Help with mid drive selection and expectations

mwinschel

10 mW
Joined
Apr 26, 2015
Messages
24
Have been researching but seem to be stuck. New to the whole e-bike thing. Here is the ad: "Aging mountain bike rider, who really likes his KTM 350 but has little time and location to ride tight singletrack seeks to have a little more fun on an old ride on his local trails." I am looking for some help in my thought process. My desire is to ride single track locally. No desire for speed but torque to maybe get up some hills, plow some new trails. Never rode an ebike, dont know what to expect. Run about 215, have a 92ish cannondale m700 I purchased in college fitted with new rockshocks that I thought might be fun to put a kit on. There appear to be three kits that I am gravitating towards. GNG new planetary, GNG chain reduced and BBS-02 mid drives. That is where I am stuck. (If there are others I am missing suggestions please). Thinking 48V 10AH system. Several questions:

1. Exptectations - In the 5-15 mph range for tight trails can I expect these kits to take me around and run up mild to moderate hills without much work? lots or work? (Is it worth the money for the systems I am considering?) Would this be equivalent to me riding say a Honda 50 or 70 in terms I can relate to?
2. My Cannondale - Is it reasonable to think that It can handle these systems? I love the bike, and it has been well cared for. Shimano Deori components I believe. I dont want to mistakenly put a 454 in a prius though.
3. Which system? Looking for something relatively stealthy, quiet and tidy. How do these three systems compare? Would the BBS-02 or GNG new planetary do what I want or are these for road bikes. GNG hasnt given me much guidance except that the chain reduced is faster than the planetary. That doesn't quantify much. BBS-02 looks like a higher quality system, also potentially more work with my headset and shifters. I think Im fine with the concept of throttle only. GNG is quite a bit less expensive. Chain reduced is a bit more obvious and louder from what I read, but does it have much more torque and power?

I would like to be around 1000 for a kit if possible. Struggling because I read from some how there is not enough torque to take them offroad and others say you would never need this much power as I read reviews of these systems....I dont want to waste what little time I have and not be happy with the results. Any input would be appreciated as I mull over whether to do this or not.
 
I only have experience with the Bafang, but that + a smaller chainring up front = lots of fun on trails. The smaller chainring on front helps correct the chainline and improve climbing. With that it will definitely take you up lots of trails with minimal work if you want.

$1000 for a kit won't leave a ton for batteries, but it should be doable.

BBS02 - $530 shipped from Greenbikekit
Alternative chainring - $80+ http://em3ev.com/store/index.php?route=product/product&product_id=197

That leaves $300 - $400 for batteries. Should be doable for 48V 10AH but I don't have a recommendation handy.

That bike looks pretty old, but you can try it and then swap the kit to a different bike later.

Sorry I can't help decide between the GNG; although I believe it is noisier, and a little more temperamental in the maintenance department.
 
If you value silent running most, the bbs02 is the one. The GNG 450w/ or new chain primary drive version has potentially a bunch more power and can more easily be swapped over to run higher voltages and adapts to many low cost higher current controllers. I like them both, but will not let folks ride my GNG setup as it is way too wild a ride in low gears with 30+amps and 72V. The BBS02 running 12s lipo with its pas setup and multiple levels is easy for anyone to just ride away. My 9 year old grand son was at home on mine after a few minutes and would not give it back. He needed me to hold it while he climbed aboard (bike was way too big for him) but was at home cow trailing it right away. In top gear it will hit 30mph but will not pull that up hills. It is more like a old honda 50, but much lighter and a whole lot more fun to ride on a good mtn bike off road. Center mount battery and it is balanced and suspension works excellent as well.
 
tln said:
I only have experience with the Bafang, but that + a smaller chainring up front = lots of fun on trails. The smaller chainring on front helps correct the chainline and improve climbing. With that it will definitely take you up lots of trails with minimal work if you want.
Alternative chainring - $80+ http://em3ev.com/store/index.php?route=product/product&product_id=197
.

Thanks very much for the input guys, every little bit gives me some more insight. Im kind of leaning to the Bafang because of relative size, noise level and stealth.

