Hub gear chain tension
dsmithave, via the Cycling UK Forum
If you are happy with the gear range – and weight – of the hub in question, then why not use it? The modern SunRace-manufactured SA hubs are a little on the heavy side compared with, say, Shimano’s Alfine 8, but will do the job. With a freewheel, there’s no force transmitted through the return run of the chain and, provided your right-hand vertical rear dropout has a derailleur boss, you can keep the chain under control using one of the many tensioners sold for this purpose. Take a look at designs by ETC, Shimano, or Surly (whose Singleator is pictured on the previous page).
Cycle’s Technical Editor