Originally Posted by
Mike Mills
The gearing on the five speed version is a bit whacked. It is the equivalent of a 52T chainwheel with the following rear cogs - 28, 23, 17, 14, 11T.
If it is possible to switch to a 40 T chainwheel X 18T cog, theequivalent rear cogs are - 37, 31, 23, 19, 15. I'm sure I would find those a much more useful set of gears.
Are the parts available? Can the hub take the torque?
P.S. - What is up with the Sturmey-Archer 8 speed hub? The lowest internal ratio is 1:1 and it goes up to 3.25:1. That's like a 52 X 5!!! It takes something like a 32 X 24 to get low gear down into the realm of a truly useful low gear.
SRAM offers cogs as large as 24T and Shimano does a 23T, as does SA, so gearing can be changed at minimal expense w/o changing the chainring. Bikesmith Design is also importing a custom made 26 tooth IGH sprocket. The normal Shimano and SRAM sprockets are interchangeable with Sturmey Archer ones. Exceptions are the SRAM iM9 sprockets and SA 8 speed sprockets. Those are each unique designs.
IMO due to the gear layout the SA 8 speed is best fitted to small wheel bikes. The gear layout is more appropriate for them.
__________________
Gear Hubs Owned: Rohloff disc brake, SRAM iM9 disc brake, SRAM P5 freewheel, Sachs Torpedo 3 speed freewheel, NuVinci CVT, Shimano Alfine SG S-501, Sturmey Archer S5-2 Alloy. Other: 83 Colnago Super Record, Univega Via De Oro
Visit and join the Yahoo Geared Hub Bikes group for support and links.
http://groups.yahoo.com/group/Geared_hub_bikes/