upgrade bafang mid-drive possible?

[mewanderinghome]

I'm looking at getting my first ebike, and leaning toward an M2S or VoltBike model, both designed around a bafang 350w mid-drive. I want torque sensing, but ideally would like a throttle as well, which these don't come with. (I also looked at Juiced torque-sensing hub drives, but have read on here those aren't as natural-feeling as mid-drives.) 2 primary questions for those experienced with mid-drives:

1) Can a bafang BBS02 750w or BBSHD 1000w be fitted into the same space in/on the bike frame that currently holds the 350w? Those motor kits look like a slightly different form factor than the 350w mid-drive. If not those, then how about the bafang M600 500w, which looks more similar (but may be a different size)?

I'm guessing I'll want more power when I can afford it; the M600 bikes I'm seeing are way more money. But I'm seeing bafang BBS02 750w motor kits for ~$350, and that I could afford as an upgrade maybe even right away.

2) Can I add a thumb throttle to the bafang 350 mid-drive, even if that requires a different controller/display/programming? If so, can you point me to what I would need to buy to make that happen? I plan on trying it without throttle for a while, but guessing there are times I might want it. I see M600 torque-sensing bikes sold with throttles, so I know that's possible. And of course BBS02/HD with throttles, but don't know if those are in configurations with the best torque-sensing.

Thanks

 

[mewanderinghome]

Looking at the less expensive 350w bike, but looking to eventually upgrade that 350w motor to at least the bafang M600 500w mid-drive that's used in the bike you posted. Do you know if that upgrade at least would be possible?

I see "mid-drive kits" for BBS**, but you're saying they won't fit in the spot in the frame of the M2S mid-drive bike?

I debated biktrix classic juggernaut which apparently uses a BBS** motor mounted mid-drive. But no torque sensor, so would have to add one like Juiced apparently does. I've read that the 'add-on' torque sensors somehow don't work as well as those integrated with mid drive motors? Smooth torque sensor operation is one of the main reasons I want a mid-drive, but also because I'd like to be able to swap between wheel sets (fatter tire for commuting on crappy quality local streets, narrower wheels for single track riding).

And do you have any idea whether adding a throttle to the 350w mid-drive motor is possible?

 

[slayer1962]

Two options in my mind and i am no pro here. Buy the one you can afford now , use it then sell it when you are done with it and ready to upgrade. I assume you would lose a good amount of money but used e bikes seem to be priced pretty high when kept in good shape.
Option 2 save your money until you can afford what you really want? I did option 2 and it took me a year and a half to save up what i needed for a 1000 watt mid drive from Bolton E bikes.
I am very happy i waited and got something with the power i wanted. I do not know what your price range is but they had a sale of $1999 a few weeks back I actually paid $2499

 

[ElevenAD]

Looking at the less expensive 350w bike, but looking to eventually upgrade that 350w motor to at least the bafang M600 500w mid-drive that's used in the bike you posted. Do you know if that upgrade at least would be possible?

I see "mid-drive kits" for BBS**, but you're saying they won't fit in the spot in the frame of the M2S mid-drive bike?

I debated biktrix classic juggernaut which apparently uses a BBS** motor mounted mid-drive. But no torque sensor, so would have to add one like Juiced apparently does. I've read that the 'add-on' torque sensors somehow don't work as well as those integrated with mid drive motors? Smooth torque sensor operation is one of the main reasons I want a mid-drive, but also because I'd like to be able to swap between wheel sets (fatter tire for commuting on crappy quality local streets, narrower wheels for single track riding).

And do you have any idea whether adding a throttle to the 350w mid-drive motor is possible?

this is just my opinion not the gospel, i think your basing to much on crap you have read, first off dont be so sure you will need to replace a cadence sensor with a torque sensor because chances are you wont bother once you get the bike especially with a company like biktrix who tune there motors pretty good, second a 350watt bafang MD is just not very much power and chances are you will very much want to upgrade in the future. i would take a chance, try the Juggernaut Classic 750 or even better the Juggernaut HD, ride it and see how you feel about the cadence sensing, if you dont like it you can simply return the bike. and also please try to find a way to actually ride a hub motor bike and judge the feel for yourself before deciding against them,you could be limiting your choices for no good reason, i say this because i have a bike with torque sensing and a Hub motor and i have a Juggernaut with a mid drive and a cadence sensor and they are both Fantastic!

 

[Dewey]

The best mid-drive kit motor with a torque sensor is the Revel Propulsion that uses the same Sempu brand bottom bracket torque sensor that Grin Tech sells for their hub motors, there’s a good comparison of torque sensors on Grins website, but I don’t know if it can fit a throttle too. For cheapness the TSDZ2 is another mid-drive kit with a more basic built in torque sensor and a throttle. Either can fit a variety of bottom bracket shell widths.

 

[mewanderinghome]

Thanks @Dewey for giving me some new leads. I would prefer a widely-used motor like Bafang, but I'll definitely check those out. @Timpo, I think I would love the g510 (Ultra_. Unfortunately, my budget is $2k max incl shipping, and I can't find an even remotely affordable full-suspension bike that uses the g510. Even searched Alibaba for g510 full suspension frames and bikes in China, but shipping is expensive (and I'm not seeing the Alibaba g510 frames on any US commercially-available bike, which makes me additionally wonder about quality). I don't mind building my own bike, just need an affordable full-suspension frame for the g510 to start with. If anyone knows of one please let me know. Otherwise may have to hire a local welder to build one maybe.

