Ride Height

[Peter Brooks]

I know that this subject has been covered many times before, but I cant find a thread to answer my question.
In the Haynes manual for the 2CV it advises setting the ride height higher at the rear than at the front.
I can see that this makes sense for the car in its original form as it was designed to carry various loads for french farmers.
My question is, that in its cut down form of the Lomax should the ride height be set at the same height at the front and the rear?
After reading the vavious other hreads I was thinking of setting it at 200 mm all round to allow for my weight over 13.5 stone and road humps, bad road surface etc.
Any views/help/comments
Peter

[Duncan Grimmond]

The lower you drop the front end the more you affect the castor angle. It's a difficult balancing act unless you have the front arms modified to allow for the lowering of the suspension. It is possible to get to the stage where you greatly enlarge the turning circle and end up with serious understeer. Somewhere in here is a drawing showing the preferred angle for the king-pins on a Lomax but I can't find it...

[Ken Hanna]

Peter,
I don't think that you've provided enough information; the measurements given in Haynes are to the _underside_ of a 'Citroen style' chassis, which is about 110mm deep.
It's been a while since I looked at a Lomax chassis, but from memory they were shallower, perhaps 60mm depth, so you'd really need to quote figures to the _top_ surface of a chassis to enable direct comparisons to be made.

Fwiw, I set standard 2CVs, Dyanes, etc, about 20mm lower at the front axle than originally recommended.
Most folk do not use their cars for traversing ploughed fields nowadays and any increase in steering effort due to the slight increase in castor angle is minimal.
Also, note that any change in the rear ride height will not affect the castor angle of the front arms, despite advice to the contrary.
However, if only one rear spring is active and there's no bump stop provided, you may wish to try test loading the back end before lowering it too much...

Ken

[Peter Brooks]

Ken, thanks for the advice. I have measured the chassis and it is 100 mm deep. I intended to set the distance between the ground and the bottom of the chassis to 200mm both front and rear which added to the chassis depth would give an overall height from the bottom of the floor pan to the ground as 300 mm. Does this sound around right or should it be lower. Peter

[howardjs]

Hi,
Yes the comments regarding the front ride height are correct, the castor angle should be 15deg. most Lomax are set lower for appearance sake, but this results in the caster angle increasing sometime to over 20deg. This results in heavy steering. Also makes the wheels look as though they are falling off when on full lock! As for the rear ride height, its a matter of how much load is in the car. If set too low the car will hit the bump stops (if you have any), and affect the look of the car's profile. If you set so the car is level along the bottom it will look as though it is dragging its rear on the ground when loaded. The new Morgan 3 wheeler is like this, it looks like it is trying to plough the grass with the back of the body. In contrast if you look at the Blackjack Avion or Zero, the rear of the body tub on these cars sweeps upwards and looks much better... I think anyway... A little higher at the back is better.

Howard

[david]

I can email the drawings to show how to alter the king pin angle...
from hints and tips some yrs ago...
David
if not done it is also difficult to make a clean 3 point turn as the wheels don't they just lean...

[howardjs]

download/file.php?id=34

[david]

The hints and tips not only show several different ride heights, but also describe how to correctly cut and revolve the stub axles to alter- regain the correct king pin angle.
David.

[Peter Brooks]

Thanks for the on line advice and the phone calls.
I will give a go and hope by trialand error I get it right.

Peter

[trikehound]

Hi,i have just set up my own car (223). I found some really good information on line plus pictures! Try entmontage-chassis suspension, clear as a bell information.It tells you to use flat ground and take off as much weight as possible .i.e. spare wheel,petrol etc. Uses the same hieghts as a 2cv,the fronts at 192.5-195.00 rear around 280 mm,looks fine to me!Do not forget to jack each wheel as the torque on the tie rod is to great otherwise! Having measured another on the road 223,this is slightly lower! Good Luck!