Mid-drive conversion question

[allu]

Hi all!

Lately I've been getting more and more into the idea of owning an e-bike. At the moment my way of commuting longer distances is by moped, but I feel like an e-bike could easily replace it. I do have a custom built Commencal Meta HT SX (2015 frame) which has been my short distance commuter and trail bike since I can't afford both. It's great fun to drive, but for longer distances commuting it's not ideal. Yes I have driven it to work several times, but without a chance to take a shower at work I usually pass that workout.

So after learning about the subject for a few months I came to a conclusion I want a legal mid drive kit. I could go up to one 1kw if I was willing to pay for some b*llshit insurance, but I rather stay in the legal limit of 250w. Recently I found em3ev selling bbs02 36v and 500w kits with 250w labels, and this is exactly what I need. The area I live in is really flat so I could live with 250w, but extra grunt is never a bad thing eh? :lol:

I do have a few questions regarding the motor: I have heard the pedal assist is not ideal on this motor, but is it really that bad? I know it has a bit of a delay on it going on and off, but especially with brake sensors can you live with it? Other thing is the power itself. How large is the difference between 250w and 500w? I heard the 250w can't top out the speed limit of 25 kph on its own, but I guess the 500w could? Not like I wouldn't be pedaling, but I would be able to reach that top speed even in snow and headwind. Also would using a smaller chainring like 34 teeth be beneficial, or is the 44 teeth stock one fine for the motor?

When it comes to the battery I've been looking for something in the 10ah range, but not much more since I want to keep the weight down. No idea how much range I would need, but if I can get 30 to 40 km on single charge that would be plenty. I'm just struggling with the amount of selection there is. I think I have decided to go with either a frame or bottle battery, depending on which one I can get for cheaper. The problem is the outrageous shipping cost of batteries. I can get a 12 ah frame pack that should be able to handle 25 amps continuous for around 450€ directly from Finland. Em3ev had the same pack for less than 300€, but shipping being over 100€ there's not much point on ordering abroad. But if anyone knows a good place to get such batteries (or any type really) that somehow have cheaper postages let me know.

Might edit later for more questions, but let's start with these.

-allu

 

[keithmac]

With the battery you are best off buying one with decent cells (Samsung seem very well liked). If buy from China and have to send it back it will be very expensive!.

I'm looking at either a BBS02 or HD and will be using it in PAS mode so very interested in the replies!.

I would buy local (ish) so if you have any warranty or back up issues you can get them sorted out straight away rather than waiting months on end. Can you imaging waiting 2 to 3 months for a battery andnit turned up dead on arrival..

 

[allu]

I would buy local (ish) so if you have any warranty or back up issues you can get them sorted out straight away rather than waiting months on end. Can you imaging waiting 2 to 3 months for a battery andnit turned up dead on arrival..

Yeah that would be... Infuriating :lol:

BMS battery has a nice looking 36v 10ah frame pack for 220€ including shipping estimate. 12.5ah version would be just 30€ extra, and they both come with chargers too! Sadly they're only rated 20 amps continuous, but if the motor was limited to 350w (18 amps) it could work. Who knows about quality though... :?

-allu

 

[amberwolf]

I highly recommend searching the forum for the vendor's name and reading everything on them before you order from anyone.

 

[rmanalan]

I just got my EM3EV BBS02/36v/25a/500w kit yesterday. Installed it on my Kona Mahuna and a few hours later was up and running. I am repurposing a 36v 10ah bottle battery from a direct drive kit I used to have on my bike. Today, I went out for a very hilly ride for around 16 miles and returned with around 25% battery life. I'm very happy with the EM3EV settings. The folks at EM3EV said that the 36v motor comes with a faster winding to compensate for the lower voltage and claim that it's virtually comparable to a 48v kit.

I also got the Lekkie Bling Ring with it... Rides real smooth across all 9 speeds.

So far I'm very happy with the kit.


