Bilstein adjustable suspension and collar limits.

[rotorwings]

(SV Duratec wet sump, 13"wheels)

After changing to 13" wheels I needed to bring the ride height up at the front.
To get 80mm under the sump and about 145mm under chases rails I have had to bring the collars right up to the end of the threaded section of the dampers. The flange that centres the spring is even a little past the end.

Is this expected? Or do I require a spacer somewhere? Or some longer springs?

See photos to understand what I mean

[rotorwings]

Eccles52 said:

I think that the black threaded collar slides onto the damper up against a circlip (or similar) and this can be moved to one of three groves. Maybe one of the other groves will lift the collar to allow the spring seat to be threaded on completely.

Ivan

Thanks Ivan, that sounds promising.

Anyone know of any instruction manual for these units? Or an exploded diagram?

[rotorwings]

Okay, I have the two front damper units off the car and can see the circlip. The next circlip position is a full 50mm higher up than the bottom one. This would mean the adjustment collars would now be all the way down instead of all the way up. This seems to be a flawed design because when you're operating around the range that I am, an adjustment up or down means removing the entire damper assembly and re positioning the circlip. I would have thought that another circlip position, higher by 1/2 the length of the threaded adjustment, would make much more sense.

Anyway, can someone confirm that this is all expected? Or is there something else I am missing?

Anyone out there running with their circllips in a higher position?

[rotorwings]

I'd be interested to know what ride height people are running?

When I had 15" wheels the collars were almost at the top (5mm of thread showing). With the 13" wheels (185 55 ZZRs), I need to be at least a little past the end of the thread to get 80mm under the sump and about 145mm under the chassis (near the suspension arm).

So, this means I should really move the circlip up to the next highest spot, but I have never seen a caterham running like this (though I have not seen too many).

Note: the ride height at the back has not changed because the total diameter of the tyre is the same as with the 15" wheels. Only the front has dropped 12mm or so.

[rotorwings]

cb4798 said:

I posted this on Blatchat.

http://www.lotus7.club/forum/techtalk/adjustable-d...

Have you moved the adjuster to the next ring yet?

How easy was it?

Yes, removing the adjuster ring is very easy. You just need to pull out one end with some needle nose pliers so that it sits just above the grove, then move around the ring pulling it out of the groove so it sits just above it (while holding the rest of the ring out with spare fingers). Once the whole ring is out of the groove, you can just wiggle it up to the next groove. This will leave some scratching on the damper body though.

Here is the problem:
There is a 15mm gap between the following 2 positions:
1) collar at the limit of the thread on the bottom ring position (IE collar all the way up)
2) collars all the way down the thread with the ring in the next highest position.

So, there is basically 15mm of adjustment that is inaccessible because of the bad design of the ring positions. There should be an additional position between the two bottom ones (25mm apart instead of 50mm). This would mean that whenever you are at the limits of the thread, you would have a position to go to that would bring the collars back to the middle of the thread. Unless I am missing something fundamental, it seems to be a bad design.

I will just go past the end of the thread by 10mm with the ring in the bottom position to achieve the setting I need. This is probably fine as the 'meat' of the top collar will still be on the thread.