Lowering the front and Raising the bump stops??

[504ka]

Ive read through many threads about lowering the front of moggys and fully understand the consequences of just dropping it on the splines/plate without further modifications, this is partially through my own experience of battering the inner wings and more through rot than damage have just finished replacing everything forward and including the door pillars.

I would like to maintain the car at its current, not excessive lowered height (stance is everything!) but obviously dont want to undo all my hard work by destroying it all. Soo, on all of the threads it is recommended that the bump stop is cut down and re shaped, which makes sense as this allows for greater upwards travel. But wouldn't re profiling the bump stop effectively increase its spring rate and reduce its ability to absorb bumps which could lead to damage? After reading on the Beardmore brothers site about the roadster pick up

http://www.beardmorebros.co.uk/website% ... pickup.htm

It says that marina torsion bars were fitted and the upper bump stops raised. What do people think about this and has anyone here done it?

I plan on also fitting tele dampeners and 50%ish Uprated torsion bars to help.[frame][/frame]

[bmcecosse]

There is very little room to take anything worthwhile off the front bump stops - and still leave them 'effective' in any way. You could fit AEON progressive stops - these are available from some of the Mini suppliers and could be adapted for use on the Minor front end. At the rear - there is more room to take an inch off the rear stops and still leave them long enough to be effective - or again -AEON progressive stops could be easily fitted. In each case - make sure the dampers have sufficient travel to allow the suspension to move full stroke assuming the stops are squashed completely flat in extremis! And as always - I recommend more viscous oil in the dampers which makes a grand difference.

[charlie_morris_minor]

The marina \ ital torsion bars need to come from the van \ pickup if i recall correctly. It was a popular mod when they were readily available in scrap yards, but as they are no longer readily available i do not beileve any one does the adpator plates any more that extend the back of the marina torsion bars to allow them to fit on to the moggy.

[504ka]

There is very little room to take anything worthwhile off the front bump stops - and still leave them 'effective' in any way. You could fit AEON progressive stops - these are available from some of the Mini suppliers and could be adapted for use on the Minor front end. At the rear - there is more room to take an inch off the rear stops and still leave them long enough to be effective - or again -AEON progressive stops could be easily fitted. In each case - make sure the dampers have sufficient travel to allow the suspension to move full stroke assuming the stops are squashed completely flat in extremis! And as always - I recommend more viscous oil in the dampers which makes a grand difference.

Thats what I figured BMC, there doesn't look like much could be taken off the fronts and I remember it used to feel quite harsh when the trunion hit them at there standard length, so trimming wouldn't help much I guess. Thats why i was thinking of raising them. I have been cleaning up the suspension components and just modelled it all up, the trunion almost touches the inner wing without bump stop when the lower wishbone touches the body. (I have trimmed the spot-welding tabby thingy and seamed the inside). Im guessing a standard bump stop wouldn't compress less than half its length, its pretty tough rubber. The bump stop is around 3 inches long so by raising it up by an inch then its should stop the suspension over travelling just before it came into contact with the body.
The progressive bump-stop is a really interesting idea that I shall go down the shed and toy with!! It might also require the inner wing to be moved up by an inch as its not going to compress to nothing. Have you used this type of bump stop? how did it feel to drive and what distance was the suspension from it when the car was static and settled?

have you used these progressive bump stops, I really like the idea exerience

[504ka]

The marina \ ital torsion bars need to come from the van \ pickup if i recall correctly. It was a popular mod when they were readily available in scrap yards, but as they are no longer readily available i do not beileve any one does the adpator plates any more that extend the back of the marina torsion bars to allow them to fit on to the moggy.

Ahhh gotcha, shame as Birmingham centre want a lot for theirs

[IslipMinor]

The front (and rear) of our Minor has been lowered about 2" for the last 40 years and works very well with slightly shortened/reprofiled front - about 1/2", (and rear about 1") bump stops. I have never tried to run it lowered without either engine oil in 'heavy duty' front dampers, or with the Marina van torsion bars fitted 15 years ago, along with Koni telescopic dampers. The only time there was any slight mark on the inner wing was a long time ago when the RH bump stop rubber came apart from its base.

If you do decide to lower it, fit a spacer of around 8mm or more between the eye bolt and the chassis leg to correct the camber geometry that goes very positive when the front is lowered, but make sure that there is at least 1 thread showing beyond the eye bolt retaining nut. Ideally a hint of negative camber improves the steering response with radial ply tyres. As a useful by-product, spacing out the eye bolt moves the end of the wishbone out, which is then brought forward slightly by the fixed length tie bar, thus increasing the castor, giving a better 'turn in' response to the steering. Win-win!

