Mid-Drive kits - where do I start?

Kmob1

1 mW
Joined
Mar 19, 2014
Messages
10
Hi guys, I've just started researching ebikes as I want to build one on a dual suspension bike. I'd like to hear feedback on what people recommend, I believe mid-drive kits are the most efficient???
 
spinningmagnets said:
D'oh!...ya beat me to it!

And that is something that doesn't happen often. Especially with mid-drives
 
teslanv said:
d8veh said:
Kmob1 said:
I believe mid-drive kits are the most efficient???

Where did you get that from? I don't believe it's true at all, and I have two of them.

Getting 13 watts/mile with my BBS02. Pretty darn good, I think.

You mean 13 Wh per mile?

Is that recumbent or something?

What is the shunt resistance on your controller?

And how fast are you traveling to get that effiency.
 
No hard data on relative efficiency, but here is subjective opinion.

The BBS02 mid-drive feels very efficient, simply because it is relatively easy to use it taking advantage of existing gearing.
EG, you can easily find the "sweet spot" in gearing for flat / uphill / downhill / city streets / open road.

With my other setups (MAC mountain bike rear-wheel, Q100 front drive folder) I find I don't really shift often.
Frankly, I hardly shift at all. I just use the throttle.

With BBS02 setup I shift all the time, and my perception is that I can always keep the bike at some sweet efficiency point as result.

Not scientific, but it just feels right. As result, I ride BBS02 setup more often than others lately.
 
cal3thousand said:
You mean 13 Wh per mile?

Is that recumbent or something?

What is the shunt resistance on your controller?

And how fast are you traveling to get that effiency.

Yes, I meant wh/mile.

You can see my bike build in my signature - It's a hardtail MTB. I generally set the PAS to level 3 of 9 and average 15-20 mph on the flat when I ride. Up hills I ride much slower, and down long, steep hills, I either coast or turn the PAS down to 0. - If I use throttle and higher PAS settings, I can easily run the efficiency down to 30 wh/mile.
 
Just use larger battery. Whats the fun in being a juice miser? Counting watts and coasting? :shock: Takes all the fun out of the hobby. Ride it like you stole it!
 
triggeraa said:
Ride it like you stole it!

Love that!

I've had good fun with cars / motorcycles / bikes with that approach. Forget failure modes, and just goose it. It is fun.

But as a builder, I'm always worried about stressing the vehicle, reducing component lifespan, etc...

Maybe we should all just swap bikes among us and "ride 'em like we stole 'em", forget the conservative builder approach to babying them.

Isn't that what they do on racing circuits? They'd never let a mechanic drive an F1 vehicle, or expect a driver to worry about system longevity.
 
teslanv said:
d8veh said:
Kmob1 said:
I believe mid-drive kits are the most efficient???

Where did you get that from? I don't believe it's true at all, and I have two of them.

Getting 13 watts/mile with my BBS02. Pretty darn good, I think.

I have two similar bikes. They have the same battery and controller. One has a GNG gen 2 with a Nuvinci N360,and the other a Bafang CST. My friend is the same weight as me and same level of unfitness. We go out for fairly long moderately hilly rides more or less side by side on these two bikes. The hub motor normally uses less power by about 10%. Sometimes they're close, but the hub motor always wins.

13wH per mile means nothing. Sometimes I get 8wH per mile from my 500w Bafang CST, sometimes 25wH per mile. It simply depends on how motivated I am to pedal. Over about 1000 miles of commuting, my Cycle Analyst showed that I used about 13wh per mile on my 500w 36v BPM with 30 amp controller. That was with moderate pedalling.

It's difficult to beat the simplicity and reliability of a single rear hub-motor. I think that the recent motors from Bafang and Xofo have raised the game a bit for the crank-drives, but you've still got the problem of crashing gears when you have to change down going up steep hills unless you get a Nuvinci.
 
Kmob1 said:
... I want to build one on a dual suspension bike. I'd like to hear feedback on what people recommend...?

Did you want to use a new or a second hand dual suspension bike?

