Hi, I’ve recently built up a monstercross around a Genesis Fortitude frameset. Currently, it’s set up SS (has sliding dropouts), but I may well want to run it geared at some point.

I have an old Tiagra long cage mech in the parts bin which will pair with the Tiagra STI lever, it used to be a 2×10 set up, but I’d probably like to go 1×10.

I’d use a 36/38 chainring, with an 11/36 or, ideally, an 11/40 cassette. Will that combination work?

Secondly, anyone know what hanger/dropout I’d need with the horizontal dropouts?

Thanks

My Tiagra 4700 reat derailleur is happy on a 11 36 cassette with no modification

My main bike is singlespeed like you, but for off-road gravel bike i.e monstercroos, 1:1 gearing (whether that’s 36*11-36 or 42*11-42, low gear is the same) was a struggle for the hilly area I live in. I am now 38*11-42 which seems spot on.

Agreed on 1:1 not being low enough. I’m now on 42/11-46 and a little lower still wouldn’t hurt. Allows you to stay seated when climbing on surfaces with limited traction.

Depends on what length and gradient off-road climbs you expect to tackle, but I’d want something like 24/38 chainset with 11-32 cassette, I have 34/34 as my easiest gear on my road bike to get me up 20%+ tarmac ramps.

My Voodoo Marasa is ~4Kg heavier than my road bike and when I don’t want to flog myself on my commute home, I use the easiest gear (26/34) up my local ramp.

Fyi my gravel bike is 28 40 up front and 36 11 out back. Loaded off road i’d want lower

Yeah, my ‘proper’ gravel bike is 2×11, 48/33 and 21/34, so just under 1:1 ratio for the lowest gear. It’s fine around north Leeds, Wharfedale trails (could sometimes do with being a bit lower)

For the monster-cross, I think I’d look at 11/40 with a 36 chainring, so the question is whether the Tiagra long cage mech will work with that? If not, might just go 2×10.