Is it normal for the front tyres to kind of drag, while moving slowly on full lock ?
Yes, which is why cars have Ackerman steering geometry. The turning radius of the two front tires (and rear) at low speed are different. So the inside steers a bit tighter radius to accommodate reducing tire's scrub during low speed cornering. However, this (just like every other aspect of engineering) is a compromise. As the tires slip angle increases with increasing lateral acceleration, less Ackerman is required than at low (or zero) slip angle. Another way of looking at it is given a corner of say 50 radius; to drive at 5 mph requires a certain steering angle. Drive the corner at 40 mph, and it will require less steering angle at a given instant in time (or more for understeer (too much slip angle) and less for oversteer (not enough slip angle)). So at low speed, Ackerman is not optimized to gain handling advantages at higher cornering forces. Best regards, Rob
Cheers Rob, I understand the Akerman principle from long time ago at college Just seems really extreme, like the wheel nuts are loose! Fed up with the sideways glances from passengers Stewart.
Race cars I've done in the past actually had negative Ackerman, and we built skinny wheels and tires to push the car in the pits and paddock because of the low speed scrub due to the steering geometry. The geometry was optimized for about 8 - 10 degrees of tire slip angle at high speed.
I had the same thing happen in my 360. The way the front tires are toed has caused increased wear on the medial edges causing the unbalanced feel of the front tires at slow speeds at full lock.
