Ã¢â‚¬Â¦but first a bit of background.
Last Fall I was looking for a replacement for my Raleigh hybrid, specifically something that would take the edge off the bone-jarring rides I was enduring on some rather poor roads. I didnÃ¢â‚¬â„¢t want a front suspension but I figured a resilient steel frame and big tires would help smooth out the bumps. The bike I settled on was a 2009 Kona Smoke 2-9.
The Kona Smoke is an inexpensive bike (list $425) with low end components, however I was buying it mainly for the frame and the ability to run big tires. The first thing I did when I got home, even before riding it, was to change out the crankset, bottom bracket, front and rear derailleurs, cassette, and seatpost. I rode it 5 times in November of 2008 and that was it.
Now that I had a new bike I ordered a motor kit for the Raleigh which consisted of a Bafang geared front motor, 36V/15A controller, 36V/9Ah SLA battery pack in a tote bag, rear trunk bag and throttle. I immediately re-laced the motor into a new rim with Wheelsmith DH13 spokes. I first hit the road with the bike in early February 2009 and chalked up 909 miles by early May (see bike review here http://www.endless-sphere.com/forums/viewtopic.php?f=6&t=8579
). I liked the bike but I wanted to try a direct drive motor. I had ordered a rear
9C motor kit from E-BikeKit but decided not to use it. Later I purchased a front
9C motor from the same guys which I intended to install on the Kona bike. However I first wanted to do a direct comparison to the Bafang so I installed the Nine Continent motor/wheel on the Raleigh using the same 36V/15A controller and 36V/6A LiMn battery pack made up of 3 Bosch Fatpack battery packs (see here: http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=7569&start=75#p147245
) which replaced the SLA pack a month earlier.
I liked the pairing of the Raleigh with the 9C motor so my original plan changed and I decided to install the orphaned Bafang motor on the KonaÃ¢â‚¬Â¦and thus the Smoke-E was born. To handle the larger 700 x 47 tires I laced the little motor into a Sun Rhyno Lite rim, reusing the 258mm DH13 spokes from the previous Sun CR18 build.
The controller is a 36V model I got from E-BikeKit.com which I modified to reduce the current from 22A to a bit over 15A. I may choose to upgrade to a 48V battery in the future and this controller can handle it. The controller is handlebar mounted because itÃ¢â‚¬â„¢s just so darn convenient. For a throttle I chose the same Bladez trigger throttle I used on the previous ebike (see here; http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=8026
) which necessitated removing the stock SRAM left shifter. A Ã¢â‚¬Å“5 speedÃ¢â‚¬Â thumb shifter I picked up from Nashbar.com for a buck now controls the front derailleur for the current 2x8 setup though I may go to a 1x9 arrangement in the future and eliminate it completely.
In the rear I opted for a Topeak Explorer rack and their DX (w/rigid sides) trunk bag with the slide on MTX system. I made a little switch box with a momentary pushbutton and 220 ohm resistor bypass to pre-charge the controller along with a 12V/50A toggle switch from RadioShack. A red LED indicates the power is on.
I took the bike out for a short shakedown ride. I came back and relocated the speedometer to the right fork as it was getting interference from the controller. I also replaced the 8 speed chain with a 9 speed chain because the 8 speed master link was interfering with the Deore LX rear derailleur roller wheels.
With the battery charged up a bit but not quite full (40.6V) I headed out again. While this bike is set up quite similar to the Raleigh I have been riding exclusively this spring the differences were immediately apparent. The most noticeable item is the handlebars, at about 2 inches higher on the Kona, which makes for what feels like a night and day difference in stance. The big tires on the Kona inflated to 40psi front/50psi rear really do soak up the bumps and overall the bike simply exudes stability.
The tires on the Kona have a 2% greater circumference compared to the Raleigh (47 vs. 35), thus the no load speed increased as you would expect, from 21.4 to 21.8 mph (at 41.3V). Out on the road the speed seems a little higher than I expected at close to 18.0 mph compared to low 17Ã¢â‚¬â„¢s when on the Raleigh. The difference might be owed to the fact that I lopped 4 feet out of the motor phase power cable for a custom fit to the controller or the controller itself or a little bit of both. In any event there was some assist available throughout the ride up to 20 mph.
Something I was very happy about was that the motor did not exhibit the vibration under load that was apparent when it was mounted on the Raleigh. Some might say itÃ¢â‚¬â„¢s the controller but I used this same model for a while on the Raleigh so I can only conclude itÃ¢â‚¬â„¢s either the wheel build, though I did each myself using the same parts and pattern, or more likely itÃ¢â‚¬â„¢s the super stiff straight front forks on the Kona compared to the slender, curved forks on the Raleigh. Whatever, it feels like a new motor.
I concluded the inaugural ride after 18.7 miles with an average speed of 17.0 mph and 6.7Wh/mile of power used or about spot-on what I would have expected when the motor was on the Raleigh. The ride quality of the Kona however is smoother and the brakes are more powerful. Well itÃ¢â‚¬â„¢s only one ride but this combo of the Kona Smoke 29Ã¢â‚¬â„¢er and the little Bafang motor is a nice package.