Hub gear chain tension

Surly Singleator
Wrong dropouts for hub gears? Fit this
I’m considering replacing the derailleur system on my commuter bike with a hub gear. What is the best way of tensioning the chain, assuming a vertical dropout? I have a couple of Sturmey 5-speeds with hub brakes. One of them is new, so it should work, and the range is as wide as the gears I actually use. Unfortunately, the frame has vertical dropouts, giving no room for chain tensioning by shifting the wheel. Any suggestions welcome, as are thoughts on the suitability of these gears.

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).

Richard Hallett

​​​Cycle’s Technical Editor

This Q&A was published in 'Cycle' the magazine for members of Cycling UK. To contact the experts, email your technical, health, legal or policy questions to or write to Cycle Q&A, PO Box 313, Scarborough, YO12 6WZ