An Electric Bike Future? Count Me In
Cars are great, cars are fun- but if you’re looking for ultimate efficiency it’s hard to beat a bicycle. Pedaled or powered a bike will get your butt across town using a tiny fraction of the energy practically any other conveyance would. Meet my latest project:
I’ve been working on the parts for this bike over the last couple months in the machine shop- I’ve changed my mind a couple times about how to put it together, but now that it’s together it’s working as well as I could have possibly expected. Let’s just take a look at the specs:
- Motor: Kollmorgen “Hi-Kol” 24v/400W brushless DC motor with integrated controller
- Motor mount: .090 304 Stainless Steel plate (CNC plasma cut) and billet aluminum
- Belt Drive: 6 Rib J-profile Ribbed V-Belt on custom machined pulleys, .070 galvanized steel tensioner, spring, automotive idler pulley. 10:1 ratio- 12″ rear, 1.2″ front
- Rear wheel: Shimano hub with IS 44mm disc hub
- Throttle: Magura 0-5k
- Batteries: 2x B&B 12v/20AH absorbed glass mat valve regulated lead acid
- Battery mount: .063 aluminum, hose clamps, zip ties
- Monitoring: Cycle Analyst
What does this all mean?
- Peak power: 1000w
- Top all electric speed: 20mph
- Range: 12-18miles
- Energy consumption: 20-30 wh/mile
25wh/mile is approximately equivalent to 1500 miles per gallon efficiency.
I just returned from an 11.68 mile ride on the bike in the Berkeley hills. I ascended Spruce to Grizzly Peak then back down Centennial Drive to Oxford, then back to the flats via Monterrey. That’s over 1100 ft. elevation change. I made it up the hill in 15 minutes, averaging almost 15mph, pedaling hard but staying in my middle gear and not working so hard (in my out of shape condition) to really feel beat up. The extra 500-800 watts of assist climbing the hills makes a world of difference. It’s almost magical. Trips that I would normally just hop in the car for due to lazyness or time pressure suddenly become bike trips with the electric assist. Added to the fact that the bike is simply a joy to ride. The motor and belt drive are quiet, the bike feels secure and stable and the bike has enough power to make riding as lively or easy as you want. Having a trouble-free charging setup and ample instrumentation thanks to the Cycle Analyst makes riding stress-free as well.
The energy used during this ride?
From what I’ve seen I don’t think this is exceptional by electric bike standards. Still, I am thrilled at the incredible comparative efficiency and effectiveness, not to mention enjoyable nature of riding this bike.