Daniel had been trying to get his electric bike built for months, until he recently joined MAKE Ventura and gained access to A LOT of tools, space to work on his project, and a community of knowledgeable people to help him. I'd put together a few hub-mounted ebike kits, and hadn't been happy with the way they'd changed the weight distribution of the bike. Daniel's mid-drive kit intrigued me, because not only was the weight better distributed (no heavy wheels), but he could still use the rear derailleur to change gears, which instead of creating an inefficient single-speed like a hub motor, created the equivalent of a 7-speed electric motor-driven transmission. How cool!
Before Daniel joined MAKE Ventura, the bike shop quoted him $75/hr to install the kit. There was a lot of retrofitting to be done, and it's possible the bike shop wouldn't have had the tools needed to get the job done. We finished in under 6 hours, and it only cost the $35/month Membership fee. We hope every member can get that kind of value from their MAKE Ventura Membership.
Here is a list of the tools we used in this project:
- Bicycle Stand
- Numerous Allen Wrenches
- Flathead and Philips Screwdrivers
- Crank Pulling Tool
- Bottom Bracket Tool
- Chain Tool
- Crescent Wrench
- Numerous Combination Wrenches
- Wire Cutters
- Air Pump
- Variable Speed Belt Grinder
- Foredom Flex-Shaft Tool
- Wrench Handle Extension
- Soldering Iron
- 1500 watt Heat Gun
- Wire Strippers
- Tire Removal Tools
- Red and Black Wire
- Electrical Tape
- Shrink Tubing
- Extension Cord
- Needle Files
- Threaded Rod and various nuts and washers
We put the bike on our bicycle stand to work on it. As the motor kit installs in the bottom bracket, our first step was to remove the bottom bracket. We removed the cranks using an Allen Wrench and a crank-pulling tool. His bike had sealed-cartridge bearings, which required a special tool, pictured above. Over the course of the project, this was the only tool we were missing, so we bought one.
Once the bottom bracket was removed, we tried to fit the motor, but it wouldn't clear the cable guide that was fastened underneath the bottom bracket. So, we removed the derailleur cables and the cable guide. We shaved down the plastic cable guide on our custom made Variable-Speed Belt Grinder, making sure to use a slow speed so we didn't melt the plastic. It came out pretty nice, and we regrooved it with our Foredom Flex Shaft Tool with a diamond disc attachment. It came out pretty good, and is pictured above.
We installed the motor, now that it fit, and positioned it in place, then tightened everything down with our more common style of Bottom Bracket Tool. We went to remove the pedals from the old cranks and realized we should have taken them off while they were still on the bike. We had no leverage and these pedals were factory-tight. We fastened them tight to one of our sturdy work tables, using a threaded rod and various nuts and washers. This gave us the leverage we needed, and the pedals were removed and put on the new cranks!
We used a chain tool to break the chain in order to remove the now useless front derailleur. We refastened the cable for the rear derailleur and made a few adjustments. Around this time, we removed the tires and added liners to prevent punctures. This bike is a tank!
The kit came with a throttle and brake levers that cut power to the motor, plus an LCD computer display. We removed the grips, shifters, and old brake levers, and installed the new brake levers and throttle. We reattached the old shifters and grips and got everything positioned for Daniel's ergonomic comfort.
The LCD computer display connects to a magnetic speed sensor on the rear wheel, so in addition to installing the LCD to the handlebars, we zip-tied a cable along the frame and fastened the magnet to one of the spokes.
We installed a rear rack for the large battery. Daniel wants a lot of range, so he chose the smaller motor and paired it with a large battery. The normal battery used with the kit is fastened right above the motor where the drink holder would go. This meant that we had to extend the power cable to the motor if we wanted to reach the rear rack.
We found some red and black wire of appropriate gauge, cut them to length, and stripped the ends. We installed the supplied terminal connectors on one end, soldered the other ends to the motor cable, wrapped them individually, and covered them in shrink tubing. We shrank the tubing with our 1500 watt Heat Gun.
We zip-tied the wiring in place and connected the battery pack to the motor. Daniel turned it on and the LCD display lit up. He took it for a test ride. Everything worked. I rode it after him, and was impressed that the pedal assist mode made the bicycle feel weightless, and the throttle provided plenty of speed, even without pedaling.
Another finished project by MAKE Ventura.