Thursday, August 21, 2008
crank transmissions, 3 found. for single chainring bikes. or more gear range.
D: the only one on the market today is the Schlumph (pic)
It has very high and low gear options. They're called the mountaindrive and the hyperspeed drive.
For somebody stuck with one chainring, or looking for more gear range, this is it.
It runs 500bux though.
D: the Dana 3 speed crank is made by an automotive company.
I cannot find anything on gear ratios or range at all. Ideas?
I saw one on sale at E-bay for 30ish bux.
I read of a Shimano 5-speed crank tranmission, but cannot locate it.
Sure, the new Rohloff will have a 580% range. And will cost 1500 bux.
The Flevobike Greenmachine embedded a gear hub in the bike frame. This allowed a bike frame that covered the chain easily. But it costs many 1000s.
By stacking a, say, I-motion9 or a NuVinci with a Schlumph, I figured I could cheap out.
If I manage to poach that Dana on E-bay, well, I just saved myself 500 bux.
The bike frame idea involves stainless steel square tubing.
I have a Schlumph at the chainring, and a NuVinci CVT drive embedded in the bike frame.
The frame tubing has 2 parts that run parallel, with occasional triangular cross struts.
Other than the hub drives, such a bike is pretty cheap to build.
Let's hope my c0sts just dropped by 500....
Eventually, for the crank-thru-front-wheel mid-steer concept, of course, I will need a Rohloff. But I hope the new 2008 model pushes down the price of the standard model.