Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Roger's new suspension aids

I think thats a very clever idea and a neat solution to a problem.
I think the price is very good too considering the work I can see that has gone into developing and manufacturing these !

These stops work really well on my 2011 4/4.
I have set the stops to 30.5mm, which seems to work very well.
On Roger's recommendation I used Bluetack as a tell tale, to get a start point.
http://www.talkmorgan.com/ubbthreads.php/galleries/565620#Post565620
The picture was set at 33mm & I lowered them to 30.5 in two stages using a block as per Rogers write up.(ensuring the rear is even)
Near us a piece of road even upsets our jaguar suspension. I have nearly got the Morgan airborne to test the stops. No crashing, just a positive "boof" and no jarring.
Her in doors has even comment on how much improved the ride is. High praise indeed as she hates the car. (in general the stops do not get impacted by the leaf spring, but when it does that is where the change is felt)
Front end is the next challenge.

Thanks IcePack


Well here’s my attempt to quantify the “boof” effect. I've been playing with numbers and apologise to all the suspension experts out there

I very crudely measured the rate of my springs using various weights and a laser off the garage roof. Yes there is loads of scope for error but came to a leaf spring rate of around 135lbf/inch.

The first graph below is the original spring’s performance. My car would typically bottom after 50 to 55mm of movement from rest.

The second graph is the combined performance with the new bigger capacity stops set 30mm above the spring. The crashing has gone and the body movement looks reduced.

I can't claim to understand the graphs but I can tell you that these bumpstops transform the car. It's absolutely the first thing I'd do to any trad. A completely brilliant invention.
Nick

Just found this thread - what a great design/idea.

I found the my axle hitting the wood inner arches within months of picking up my new 4/4. I trimmed out the recesses to stop the axle hitting the body. Then the prop started rubbing - only when road undulations were taken whilst accelerating - didn't have much luck curing that - tried trimming the metal on the tunnel where it rubbed but that didn't help much. Things improved a bit when I got adjustable dampers and a Panard rod fitted - bottoming out stopped for a while.

However still occasionally, with foot down and loaded with 2 people on a full tank it still bottoms out. Worse when the car is driven with enthusiasm, frustrating to say the least. Just about all cars and vans I see in my day job MOT testing have a form of bump stop. Vehicles with leaf springs all seem to. Some are quite battered so obviously come into contact. I'm not surprised to read the comments of those who are lucky enough to have a set fitted to their car - strikes me our cars are crying out for a form of bump stop. I had been trying to cobble something together myself, with no success I'm afraid. Then I found the pictures within this thread.

Wow - really neat - can I have a set please?

Anybody try on a plus 8 mine is a 2000 and sounds like a great idea and improvement

Thanks Andy. As a tester if a car's suspension impacted or was contacting the bodywork would that not be an automatic mot failure from a safety perspective?

PS. Dropping the next batch off for welding on Monday.

Interesting graphs Rog. Tempted to compare with factory 5 link rear with coil spring dampers. The published rate of each coil is 225lbf/inch, allowing only 27mm of compression between unloaded and static load (spare wheel + half tank). Although on a Roadster, I imagine the rear loads are not so different on a 4/4, so you can see why we complain of harsh ride

Rog, can you put me on your waiting list please. Suspension is next un my 'upgrade list'.

your idea looks brill.

Gary

MOT wise - during may 2018 the manual ( testing bible) was re-written. Before that date it mentioned bump stops as a non-testable item. Now they are not mentioned at all, but a suspension component missing is a fail. So it could be argued that a missing bump ( where fitted as standard - note NOT a Morgan trad) should fail - after all its a suspension component. If there is evidence that the suspension has been bottoming out ( eg tyre witness marks on body) its not a fail unless contact is seen during the test.

Rubber bump stops seem to hold up well - sometimes they corroded at the base and can fall off. Worse for durability are the dense foam ones - I see these in various states of degradation on vans, likely where heavy loading has likely over-worked them. I have never come across a leaf spring that's inverted but seen many broken ones. Its amazing how much deflection/movement a leaf spring has when in use. Any suspension unit - leaf, coil, strut, shock etc has to be doing its job - if the body is sitting on its bump stops then it obviously isn't working and would fail.

Motorhomes however sometimes have aftermarket "spring assistors" - these look a bit like bump stops ( sometimes air filled) and are sandwiched between spring and body in constant contact - these are Ok.
Gets a bit complex this MOT stuff - if in doubt "what does it actually say in the manual" is the golden rule.

Rog , great news that you have another batch of the Morgan bump stops in production - very excited about fitting/trying them in my car.