Sounds like you like to live with danger, excuse me for saying so..
Did think about you some few days ago. Comming from the shop, two bags of groceryes, my 26 kg dog and myself on the bike ging down a small hill. Suddenly the donorbikes bb axel dropped out of the dropouts of the main bike (remember I told you not to do it the way I did?). If it had happened in the speed you used to ride yours I do not know what would have happened. We skidded on the senter kickstand for many meters until I realised what had happened, that I was still balancing the thing (dog still sitting in his place) and decided to try to breake. It worked. Just a small scratch on one knee.
This has happend once before, but in a much more safe way, just noticed the rig was a bit "soft" when riding it and not quite straight. Think I was too fast and too lazy when repairing it. I am thinking I should change the setup a little, and also maybe change to a hub gear. The thing is I like this bike so much I do not want to start working on it in fear of that I get into problems so it is not ridable for days (also want to change the rear triangle to a alu one I just found for weight reasons). 80% of my riding is done on this bike since I almost always ride with my dog, and most of the time much longer than he can run.
Did approx 40 km today. He was riding on the bike for approx half of this.