Originally Posted by
ehcoplex
I think I've decided to go with 45/37 double up front and a freewheel with a 32 or 34 large cog. The 52t chainring I have is bent and I'm not sure I'd be able to straighten it out, so going with a triple in the front would mean all new chainrings, and with the SLJ GT I've got I should be OK with the larger cogs in the back. From a purely aesthetic point, a triple with a smaller freewheel would be a bit more 'stealth', and since I have a longer spindle maybe I'll end up there at some point (and my 50+ year old knees may demand it....), but for now doing/buying less is 'more'!
As Sd5782 noted in #33, if you're using a six-speed freewheel, it's hard to get even spacing between gears with the setup you have in mind. But if you go to a five-speed freewheel, you get very nice, even spacing with a 14, 17, 21, 26, freewheel. The jumps between gears are relatively wide, but I have used that combination often and like it.
I may have mentioned this before, but the best gear calculator I have found is this one:
Bicycle Gear Calculator
Very easy to use and gives a nice visual representation of all the possible combinations.
The 14-17-21-26-32 would combine well with your planned 45-37, and equally well--maybe a little better--with a 46-37. Stronglight rings in 46 teeth are not abundant, but they're out there. That would give you a slightly higher top gear.
Another benefit to that setup: five-speed freewheels in that 14-32 combination were popular in half-step applications, so you might well be able to find an existing example, rather than having to assemble your own. And you'd keep the 120 dropout spacing.
EDIT: This one, for example:
https://www.ebay.com/itm/25517088792...8AAOSwcQxhYZ8P
Not hard to find, evidently--there are several others listed now as well.