Wilderness Energy System on 2001 Cannondale 900


New member
Local time
11:25 AM
Jul 8, 2018
Hello everyone,

I just finished to install the Wilderness Energy System on my 2001 Cannondale 900 sx Jekyll. The 600 watt 36 volt brushless motor makes a little humming/whistling noise when it works a little harder in the hills. I was wondering if that was normal?

Also I have An aluminum Rock Shox Dart 3 on this bike. And I have been told that the torque may be too strong for that fork and I should have use a stronger fork made of steel. What do you think ?

Thank you all!
I've been investigating electric motor kits myself and I've read that you should use a steel fork. However I've seen a number of complete electric bikes available that use an aluminum suspension fork. The biggest concern is that the axle may twist in the fork. There are torque arms available. You might want to look at them.

Could you tell me how far you ride your bike and if you ride hills do you notice a huge battery drain? I've heard that this is a problem with hub motors, especially the direct drive ones. Is your motor geared or direct? Do you ride mostly asphalt, trails, or off-road?
Just thought I'd throw my thoughts in.

Bike = norco 2005 front suspension forks motors = 1st 407 Crystalyte kit no torque arms distance traveled 5500km problems none. Controller is an instant start, hilly and flat terrain towing trailer a number of times with up 150lbs.

2nd. BMC geared hub motor no torque arms so far 3,000km problems none. Voltage = 48 volts Controller = 20 amp Wattage of motors is 48 x 20 or 960w

Torque arms are for people who do not know enough to fully tighten down the axle nuts and how to fully seat the axle in the drop-outs before FULLY TiGHTENING AXLE NUTS AND CHECKING THEY ARE TIGHT EVERY RIDE. Torque arms should be used on higher wattage motors than a WE kit with 36v and 10amp controller only a 360w output.

Just be careful out there
Thank you everyone for your inputs. Well, I am still working on the fork thing. With all that rain we just got, I have not enjoyed my bike a lot lately. I have a direct drive ( 600W hub you can see the picture) so far everything works well. My usual ride has a long steep hill almost a mile (US) and that reduces my range to 17 miles. Still not bad since this is all in the city (San Francisco, Ca). If I go to the beach, I can easily go up to 20 miles, but I help quite a bit. Also, I don't ride off road anymore. the kit itself is close to 50 Lbs (US) and this makes the bike a little top heavy. It would be very difficult to go Down hill, jump and do other off road tricks. Maybe a lighter Lipo battery would fix this problem.