The BBS01 and BBS02 kits are designed for a 68mm bottom bracket. This limits your choice of dual suspension frames some what. Some users have fitted them to a 73mm bottom bracket by reducing the width a bit with a grinder and/or only fitting 1 of the M33 rings to secure the motor with plenty of loctite.
There is a frame adapter available to convert a BB30 press fit frame to an English thread type, so this may be an option also.
 
d8veh said:
I have two similar bikes. They have the same battery and controller. One has a GNG gen 2 with a Nuvinci N360,and the other a Bafang CST. My friend is the same weight as me and same level of unfitness. We go out for fairly long moderately hilly rides more or less side by side on these two bikes. The hub motor normally uses less power by about 10%. Sometimes they're close, but the hub motor always wins.

13wH per mile means nothing. Sometimes I get 8wH per mile from my 500w Bafang CST, sometimes 25wH per mile. It simply depends on how motivated I am to pedal. Over about 1000 miles of commuting, my Cycle Analyst showed that I used about 13wh per mile on my 500w 36v BPM with 30 amp controller. That was with moderate pedalling.

It's difficult to beat the simplicity and reliability of a single rear hub-motor. I think that the recent motors from Bafang and Xofo have raised the game a bit for the crank-drives, but you've still got the problem of crashing gears when you have to change down going up steep hills unless you get a Nuvinci.

I have heard that the Nuvinci' are a source of efficiency loss. If one is paired with a mid drive, perhaps that would account for less than stellar efficiency. That being said, efficiency is most dependent on the rider and how much they are pedaling. One could easily claim 5 watt-hours per mile if they were a skilled cyclist and used the PAS on the lowest setting at all times.
All I know is that I enjoy the hell out of riding my bike, whether I am commuting to my job or tearing around the park near my house at WOT. And I can go up some damn steep hills without pedaling if I so choose.
 
Bafang BBS02 Mid Drives: http://endless-sphere.com/forums/viewtopic.php?f=28&t=50104
LighteningRod's Kit: http://endless-sphere.com/forums/viewtopic.php?f=28&t=57720

These two kits are probably the best on the market right now, as far as aftermarket Mid-Drives..

By best two i think you mean cheapest and not best as their is other higher quality mid drives kits like the ECOSPEED, EGO kit and AFT mid drive kits that are better quality and more reliable but more expensive. These kits seem to work without people needing to upgrade them or have problems with them.

The best of these for performance +40mph, efficiency with ceramic bearings and cost seems to be this one recent builds here :

http://endless-sphere.com/forums/viewtopic.php?f=28&t=55066

http://endless-sphere.com/forums/viewtopic.php?f=6&t=57337

http://endless-sphere.com/forums/viewtopic.php?f=28&t=55964

ecospeed recent build also

http://endless-sphere.com/forums/viewtopic.php?f=4&t=48521&p=869133&hilit=+ecospeed#p869133

ego kit

http://endless-sphere.com/forums/viewtopic.php?f=28&t=51567
 
thanks for the links guys, i will look through them. I want a kit that is high efficiency as i want to travel very long distances offroad and i have lots of hills i want to use it on hence why i think i need a mid drive , that GNG kit i already saw some threads about but i think the kit looks ugly and home made with the exposed belts etc so i will look at other options like the bafang or AFT, they look nicer and more compact
 
d8veh said:
I think that the recent motors from Bafang and Xofo have raised the game a bit for the crank-drives, but you've still got the problem of crashing gears when you have to change down going up steep hills unless you get a Nuvinci.

I am curious about the "crashing gears" comment. Is this something of an issue with e-bikes (I guessing non-pedelec) because as a cyclist on a non e-bike this is is easily avoided by good riding technique, e.g., getting the gear right first; easing off a moment to change etc.

Andrew
 
Try to ride one first. Try a hub.
Decide if you mostly want to go offroad or on.

As a guy who owns 3 or 4 each of hub bikes and mid drives at any one time they are a very different beast. Efficiency is fine but for an extra fifty bucks on batteries and a cheaper hub drive efficiency can be a distracting point.
 
