The 93 cranks, their 86bcd cousins, as well as the similar SR Apex cranks are possibly the 3 most troublesome '70's cranks in terms of using modern chain. Credit the thick spider tabs and rings themselves, which lack the beveled inner side below the teeth.
Even 1950's steel Stronglight cranksets handle 9-speed chains in my limited experience, but not the above 3, which can have the chain skating and/or getting wedged between rings (causing immediate bending/dishing of the rings) even when used with common 7/8 speed Shimano HG chain.
Since I've used 93's for lots of my riding, I've have to remove the inner ring and bend each tooth <1mm or so to the right. Simply beveling the inner ring's teeth, which similarly re-locates the tips of the teeth rightward, also curiously led to the chain getting tossed to the inside (but ultimately might have been simply a matter of too much beveling on my part). For what it's worth, I can bend all of a ring's teeth within a few minutes and have yet to break one using a 6" adj wrench.
David Snyder Auburn, CA usa
----- Original Messages -----
Jim Carter wrote:
Not exactly the same, but I am using a Stronglight 104 crankset with what I believe is an 105 bis 52t outer ring (drillium), an unknown model 42t inner ring (maybe 93) with an 8s chain (either a SRAM PC-48 or PC-58) and have not had any issues. It's on an OT, but not OE '83 Trek 600.
Emerson Johnston wrote:
Has anyone used a Stronglight 105 inner ring on a 93 crank with a modern 8 speed chain. I think the chain might get stuck between the outer an inner rings?
The teeth are beveled on both sides of the 105 ring so that if a 105 ring were used on a 93 crankarm the effective separation between the chain rings is increased slightly I dont think having both 105 inner and outer rings would work but having just the 105 inner might.
Thanks in advance