Bump Steer ....on a Morgan Three Wheeler

[paul jacobs]

Right, now we are getting technical, great.

 

Peter, you ask what the actual symptons are? My first feeling was that I was not experiencing bump steer as such, but violent kickback through the steering wheel when one wheel or the other drops into a pothole, or goes over uneven road surface, which is why I am trying the steering damper. I'm wondering if the size of the wheels, 19" and obviously narrow, have something to do with it?

 

The steering is pretty lifeless and dull, and I do not have much confidence in it, being difficult to place the car accurately on the road, and it weights up a bit when starting to turn a corner, there isn't very much self centering, the wheel is just quite heavy. It appears to be quite stable under braking though. When bouncing on the front end the wheels can be seen to go in and out quite easily.

 

Paul

 

[BenF]

I think Peter is really onto something with the kingpin offset (point 2 in his post).

 

What is alarming from the photo in Arnie's post is that mount for the spring/damper unit is about 1/3 of the way along the length of the bottom wishbone! Poor structurally, although presumably for packaging reasons that was the least worst solution.

 

Ben

[6speedmanual]

Hi Ben

Yes, I was going to mention that, but thought my post was getting a bit long aleady.

Hope we have not killed this the 3 wheeler dreaam with all this critical analysis.

I like that Mog. More conpanies should do crazy stuff. Only Morgan can get away with it due to their eccentricity. Just I feel they should in this era make a proper job of it not a "characture" / "toon" machine. They seem to have put giod engineering into their latest 4 wheelers.

I do like that Mog....

Peter

 

Edited out post pub typos

 

Edited by - 6speedmanual on 18 Aug 2012 06:05:20

[paul jacobs]

I don't think it is a matter of killing the dream Peter, as the car is just so much fun, but as the factory don't seem interested at the moment, my plea for help is more a matter of getting it to work properly, so it can be even more fun.

The whole front end set up is a little odd, at least to someone weened on Sevens, but as you say, it is quite difficult to package it around the engine and exhaust pipes, which incidentally restrict the turning circle drastically.

 

Paul