Was out for my first trip of the season last weekend when I felt something give in the seat. Twisting around, I could see a white rib sticking up several inches out of the seat on one side. I pushed it back in several times but it would quickly work itself back out. Finally I gave up on it and just tried position myself as comfortably as possible in the now lopsided seat. However, I guess that put too much strain on the other side because half an hour later that side also gave way. From that point on pedaling became extremely uncomfortable on my lower back. When it became too excruciating, I hauled on my bow line with my non-rudder hand to relieve the pressure on my back. Luckily I was on the way home and had only a few miles to go.
When I finally did get back, I examined the seat and found that both of the back straps had been torn off, allowing the ribs to escape their sleeves:
The material of each sleeve is doubled over by 3/4" at each end, forming small pockets presumably designed to trap the ends of the ribs. Those pockets are still intact, so either the ribs were never put into those pockets or the ribs managed to slip out. However, it's hard to see how the latter would happen in ordinary use as the ribs would be a pretty tight fit in the pockets. Anyway, with the ribs out of the pockets, the only thing holding them in was the stitching of the straps, and that wasn't strong enough.
So now I'm wondering what's the best way to fix it. I had no luck trying to get the ribs back into the pockets. Is there a trick to it, or are the sleeves sewn onto the seat with the ribs already inserted? And then how to keep them from coming out again (assuming they were correctly assembled in the first place)? Maybe drill the ribs and rivet the whole thing together? Any ideas appreciated.
