Originally Posted by
79pmooney
The UO-8s that Bicycle Exchange sole in 1967 came 52-36 x 14-26. My friends bought these. I had my FW swapped to a 28 and destroyed several derailleurs. Granted my bike was not very well serviced but it was also obvious that I was pushing the physical limits of the plastic bodied derailleur with my setup. I would strongly advise going to narrower gearing if you choose to go Simplex unless there is concrete evidence that the later Simplexes were of a different geometry or construction.
Ben
That sounds like the case of a somewhat too-tight chain, i.e. some combination of too-short chain and axle (derailer claw) position left in a rear-most position in the dropout slot.
My Steyr Clubman came stock with 52-36 and 14-28t, which worked smoothly and reliably until I fitted a 13-24t five-speed UG freewheel and slightly tightened the Simplex Prestige cage pivot spring to tighten up the chain gap between the top pulley and the 4t-smaller freewheel.
I found this gearing (and shifting performance) to be suitable for the more-sporting group rides here in the foothills. I challenged myself to keep up on the usual rides using only five cogs when I found that the Phil-hubbed wheelset I wanted to use would handle five cogs and no more, and then I surprised myself by keeping up on those rides!
That said, I find that I prefer using a 52-42 chainset with a 13-28t
six-speed UG freewheel, which yields that exact same range of gearing while needing relatively little modification to a typical, English-threaded Normandy hub's rear axle spacing.
For reference, 36/24 = 39/26 = 42/28 = 45/30