[polo2k]

On Igor Im probably going to use a bumpstop on the shaft like this:

[bmcecosse]

And where will you put the shaft...he asks innocently..... The forces on the mounting point will be enormous - especially on full bump.... I have used the Aeon bump stops on a Mini - but not on a Minor. The standard front stops are pretty well 'solid' - so hitting them is not much better than hitting the steel inner wing! I have thought in the past of trying to relocate the front dampers lower and slightly inboard - so at rest the top arm is horizontal (or even slightly angled upwards) and will therefore make the front hub go negative on bump. How to arrange a good solid mounting for it is the problem - but if extensive welding is in hand anyway - it shouldn't be too difficult. And yes as Richard points out - some negative camber and a bit more castor is ideal - and costs nothing !!

[polo2k]

There are plans a-foot. Hopefully ill be out there this eve so ill try and get the mountings all set up

[rayofleamington]

There is very little room to take anything worthwhile off the front bump stops - and still leave them 'effective' in any way.

I can only guess that is pure conjecture?
I've shortened the front bump stops on lowered cars with no problems at all - as have dozens if not hundreds of others.
The bump stop is pretty hard - as already mentioned on the thread, so reshaping to keep the vaguely 'cone shape' helps to make it more progressive. Simply cutting an inch off it 'flat ended' will make it more of a thump than originally intended.

The other reason for the bump stop design is to limit the torsion bar travel - if the trunnion goes as far as the inner wing you are are at the elastic limit. When the suspension is lowered the travel to inner wing is less and therefore you've not got the problem of taking the torsion bar to yield condition. Changing to uprated torsion bars does beg the question about how far the suspension can travel before the bar yields however as most people use them in conjunction with lowering, that's less of an issue.

[bmcecosse]

I did say 'and leave them effective' - obviously they can be shortened.......

[moggles]

Ray raises some very good points about the reasons for having the bump stops, and why they are so hard.

My approach has been to soften the existing bumpstops and make them more progressive. I've always had good results by taking to a new bumpstop with a 1/4 inch drill and making a series of drill holes into the rubber, with decreasing frequency the closer to the base. I first did this with my 55 van about 15 years ago, and 110,000 miles later the bumpstops are still in place, neither having fallen off nor split or crumbled. This seems to be longer than standard bumpstops last on standard ride height, and nor is there any sign of the distortion of the panel above the bumpstops.

I also drill throught the metal baseplate of the bumpstop, and screw in a 35mm self tapping screw. This seems to resist the shearing forces on the bumpstop, and makes them last much longer.

[rayofleamington]

I first did this with my 55 van about 15 years ago, and 110,000 miles later the bumpstops are still in place, neither having fallen off nor split or crumbled. This seems to be longer than standard bumpstops last on standard ride height, and nor is there any sign of the distortion of the panel above the bumpstops.

I also drill throught the metal baseplate of the bumpstop, and screw in a 35mm self tapping screw. This seems to resist the shearing forces on the bumpstop, and makes them last much longer.

Wow -fabulous tip
I'd wondered about reshaping them externally but now you've mentioned it, cross drilling them is a far better idea! With 110k miles proof that it works, the idea is hard to beat.
I'll probably be doing that on my cut down ones on the project (low rider) Minor.

[504ka]

Big thanks IslipMinor, that has given me the confidence not to raise the stops. I cleaned all of the suspension components up tonight so shall be assembling both sides tomorrow to check everything is swinging around aOK! I have replaced both inner wings so I will also check that they are of the same height as each other relative as well as I have a suspicion they are not :S,, will tell more tomorrow with sum pics. Might even get a resto tread up.

Loving the idea of drilling the stops, are you making this holes down the centre axis of the stop or radially?

Also as a matter of interest my friend has just replaced his brakes on his Rover 100,,, so 2 callipers and discs are available for offering up to the Moggy I think ive read all the posts on here regarding disc conversions and know many peoples views but will be giving this a go anyone heard of this being done before or possible issues? The discs are 240mm dia and can be upgraded to mgf ones which are vented. I figure that seeing as i shall be running 13" wheels same as the metro and mgf there shouldn't be and performance issues I have got access to a machine shop (turning id of disc, new holes and mounting plate
0 and whilst i have a basic understanding of the machines I can get anything made up.

I also am aware of the required master cylinder mods and shall be giving the brakes a shot with the original master cylinder first but am thinking of using the metro master cyl through a linkage mechanism from the original pedal, forwards to the engine bay and have the MC mounted vertically next to the starter motor. Would be neat to fill that space and keeps me away from bulk head mods, which could be a DVLA issue.

[bmcecosse]

MGF wheels are 15", later models 16".

[504ka]

Booom!, all the better!