Odd Japanese domestic ebike

spinnanz

Member
Recently picked up this Yamaha powered Bridgestone JDM ebike, running a 24v system. The BMS has failed so been bypassed. It's a smart bms but oddly the bike still works fine albeit with no voltage or km remaining on the display or chajrge lights on the battery.

It's got a few weird things, tyre pressure sensors, a rear wheel lock that elso engages a steering lock, a solar powered rear light.

Can anyone ID the motor? I'm wanting to know if it's capable of running a 36v battery and a generic external controller. The current controller only provides power up 24kph
 

Attachments

  • IMG_20241101_201558.jpg
    IMG_20241101_201558.jpg
    351.8 KB · Views: 52
  • IMG_20241101_202514.jpg
    IMG_20241101_202514.jpg
    147.9 KB · Views: 46
  • IMG_20241101_202019.jpg
    IMG_20241101_202019.jpg
    356.2 KB · Views: 38
  • IMG_20241101_202015.jpg
    IMG_20241101_202015.jpg
    347.9 KB · Views: 43
  • IMG_20241101_201841.jpg
    IMG_20241101_201841.jpg
    350.1 KB · Views: 37
  • IMG_20241101_201833.jpg
    IMG_20241101_201833.jpg
    232.2 KB · Views: 34
  • IMG_20241101_201736.jpg
    IMG_20241101_201736.jpg
    125.8 KB · Views: 39
  • IMG_20241101_201603.jpg
    IMG_20241101_201603.jpg
    289.7 KB · Views: 41
  • IMG_20241101_201614.jpg
    IMG_20241101_201614.jpg
    110.9 KB · Views: 46
  • IMG_20241101_201620.jpg
    IMG_20241101_201620.jpg
    289.3 KB · Views: 45
  • IMG_20241101_201641.jpg
    IMG_20241101_201641.jpg
    240.8 KB · Views: 42
  • IMG_20241101_201713.jpg
    IMG_20241101_201713.jpg
    220.9 KB · Views: 46
  • IMG_20241101_201724.jpg
    IMG_20241101_201724.jpg
    416.2 KB · Views: 51
I sense a rupture in the force after you mentioned disconnecting the bms.
Not likely. It's currently only being charged to 25.2v rather than it's max of 29.4v.

The cells are likely around 13 years old so a repack is in order anyway, along with a bms.

Repacking is my little sideline money maker.

This is a recent 36v to 48v I built.
 

Attachments

  • IMG_20241017_161744.jpg
    IMG_20241017_161744.jpg
    229.6 KB · Views: 38
The motor looks like the original Yamaha motor that they brought to the Japanese market 30yrs ago. At that time 24v SLA batteries were in use and were upgraded to 36v NiMH or LifePo4 type cells as the concept of ebikes matured. It wouldn't surprise me that the motor would be able to withstand the bump to 36v as the internal windings are most likely overbuilt to begin with? Certainly wouldn't hurt to try if you want to get more performance out of it but the bike as a whole without working it over isn't going to be worth much to you I suppose.
 
The motor looks like the original Yamaha motor that they brought to the Japanese market 30yrs ago. At that time 24v SLA batteries were in use and were upgraded to 36v NiMH or LifePo4 type cells as the concept of ebikes matured. It wouldn't surprise me that the motor would be able to withstand the bump to 36v as the internal windings are most likely overbuilt to begin with? Certainly wouldn't hurt to try if you want to get more performance out of it but the bike as a whole without working it over isn't going to be worth much to you I suppose.
It works as such with 24v but it's very very low power due to the Jap laws it needed to comply with, 250w, max of 1:2 assistance below 10kph, no assistance much above 20kph.

I've managed to find an exploded diagram of the motor which shows the hall sensor and coil location so I think I can tap into it there, bypassing the 24v gear. Even if I don't increase the wattage it means I can bypass top speed and use a throttle.
 
Back