Originally Posted by
joedab
I wouldn't say I am shifting improperly as this would be the method with only one front chainring, though I can see how leveraging the chain against cogs with more teeth would put less wear on the drivetrain over time. I usually don't encounter enough long downhills to necessitate shifting to the larger ring, and with my shifters on the downtube, I have become accustomed to keeping my left hand on the bars while sparing my right for the shifting.
This bike for a novice rider and therefore I would like it to have as few restrictions as possible. I have tried 'transplanting' foreign spindles into existing cups and have not been able to adjust them properly; there are standards for the thread pitch and diameter, but I think the diameter of the race from different models/manufacturers can vary and therefore do not guarantee a proper mesh.
I know it's a completely egregious solution, but I am leaning toward tweaking the rear triangle slightly to the left, partly because this how I found it before the cold set. It is currently centered, measuring the same distance from the seat tube to a thin cord strung around the headtube between the two rear dropouts. But since it only rubs whilst in the one smallest cog, I figure the adjustment would be minimal and unnoticeable. The rear wheel can also be rotated slightly counter-clockwise (from above) to compensate.
Then although the chainring to seat tube distance and spindle length seems to be spot on according to sheldon brown's specs for double cranks, it does seem a bit close to the chainstay and so will try to dig up a slightly longer spindle and hope it meshes, but if not would consider going with the former fix. I have pictures comparing the range of the chainline and a pic of the proximity of the crank to the chainstay.
Say it any way you want -- it's still cross chaining and the drivetrain was not made to do that. See photographic proof above.