Originally Posted by BlazingPedals
I'm just making a SWAG (Scientific Wild-@ssed Guess) here, but is this trike a delta trike with disc brakes on each rear wheel? Because what you're describing sounds sort of like what I ran into when I did some brake work on my bike the other night. The caliper was too low, which caused the top of the caliper to make contact with the edge of the disc rotor. If there's a little play in your wheel bearings, I can see this happening only when a rider is on it. The solution is to shim the brake caliper out further (radially.) I don't have a Sun, so I can't advise how it would be done, but you should be able to test my theory and if that's what it is the bike shop should be able to figure it out from there.
NO this is not a brake problem....my brake makes some rubbing noises that are much higher pitched. I can quiet the brake by gently squeezing the brake lever.
Our noise is only made when we are applying power to the pedals, and the noise gets louder when we shift up into each gear. It is a loud clack, clack, clack....people can hear me coming for half a block away....it is embarassing.
If it was the brake it should be noisy all the time while we are in motion....but thank you for your suggestion.