belt drives are not zero maintenance, they wear and need to be renewed at appropriate intervals. in some drier environments they tend to make noice, then need lubrication with for example paraffin.

in my life i have snapped off a belt drive on bike just once, butvwas then glad to have brought a spare. doesnt weigh much, its a good thing to bring along. of course i dont go with chaindriven bikes without some spare locks and and a chainbreaker, but those find use underways more often, in my case every one or two years.

and on cars snapped two camshaft belts in my life. shit that should not happen, but it does regardless.

have also once by accident as the gear cable failed massacred the internals of a three speed hub gear. not a too convenient situation it was.

hub gears are delicate gadgets in my view not optimal for touring. sorry alee, we can just agree to disagree there. you may be in for a change of opinion once the shit hits the fan also for you. it is likely to happen sooner or later.

keep up the good work with your interesting blog!

The zero maintenance of a belt drive is one reason to fit them on a touring bike not to exclude because they may go wrong i.e. break which I have never ever heard of happening except in car engines but these belts spin at much higher speeds and are subjected to much higher torque figures.

Thanks! I will look at it.

There is! Friction Facts worked out that it’s about 1-watt less efficient to use a belt. http://www.bikeradar.com/road/news/article/chain-or-belt-drive-which-is-faster-36074/

I would have also been interested to learn about the difference of efficiency between a conventional chain and a belt drive on these hubs. Is there a study somewhere on this subject?

Just in case facebook is making getting there difficult try this link & scroll down to August 14th. Sorry, I am not very good at all this weird Facebook stuff. – https://www.facebook.com/Internal-Gear-Hubs-296893474108569/

Here Alee, you can see for yourself how changing the sprockets dramatically changes the efficiency. Granted you operate these ratios at your own risk but unless you are really over stressing your drivetrain I don’t see any reason for on road riding that you can’t safely operate in these ranges. I have run my Alfine 11 set up this way for the past 2 years completely problem free but I am careful of over doing the torque just to be on the safe side. – Please scroll down the page for the results that I achieved.

While changing the sprocket ratios will undoubtedly show some variation in the drivetrain efficiency, it does add complexity to the testing because different gearbox systems require different drive ratios to achieve comparable gear ranges. The sprockets used for the Shimano/Nuvinci hubs were 42-20t, while the Rohloff had 42-16t due to its wider gear range. The Pinion gearbox has a wider gear range again, so the drive ratio is 32-24t which equates to the same lowest gear as the Rohloff hub.

These are all pretty common sprocket sizes spec’d on stock bikes with these gearboxes, so I therefore think the testing is reasonable enough (although I’d really like to know if a 42-32t drive ratio with the Pinion makes any difference, not that those parts are available).

as only one planetary gear gets used at the time, the price in terms of drag for 3 and 5-speed s-a should be roughly the same, and indeed is according to my subjective experience. i feel in both cases it is acceptable and small, but not negligable. they have been tested in the past, if i remember correctly drag at 100-150 watts is 4-5 percent in direct drive, and 7-8 percent when the internal gears are engaged.

but in other models, like the ones above where epicyclic gears are at times put in series, there is even a drag to crank the drag. ouch.

if you lay the bike over on the side and roll the wheel it is possible to get synthetic oil into the hub via the bearings. clean it first.