For some strange reason, most recumbents are designed to be twitchy. This may be from bad advice
from the technical community or because the early builders were criterium racers. Who knows.
Now we have a whole generation of riders that think it's good to be at complete attention when
riding and that they must hold the handlebars with their fingertips. It isn't necessary for our
bikes to be so light handling. Yet, some racers even think that a light fingered bike will be
faster. History indicates the opposite. Greg Lemond rode a bike with touring geometry in the TDF. He
did so because he wanted to use most of his energy being a motor and less being a pilot.
A high speed bike should feel more like a motor cycle. It should have a little fork flop to act as
an autopilot and turn into a roll. It should also have an adequate amount of control spring. Mark
Stonich calls this "centering force". AS the bike goes faster, it should be harder to turn the
handlebars.
Control spring can be gained in several ways.
More Trail (which also increases fork flop, sometime too much) Heavier wheels (motor cycles have
little problem with too little control spring" Tiller if you pull back, or Stem if you push forward,
on the handlebars. Actual springs in the control system.
I have an equation in my book that predicts "twitchy"
B/m(1/Kx2 + 1/h2)
B is the horizontal distance of the cg of the bike (your belly button) from the rear wheel contact
point. m is the mass of the bike and rider Kx is a function of the seat back recline angle h is the
vertical distance of the cg from the ground.
So a bike will be more twitchy as the seat moves forward and down. It will also be more twitchy as
the seat back reclines. It will be less twitchy as the bike/rider gets heavier.
A classic method of helping a person adjust to a recumbent is to turn the fork around to
increase trail.
Good luck. Your question is IMHO one of the reasons that recumbents haven't been more
quickly accepted.
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