interesting !joshuagore wrote: ↑Fri Mar 13, 2020 1:14 am....Jim Papadopoulos https://www.nature.com/news/the-bicycle ... cs-1.20281 or you can go back to the work of Tony Faole in Motorcycle Chassis and Handling and Dynamics.
...I have been building riding and tinkering with zero trail or reducing trail suspension, and traditional suspension using bicycles and the larger 'mid fat' tire carcasses available ....
....on a zero trail setup, or negative trail front suspension I CAN ride no handed, but it isn't always easy ....
the Nature link shows what might be called balanced steering geometry
ie the 'weight' on the steered wheel not trying to increase (aka 'flop') or decrease the steering angle
this 'balance' happening due to the steering axis exactly bisecting the 'rolling radius' (line from wheel centre to ground)
for each steering axis angle there is only one fork offset aka rake dimension that gives this 'balance'
that's why traditionally each different frame angle had its (correspondingly different) fork rake
using any other fork offset (too often done in this carbon age) gives a bicycle that cannot be ridden 'hands-off'
reducing trail (or increasing it) will lose this 'balance' unless corresponding alterations to offset are made
yes Tony Foale's work was interesting - did it benefit anything ?
yes Moto GP etc knowingly departs from 'balanced' geometry
and off-road does - as soft surfaces make the mechanical drag on the wheel act ahead of the rolling radius ?
and yes motor cycle tyres are much wider than bicycle tyres