Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 ohlins

Here's the bulk of the text that I sent to M3W55, which hopefully will give some info on both the Ohlins shocks and shocks generally. I will stress that I really don't know the exact spec of the kit that BG and KH are currently supplying so take any settings with a pinch of salt! (I've already softened all 4 shocks off by a couple of clicks since writing it)

I'll be down in the garage this afternoon and will see what I have them set to, but there is no guarantee that yours will be exactly the same as mine internally nor that they will have the same springs. The history of the Ohlins shocks for the M3W is that an owner in Florida was friends with an Ohlins dealer who did the donkey work of finding apparopriate shocks and springs, I then got the spec sheet for that first set which I sent to Ben at BG Motorsport. Since then I believe that Krazy Horse have become an agent for the M3W Ohlins via BG, I simply don't know if they have changed anything. I don't even know if Ben is exclusively supplying Krazy Horse or not.

A lot of what follows sounds like sweeping statements about the M3W and while I know it applies to quite a few M3Ws I've looked at (and definitely to all three chassis that I've had so far!) changes/improvements may have been made by the time your one was built. That last bit is very doubtful. laugh Many apologies also if any of this falls into the "teaching granny to suck eggs" category

The main fitting issue at the fronts is not unique to Ohlins; basically the top mount brackets are considerably wider apart than the length of the inner tube of the original shock and wishbone bushes so the brackets get bent in to try and grip the bushes. With the standard set up if you get the feeling that there is uncontrolled wheel movement before anything useful happens in the suspension and likewise at the top of the travel when the end stop gets hit then you're getting a decent feel for what is actually happening. My first action for this was to straighten the factory-bent brackets back to parallel then use washers to take up the space created on the wishbone and shock mounts. I also did a couple of the bottom wishbone mounts though these weren't anything like as bad as the tops. This allowed the bushes to be gripped almost adequately and improved things quite a bit. When I got the Ohlins, I measured the bracket gaps and gave them to Ben who machined up top hat spacers to fit in the shock spherical bearings to suit the gaps on my car. I don't know what top hats you will get, but a bit of measuring, straightening of brackets and persuasion may be required to get them in. Ideally they should be a snug fit between the brackets before tightening the bolts. If the brackets are straight and there is free space between them and the top hats then more measuring and getting new top hats is what is required but washers as packers will do for a while.
The other issue at the front is that the top brackets are really quite small; i.e. the bolt hole is not very far away from the chassis tube. With the standard shocks which have a thin steel bush housing over a thin bush this isn't a problem but the Ohlins have a much thicker aluminium housing over a bulkier spherical bearing so need more clearance. I have filed a flat on the outside of the aluminium housings where they foul on the chassis tube to give clearance, otherwise the contact can put a bending moment on the shock which can accelerate wear on the bushings and seals. The flat is only a little more than 1mm deep so no great problem to do. The tops of the rear shocks have a similar issue and solution. The bottom mounts front and rear haven't had this issue on mine at least.

At the back you might have similar issues with bent/wide brackets to the front so same comments apply as to the fronts.
The right (brake drum) side rear shock is unlikely to have any further fitting issues. The left (belt) side shock is more complicated. These shocks have a larger outside diameter than the originals so clearance has to be found between the belt and the fuel tank. This generally means that the top hat spacers have to be asymmetrical; the outside spacer being much thinner than the inside spacer so as to move the shock away from the belt. This is complicated by the left-right position of the entire swingarm being adjustable and can vary widely from car to car, presumably depending on who assembled it last. I believe that on some cars the swing arm has been far enough over to the left that there really isn't enough space for the Ohlins shock (and probably wasn't enough space for the original either). In this case it might be necessary to move the swingarm over a bit to the right which isn't necessarily all that difficult but is a bit involved and a pain to do.

Setting them up is a bit vague with no definitely right and definitely wrong settings. For preload (often thought of as ride-height) adjustment, for a road car I would just make sure that things are even left to right and "look right". This will probably be a little lower than standard but not necessarily by much. You also need to avoid contact with the exhaust headers at the front though the headers themselves can be moved a bit too. Then turn the damping adjusters gently all the way to maximum (clockwise when looking along the shock from the adjuster end) and back out by (say) 15 clicks then have a bounce on the car. If it seems to come back up very slowly indeed then back off a couple of clicks further, conversely, if it comes back up very quickly then a couple of clicks towards maximum should calm it down. If it seems to be somewhere in between the two then take it for a drive! There is a wide window of adjustment that works, particularly on the road (track use is a bit different) and it is well worth having a blast along a favourite bit of road then adding a couple of clicks and seeing if it feels better. If you go too far and find that on a series of bumps you seem to be getting lower and running out of travel (pumping down) then you probably have too much damping so back it off a bit. On the road, even for properly go for it driving, you get to a point where a click or two in one direction improves things a bit on one corner/bump but makes it slightly worse on another so you'll probably rapidly find a compromise that works for you and stop adjusting them! I have very rarely adjusted mine after the initial set up though last year on the Caramulo hill climb there was one corner with a dip at the apex that was causing a bit of a lurch when taken at proper speed; two clicks more on both front shocks made the dip disappear and gave a slight improvement elsewhere but I didn't get far after the event before backing them back off to get "road" handling and comfort back.

Once you've got decent shocks fitted, then getting the tyre pressure on the front up really helps too. I run 36psi in Blockleys, some have said that it's too harsh with the standard shocks, and they are probably right, but with decent shocks the additional feel and grip is quite surprising. I've been running 0 toe in (parallel) and it seems to work for me though I could really do with getting my finger out and checking what it has drifted to!

This all seems very long winded and involved but in reality it's not that bad and much of the hassle involved should apply to fitting the standard suspension parts properly anyway.


Front shocks set at 9 from maximum, preload set as per the photo below.
Rear shocks set at 10 from maximum with preload set at maximum.

Rear shock preload and asymmetric top hats;


Rear spring code;


Front shock preload;


Front spring code;


The preloads are as per how I've been running them but the damping settings are after they've been off the car for a while while I painted brackets and various other tasks including taking the springs off to clean them properly so might not be exactly how I like them once I have had a chance to drive them properly.