Aushiker said:
d8veh said:
I think that the recent motors from Bafang and Xofo have raised the game a bit for the crank-drives, but you've still got the problem of crashing gears when you have to change down going up steep hills unless you get a Nuvinci.

I am curious about the "crashing gears" comment. Is this something of an issue with e-bikes (I guessing non-pedelec) because as a cyclist on a non e-bike this is is easily avoided by good riding technique, e.g., getting the gear right first; easing off a moment to change etc.

Andrew
The motor can put a lot more tension on the chain than you can. It's therefore almost impossible to change gear with the power on. it's even worse when you use a PAS, because the motor runs on for a bit after you stop pedalling. If you get a crank-drive, you'll see what I mean. Imagine trying to change gear on a motorcycle without a clutch. It's OK on the flat, and down-hill, but when you're going up-hill with more power, it's a different story.
 
d8veh said:
The motor can put a lot more tension on the chain than you can. It's therefore almost impossible to change gear with the power on. it's even worse when you use a PAS, because the motor runs on for a bit after you stop pedalling. If you get a crank-drive, you'll see what I mean. Imagine trying to change gear on a motorcycle without a clutch. It's OK on the flat, and down-hill, but when you're going up-hill with more power, it's a different story.

Thanks for the clarification. It hadn't occurred to me a PAS could run on.

Thanks
Andrew
 
Thanks for the feedback.

After reading some bad things recently about Bafang and all the failures they're having, I'll be looking at other

http://forums.whirlpool.net.au/forum-replies.cfm?t=2043397&p=42

This one looks good

http://endless-sphere.com/forums/viewtopic.php?f=6&t=57337&start=25
 
I really like the AFT mid drive but it's expensive. The AFT motor is a cyclone motor without the upgrades (oil, ceramic bearings, etc). So you can just get cyclone kit also for much cheaper.

However, Jim, at AFT, customer service is top notch! I haven't heard anyone have complaints with AFT who has one. It has a lot of cool upgrades like external oil reservoir.

It's my first mid drive so can't really compare to any others. It seems like a very solid setup and getting beat up on the trails and no signs of breaking down. Very happy with it!

With gng, you have a great support base here and cost is much cheaper.

The cyclone motors are somewhat noisy so keep that in mind. Mid drives also have a lot of moving parts and require more maintenance.

I would go with this or LR mid drive.
 
[Re: Mid-Drive kits - where do I start?
by drew12345 » Mon Apr 14, 2014 3:55 pm
I really like the AFT mid drive but it's expensive. The AFT motor is a cyclone motor without the upgrades (oil, ceramic bearings, etc). So you can just get cyclone kit also for much cheaper.

However, Jim, at AFT, customer service is top notch! I haven't heard anyone have complaints with AFT who has one. It has a lot of cool upgrades like external oil reservoir.

It's my first mid drive so can't really compare to any others. It seems like a very solid setup and getting beat up on the trails and no signs of breaking down. Very happy with it!

With gng, you have a great support base here and cost is much cheaper.

The cyclone motors are somewhat noisy so keep that in mind. Mid drives also have a lot of moving parts and require more maintenance. /quote]

Thanks for the feedback. The AFT kit costs seem reasonable if the kits work reliably and there is good customer support. To me the most important thing is reliability as i will ride it to work and dont want breakdowns . Also don't have the time to repair and upgrade it like the gng kits need. Costs also seem a lot lower then the other high quality mid drive kits like the EGO or ECOSPEED...
 
Ego kits use the same cyclone motors I believe. Direct Drive Hubs are the most reliable. I believe they only have one moving part. I also have a direct drive and think that will outlast my mid drive. If are riding off road, I really like mid drives. If just for commuting, I would prefer a direct drive. If you want to know how commuting is on AFT, Harold25 is using for commuting. You can ask him about it.
 
I have a Cyclone 1600w motor driving through a Nuvinci 360 using a 44v,20amp lipo battery... 17.9mph in high gear...29.6mph in low gear with a 20" drive wheel ..well over 2000 miles with no problems.. whats better?? :mrgreen:
 
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