Sent from my iPhone using Tapatalk

 

[dogman dan]

Re 250w. In heavy sand, thick snow, wind, hills, anything that sucks your wheel will be much slower with 250w max, than with 500w max. With mid drive and a low enough gear, you can plow through anything with just 250w, and your 100-200w of pedal power. But laws of physics apply, and you will plow through slower with less watts. Huge wind, 50 kph wind,, will slow the hell out of a low watt setup.

So I'd say if you can get the 500w with a 250w label, go for that.

As for the PAS, I'm pretty sure you get a throttle override on the kit. Throttle to start, then start using the PAS is one solution to annoying pas lag. Me, Id find a way to run without the PAS altogether. Not legally needed where I am, so....

If a throttle is illegal, you could hack up a secret go switch. Push button that would deliver half throttle.

 

[allu]

I just got my EM3EV BBS02/36v/25a/500w kit yesterday. Installed it on my Kona Mahuna and a few hours later was up and running. I am repurposing a 36v 10ah bottle battery from a direct drive kit I used to have on my bike. Today, I went out for a very hilly ride for around 16 miles and returned with around 25% battery life. I'm very happy with the EM3EV settings. The folks at EM3EV said that the 36v motor comes with a faster winding to compensate for the lower voltage and claim that it's virtually comparable to a 48v kit.

I also got the Lekkie Bling Ring with it... Rides real smooth across all 9 speeds.

So far I'm very happy with the kit.

Glad to hear good opinions on the Kit. How is the pedal assist on it or were you using throttle?

As for the PAS, I'm pretty sure you get a throttle override on the kit. Throttle to start, then start using the PAS is one solution to annoying pas lag. Me, Id find a way to run without the PAS altogether. Not legally needed where I am, so....

If a throttle is illegal, you could hack up a secret go switch. Push button that would deliver half throttle.

Non-plowed roads are not too uncommon here in the winter time, so a bit of extra power would definitely help. So if I end up getting this kit I'll go for the 500w one.

Honestly I'd rather go fully legal than hack a secret switch, my moped is illegal enough already and I'm tired of being afraid of being pulled over :lol: After learning about the "new" TSDZ2 mid drive with torque sensor I haven't been able to decide whether to go with safe bafang or take a risk but possibly get a way better pedal assist with torque sensor. The latter has pretty mixed reviews, for some it works great while others weren't so lucky. Why can't someone come up with the perfect mid drive that does everything perfectly and costs next to nothing... :lol:

-allu

 

[d8veh]

I don't know where you heard about the PAS from. I guess is was from somebody that didn't know what he was talking about because when you have PAS and throttle, there's not many times when you want to use the throttle.

The important thing with the battery is that it can provide enough current. If you have a 25A controller, you need a battery that can provide 25A continuously, not 25A maximum.

There's nothing to say that a torque sensor is better than a movement sensor. There's advantages and disadvantages with both systems. I prefer a movement sensor. The best systems use both.

 

[keithmac]

I'm in the same boat, the TSDZ2 with pedal torque sensing sounds a better fit for how I ride but what's the reliability like?.

Had made my mind up on a BBS setup but the torque sensing PAS would be a big improvement for actually using the bike.

On the other tread one let go at very low mileage though..

 

[d8veh]

I'm in the same boat, the TSDZ2 with pedal torque sensing sounds a better fit for how I ride but what's the reliability like?.

Had made my mind up on a BBS setup but the torque sensing PAS would be a big improvement for actually using the bike.

On the other tread one let go at very low mileage though..

You should try one first before committing. So far, every Chinese torque sensor bike that I've tried wasn't ideal.

 

[keithmac]

There's a couple of reports of them cutting out/ no pas assist after turning on etc.

Might stick to the proven BBS I think..

 

[allu]

I don't know where you heard about the PAS from. I guess is was from somebody that didn't know what he was talking about because when you have PAS and throttle, there's not many times when you want to use the throttle.

The important thing with the battery is that it can provide enough current. If you have a 25A controller, you need a battery that can provide 25A continuously, not 25A maximum.

