DIY ebike build

[walkachalka]

Hi
Looking for some advice here on starting a ebike build/ options
Based on the research I've done I'm considering a few options.

Riding style/ uses for the bike:
Mostly Commuter 20km one way and then weekend warrior:
70% pavement, gravel, commuter,
30% single-track mtb style trails (novice, nothing crazy like downhill west coast mtb trails, its pretty flat here)

Options considering:

Get a used giant, trek, specialized hardtail as a starting point. Or full suspension bike if I see one and the price is right.

Looking for Light weight rear geared hub motor (500w?) plenty of torque would be nice

**do you have any recommendations for a reliable torquey geared hub motor kit with shipping to Canada?
That ship with 29inch or 26inch rims.

In terms of controller options is also where I could use some recommendations for compatibility with hub motors. I don’t really have an idea of what controllers are compatible with what motors...

I would like some flexibility to push the hub motor hard.

Battery options I have a couple places to get custom battery packs. Maybe 52v or 60v (going fast in fun +32kmh)

So first option I was considering was geared rear hub motor

Second option I was considering / looking for would be a quiet (stealth) mid drive motor.
Lots of options in this category. Reliability seems like a big concern here and replacement parts.
Latest one I seen might work well would be torque sensing New 52v tongsheng tsdz2. Maybe it's more reliable than previous versions?

Feedback here is welcome. BBSHD is popular choice for reliable but not torque sensing it seems

Last option I was considering is just say screw it and just buy

(50lb) Envo D35 with a warranty or a used E-MTB hardtail with mid drive motor (3k -4k)

With a e-mtb has anyone removed the speed limiter? Based on the research I've done I have to order a 200-300$ chip and hope it works

 

[EMGX]

I don't have any specific recommendations for you but was wondering why you think a tsdz2 isn't reliable. I have two tsdz2 ~2yrs old. No problems of any kind and I've installed them on 6 of my bikes (taking off and putting on). Super simple to install on compatible frames (despite opinions to the contrary that you might see posted by the inexperienced), performance similar to my gravel bike with a yamaha PW-SE mid drive. As far as I have seen virtually all parts/components are easily available and relatively inexpensive. Biggest issue I can think of is chainline which is not optimal when on largest rear cassette sprocket even using the dished chainrings. Limited chainring choices. I have 3 chainrings, stock 5mm dished 42t, 42t 10mm dished and a 34t 5mm dished that mounts directly to the motor without use of a spider. Theoretically you can run a double chainring with regular flat chainrings but the chainline could be exceptionally bad in low gears.

 

[rich c]

Personally, I don't consider anything with a cadence sensor to be good for mtb riding. I want instant pedal response with power provided by a torque sensor and not wait for some pedal movement to pass a magnet past a sensor before the motor power kicks in.

 

[walkachalka]

Thanks EMGX, sorry I didn't mean to say that the tsdz2 was not reliable.
I can't really comment on the reliability of that motor, I haven't personally used it.
I mostly meant that I heard they released a new 52v version of the motor and maybe it might be more reliable then previous versions if there were improvements

Yes, I am a bit worried about chain lines with mid drives and slightly worried about chains coming off or breaking on the trails

 

[tomjasz]

**do you have any recommendations for a reliable torquey geared hub motor kit with shipping to Canada?
That ship with 29inch or 26inch rims.

ebikes.ca in Canada!

 

[tomjasz]

I don't have any specific recommendations for you but was wondering why you think a tsdz2 isn't reliable.

The earliest version was not as reliable as they've become. We trialed samples maybe 5 years ago. I donated the bike to a less fortunate fellow and he's put 3500 miles on it and I donated another $200 in repair parts. Over that time. In fairness, it is road hard and put up wet. The worst issues were with the displays and firmware. That has also been significantly improved.

 

[EMGX]

Thanks EMGX, sorry I didn't mean to say that the tsdz2 was not reliable.
I can't really comment on the reliability of that motor, I haven't personally used it.
I mostly meant that I heard they released a new 52v version of the motor and maybe it might be more reliable then previous versions if there were improvements

Yes, I am a bit worried about chain lines with mid drives and slightly worried about chains coming off or breaking on the trails

The chainline is bad when on largest rear cogs. Even with a narrow/wide chainring the chain comes off if I try quickly shifting more than one cog at a time on the largest sprockets.
FWIW I have an old Schwinn Sierra mountain bike that I put a 500w rear hub motor on. It works pretty well, with a 12 magnet cadence sensor it takes maybe 1/4 to 1/3 crank rotation for the motor to kick in. Not such a big deal when you can be in the really low gearing available with a triple front and a 22t chainring at your disposal because you don't have to depend much on the motor to spin the crank with very low gearing.
I live on a mountain (not a very big one but a mountain none the less with some very steep inclines) and the 500w hub motor climbs as well as my mid drives. The KT controller indicates that it can draw up to close to 1000w when really pushed to see what it would draw. The motor has never gotten hot but the controller would get very hot if in any enclosure at all, it needs open air for cooling. I'm not sure how the KT controller works to deliver power but it isn't the "on/off" speed based sensation that some people describe. I think it has a simulated torque sensing (power based rather than speed based) setting. Still I prefer torque sensing that the Yamaha and tsdz2 provide and haven't ridden the rear hub bike in probably a year.

