Originally Posted by
Jipe
More than 16t difference between chainrings doesn't work well with most front derailleur.
With a very big chainring, such a big difference in teeth is necessary to have a big enough difference in percentage (16t difference with a 60t chainring is only about 27%)
The shape of the front derailleur is also usually not designed for chainrings above 53 or 55t
Yes, exactly.
I am impressed with current doubles that do a 16T difference effortlessly (though I am using a triple FD, just to have a cage with greater height, so less likely to drag the chain, even if on the small/small combo), even with a stamped large ring that does not have distinct added lift pins. With lift pins, my bet is I could stretch my 50/34 into a 52 or 53 high, but like you said, that's a small percentage increase. I'll be watching the industry in coming years to see if they stretch that 16T standard. But it appears I can't go smaller than 34 on 110mm BCD, so I'd probably need to have the inner on a 74mm BCD, but if set up like current triples, that's too far inboard, I'd need the same chainline as current, which I think someone mentioned 43.5mm in a different thread, that sounds familiar.