28 Dec 2014: Gears – back to the drawing board…

This is what the geartrain now looks like. It’s a 4-speed 14-28 tooth freewheel with a narrow 3/32″ chain. I’ve had to admit that my attempts to get the Simplex 303 derailleur to work on a 5-speed freewheel and 3/32″ chain have failed – the derailleur just won’t shift far enough. I do have an alternative 1/8″ chain and freewheel that the 303 derailleur was designed for, but that won’t give me the low gears I need for hill-climbing, and the 1/8″ chain can’t be made to shift properly at the front on the double chainrings. So I’ve reluctantly spent some more money on another derailleur. This is another Simplex model, patented in the year of my birth and introduced in 1952 as the “Grand Tourisme” or “Rigidex” model. The version I have probably dates from the mid 1950s, but it’s “new old stock”, meaning that it has never been mounted on a bike and is, essentially, brand new.

But there are problems. One is that my Ellis-Briggs frame doesn’t have the two-hole fixing tab that this derailleur requires. Another is that the derailleur was not complete – there should be a long external spring, anchored to the frame, to maintain chain tension. But my favourite seller, Reperages, came to the rescue! I managed to buy from them an alloy gear hanger that replaces the derailleur mounting plate and can be bolted to the chainstay. It means I don’t have to get the frame altered.

I also asked Reperages to find me a tension spring. I didn’t have high hopes but, to my great surprise, they managed to find one for me.

The result is the gearing setup at the top of the page. It seems to shift smoothly, so I hope it’ll be usable.