Junior Member
Join Date: Oct 2017
Location: Ottawa, ON, Canada
Posts: 150
Bikes: 1974 PX-10E sold, 1977 Witcomb stolen, 1980 Roberts 1 speed, 1987 Cyclops 3 x 6 friction triple crank, 2010 Masi Commuter 1 speed, 2017 Ribble 525 2 x 10 with Ergos
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So by now it must be clear that:
1. A doublized triple is cheap and effective, if you can find the rings you want. You can find 44T and 446T middle rings, ie with shift aids, in 110 or 130 BCD if you look.
2. You don't have to live with crazy big gaps on your cassette
3. Manufacturers' capacity specs are guides, not laws.
On thing to watch out for though: On your small ring and small end of the cassette, the chain comes very close to and sometimes touches the inside edge of the big ring at its back end. This gets worse with shorter chain stays and bigger chainring gaps. At best this can make an annoying noise, at worst it can cause un-intended chainring upshifts (thanks to the shift aids grabbing the chain) with grizzly consequences when the chain get to the FD cage. This is one of the good reasons to respect the 16 tooth difference manufacturers push. A couple of possible work-arounds:
1. Space the chainrings a bit further apart with chainring spacers. This can allow the chain to get hung up between rings, so reduce your spacers if that happens. I have wondered about adding bumps of epoxy to the inside of the big ring to prevent hang-up, but haven't actually tried it.
2. Bias your chainset outward 2-3 mm with a bottom bracket spacer under the fixed cup or with a longer BB. This will make the "big-big" combination noisy and rough, but at least the "small-small" will be safe due to reduced chain angle in those gears.
Such freedom to fiddle is one reason I stick to square-taper bottom brackets.
oldschoolbike