There's nothing to say that a torque sensor is better than a movement sensor. There's advantages and disadvantages with both systems. I prefer a movement sensor. The best systems use both.

For example here they don't particularly praise the pedal assist. But it sounds a lot better after reprogramming, but it still can't sense the power you're applying. For me torque sensor is important since I'd like to get some exercise too instead of being able to just cheat and soft pedal. I could live without it, but it would be a nice addition. I could totally give a go for the new TSDZ2 mid drive if I found an European supplier, just to be safe in case something goes wrong and warranty is needed.

Has anyone used an aftermarket torque sensor with cycle analyst and small hub motor and how did they work? A small hub motor is not ideal for off road riding but just an idea

When it comes to the battery awfully many Chinese frame packs seem to be only rated for 20 amps continuous which has gotten me thinking of running the kit on lower amps and saving a bit on battery, but we'll see. These new options have made my decision awfully lot harder :lol:

-allu

 

[keithmac]

I've found a UK supplier for the TSDZ2 but leaning towards the BBS-HD due to reliability and noise?.

Decisions, decisions...

 

[ScooterMan101]

@ Allu

" For me torque sensor is important since I'd like to get some exercise too instead of being able to just cheat and soft pedal. "


Me ...
For many of us a torque sensor does not work , because when you can not put too much torque into the crank arms/pedals
it is a ( Dumb sensor ), meaning it does not give you the power/speed you want/need for the ride you are doing .

A better system is a ... Throttle / Gears / Garmin GPS with cadence sensor !

What you do is use the throttle to get to the speed you desire, then using the gearing on the bike , the more gears the better for your knees/legs , you enter the right gear for that speed .... at the cadence that is best for your knees and legs and cardiovascular system.
What I describe above is the smartest , best way .
You can then ride more accurately on each different day , because your body is different / is stronger on some days than other days.

Using the above , Smarter than PAS/Torque sensors, way I still burn the same amount of calories, and have the same or even better,
a less average heart rate ( BPM ) .
With the Advantage of Going Further and Faster,
I can finally, after years of riding , ride with other bike riders and keep up with them and go as far as them, within my batteries capacity.
Throttles are better , you just need to know how to use them.

 

[ScooterMan101]

One person here, on a different thread , is now , after owing 2 befang BBSxx motors , is asking for advice on what hub motor to use ,
he is ready to go back to/ or use for the first time a hub motor.
He said that one of the Befang BBSxx motor lasted 2 thousand miles and the other one only 1 thousand, he also said he was easy on the motors and shifted correctly, etc.

I am ready to try a mid-drive, but for me the BBSxx is too much weight , too much $ , needs more $ for the shift sensor, and even more for a adaptor spider to use a better and/or bigger chainring.

What is the cost in England between the BBSxx or BBHD, and the TSDZ2 ?

I've found a UK supplier for the TSDZ2 but leaning towards the BBS-HD due to reliability and noise?.

Decisions, decisions...

 

[ScooterMan101]

allu,

Where are you riding off road ?
What kind of percentages of steepness are the hills you want to ride up and for how far ?

I now have 12 rides on a Q100c CST hub motor , 201 rpm version, with a 27.5 ( 650b ) wheel/tire, Road/Gravel bike , and it works just fine on , up to 6 % grades/inclines with medium effort on the cranks/pedals from me.
it still goes up 11-12 % hills, that are short , but with the higher % climbs I really put allot of effort into pedaling like max effort from me , my heart rate up to 150 - 160 bpm , to help it not over heat/bog down.

That is on a bike that weighed 21-22 lbs before adding the motor/controller/battery.
so keep that in mind.
with a heaver bike you might want a heaver and stronger motor like the Q128 , or the Mac , the Mac has plenty of power to go up hills, you just need to get the slower/more torque wind version. or lace a 201 speed Q100c CST hub to a 26 inch wheel.

I am ready to get a mid-drive to compare to the Slow hub motor , but that is off in the future when mid-drives come down in price and weight, and even then ...
only because I live with hills, and Mountains all around me that I want to climb up. ( 3- 13 % grades )
otherwise I would just stay with the Q100c CST and/or Mac hub motors .

