Bump stops

John Murch · Posted: Sat Aug 18, 2018 6:09 am Post subject: Bump stops

The rear suspension rubber bump stops on my car must be decades old and are nearly as hard as the steel of the chassis, so do little to relieve the thump when the suspension bottoms. (There is only about 4.5 inches of travel between axle and chassis).
Finding a softer alternative is proving difficult - does anyone have any ideas?

I could, I suppose get the springs reset and raise the ride height but don’t want to as I like the car’s current stance.

Robert Zannetti · Guest

I have just measured mine and the clearance between the axle (actually a collar round the axle close to the hub) and the chassis is 5.25". In the same manner as yours the bump stop has no detectable flex and is probably as old as the car (1925). I shall watch for any replies you get for their replacement!

John Murch · Posted: Sat Aug 18, 2018 8:05 am Post subject:

My stops are bolted in place with two fixings about 3 3/8 inches apart, if this is a standard dimension, I would consider having a little batch made.

John Murch · Posted: Mon Aug 20, 2018 10:50 am Post subject:

I have found a firm that could manufacture these bump stops, probably using a much more efficient material than originally used.
I have asked the spares scheme if they are interested in taking it on, if they are not, I shall have some made for myself and would have extras done at the same time.
Would anyone be able to advise me, should I sell on the extras, do I lay myself open to all kind of potentially nasty legal liability?

John Murch · Posted: Mon Aug 20, 2018 1:04 pm Post subject:

I have just discovered that both RC Moss and William Medcalf can (apparently) supply bump stops, so will investigate these.

John Murch · Posted: Tue Aug 28, 2018 2:42 pm Post subject:

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These are the bump stops supplied by Benchmark Engineering - I have ordered a pair, they should be rather more progressive than the standard item.

These can be supplied by RC Moss and are to the original design (I think).

http://www.vintagebentleys.com

John Murch · Posted: Fri Sep 14, 2018 10:29 am Post subject:

Benchmark were most efficient in sending me the bump stops and said that I could return them if on inspection they didn’t suit.
I did return them (for a prompt refund), they are probably great for a Peking/Paris rally car, but were still on the hard side and left me with very little suspension travel.
I am going to experiment with some Ford Transit stops (in luminous yellow, which will rapidly change to grime colour!).

Robert Zannetti · Guest

As indicated above I was keen to replace my rather solid bump stops but decided to fabricate my own. I know this sounds a little "Practical Boatowner" but read on. Material was a lump of rubber that is sold as a jacking pad for four point lifts, It can be cut using a saw but the more open the blades the better. I tried on my mechanical saw (aquired from the late great Laurie Fox) but the teeth were too fine. The best results came from my Radial saw that had a 'rip saw' blade where the teeth were big and apart! As can be seen pretty well the whole thing can be made with the saw except the hole. I drilled this on the bench drill, finished off with a Dremel. An American website suggested that the machining could be facilitated by freezing the block in liquid nitrogen but despite looking very carefully found that I did not have any.

John Murch · Posted: Tue Nov 20, 2018 12:06 pm Post subject:

That looks an excellent job. At present I have one modified transit stop fitted, the other one is resisting my efforts to get it off.