He guys, I want to build my dad a cheap gravel/road bike. He never had one and just turned 76 - his dream is one day being able to ride AlpDHuez. That's wh I want to build him the right tool for this.
I think he'll need something in the Area of 46-51, so having a small reduction overall would be nice.
I heard lots of the Atwood but there are a gazillion versions on AliExpress- can anyone pinpoint me in the right direction for it? I'd guess leaving any front derailleur and problems will be easier overall...so 1x12? 1x11 should do it?
Not sure what you mean by 46-51.
If cheap, i'd look at an Alix double chainring that's less than 50 teeth in the big ring (i forgot the options, but there's a 48 and matching small ring, 46 and matching, and so on). And a cassette that's like 11s 36T. Shimano 105 mechanical handles 36T, maybe even more (in which case, get more than 36). A 76 yo will not complain that he spins out in the descents, but should obviously get at least a 1-1 ratio.
Such a setup would still be a legit looking road bike.
Gravel gearing, i know nothing about. I just know from personal experience that it's a bit of an insult to say you can have a gravel bike and road bike in one bike. Either that gets you a dog of a road bike, or you need a very big FTP to go uphill gravel sections.