Has anyone used an aftermarket torque sensor with cycle analyst and small hub motor and how did they work? A small hub motor is not ideal for off road riding but just an idea

When it comes to the battery awfully many Chinese frame packs seem to be only rated for 20 amps continuous which has gotten me thinking of running the kit on lower amps and saving a bit on battery, but we'll see. These new options have made my decision awfully lot harder :lol:

-allu

 

[allu]

allu,

Where are you riding off road ?
What kind of percentages of steepness are the hills you want to ride up and for how far ?

I now have 12 rides on a Q100c CST hub motor , 201 rpm version, with a 27.5 ( 650b ) wheel/tire, Road/Gravel bike , and it works just fine on , up to 6 % grades/inclines with medium effort on the cranks/pedals from me.
it still goes up 11-12 % hills, that are short , but with the higher % climbs I really put allot of effort into pedaling like max effort from me , my heart rate up to 150 - 160 bpm , to help it not over heat/bog down.

That is on a bike that weighed 21-22 lbs before adding the motor/controller/battery.
so keep that in mind.
with a heaver bike you might want a heaver and stronger motor like the Q128 , or the Mac , the Mac has plenty of power to go up hills, you just need to get the slower/more torque wind version. or lace a 201 speed Q100c CST hub to a 26 inch wheel.

I am ready to get a mid-drive to compare to the Slow hub motor , but that is off in the future when mid-drives come down in price and weight, and even then ...
only because I live with hills, and Mountains all around me that I want to climb up. ( 3- 13 % grades )
otherwise I would just stay with the Q100c CST and/or Mac hub motors .

Regarding the throttle suggestion: unfortunately having a separate throttle is illegal and would require a BS insurance for the bicycle, so I'd rather not go that way.

I'm pretty sure a small hub motor would be enough here. The hills are minimal and generally speaking not that deep, except for some climbs I can find in the forest. Also my bike is not all that heavy, I'd say 25 pounds and even less after I convert it into a single chain ring setup. What I've always been concerned about is how durable the hub motors are construction wise? Like will the axle held up urban assault kind of driving with little jump here and there?

Do you happen to know which hub motor setup is the lightest on the market? Just to keep the core function as a bicycle there would be nice to have a really lightweight setup that wouldn't slow you down too much even if the battery died. Thanks for your help!

-allu

 

[ScooterMan101]

allu,

I do not know what the lightest weight motor on the market is, however it probably is the little Q100c cst.
My bare hub ( Q100c CST 201 rpm ) weighs 2.06 kg, that is very light for an electric motor . ( it comes in 201 or 328 rpm and 36 or 32 holes for spokes, so you can use a 32 spoke hole rim as long as you are careful at ordering and make sure you order the 32 spoke hole one.
The axle will hold up it is 9-10 mm on the flat part / thinnest part of the axle, I would be more concerned with the dropouts on the bike you have, if you are going to jump, ride rough pavement/dirt, you could get a full suspension frame and transfer most of the parts over to the full suspension frame .
I can provide a link if you like , there are places that buy whole bikes then part them out. shipping would be less than a whole bike, and for you in High Import Tax Rate Countries , it is cheaper that way as well.

( or you could hop on a WOW Air flight and pick up a frame yourself, and have a nice Holiday. )

For comparison of riding a e-bike when the battery runs low, or just to extend your range.

My 31-32 pound mountain bike with 9.5 pound Mac motor and 48 volt battery with touring tires was not pleasant to ride with motor off.

Now with just 12 rides on my 21-22 pound Gravel/Road bike , with 4.5 pound hub Q100c CST motor and 48 volt 8 pound battery, is a pleasure to ride with motor off. I do it a few times each ride, especially on a 1 to 2% or more % down hill section of a ride.

