This is the first time I’ve seen this particular failure. Maybe others have seen it. This was on a DFXL but could happen with similarly designed struts of other velomobiles.

My buddy complained to me that on left turns, his right front wheel of his DFXL (my former DFXL) has started dragging on the wheel well wall. So I looked for the obvious things like broken ball joints, bent tie, camber and trailing rods, broken inboard mounting points for the camber rods, egged out hole in the strut tower, broken spokes. I removed and inspected the strut and axle for anything obviously bent or broken. Nothing there.

Then, after putting it all back together, I grabbed and rocked the wheel from top to bottom. There was a lot of slop in that motion, but I couldn’t see where the excess play was located. I removed the wheel and screwed in a long M8 bolt into the axle to give me some leverage. When I rocked the axle up and down, I could see some movement between the strut tube and the strut base.

The strut tube is normally bonded (loctited) inside of the strut base and there should be no movement between them. I removed and completely disassembled the strut in order to re-bond the 2 pieces. The axle is also normally bonded in the strut base, but I could turn the axle. So I tapped the axle out of the base to have a look. I was surprised that after a gentle tug, the strut tube slid right out of the strut base. Upon closer inspection, I could see that the strut tube had cracked at the axle hole. I would never have seen this crack if I hadn’t removed the axle which allowed the strut tube to be pulled out of the base and inspected.