Broken ST1 Stromer Hub, Looking For Conversion Kit While Keeping The Stromer Frame/Battery

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neeks   100 µW

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Broken ST1 Stromer Hub, Looking For Conversion Kit While Keeping The Stromer Frame/Battery

Post by neeks » Nov 20 2019 9:19pm

Hello, wondering if anyone knows of any conversion kits that could be used to replace my broken ST1 Stromers. I have a few perfectly good Stromer Bikes/Batteries but all of them have broken motor hubs.

Any direction towards what kind of kits I could use, if possible, to make good use of the frame and battery of the Stromers.

Thanks.

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amberwolf   100 GW

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Re: Broken ST1 Stromer Hub, Looking For Conversion Kit While Keeping The Stromer Frame/Battery

Post by amberwolf » Nov 20 2019 9:47pm

You can use the original motor wheel itself, with the motor--but you have to take the wheel apart on one side to take the hub apart to get the old controller out, and add a cable from the phase and hall wires inside to the outside, to run via an external controller.

There's a few Stromer threads around the forum with some info on that:
search.php?keywords=stromer*&terms=all& ... mit=Search

like these two
viewtopic.php?f=2&t=86600
viewtopic.php?f=6&t=63809

AFAIK, any regular BLDC controller can run the UltraMotor hubmotors in these things; just use one appropriate to the motor wattage you've got, and the battery capability youve got (so it doesn't draw more amps than your battery was designed to output, and doesn't overheat the motor).


If the battery you have is one of the ones that only turns on it's output for the original controller and LCD, then you'll either need to replace it's BMS with a "standard" one, or wire around it's output FETs (which will defeat it's ability to protect the battery from overdischarge).

If you can't do that, or don't want to, and/or you need more power than that battery can supply, you'd have to replace it with a different battery (external rackmount, for instance, or something in the triangle, or elsewhere; lots of options depending on what you need out of it).


The Stromer LCD won't work with whatever elseyou put on there, and neither will any PAS or torque sensing it came with, so those will have to be replaced with ones that come with the new controller.


If you literally just want a motor/controller/display kit that will work, it's likely that any typical 500w rear hubmotor kit will fit on there, though you may need spacers to make the wheel fit without bending the frame in--I think the stromer motor's axle shoulders are wider than the common 135mm bike dropouts most rear hubs were made to fit in--something more like 140-150mm, IIRC. It's in my thread linked above.

A fatbike hubmotor might fit in it's place, but the fatbike *rim* probably won't, so you'd likely have to relace the fatbike motor into a rim that will fit on this frame. (like the orignal off the old motor; you'd just need to measure it and the new motor to get new spokes, like here at the https://www.ebikes.ca/tools/spoke-calc.html page).

neeks   100 µW

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Posts: 7
Joined: Nov 20 2019 9:03pm

Re: Broken ST1 Stromer Hub, Looking For Conversion Kit While Keeping The Stromer Frame/Battery

Post by neeks » Nov 20 2019 10:20pm

Thanks for the detailed reply. Never considered using an external controller. I spent the day actually removing one of the hubs apart with a gear puller to solder some stripped wires, but I have have no idea how to put the hub plates back together. Not sure if its because I used 20 gauge wires which are slightly thicker than the tiny ones inside.

AS for my other broken hubs, I might consider going down the route with an external controller. All this is way over my head since I have just started learning about building ebikes.

How do you find out if the Stromer battery turns on its output from the original controller? The battery is like the one shown here only the yellow and blue version. viewtopic.php?f=6&t=63809&start=25#p962191

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