Giniw

Thanks! For your info, my Esprit is still on its wheels so it should be OK for yours as well! By the way, when you install the rear dampers on the car (assuming you haven't done it already) you might struggle a bit because, being gas dampers, the new shocks won't stay pushed as the old ones. In a nutshell you need to push the #65 stud as pictured on the parts manual (see picture on the linked thread), insert the top end of the shock in the upper cup, then slide the #65 stud back in the bottom hole of the shock. The problem is the stud is often seized, and the alloy hub carrier is fragile. So you really don't want to use too much force to slide the stud (FYI the stud itself is in a steel sleeve, #66 on the drawing). It's all being discussed on the following thread from the post I link to the end of the thread (and maybe elsewhere of course):

Thanks a lot! Did they take the opportunity to lower the engine?

As it was apparently already assembled by Bilstein (or whoever packed it — mine was all in separated parts) it is probably mounted dry, so, as @Mightymetro said, I suspect it was so offset toward the bottom bush that the top one was already too squashed to allow the spacer to slide up? @Mightymetro > Now the spacer is in contact with both the top and bottom washers, do you confirm it looks as squashed as mine? (like on the photos on the other thread I linked)

I am not 100% sure but still pretty confident there were actually two tubes joining in the middle on the original ones from the 90s (one for each bush). But I would have to check.

Thank you very much! (not that I am sure I will buy one, but it's a bit tempting!)

So you do have a spacer?

This is very strange as my LOTAC set (S4s) did have a spacer tube included for each damper?! (both front and rear) see https://www.thelotusforums.com/forums/topic/25978-bilstein-shocks/?tab=comments#comment-764243 https://www.thelotusforums.com/forums/topic/25978-bilstein-shocks/?tab=comments#comment-764242 ( the washers arrangement is wrong on these photos) (As for the part diagram it's from the original system anyway so unfortunately it doesn't help.)

There should be a tube which is meant to be installed as a sleeve between the stem and the bushes Similar to the red thing I drew there: https://www.thelotusforums.com/forums/topic/25978-bilstein-shocks/?page=2&tab=comments#comment-766425

Including VAT? (is it an online shop?)

As there is a little bit of what looks like a blue cover on the damper stem I wouldn't be surprised it's a LOTAC set? Anyway I hesitated the same when I did it on my car and in the end nobody really knows for sure apparently. What I understand is that the spacer tube should touch both the bottom and upper washers anyway, and that is what it looks like when it is the case (=bush very squashed) Indeed, I have the same spring compressor and the yellow parts are plastic. I ended up using some gaffer tape.

Well maybe (I honestly don't know) but aren't you happier with new tyres than with old dry ones? As @Jacques just said everything counts (keeping in mind that the parts can't be new for ever obviously so a little wear or loss in performance is inevitable indeed) It's not the Esprit one so the actual numbers for us could be different. I will have to check with the real measurement of an Esprit AR bar. Anyone has its dimensions? I have two of them taken appart but not here with me.

Yes I agree it's not huge but still not negligible. I wouldn't say it becomes unsafe, although if I am not wrong a reduced rate would increase the car tendency to oversteer. But again, as I said on the open road at legal speed it's probably not a real problem ... ^^ You couldn't indeed as you don't have the full data of the bar I checked ^^ (which is not an Esprit anti-roll bar — I could do it as well but I don't have its measurements here)

Both the reference bar and the reduced diameter bar are virtual: I got these results with a finite element analysis software (thanks to a spring and anti-roll bars dedicated simulation platform)

I just made a simulation of a uniform thickness loss of a realistic anti-roll bar (not Esprit or even Lotus related though, just a random but realistic anti-roll bar). It's the first bar I found so it's a tube but anyway. The reference one (=new) is 26.5mm in external diameter and 17.5mm internal diameter. Its stiffness is 42.449 N/mm (~55754.828 N.m/rad) I then reduced its external diameter to 26.3mm (0.1mm loss on the external surface), kept all the rest unchanged (id=17.5mm). Its stiffness is 40.841 N/mm (~53643.121 N.m/rad) So I am afraid I don't agree too much with @drdoom, I would suggest to not sand blast any elastic suspension component (coil spring or anti-roll bar) as the external diameter is quite significant. And that is for the diameter alone, whereas some (most?) bars are actually quenched so a hardened surface removal may have an even greater impact. And then there are the steel fatigue which may change the bar stiffness too, and so on. I don't know too well to be honest. => Anyway, keep your suspension rust clean and rust free! Now, in real life on the open road at legal speed, will that make any real difference? I suspect not so much — still, I changed mine since it had been scrapped by something on the road before I bought the car!