David...
1) You start 'point 1)' by discussing an infinitely stiff kart and then promtly start discussing 'flex'. ... you can't DO that.
You are making a wrong assumption.... you are assuming that we take the 'mid corner' with lock applied..... the quick guys do NOT! They 'turn-in' in various ways but, once the transition from 'turn-in' to 'mid corner' has ben made, the steering wheel returns to dead-ahead. In that way (other than any flexion in the chassis 'under-load' or 'roll' induced by having the CoF above the contact point... which IS significant), the weight is 'evenly' distributed on all FOUR wheels.
Look at ANY quick kart/driver in any corner long enough (after turn-in is complete) and you'll find it's pointing at a 'tangent' to the inner-kerb to which it is adjacent. That requires a 'dead-ahead' steering position and a 'slip angle' on the chassis.
2) Again, watch the quick guys.... they adjust their seating position (ie., their position IN the seat). Hopping can be reduced by HOW you sit in the seat. For example, if you sit 'stiff-as-a-board' gripping the wheel for 'grim-death' (commoonly called 'all-teeth-and-elbows'), you get ADDITIONAL hopping because the chassis starts to 'bounce' on the inner wheels. If you 'soften' your 'stance' you absorb and 'dampen' any 'bounce'.
Many karts have their seat with the bottom 'above' the lowest point in the chassis rails.... on most circuits, you only need 1cm ground clearance so long as you don't take the centre of the kart over the kerbs. In that way, you can lower the seat so it's BELOW the chassis rail.
If you are carrying lead, lower it down the seat. Make sure that you have the lowest engine mount. Run LESS fuel (more fuel sits higher-up the tank), use a lighter helmet, LOSE WEIGHT (ohhh, pot and kettle come to mind here!), hire a SHORT DRIVER! And so on.
3) Work out how MUCH the axles flexes at maximum load. The tell me it's enough to explain the angle that the kart 'rises to' in hopping.... it ISN'T. The hopping is NOT axle or CHASSIS flex! It's simply a cycle of grip-release.
I can comprehend your argument that it's the 'vibration frequency' (natural 'tone') of the axle that drivers 'feel' when they change axle..... BUT.... all THAT does is to reduce grip. Fitting an axle where the 'frequency' of the axle is 'perfect' would be INCREASING the grip. If you choose the axle to REDUCE the grip.... you may as well do it cheaply by pouring water on the tyres mid-corner....
Ian
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