I would look into cupping or simply low tire pressure. I know when Lola's front tire is low ( 35 psi ) because she will wiggle. Put 40 in there and she smooths out.

Here's another wierd harmonic thing- I can ride a passenger or carry a heavy load with no wobble, but put 5 or 10 pounds back there and here goes the wobble.


2005 Model . Two Fast Eddy stickers , a bell and a clock . She's Lola . She tinkles and keeps time . http://s649.photobucket.com/albums/uu211/britbike05/