 

[walkachalka]

The chainline is bad when on largest rear cogs. Even with a narrow/wide chainring the chain comes off if I try quickly shifting more than one cog at a time on the largest sprockets.
FWIW I have an old Schwinn Sierra mountain bike that I put a 500w rear hub motor on. It works pretty well, with a 12 magnet cadence sensor it takes maybe 1/4 to 1/3 crank rotation for the motor to kick in. Not such a big deal when you can be in the really low gearing available with a triple front and a 22t chainring at your disposal because you don't have to depend much on the motor to spin the crank with very low gearing.
I live on a mountain (not a very big one but a mountain none the less with some very steep inclines) and the 500w hub motor climbs as well as my mid drives. The KT controller indicates that it can draw up to close to 1000w when really pushed to see what it would draw. The motor has never gotten hot but the controller would get very hot if in any enclosure at all, it needs open air for cooling. I'm not sure how the KT controller works to deliver power but it isn't the "on/off" speed based sensation that some people describe. I think it has a simulated torque sensing (power based rather than speed based) setting. Still I prefer torque sensing that the Yamaha and tsdz2 provide and haven't ridden the rear hub bike in probably a year.

Does the KT in "KT controller" stand for anything or is that the brand name of the controller? Just never heard of it.

Do you know for controllers, do they have to be paired with a specific hub motor to ensure they will work together?

Thanks for the info so far

 

[EMGX]

KT is the common abbreviation for KunTeng brand. In my limited experience motor and controller don't have to be paired. I put a geared front hub motor on my wife's Biria easy step bike and used the KT controller on it, it works fine even though the motor is rated 36v 250w with a KT 22a max controller at either 36v or 48v (the controller recognizes the battery and automatically adjusts for 36v or 48v parameters). I've ridden that bike for miles up fairly steep roads without the motor getting hot.

edit:
the connectors on the motor and controller have to match. The MXUS geared front hub motor that I put on my wife's bike had different connectors than the WP (stands for waterproof, I think) connector on the KT controller. I bought a WP extension cable, cut it in half and soldered the wires from the motor to the connector so they could be connected together.

 

[m@Robertson]

'high torque' and 'hub motor' are sort of mutually exclusive. Yes you can get some pretty good torque ratings on a spec sheet out of the motors, but no matter what they are inherently single speed since they power the bike thru the axle. Think of whether or not you would be at a disadvantage riding a single speed bike across your terrain no matter how strong your lungs and legs are. The hub motor is similarly, inherently out of its element.

You may get it to perform acceptably, but it will never be at its best. I retired a 2wd super-powerful dual hub bike because I didn't want to kill it taking hills. I've kept it on flat ground where it shines. It can climb anything, but not daily for months or years. I would second the recommendation to ebikes.ca (Grin Technologies) if a hub in Canada is where you want to go.

I'll make the case for a mid drive in the conditions you describe. The fears over chain alignment and wear/tear go away if you build the bike right, and this has to happen when you make the frame choice and continues from there. The mid drive will have higher torque numbers on paper, and will give superior performance as well given the fact it can use the gears to better get up a hill - just like you do.

I've just finished this little magnum opus which discusses what to look for in a frame and how to gauge whether the motor is going to be a good fit. Also look for the 'how to ride a mid drive without breaking it' article, which links directly to discussion of suitable drivetrain and hub hardware. Lastly look for the 'BBSHD settings for the pedaling cyclist' which as far as I'm concerned eliminates the issue of no torque sensing.

I do 52v batteries exclusively. With a 30a BBSHD that makes for sustained output as high as 1750w on a full charge. Then I dial back the PAS to lower output levels - which retains the ability to hammer the throttle if I please - so I end up with an overbuilt motor that is usually running at half strength or better. The idea is for a commuter that lasts forever, and dating back to 2017 none of my BBSHD builds have had internal failures.

