Trike Oscillation or 'wag.'
New riders of tadpole trikes may experience weaving as they ride.
On an upright 'wedgie' bike, you grip the handlebars fairly firmly and use steering and body weight transfer to keep the bicycle upright and to correct for oscillations due to pedal pressure.
On a tadpole trike, the same technique will cause the trike to weave from side to side - so we have to unlearn the wedgie technique and just lay back, lightly holding the steering and conciously keeping the torso still as we apply power in a full circle to the pedals.
The secret is to isolate the engine (you) from the trike.
The most common problem is pushing and pulling on the steering as you pedal. On a wedgie, you can pull up on the handlebars to increase power. You don't do this on a trike - it's not effective and the sensitive steering of these advanced forms of transport means that you will unconciously steer from side to side.
To increase power, learn to use the full pedal circle - pushing with one leg while pulling with the other and blending the two movements into a smooth circle. At the same time you can brace your back against the seat. This will increase power dramatically BUT IF YOU ARE NOT ACCLIMATISED IT WILL DAMAGE YOUR KNEES. Strengthen your knees gradually over a period of at least six months. This does seem overly cautious but please be warned - knees are vulnerable.
If you get persistent knee pain and you are not straining your knees by pushing then you may be able to correct the problem by using one or more of the following.
Mark the boom and adjust it in or out by five millimetres or less (yes, it's that sensitive.) Ride at least 20 kms, preferably 50, to see if there's an improvement.
Try shorter cranks. I'm six feet (1800 mm) tall and I'm using 147mm cranks. They've dramatically reduced my knee pain.
Get some kneesavers - they extend the pedals out by 3/8th (10mm) to straighten the line between the pedal and your knee.