Hi All,
I've just rebuilt my recently-acquired Claud Butler, 'Electron' Super Five model. It's a lovely, smooth ride, too. The problem is that when I change gear, the chain also derails off the chainwheel, almost every time. Yes, I can reach down and lift it back on, but that's a bit dangerous in traffic. It's when changing to a higher gear only, I can look down to watch the process, and see the nice, smooth change at the back as the chain flicks across to the next smaller sprocket, and then watch the 'wave' in the chain travel along to the chainwheel, and presto! off again.
I should mention that the chain is a new Sram PC 38, a low budget chain, sure, but my other bikes with this chain don't misbehave in this fashion.
I know that some other bikes had this problem in the past, and one cure was to fit a front der. mech. as a 'chain keeper' for the single chainwheel. I'm not sure I want to do that.
The bike had been fitted, at some time, with a six-speed cluster, which required two heavy washers to be added on the axle to allow the chain to clear the stay. That left only two or three threads for the R/H axle nut. Luckily, I've managed to recover the threads, and adjust accordingly. That plus the derailleur was bolted hard on the hanger, so it couldn't pivot. Aaarrrggghhh!!! There's a used Suntour five-speed cluster on now, a good one.
The chainwheel looks good, i.e., not worn out. The chainline, well I think it's a straight line when on 2 nd gear. And I swear there's only 20 to 25 thou" between the R/H crank arm and the chain, when in top gear. The cotter pins don't allow for any lateral adjustment :-(
I can't help feeling that this frame was originally meant to take a gear hub, i.e. a single chainline, and that the derailleur was added perhaps to fill a gap in the model range.
Any suggestions will be much appreciated.
Paul Aslanides.
Ferntree Gully.
Melbourne.