Originally Posted by
stevevance
I haven't thought about a front chain ring size for the Yuba Mundo with IGH I want to build soon.
My plan right now is to use the Shimano Alfine. But what would be the best size front chain ring? I don't want to use a front derailleur.
As a data point - I've been running a 32T x 21T setup on my Surly Pugsley [effective 29" wheel] with an Alfine incl. some fully loaded dirt touring in the mtns. I'd want at least that low of a gear on a dedicated cargo bike unless you live somewhere uber flat. I haven't had any issues with my Alfine even though it's been abused quite a lot for 16 months+ as one of my most used bikes.
Alfine cogs are cheap so I'd try a ratio that seems sensible to you and buy one or two extra cogs as needed to dial in the gear range.
Keep in mind I'm not a monster so the amount of torque I can apply to the pedals is limited.