Hi everyone,
I'm Ben from France, new on this forum, and I started to convert a YAMAHA YZF 250 2007 to electric to make myself a good electric enduro bike and go riding on the weekend.
I bought a QS138 90H motor for this built, and plan to:
- Control it with a Silixcon SL
- Feed it with a 20S15 (or 16)P MOLICEL P42A pack so 4 to 5 kWh
Idea is to get about 22kW peak, as it seems to be a classic with this motor setup.
My first point is about transmission. I calculated that a (more or less) 5.5 gear ration between motor and rear wheel would be cool to reach 90km/h at 4000RPM at the motor and have good torque for enduro.
Option 1: Use the original 14T 428 type sprocket of the motor and use it with a custom 76T 428 type sprocket at the rear wheel.
Advantage: easy motor mount, compact design in the frame area (more space for batteries)
Disadvantages: weak chain (428), verry large and custom made rear sprocket
Option 2: Make a 2 stages transmission using the 22T original belt sproket of the motor with a 44T pulley and then a YZF standards 520 14T and 49T sprokets for the second stage, with a custom built axle in the middle.
Advantage: more tunning possibilities, only "on the shelf" belt, sprockets, chain, strong 520 type chain etc...
Disadvantages: complex motor mounting, need for an expensive custom middle axle, usiong more space in the batteries area.
According to your experience, what's your opinion about this choice?
Other question: Do you know which belt standard is used on the original 22T belt sprocket of the QS138 90h?
Thanks a lot in advance!!!
I already 3D printed the QS138 motor, and it mounts verry easily in single stage transmission position, only by re-drilling the bracket hole to 16mm, making a set of simple sheet metal brackets and grinding the frame a tiny little bit.
I'm Ben from France, new on this forum, and I started to convert a YAMAHA YZF 250 2007 to electric to make myself a good electric enduro bike and go riding on the weekend.
I bought a QS138 90H motor for this built, and plan to:
- Control it with a Silixcon SL
- Feed it with a 20S15 (or 16)P MOLICEL P42A pack so 4 to 5 kWh
Idea is to get about 22kW peak, as it seems to be a classic with this motor setup.
My first point is about transmission. I calculated that a (more or less) 5.5 gear ration between motor and rear wheel would be cool to reach 90km/h at 4000RPM at the motor and have good torque for enduro.
Option 1: Use the original 14T 428 type sprocket of the motor and use it with a custom 76T 428 type sprocket at the rear wheel.
Advantage: easy motor mount, compact design in the frame area (more space for batteries)
Disadvantages: weak chain (428), verry large and custom made rear sprocket
Option 2: Make a 2 stages transmission using the 22T original belt sproket of the motor with a 44T pulley and then a YZF standards 520 14T and 49T sprokets for the second stage, with a custom built axle in the middle.
Advantage: more tunning possibilities, only "on the shelf" belt, sprockets, chain, strong 520 type chain etc...
Disadvantages: complex motor mounting, need for an expensive custom middle axle, usiong more space in the batteries area.
According to your experience, what's your opinion about this choice?
Other question: Do you know which belt standard is used on the original 22T belt sprocket of the QS138 90h?
Thanks a lot in advance!!!
I already 3D printed the QS138 motor, and it mounts verry easily in single stage transmission position, only by re-drilling the bracket hole to 16mm, making a set of simple sheet metal brackets and grinding the frame a tiny little bit.