I’m building up a hardtail (Singular Gryphon) 29er with an Alfine 8 hub and am srtruggling to figure chainring and sprocket combo. Obviously the chainring is the most important and I don’t mind messing about with the sprocket (16, 18, 19, 20, 21, 22 or 23). The hubs ratios are from low 0.527 to high 1.615.
I’m looking more for hill climbing ability than top speed, it will be mainly ridden on fire roads, gravel tracks, bridleways and maybe 20% road.
– anybody got any experience on running an Alfine 8 on a 29er? Or has a good grasp of ratios?
Cheers

Dunno about alfines, but a 29er “feels” about 2 teeth harder than a 26er to pedal, if that makes sense? 32:18 ss compared to 32:16 I run on 26s.

An 18 tooth on the alfine gives you roughly the same spread as a standard 9 speed cassette if that helps you work out what you need.

I use my alfine 8 29er in the lakes and run 32:20. This gives me a good spread for climbing and descending. I would reccomend starting with that and adjusting the range up or down to suit your needs.

use whatever gear you think you will be in most of the time – i.e. if you were to run it SS what would you use? For the sort of use you are talking about I’d expect something like 34-16 would be a good place to start. What kind of tyres do you plan on using?

I’ve no experience of SS but would like it to feel like a low geared road bike.
Tyres…there’s another decision to make, for what I’m planning on using it for I’m thinking something like Conti Race Kings, Kenda Nevagal or Swalbe Racing Ralphs….size wise I would think around 2.2 to keep it rolling well. Again any suggestions are welcome.

I’d say all of those tyres (especially the Nevegals which are very different from the other two) are overkill for the kind of riding you describe. I’d be looking at something like a Schwalbe Marathon XR in a 45 or so.