galp
100 W
Here's my Giant Glory 1 downhill bike conversion.
[youtube]mw0MbFbwiJo[/youtube]
The bike used for this project is a downhill bike Giant Glory 1. It is a full suspension 26" bicycle with 180 mm front and 200mm back travel.
Before mounting the rear motor wheel some modifications had to be made. Because the existing rear hub was "thru axle" I had to machine two mounts the change it to standard 150 mm dropout in which the motor wheel fit. Because the new axis of rotation is now 32 mm off center the disc brake mount had to be modified. The disc brake rotor was also replaced with a bigger one.
Before machining the mount from aluminum I made few test mounts from MDF wood. The mount was spot-on after 3 iterations of trial and error. It was then machined from 20 mm thick 5083 aluminum alloy plate.
All fixtures for batteries and electronics were made to clamp the frame. The motor mounts are also screwed into existing holes and clamped. There was no drilling or any other modification to the frame. The whole conversion was set to be completely reversible without any damage to the frame or bike as a whole. The reason behind that is the cost of a downhill bike.
Peak power is rated to 5 kW. With 26" tire maximum reachable speed is 120 km/h. Rated peak torque is 150 Nm. This means in theory with 26" tires and 70 kg rider the peak acceleration is about 0.45G.
The motor controller came in a kit with the hub motor. It is advertised to deliver up to 80A phase current. Along with LCD screen interface that also came in a kit they offer some nice features such as password locking, realtime speed and power monitoring and adjusting various BLDC parameters. The motor controller uses hall sensors and is most likely square wave (based on vibrations at low speed).
Battery pack consist of 100 18650 cells wired in 20S5P scheme. Individual cells were ordered with solder tags already welded. Laser cut copper parts are be used to connect cells together to form a pack. Each cell is inserted in a plastic frame that is assembled like lego bricks. Solder tags are soldered to copper part for electrical connection.
Pack is split in 3 smaller packs to fit on the frame. Two large parts in configuration 8S5P and one smaller in configuration 4S5P. All packs are connected to a single 80A BMS.
Nominal voltage of the pack is 72V. Cells are rated to deliver 20A continiously which means the pack current capacity is 100A. With 2.5 Ah capacity for each cell the total pack capacity is 12.5 Ah or 900 Wh.
To complete the battery pack 20S 80A BMS is installed. It protects the battery in case of over-discharge, over-charge and over-current. It also balances individual elements wired in series so a simple CC/CV charger can be used.
Electric drive:
-Power: 5 kW
-Peak torque 150 Nm
-Square wave ESC
-Top speed ~100 km/h, freewheel 120 km/h, limited 25 km/h
Investment:
-Used bike 920€
-Motor and electronics 800€
-Battery cells 350€
-BMS and charger 150€
-Other small stuff 200€
Total: ~ 2.4k€
[youtube]mw0MbFbwiJo[/youtube]
The bike used for this project is a downhill bike Giant Glory 1. It is a full suspension 26" bicycle with 180 mm front and 200mm back travel.
Before mounting the rear motor wheel some modifications had to be made. Because the existing rear hub was "thru axle" I had to machine two mounts the change it to standard 150 mm dropout in which the motor wheel fit. Because the new axis of rotation is now 32 mm off center the disc brake mount had to be modified. The disc brake rotor was also replaced with a bigger one.
Before machining the mount from aluminum I made few test mounts from MDF wood. The mount was spot-on after 3 iterations of trial and error. It was then machined from 20 mm thick 5083 aluminum alloy plate.
All fixtures for batteries and electronics were made to clamp the frame. The motor mounts are also screwed into existing holes and clamped. There was no drilling or any other modification to the frame. The whole conversion was set to be completely reversible without any damage to the frame or bike as a whole. The reason behind that is the cost of a downhill bike.
Peak power is rated to 5 kW. With 26" tire maximum reachable speed is 120 km/h. Rated peak torque is 150 Nm. This means in theory with 26" tires and 70 kg rider the peak acceleration is about 0.45G.
The motor controller came in a kit with the hub motor. It is advertised to deliver up to 80A phase current. Along with LCD screen interface that also came in a kit they offer some nice features such as password locking, realtime speed and power monitoring and adjusting various BLDC parameters. The motor controller uses hall sensors and is most likely square wave (based on vibrations at low speed).
Battery pack consist of 100 18650 cells wired in 20S5P scheme. Individual cells were ordered with solder tags already welded. Laser cut copper parts are be used to connect cells together to form a pack. Each cell is inserted in a plastic frame that is assembled like lego bricks. Solder tags are soldered to copper part for electrical connection.
Pack is split in 3 smaller packs to fit on the frame. Two large parts in configuration 8S5P and one smaller in configuration 4S5P. All packs are connected to a single 80A BMS.
Nominal voltage of the pack is 72V. Cells are rated to deliver 20A continiously which means the pack current capacity is 100A. With 2.5 Ah capacity for each cell the total pack capacity is 12.5 Ah or 900 Wh.
To complete the battery pack 20S 80A BMS is installed. It protects the battery in case of over-discharge, over-charge and over-current. It also balances individual elements wired in series so a simple CC/CV charger can be used.
Electric drive:
-Power: 5 kW
-Peak torque 150 Nm
-Square wave ESC
-Top speed ~100 km/h, freewheel 120 km/h, limited 25 km/h
Investment:
-Used bike 920€
-Motor and electronics 800€
-Battery cells 350€
-BMS and charger 150€
-Other small stuff 200€
Total: ~ 2.4k€