a kind of long-term swap to see how we get on? I've got a set of standard springs and dampers in a box in the garage, but I don't see myself fitting them for a few months yet, due to time and other committments etc. ☹️

[Bricol]

I'm in silsden, t'other side of keighley, but do wander in the halifax and even leeds direction occasionally. In durham at moment with the car.

[James7]

Thanks for the replies all.

 

Bri, I have family in Skipton (and Halifax) and pass near to Silsden not infrequently so we may be able to arrange something convenient. I’ll BM you my details, thanks.

 

Mankee, thanks for your swap offer, if I decide to give the standard springs a go I’ll be in touch. What springs are you currently running on your car? How do you find them? Any idea of the history and condition of your standard springs? Mine are in good condition, minimal marking / stone chippng and I believe have only been used for road and track days for the last few years, never actually raced.

 

I don’t have anything else to compare against on track but to me the springs feel good. The car feels stable with very little roll. If I only used my car on track I’d keep them as they are, it’s only on road that I find them a problem.

 

James

[Mankee]

James, I am currently running with unknown Bilsteins and unknown springs! It seems to handle quite well, but, like yourself, I don't actually have anything to compare them to.

 

I bought some lightly used standard springs and dampers from another Blatchatter, which are the ones sat in a box at the moment. The springs are actually in really, really good condition. Think they have covered around 10k miles. I have a photo which I can forward on to you from the original seller.