So I want to weld up my own steel ebike frame.....

[hamncheez]

So I'm looking to weld up my own steel (long travel, high pivot with an idler pulley) ebike frame. Initially, I was just going to use the TSDZ2 or something similar, but now I'm curious about using a true mid-mount motor, like the bafang m500.

Looking around at what major manufacturers are up to, it seems every single new ebike out there is using the Shimano e8000 drive system. I've also seen that Bosch Performance CX is only 2.8 pounds for the motor. It just seems that there are better drive systems than Bafang.

I realize its nearly impossible to buy a shimano system (unless its a shady listing on ebay) and you have to have dealer software to program it. Its also pricey. I'm sure Brose/Bosch has similar limitations for the DIY guy. Does anyone know if its worth pursuing these "better" performing systems for just 2-3 frames? Or should I stick with Bafang?

Finally, are there any resources for schematics or CAD files of the motor unit themselves? Hard to design a mid-mount frame if I don't know the dimensions of the motor case and battery. I can't find anything for any brand.

Thanks!

 

[Gary]

You can buy everything needed for a shimano system.. Separately they add up to an amount that would make your eyes water.

 

[hamncheez]

You can buy everything needed for a shimano system.. Separately they add up to an amount that would make your eyes water.

I see that after perusing other threads.

I wonder why all the new brands are using Shimano? Maybe their OE prices are amazing.

 

[Gary]

Yes. OE prices are far more favourable. But also very attractive when tied in with their other drivetrain /braking components and partner brands.
Same deal with SRAM /Rockshox but they don't have an EMTB motor. Which is why you'll often find sram /rs on many bosch equipped bikes

 

[freerider]

Nice idea, I wish I was good at welding
Have you tried the TSDZ2? On another forum a guy was using one but has switched to another motor
I won't post a link to another forum, particularly as this is my 1st post but if you're interested google 'My attempt at lightweight, torque based EMTB'
Good luck!

 

[Mikerb]

Whatever motor a brand chooses to use, they vary in how/at what angle they mount them so I would have thought your safest bet would be to decide on a motor first and buy it...then design your frame around it.
I also suggest you go for broke and design your bike using a carbon belt and gearbox rather than a derailleur. Your choice of gearbox may also determine whether you go for a mid mounted motor or not.

 

[hamncheez]

Have you tried the TSDZ2?...

No, but I have heard about the reliability of bolt-on applications for actual mountain biking, which is why I want to do a true mid-mount design. I just can't find any CAD or spec files for the various mounts.

 

[hamncheez]

Whatever motor a brand chooses to use, they vary in how/at what angle they mount them so I would have thought your safest bet would be to decide on a motor first and buy it...then design your frame around it.

Ya, that might have to be my plan. I really, really would like to get the formal specs because anything I order will probably be 6-9 months out, and I'd like to work on the frame in the meanwhile....

 

[freerider]

No, but I have heard about the reliability of bolt-on applications for actual mountain biking, which is why I want to do a true mid-mount design. I just can't find any CAD or spec files for the various mounts.

Going off on a tangent but have you thought about one of those 'skateboard motors'? Again interesting thread on another forum google 'My RC Mid Drive with Single Stage Reduction'
Quote 'With the 6384 (and really the 6374), I have plenty of power, and now I rarely drop down to the granny ring on either bike. Note that I still put in some effort (but not enough to blow my knee out...)'
I bought one of those 6384s via aliexpress and a mini fsesc controller and they cost like 'feck all'! I'm talking circa 90 bucks delivered for both I think it was
Shame I'm not in the States, I'd let you borrow the motor and the controller and see what you come up with!

 

[hamncheez]

Going off on a tangent but have you thought about one of those 'skateboard motors'? Again interesting thread on another forum google 'My RC Mid Drive with Single Stage Reduction'
Quote 'With the 6384 (and really the 6374), I have plenty of power, and now I rarely drop down to the granny ring on either bike. Note that I still put in some effort (but not enough to blow my knee out...)'
I bought one of those 6384s via aliexpress and a mini fsesc controller and they cost like 'feck all'! I'm talking circa 90 bucks delivered for both I think it was
Shame I'm not in the States, I'd let you borrow the motor and the controller and see what you come up with!

Yes, but I want a torque sensor, not a throttle.

 

[04fuxake]

Check out Paul Brodie's channel on YouTube. He builds up an e-bike frame around a Bosch motor with twin batteries.

 

[hamncheez]

Check out Paul Brodie's channel on YouTube. He builds up an e-bike frame around a Bosch motor with twin batteries.

It never says how he was able to buy the Bosch motor or mount!

 

[R120]

Motor Cabinet: Shimano Steps — TI CYCLES FABRICATION

TiCycleTubes design Lightweight Steel Motor Mount Bracket E6100, E7000, E8000, EP8

www.ticycles.com

 

[R120]

Electric Motor Mounts & Jigs

We carry Columbus tubing as well as lugs, dropouts, fork crowns, and braze-ons. We also have proprietary goods and items from Gasflux, Harris, Weld Mold, 3M.

framebuildersupply.com

 

[04fuxake]

It never says how he was able to buy the Bosch motor or mount!

Technically, I don't think he did, it was a student of his I think who bought the mounts.

 

[hamncheez]

Electric Motor Mounts & Jigs

We carry Columbus tubing as well as lugs, dropouts, fork crowns, and braze-ons. We also have proprietary goods and items from Gasflux, Harris, Weld Mold, 3M.

framebuildersupply.com

Sorry for the late reply; these are great! Only issue is that they don't carry Bafang, and I can't get Shimano, Brose, or Bosch to reply to my inquiries, let alone sell me one. You can find Shimano's E8000 on ebay, but its sketchy.

 

[Mabman]

Motor Cabinet: Shimano Steps — TI CYCLES FABRICATION

TiCycleTubes design Lightweight Steel Motor Mount Bracket E6100, E7000, E8000, EP8

www.ticycles.com

View attachment 56853

Dang that's ugly