Originally Posted by rogermo
If you are useing regular bike forks you could try bending the forks for more rake, which will reduce wheel flop. ( Go to recycledrecumbents.com) ADC shows how to bend you forks and so much more all for free. Hope this helps Rogermo
Hi Rogermo,
Having built many "choppers" in the late 70's I always found that fork flop was a function of too much rake. In fact my last chopper built in 83 had a very radical fork rake angle and suffered from an excessive amount of flop. (still easily ridable but no chance of hands off)
A standard wedgie also has fork flop albeit only about 3/16". It seems to me that the only way to get rid of fork flop is to have zero trail, ie the tire contact patch being directly under the steering axis so that when the wheel turned the contact patch remains under the steering axis. or with a 90 degree head angle, then any form of trail would produce the famous supermarket trolly shimmy.
The function of fork rake angles (as opposed to steering head angles) is to move the "trail" closer to the steering axis
It is my understanding that "trail" is the "magic" dimension, too little and the bike is a "lively" steerer, too much and its a "slow" steerer.
I am considering removing the front hangers and welding a set on with a series of slots to check this out.
Yesterday we experimented with the height of the handlebars and found that having the hands level with the shoulders gave a far more positive and secure feeling. Interesting but I would not like to do many miles in that position.
Originally Posted by sch
in my experience the LWB with
relaxed angles on the front and reduced front wheel loading, it takes less for the front wheel to slide
out and hence to fall. Since you are only 15" up, the fall is benign, a bit of road rash on the hip. You learn to keep an eagle eye for sand, gravel, thick paint strips on damp roads and recently clay mud
Its the reduced front wheel loading that lets it slip in the gravel. Our CofG is low down but sits in the rear third approx so letting the very light front contact bounce (more like weight off in skiing) and skip. (I think)
I'm not an engineer and only have seat of the pants experience so If I am wrong here please let me know.