@ElevenAD I'm pretty certain I'll want a quality torque sensor from what I've read. I don't have any locally available to try- wish I did. But I want the most natural pedal feel possible for my single track riding, and from a lot of research, it sounds like that means I want a good torque sensor. I also want to be able to swap fat-tire (commuting) to single-track wheelsets (unless I have 2 entirely different bikes, which I can't afford), so leaning away from hub drive (although hub drive on both wheels is tempting in a different, expensive way

 

[tomjasz]

1) Can a bafang BBS02 750w or BBSHD 1000w be fitted into the same space in/on the bike frame that currently holds the 350w? Those motor kits look like a slightly different form factor than the 350w mid-drive. If not those, then how about the bafang M600 500w, which looks more similar (but may be a different size)?

Yes, plug and play

2) Can I add a thumb throttle to the bafang 350 mid-drive,

Some builders had motor setup and they can't be fitted with a throttle. But please confirm which 350W model you have. If it's a BBS01 350W it should have a throttle option. I'd need more details here.

$350 for a BBS02B 750W is to low to be for real. Might be old stock? Or worse yet a scam. I can't buy thatmotor wholesale at that price.

BBSHD is the toughest and most reliable for most riders. BBS02B motors are sometimes overheated by riders lugging the motor and not shifting when coming to a stop and trying to throttle away fro the stop BBS02 motors need to be wound up at higher RPM

 

[tomjasz]

Thanks @Dewey for giving me some new leads. I would prefer a widely-used motor like Bafang,

Grin is widely accepted by those who know eBike kits as the premier reseller. FWIW.

You'll not find any torque sensing in BBSxx versions of Bafang mid drives.

 

[mewanderinghome]

@Thomas Jaszewski thanks for the input. Yeah I was talking about the 350w Max mid-drive, and apparently it doesn't even allow the Max Ultra (g510) to fit into the same spot. I'd be happy to go with a BBSHD mid-drive since it's a widely-tested and liked motor, but I'm pretty certain I want torque sensing. Is it possible to use a mid-drive BBSHD with the Sempu torque sensing bottom bracket from Grin? Or any other torque sensor (since it sounds like there are some that sense the torque in very different ways than at the crank)?

The TDSZ2 that @Dewey suggested seems to check all the boxes for me if it's got a torque sensor and throttle. But it's out of stock at Luna, is less powerful and costs more than the g510 (also out of stock), and I'm not stoked about using an expensive, less-known motor when the Bafang g510 seems to be becoming a very popular choice. So I started looking at g510 frames and bikes off Alibaba. There is this. Looks like shipping on most bikes is ~$600 more, which puts it in my budget (or very close) and gets me the g510 plus purpose-built frame. But I'm nervous about ordering a complete bike off of Alibaba. Anyone have good/bad experiences with that? I don't mind waiting for delivery, I would go over it with a fine-toothed comb adjusting everything properly, and I'm not opposed to replacing cheap parts, charging the battery in a fire safe with a quality charger like Luna's or the Satiator, and even getting better cells put into the battery if necessary relatively soon (although I know that will be expensive).

I just don't want to be scammed. Anyone know if I'm likely to actually get that Alibaba bike, pretty much as advertised if I order it?

 

[Dewey]

The TDSZ2 that Dewey suggested seems to check all the boxes for me...I just don't want to be scammed.

There were a couple other Tongsheng US dealers listed at the end of Ron's article on the motor https://www.electricbike.com/tsdz2-750w-mid-drive-torque-sensing/, you might want to ask around on the Reddit ebikes or Endless Sphere forums to get an idea of their reputation before you pay. And here's Ron's article on the Revel https://www.electricbike.com/the-revel-propulsion-lightweight-350w-mid-drive/

 

[tomjasz]

Is it possible to use a mid-drive BBSHD with the Sempu torque sensing bottom bracket from Grin? Or any other torque sensor (since it sounds like there are some that sense the torque in very different ways than at the crank)?

No. BBSxx series are not compatible with Max and Ultra. Different beasts. BBSxx and TSDZ2 mount in standard bottom brackets. Apples and oranges.

TSDZ2 motors need aftermarket work in upgrading firmware. Very much a DIY build and update.

 

[mewanderinghome]

Thanks but I understand now about the proprietary frames. I'm separately wondering if there's any means of using a torque sensor with the BBSHD mid drive (like you can use a torque sensor with the Bafang hub drives). I'm guessing you can't use the Sempu bottom bracket torque sensor simply because they'd both consume the same space, but the Grin site discusses all kinds of torque sensors measuring chain tension, rear cog etc so I'm thinking there might be some torque sensor out there that could work with BBSHD. I'm probably leaning in the direction of buying or asking a welder to build a g510 frame, but if the BBSHD mid drive plus torque sensor were less expensive and more reliable, then I might look into that.