Deacon P, Sounds like you chose a cog on your cassette that was outboard of the position of your chainring in front, so the chainline itself was acting like a derailer trying to shift you into a bigger (inner) rear cog, which the chain was too short to accommodate and which your legs were plenty strong enough to annihilate. No doubt the ramps on the whatever-glide cassette were complicit in lifting the chain up to the bigger cog.
I've done the same conversion - under duress, in the field. I was riding my old mountain bike on a trail in the forest near my parents' house, climbing a reasonably steep hill, when my chain got wedged in front. I suppose I was shifting to my granny and thought it had gone cleanly to the small ring, but the one thing I remember for sure was that I proceeded to pedal full force, felt a moment of binding and then BANG! I was sure I had broken the chain, but the chain and I were in fact strong enough to shear the rear derailer in two pieces right through the thickest part of the body! I guess the chain got jammed on the slack side in front and couldn't feed any more chain to the derailer, which continued to get pulled by the tensioned side of the chain. This bike did not have a U-brake (which had been responsible for most of my previous occurrences of chain suck) but it is entirely likely that the chain and rings were worn out, underlubricated, and/or grimy from previous overlubrication. Not wanting to push a disabled bike up a long hill home, I broke the chain and removed the rear derailer (which still had the chain fed through the pulleys), placed the chain on the middle ring in front, and stretched the chain to the middle of the cassette, hoping to find a magic gear in the middle that would fit an integer number of chain links with a reasonable all-around gearing. I found one that worked, used my link tool to shorten the chain, and put it back together (I think with a master link) as a singlespeed, which I proceeded to ride up the hill home. I was not yet much of a bike mechanic so I was quite proud of myself at the time. The chain held its position on the rear cassette for the short ride home, but I wonder if I had continued to ride it if it would eventually have wandered to an adjacent cog, and if so, in the slacker (i.e. non-destructive) direction, or in the direction you seem to have experienced. I enjoy your ride stories and sardonic grins. Daniel M Berkeley, CA -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at https://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.
