Originally Posted by
Duke7777
iab - Looking at your Cinelli, I see how you are able to get your GS to work on a 28. The small difference between chainring sizes allows you to have the jockey cage fairly wound up even when on the small ring. I would assume the OP is planning to use chainrings with a wider spacing than on your Cinelli, as it sounds like he is seeking fairly low gearing. Also, I suspect you would twist your hanger and/or derailleur if you inadvertently shifted onto the big cog while on the big ring. To avoid this grief, most folks prefer to make the chain long enough to permit the large-large combination, even if they never intend to use it. So yes, you can make a GS work on a 28, but there are necessary compromises that may defeat the purpose in wanting to use the 28 in the first place.
Those are really good points!
Especially with bigger difference in chainring size, a too-tight chain can damage a lot of parts fast, everything from the frame to the hub and axle, to the chainset, chain, all because the chain isn't long enough to handle the biggest sprockets.
Oddly enough, with many derailers the one thing that [I]won't[I] be damaged from such an occurrence is the derailer itself, as the cage may swing fully out of the way of a full-tight chain!
The leverage that one can exert over the tension of the chain when the chain comes up short must not be under-estimated, and if the chain simply breaks you would be quite fortunate in that case.