As Robbie said above.......
Roadsters of that era had Devol bushes and steering damper blades. The track rod angles were compromised leading to bump steer. The first owner of my Roadster was so unhappy with the steering feel that he had some quite direct exchanges with MMC, because he thought it was dangerous. The outcome was that before I took over, the stub axles were replaced with bronze bushes, and this levelled up the track rods, thereby improving steering feel. Now my Roadster track rods are almost level, and the track rod ends are below the steering arms.
A 2004 Roadster will more than likely have had a kingpin change, so may not still be to original spec.
What puzzles me is that the S1 Roadster continued most of the Plus 8 specification. Mine even has front springs marked Plus 8, and yet I've never heard a Plus 8 owner of the 2000 era complain about bump steer. Maybe the steering rack was moved.
Something was perhaps really different, but I do not know the exact anatomy of a +8. What I do know is that the track rod on a Roadster is fixed to the stub axle in such a way that it is not level to the ground. They end up on top of the fixation bracket on the stub axle, thus pointing slightly upwards. This ended up considered as a failure, increasing bump steer. On other cars (as far as I know, and possibly including the +8?) they are fit on the underside of the bracket, as experience has shown they should be.
Mulberry used to offer a service to correct this: you sent in your stub axle, they re-machined it so you could re-fit the track rods with the fixation bolts switched 180 degrees and the rod fit on the underside of the bracket. They do not advertise this any more, but they might still do it on request.
My car is also Roadster S1, but it is the only Morgan that I have extensive experience with - so I cannot compare. But I am rather happy now: after having installed BRBs (which calmed down the front end), Panhard rod (calming down the rear, much more precise cornering), steering damper (reducing, but not eliminating bump steer) and finally fitting power assisted steering (which made road handling in all circumstances a breeze). PAS is not a DIY job (at least not for me), the rest was. Fun to see the improvement after each mod. My recommendation? Provided bump steer really is the problem, a steering damper.
DaveW, your instruction for fitting it was extremely valuable - as I now have fitted two more dampers on friend's cars.