The Q100c CST is However, a motor that needs pedal assistance, you must exercise , or go slow, it is not a moped, or light motorcycle. that is what the 9.5 pound and heaver DD hub motors , 750 - 1,000 watt and 1500 watt and 3,000 watt motors are for.

I'm pretty sure a small hub motor would be enough here. The hills are minimal and generally speaking not that deep, except for some climbs I can find in the forest. Also my bike is not all that heavy, I'd say 25 pounds and even less after I convert it into a single chain ring setup. What I've always been concerned about is how durable the hub motors are construction wise? Like will the axle held up urban assault kind of driving with little jump here and there?

Do you happen to know which hub motor setup is the lightest on the market? Just to keep the core function as a bicycle there would be nice to have a really lightweight setup that wouldn't slow you down too much even if the battery died. Thanks for your help!

-allu

 

[allu]

allu,

I do not know what the lightest weight motor on the market is, however it probably is the little Q100c cst.
My bare hub ( Q100c CST 201 rpm ) weighs 2.06 kg, that is very light for an electric motor . ( it comes in 201 or 328 rpm and 36 or 32 holes for spokes, so you can use a 32 spoke hole rim as long as you are careful at ordering and make sure you order the 32 spoke hole one.
The axle will hold up it is 9-10 mm on the flat part / thinnest part of the axle, I would be more concerned with the dropouts on the bike you have, if you are going to jump, ride rough pavement/dirt, you could get a full suspension frame and transfer most of the parts over to the full suspension frame .
I can provide a link if you like , there are places that buy whole bikes then part them out. shipping would be less than a whole bike, and for you in High Import Tax Rate Countries , it is cheaper that way as well.

( or you could hop on a WOW Air flight and pick up a frame yourself, and have a nice Holiday. )

For comparison of riding a e-bike when the battery runs low, or just to extend your range.

My 31-32 pound mountain bike with 9.5 pound Mac motor and 48 volt battery with touring tires was not pleasant to ride with motor off.

Now with just 12 rides on my 21-22 pound Gravel/Road bike , with 4.5 pound hub Q100c CST motor and 48 volt 8 pound battery, is a pleasure to ride with motor off. I do it a few times each ride, especially on a 1 to 2% or more % down hill section of a ride.

The Q100c CST is However, a motor that needs pedal assistance, you must exercise , or go slow, it is not a moped, or light motorcycle. that is what the 9.5 pound and heaver DD hub motors , 750 - 1,000 watt and 1500 watt and 3,000 watt motors are for.

I will stay with my current frame for now, but will keep that in mind if I ever decide to change the frame.

Thanks for the info! Much appreciated, you've given me even more to think about. We'll see what I end up getting, but I'll make sure to make a new topic once I have gotten everything set up

-allu

 

[ScooterMan101]

allu,

While going back and reading this thread again, I do not mean to talk you out of a mid drive,
it's just that , you do not really need a mid drive unless you are riding up hills in excess of 4%-5% or more , and even then steep hills , that are more than 100 meters in length.
( at least on my 21-22 pound road bike, with my medium body weight this is the case,
other heaver bikes , heaver bikes with mountain tires, and heaver riders might benefit more with a mid - drive if they go up hills every day ).

The current mid-drive models ( Befang BBSxx ) are heavy, and expensive , more expensive than a simple low power hub motor .

That might change with the new TSDZ2 , it is lighter if the specs are honest, then it is about 2 pounds , ( almost a Kilo ) less than the Befang,
so that is one improvement that many of us have been waiting for, it is however only $ 50 U.S. less in price, so there still needs to be more
competition for prices on a mid-drive to get more reasonable.

The SDZ2 is new, and on another thread there are some people that are having some/a problem with it, But then again that same thing happened 2 years ago when the BBSxx was new .
So the problems should be worked out in the future, the question is how far off into the future ?
As soon as the problems are solved, I want to try one for myself, but that is only because I live with some very steep hills, and long roads up mountains where I live.

We will love to hear and see what you do wind up with, which ever you chose , mid-drive or small hub, you can always get the other system in the future and use the same battery.