How To Build An Ebike From Scratch

You want to build an ebike, but the project seems overwhelming. Lets de-mystify the entire process, including planning, parts and perfecting the end result.

talesontwowheels.com

Now that the above monster is finished I'm going to be doing a companion to the 'how to ride it' article with 'How To Build A Mid Drive Ebike That Doesn't Break'. Its on a fast track for July release - This topic comes up a lot and I just want to link to an article and save my fingertips

 

[AHicks]

Personally, I don't consider anything with a cadence sensor to be good for mtb riding. I want instant pedal response with power provided by a torque sensor and not wait for some pedal movement to pass a magnet past a sensor before the motor power kicks in.

News flash: most torque sensing bikes have built in cadence sensors! It would be difficult to build one that didn't want to take off out from under you while you were climbing on if that were not the case....

 

[AHicks]

Hi
Looking for some advice here on starting a ebike build/ options
Based on the research I've done I'm considering a few options.

Riding style/ uses for the bike:
Mostly Commuter 20km one way and then weekend warrior:
70% pavement, gravel, commuter,
30% single-track mtb style trails (novice, nothing crazy like downhill west coast mtb trails, its pretty flat here)

Options considering:

Get a used giant, trek, specialized hardtail as a starting point. Or full suspension bike if I see one and the price is right.

Looking for Light weight rear geared hub motor (500w?) plenty of torque would be nice

**do you have any recommendations for a reliable torquey geared hub motor kit with shipping to Canada?
That ship with 29inch or 26inch rims.

In terms of controller options is also where I could use some recommendations for compatibility with hub motors. I don’t really have an idea of what controllers are compatible with what motors...

I would like some flexibility to push the hub motor hard.

Battery options I have a couple places to get custom battery packs. Maybe 52v or 60v (going fast in fun +32kmh)

So first option I was considering was geared rear hub motor

Second option I was considering / looking for would be a quiet (stealth) mid drive motor.
Lots of options in this category. Reliability seems like a big concern here and replacement parts.
Latest one I seen might work well would be torque sensing New 52v tongsheng tsdz2. Maybe it's more reliable than previous versions?

Feedback here is welcome. BBSHD is popular choice for reliable but not torque sensing it seems

Last option I was considering is just say screw it and just buy

(50lb) Envo D35 with a warranty or a used E-MTB hardtail with mid drive motor (3k -4k)

With a e-mtb has anyone removed the speed limiter? Based on the research I've done I have to order a 200-300$ chip and hope it works

Wow, you are jumping all over the ball park with some of these comments.

First, you mention the positive feedback on the BBSHD, then you discount it because there's no torque sensing? Torque sensing is not on your want list and none of your other options include it. If you want a motor you can hammer on under all sorts of different conditions, this motor has a great reputation for doing just that. Bonus is it comes with a built in controller so you don't have to be concerned about matching it up. Down side, if there is one, they don't get along well with high voltage batteries. With 160nm on tap when powered by a 48v battery, there's really no need to go big voltage.

I really enjoy something like a 500w geared hub bike. Especially one that's been coupled with a KT controller. They're brain dead simple to ride and maintain for starters. That's a big deal for a lot of riders. The 500w motors can get pretty "sporty" when fed a diet of 1000w (possible using a 22a or bigger KT controller) for short term blasts, but they're going to need a cool down period between these sprints. That in mind, I would never endorse one of these if you were planning on pushing it real hard. Generally a lighter bike because you don't need the big battery necessary with more power.

Neither of the examples above would have a speed limiter.

If I can make a suggestion, it would be to spend some time working on more focus in what you are trying to do. Riding a few different e-bikes an outstanding plan to help do that if there's any way possible. Otherwise, it's back to reading everything you can find. To help further, I'd like to know about what you weigh (big guys need more power), and the terrain you ride most often. How likely is it you're going to be riding in big hills? That being the case, we can eliminate the hub drives...

 

[tomjasz]

I do 52v batteries exclusively.

you never had the pleasure of getting the firmware version that locked out 52V? What a nightmare that was...

 

[Bobber]

I converted my Specialized Crosstrail. These bikes are a crossover trail/street bike with skinnier tires and lighter weight than a MTB. I rode trails all the time before electrification but now I get really tired of the massive cleanup if it's muddy out so mainly street now unless it's pretty dry. My advice is to get something similar because it's the best of both worlds.

 

[m@Robertson]

you never had the pleasure of getting the firmware version that locked out 52V? What a nightmare that was...

Yeah I missed that party entirely. I heard about it, but while it was going on I didn't need to buy a BBSHD. the two I bought recently don't have the 'issue'

 

[tomjasz]

Yeah I missed that party entirely. I heard about it, but while it was going on I didn't need to buy a BBSHD. the two I bought recently don't have the 'issue'

Did you have any of the HDs with older rotor shaft?

 

[m@Robertson]

Did you have any of the HDs with older rotor shaft?

Probably since mine go back to I think 2017. But I have never had one snap so never had to dig in.