Added new 8 speed hub
Posted by Bob Dold on Tuesday, December 5, 2006 12:24 AM
Finally received the Sturmey Archer 8 speed rear wheel today after lacing it up and having it tensioned and trued up. This should fix the problems with the chain coming off due to the rear derailleur. The hub has a gear ratio of 1:1 to 3.05:1, with the standard 25 toothe sprocket it has a 1st gear speed of 11MPH and 8th gear speed of 30 MPH. I hope to find a bigger rear sprocket to lower the speeds a little to get more torque available for the hills.
Plot shown below is the results of the test performed yesterday before the 8 speed hub was added, and the trike was fixed at one speed. The gearing allowed 8 MPH up a 10% grade at 1000 watts.
I have some problems with the omega voltage logger as it is only reading in .05 volt increments, resulting in current readings in 5 amp steps. The stated resolution is supposed to be .01 volts which would give 1 amp steps if working correctly.