Bump stop on a Chrome Bumper

How much space should there be between the bump stop and the lower spring pan?

I guess you mean between the rubber bump stop and the pedestal/plate on the axle that it bumps against?
When the car is at ride height there should be at least 2.25 inches, to ovoid snap over steer, say the experts. It is going to depend to a certain extent on spring rate. I do know that I have snap over steer at 1.5 inches. I cut about 20mm off the rubber and it went away.

Thank you Peter.

My bump stop has been both cut and has had the spacer removed too (along with a modification to the bump stop "braket" to account for the missing spacer).

Is too much space a bad thing?

I am not sure what you mean by spacer.
http://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=29025
If you mean the pedestal (#13). I would replace it, if you've got room. My memory is vague on this but I think it was around 10mm thick.
However, as long as your shocker is not being damaged by excessive upward travel (and you can measure that by unbolting the shocker arm) you should be fine.

Hi Peter,

I see where the confusion lies. I'm speaking about the FRONT bump stop relative to the where it contacts the lower spring pan. I guess I should have put "Front" in the title.

Oh :S

I can't see a problem, anyone else?
Bump stopping is going to work better with a full bump stop, but not much. I've got mine cut, but I haven't removed the spacer.
I'm going to replace them with a new set soon, on general principles. I intend removing the spacer and cutting the metal. I don't have a tig and I suspect an arch welder will just melt the rubber, so I might try just a single centre bolt instead as each half has its own pair of bolts any way

remove the spacer, cut the bumpstop in two and bolt it back.....don't weld.

Ok I'll bite what about the rear,what about the rear why is it needed I have lowered my 75 anf keep bottoming out but it is still 1/2 to high. Wasn't the chrome bump stop located under the "added Nader" what would happen if it was changed to give more area?

When I first lowered my rubber bumper about 2 inches, I left the rear bump top alone. I then found that I had ferocious snap over steer. Snap oversteer occurs when the bump stop contacts prematurely on the outside, side, in a corner. ie When turning right, this would be the left hand side, the outside This in turn levers weight off the inside wheel (the Right hand side in this example). A sudden decease in tyre area on the road, and a dramatic loss of grip at the rear. The car will have a tenancy to fish tail in the rear, if you are quick enough to catch it. If you are not quick enough, and you can't be quick every time, then you will put the car in an end for end spin. I managed a 7 turn spin one day and promptly decided to find the cause of this.
I found a net site, some guy in New Zealand if I remember rightly, that recommend that you have at least 2.25 inches between the bump stop and the pedestal on the axle. At the time I had about 1.5 inches. I cut about 20 mm (to the line you'll see) off the rubber bump stop and the snap oversteer completely disappeared as if by magic. The quickest, cheapest, easiest and most successful suspension change I have ever made!

The rear anti sway bar should not be used on MGB's at chrome bumper ride height for a similar reason. You do not get snap oversteer as produced by sudden bumpstop contact. You do get a more gradual effect. At chrome bumper ride height the rear antisway bar does more harm than good. At rubber bumper ride height the amount of roll it reduces makes it worth the loss of grip, trade off.

About this much when off the ground



Hell, I don't know and it's too cold (19 degrees) to go out there and measure, sorry.

great picture Peter.... on a car that has short front coil springs, you could get bottoming on the bumpstop, so...............take it off, cut it in two and bolt back on leaving out the alloy spacer. Might have to trim the cut a couple of times until you get it right and both pieces will bolt back on without hitting each other. That answer the question on the front?