Posts Tagged ‘gears’

Shimano announces a 11 gear hub. The range will be 409% (Alfine 8 gear 307%). The hub runs in a oil bath like the Rohloff Speddhub. This should result a higher efficiency and longer lifetime. The price will be 300,- Euro release data is September 2010.

Check out our official Alfine 11 page for more info.

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The Shimano Alfine hubstrip is online.

The hub was part of a Downhill bike. I estimate that the hub was around 400km in use. All internal parts are greased with a white grease. Even the filigree ratchets which is very unusual. On a few pictures you´ll see metal dust on the white grease as a result of a massive metal abrasion. This is a normal process in the beginning of a hub life. The internal parts are new machined and do not fit perfect into each other. In the first kilometers of usage this “shake down” process produces a lot of metal dust. For a long hub life it´s important to clean an regrease the hub.

To optimize the efficiency of the hub it´s necessary to use grease and oil for the different internal parts. Shimano uses 100% grease inside the hub. This has the advantage of long maintenance intervals. The grease will last a whole hub life!

But the efficiency is bad. For sportive purpose like the Alfine is designed it makes sense to optimize the lubrication and have a one or two year maintenance interval. I my eyes it makes sense to use grease and special oil for the different parts inside the hub. It would not be possible to go for 100% like the Speedhub because of the hub shell / dust cap seal. This seal is not designed to prevent that the oil will leake out of the hub. There is a fantastic article from Chester Kyle and Frank Berto published in the Technical Journal of the IHPVA issue 52. (Also interesting to read is the feedback from Bernd Rohloff in the following issues. A great scientific showdown!)

“The grease in the Sachs 3 and the
Sturmey Archer 3-speeds was replaced
with light oil, and unlike the other hub
gear transmissions, the efficiencies of
the Sachs 3 and Sturmey 3, compare
well with the best of the derailleur
transmissions (figs. 7, 9, and 12).
Also, these transmissions were worn
in, whereas many of the others were
new. Manufacturers would do well to
replace heavy grease in their hub gears
with light oil. Although oil wouldn’t
last as long as grease, the energy
savings would be significant. Unfortunately
commuters have a tendency
to ignore maintenance until something
breaks, so light oil probably wouldn’t
be a popular choice. ”

I´ll give you feedback about my experience. One of my hubs is running since 7 month with special lubrication!

Check also movie 1 (original greased hub) and 6 (special oil lubricated hub) for the differences according ease of rotation.

Details are stored on the Alfine static page.