Bump Steer - Part 2 - Theory Into Practice - Part 2!

Did it all again with the steering rack locked - still the same. Fiddled around with the rack height but still couldn't get it any better.

I also double checked the effect of lateral hub movement and the fact that the laser was at a very slight angle - less than 0.25mm (by calculation) on the measurements on the graph paper.

Double checked my trigonometry - OK

??

Having done a trawl on the Internet it appears to be the case that you can never eliminate bump steer in the majority of cases. The aim of the exercise is to minimise it as much as possible. For a given suspension geometry this becomes increasingly difficult at the extremes of suspension travel.

You have to ask the question if the Jag Suspension was ever designed with zero bump steer in mind? - either way we are kind of stuck with it!

Looking back at the graph you can see that changes in toe-in are minimal for most of the suspension range - only at the extremes does it increase. Let's face it - at full droop (i.e. wheels off the ground!) the last thing on my mind will be bump steer!

The change in camber is interesting and to some extents is intended to cater for the effects of roll when cornering. It is fixed by the geometry of the wishbone pivots and cannot therefore be changed.

Now for the best bit-

Where did the rack end up? -

Within half a gnats tadger of where it was set using the parallel straight edge method!!!!

That's engineers for you!

P.S. Check your ride height toe-in after all this and adjust as necessary. Which reminds me - I need to do mine!