not really designed for high speeds, but id expect more than 15mph... tadpoles should be just as stable as a four wheeler... which are as twitchy as the steering ratio...if its direct 1:1, its like a gokart or quad bike, and barely touching the wheel/bars will make it spin... lengthening the arms at the front wheels, shortening the arm on the steering column will raise the ratio,requiring more turn of the handlebars to turn as sharp at the wheels.
is it the small front wheels or big wheeler? how tight are all the steering links? checked alignment/akermans yet? any sloppiness will increase the twitching. any angles that arent correct will affect stability.
leaning your body into turns?
if everythings checking out ok, possibly a steering damper would help. not much you can do about weight placement without modifying things, nor can you do much about steering geometry, which id expect to be pretty well much spot on... other than the fine tuning.
was it assembled when you bought it, and more importantly...WHO assembled it? never trust the monkeys at bike shops to get it right!
reading material... so its a trike, and not a car...the steering geometry is still EXACTLY the same with two front wheels...
http://www.carbibles.com/steering_bible.html
