A usually reliable source wrote:
>Excess drag or difficult freewheeling in any hub gear with compound pinions
>(with Sturmeys - FW, AM, KS, KSW, TC) is due to the pinions not being timed.
Excess drag may be caused by this, but not difficult freewheeling,
since the pinions don't rotate when the bike is coasting.
>The front [right-hand, or top in normal assembly orientation -scb]
>faces of the planet pinions have a small line on them between the
>two sets of teeth. The pinions must be fitted such that the line on each
>pinion points outwards perfectly radially all at the same time - its a lot
>easier to see what I mean in a pic - see
>http://www.toehead.demon.co.uk/fw.htm for the FW diagram, the principle is
>the same for all the gears with compound pinions. The acid test is to fit
>the pinions as perfectly as you can and then slide the gear ring on. Rotate
>the gear ring - this should feel absolutely smooth without any spots which
>feel in the least bit tight. Mistimed pinions can result in stripped sun
>gears and the gears will not freewheel correctly... There are other
>essentials to observe when reassembling Sturmey gears too and if you are
>interested in these gears a copy of the 1956 Sturmey catalogue is essential;
>it and instructions for other Sturmey and BSA gears are available in PDF
>format at http://www.users.globalnet.co.uk/
This is all correct, but I'm sure that Harvey and Larry already knew that.
Other possible causes of excess drag include: too tight cone adjustment, excessive chain tension, or an upside-down bearing retainer.
Sheldon "Timing Is Everything" Brown
Newtonville, Massachusetts
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