On a long distance ride the riders behind me noticed a puff of smoke and smell of rubber when I hit a bump. I have my preset at 25, because I am carrying 6 days of cloths for wife and I. I was thinking of adjusting the based of the spring to hopefully add a little height. Can't budge it. Bent spanner wrench. Tried lifting at frame to relieve pressure on spring and lifting under differential, no luck. I am open for suggestion. Trike has 42K miles, 2010GL 1800. Did replace rear tires with exact same tire.