Counter steering...little known or understood



Because JosephGarcia indicated an issue with his springer forks, I thought I'd post something about counter steering.
Bicycles and motorcyles have to use it inorder to turn. When cornoring at speed and running wide in the turn, one counter steers to bring the bike down to stay off the shoulder or worse out of the way of on coming traffic.

Not understanding counter steering and being able to use it at will(instead of unconsiously) is a real issue with many riders. The other major issue is target fixation. Read this or Google for something better.

Video showing counter steering It gets good at 2 minuets so don't rush it.

So...What do loose forks have to do with counter steering? As rotational speed increase so does the inertial mass of the tires/wheel assy. These guys are the gyros we balance on and the really resist a change in direction. This is why spinning tops don't fall over.
So a loose fork will act like a spring causing instability. At high speeds on a motorcycle a full on tank slapper can occure.
Raked out front end are slow steering and are less suseptable to oscillations, even when they become loose/worn.
Steering head bearing are often neglected and do need servicing. On some motorcycles over tightening can cause issues particularly when ball bearings are used, tapered rollers are very tolerant of over pre-loading.

The thing is, issues that never happened at 15mph seem to really magnify at 30mph++ when a loose fork is trying to change the direction of a tire that has gained 4 times the inertial mass by going from 15 to 30mph. Now figure going from 15 to 45mph and things get real interesting in a big hurry.
I can hear it now. "Hey Ol' Pete, my rig is super stable at 44mph." I say, OK, go that fast and then change direction to avoid a rock or pot hole. :eek: :)

The front end of a bike is uber-important, from tire pressue, to spokes, to wheel bearing, to forks, then steering head bearings. Shoot! Guys that race super stock motor cycles strip them down and have brand new frames lazer beam bending. :eek: New $10k+ bikes and the frames are not true enough for the track.

JosephGarcia, I don't know what to tell ya. High end springers have bushings or bearings that can be replaced. If your forks have neither, maybe a machinest could hone/ream them out for oversized pivot pins. You might get bigger pins to fit but the holes would be untrue and the service life very short.

The best M/C or bicycle front end ever made was called girder.