Surly Straggler build.

[winjohn]

I am building a Surly Straggler for my mate who wants to use it as an all road/gravel bike and wants a decent low range on it, he is in his 60s so is unlikely to need a 50 x 11 speed high range. It will be drop bar, mechanical discs and probably sticking with the 9x2 to be able to utilise the existing shifters. I have a rapid rise Shimano xt rear mech that he quite wants me to use also.
My question is though what are people's thoughts on the best chainwheel/rear cassette combo for a decent range sticking with a 2x9 set up?

 

[hamster]

In order for just about anyone to get up a hill, then a gear range of around 20"-26" is needed.
Showing my workings: 25"/29" = 0.86.
Using an 12-36 cassette (readily available) then that's 30T inner, maybe if he's fit a 34T
Something like 90"-100" for top, so that's around 46T outer, although a 50T will still work with a GS short cage MTB rear mech.

So a stock compact road 50/34 would be OK, or an MTB double using say a 32/46 and omitting the granny.