A search on cracked Kurt Rock and Roll brought me here. I’m not sure that this is germane to the OP’s question, but after about 6K miles, I discovered that my R&R was cracked (pretty catastrophically, and I caught myself right as I felt like I was falling over). I’m 195-200#, and don’t do out-of-saddle on my trainer. I was having problems with what I thought was a failing power unit, I think the failing frame was the root cause. The more I search, the more it seems like fatigue cracking beginning at the welds may be a problem. I was wondering for awhile what those little “ting” noises I was hearing post-ride were (I had thought it was maybe spokes releasing built-up tension or the power unit cooling). So I guess if you’re using an R&R, pay attention to unusual noises, consider the frame when troubleshooting power unit issues, and periodically inspect for cracks or deformation near the welds.