There is a lot of confusion about shocks..perhaps more so in our community because of the ...er...slower development of Morgan suspension dynamics.

Firstly, why adjustable shocks?

Springs and tyres are the first line of defense against road impacts. Shocks aren't. However, shocks can make driving a far more enjoyable and effective experience. Shocks are harmonic balancers primarily, and can change the harsh oscillations of a road impact to something we find pleasant..even fun. They can also influence spring function to a degree.

Like any instrument, each car model will react and resonate differently as a function of its structural dynamics, springs and tyres. Each car model, depending on its shock angling, will operate well with only few shocks unless it is one of the more widely produced mid-range set-ups. Morgans are not widely produced. Neither are they even close to a standard set-up. In such a case, an adjustable shock becomes wise so that a "best" fit can be found with adjusting rather than pot luck with a blind purchase of a shock made for somebody else's marque.

KONI

Assuming you are buying their 80-series (their mid-range product), this is a great shock and to my mind, better than the Spax for most of us. It has great "internals" and they can be rebuilt. It is adjustable to 3-4 positions by twisting the shock (which means one end must be detached from its post). In my discussions with Koni, they cannot see how a Morgan would require anything more for road use than their softest setting....always. Their softest setting is softer than the Spax softest setting.

There are two types of adjustment possible. Rebound and compression. The Koni 80-series adjustment is only for rebound not for compression. The compression rate is fixed at the factory. Though they do not advertise it, you can ask for Koni shocks to be altered to have a compression adjuster added as well..either before or after purchase (and paying more).

According to the Koni, when rebound is the only thing that can be adjusted, the only thing that will happen if you make the Koni's firmer (feeling that this will help you carry rear luggage) is that you will have an uncomfortable trip. With a adjustable rebound only ..don't touch it after you have found you happy spot...unless you are one of the 1% racers. In that case, at the track, increase the firmness to speed the wheel back to the track (and if you have a compression adjuster as well make it as SOFT as possible.)

As well, please remember that your ability to adjust your Konis is destroyed after the first bottoming or topping out. There are little teeth that engage the adjustment mechanism in the shock and these bend when the shock goes beyond its extremes. The shock will continue to function perfectly but will remain in the last setting before the teeth were mangled forever...or until the shock is rebuilt. Frankly, in view
of the above and if it is in the right setting, who cares? Many of us will keep fiddling anyway not knowing that we are adjusting nothing.

Adjustment Procedure for KONI  80 Series (For Morgans)

Rebound Adjustment Procedures

Remove the shock absorber from the vehicle and  hold it vertically with the lower eye or pin
attached in a vise. Use clamp plates to prevent damage.

Fully collapse the shock absorber, at the same  time turning the dust cap or piston rod slowly to the left (counterclockwise), until it is felt that the cams of the adjustment nut engage in the recesses of the foot valve assembly.

Some shock absorbers include a bump rubber concealed under the dust cover and it must be removed prior to adjusting.

The damper may have already been adjusted. Therefore check whether the shock absorber is in the adjustment position or not by keeping it collapsed and gently turning it further to the left counting at the same time the half turns until a stop is felt. Stop turning then and do not use force.

Keeping the shock absorber collapsed, make 1 half turn (180 degrees) to the right (clockwise). In case of prior adjustment add the number of half the turns previously found. The total range is about 5 half turns.

Pull the shock absorber out vertically without turning for at least 1 cm to disengage the adjusting mechanism. The dust cap or piston rod may now be turned freely.

 
 

SPAX

Spax has gone through a number of hands..and insolvencies. Servicing is nowhere near Konis. On the other hand, their gas shock series are the top of their line  and gas is great shock technology, so we are comparing the top of one line to the mid-range in the other.

The adjustment for Spax (14 rear and 5 front) is simply a turn of a screw on the shock body and a feel for the clicks (or simply go to the end and count turns to the other end and adjust accordingly.) The screw
adjusts rebound as well...so much for "firming it for luggage". (I used to that years ago before each trip and then found myself adjust right back to where I started on the first day's drive showing me my backside was a better judge than my brains). Sadly. the adjustment at the rears is made difficult by the MMC setup as the adjustment knob faces away from easy access.

There was a comment that too many adjustments on Spax was unnecessarily confusing. It isn't..but more importantly when the shock begins to go you have 14 adjustments to keep the shock a that rebound rate you like. That alone will give you another 10,000 miles on a fading Spax without a sacrifice of any ride quality. In that case, you are adjusting the shock to keep it at the SAME firmness.

Spax adjustment is not destroyed by bottoming or topping out. The ideal setting in the rear for Morgans is the most soft to two from the most soft. In front, it is the softest or the one next to it. The only time a change from that is warranted is when I am at the race track.

It is relatively easy to adjust Spax yourself. Find a stretch of familiar road with familiar bumps and that will be your laboratory. Go up and down and adjust the rear shocks (first) until you go over a bump and react with 1.5 bounces (1.5 bounces is the ticket for any shock and normal driving). Then put on the front Spax and set them to softest and see how it feels, then try one up and do the same..then choose the better one. Koni is even easier..for road driving always the softest both ends. Sounds sensible to me and Koni swears by it.

Rutherford AVOs

In both the case of Spax and Koni, the shocks offered are stock items, not specially made and adjusted to the needs of a Morgan. In contrast to this, in 2002/2003, the Morgan aftermarket suspension guru, David Rutherford, spent some time in 2002/2003 with AVO, a small but well-respected shock maker to come up with a better "fit". It worked!

Firstly, the range of extension and compression has been adjusted to meet a Morgan's needs. This makes bottoming out far less likely and makes the most of the tiny suspension "travel" area a Morgan provides. A rubber stop has been incorporated to deal with the impact that CAN happen when we push our Morgans too far and the same stop protects the innards of the shock , unlike Koni where the adjustment mechanism is broken forever. the first time you bottom out.

The adjustment is done with a well placed round dial on the shock body, easy to turn by hand without a tool. The shock has 10 dampening levels. The finish  and dust cover is superior to Koni and Spax and the bumpers are neoprene rather than their rubber (which dries out and cracks).  The included fittings are of a better quality than Spax and Koni.

The dampening has been as soft as Koni up to harder than Spax's highest level. (I use the softest setting on the rear and level 3 on the front). N.B. Please note that the adjustment must be regularly changed to keep it effective.

These are the very best of the three and happily the cheapest...(at the time of this writing.) They can be purchased through Rutherford Engineering or Heart of England Morgans.

N.B. There is another AVO shock designed for Morgans and sold by AVO directly or through other suppliers. It is disappointing and best avoided.

P.S. The writer has no interest in and has been offered no inducement by any of these companies.