I have a new bike ( Clean 1973 Raleigh Gransport, $75 shipped, whoo-hoo!) with a Stronglight 93 crankset. A previous owner chucked the outer chainguard, moved the middle ring to outer position, added a 48T middle ring, to get a triple (42 - 48 - 52)
The chain looks like an early 1990's sedisport.
Shifting from middle ring to large ring, the chain frequently jams between the chainrings. These are original 1970's stronglight rings which have a shoulder on one side only. The shoulder on the side where the countersunk hole for the chainring bolts is. In its current configuration, the shoulder from inner-middle-outer when looking down while riding in the saddle are on the left, left, right. This keeps the middle and outer rings as close as possible together, flat-side of these rings against the spider.
When i shift onto the middle ring, the chain appears to be centered between the inner and outer rings.
Is this crankset unfriendly to narrow chains ??
- Don Gillies
San Diego, CA