Wondering what size chainring you are thinking might work well. The one you showed is only a 42, do you think that is small enough? I was going to order it with a 44, which seemed close. Several sites have options for chainring adapters in my existing middle ring size of mid 30s (thinking 36-37 maybe?).
http://california-ebike.com/product/bafang-ba104-chainring-adapter/
http://www.lectriccycles.com/4-bolt-chainring-adapter/
Figured that would give a good amount of torque. Thoughts?
 
speedmd said:
If you value silent running most, the bbs02 is the one. The GNG 450w/ or new chain primary drive version has potentially a bunch more power and can more easily be swapped over to run higher voltages and adapts to many low cost higher current controllers. I like them both, but will not let folks ride my GNG setup as it is way too wild a ride in low gears with 30+amps and 72V. The BBS02 running 12s lipo with its pas setup and multiple levels is easy for anyone to just ride away. My 9 year old grand son was at home on mine after a few minutes and would not give it back. He needed me to hold it while he climbed aboard (bike was way too big for him) but was at home cow trailing it right away. In top gear it will hit 30mph but will not pull that up hills. It is more like a old honda 50, but much lighter and a whole lot more fun to ride on a good mtn bike off road. Center mount battery and it is balanced and suspension works excellent as well.

Awesome. Thanks. Can you provide any thoughts on the 500w planetary powered vs chain reduced. Are they close? Same question on the GNG planetary vs BBS02. Heard the old version of the GNG had heat issues, but it appears that they have changed it. If that one just werent so damn shiny......:)
 
mwinschel said:
Wondering what size chainring you are thinking might work well. The one you showed is only a 42, do you think that is small enough? I was going to order it with a 44, which seemed close. Several sites have options for chainring adapters in my existing middle ring size of mid 30s (thinking 36-37 maybe?).
http://california-ebike.com/product/bafang-ba104-chainring-adapter/
http://www.lectriccycles.com/4-bolt-chainring-adapter/
Figured that would give a good amount of torque. Thoughts?

The 44 gears are pretty cheap to try, and will probably do the job, the 42 just fixes the chain line more. for me, the torque from the 42 has been plenty, even without going to a 34 or higher in the rear.

I think the chainring adaptors make the chain line worse but your bike will determine if that matters :)
 
i only have the gng belted (converted to chain) so i only have 1st hand experience w/ this one

GNG belted. latest version has a bit wider belt but durability is still questionable. cadence still too fast for you to keep up with the pedals to contribute power when at full-throttle. cadence probably OK at 36v but at this power level it won't take you up some steep hills

GNG chain. very noisy! same cadence issues. you needs lots of mods to fix the cadence like this:

zSAo1Ug.jpg


BBS02. it's a tightly integrated package so when something breaks it's going to be difficult to fix. read about the burnt controllers. this is the advantage of the GNG, easy to fix. personally i wouldn't buy the BBS02...

the GNG aren't plug and play make no mistake. if you just want to get up the hills perhaps you're better off with a 12T mac motor? from em3ev.com. a lot less fuss to keep running but you're basically stuck to "one gear". but if you skills to do mods the GNG will give you more power and versatility
 
I have no experience with the gng2 http://endless-sphere.com/forums/viewtopic.php?f=28&t=45740&hilit=gng2

Looks like it would be closer to performance of the BBS02. Still noisy in comparison, freewheeling crank issues, no pas or power selection choices. Much easier to tinker with as there is a big world of ebike controllers that will run it. I have had a half dozen different ones running mine. The BBS02 is a bit new and only a few have been setup and run on alternate outside controllers. Stock ones are reasonable priced and easy to replace and do work quite well. I am on my third one. First one was infant mortality, and second was my fault. Hopefully the third one will last forever.
 
The bbso2 system is definitely the best option as far as ease use & installation. I have two 750w versions & take them on my local trails pretty regularly. They can climb steep grades with out a problem & w/virtually no maintenance. The only thing is they aren't made for big drops or jumps. The square spindle is the weak point & will bend or break. I have no experience with the regular GNG kits but I do have an AFT 1680w, which I think is a modified heavy duty version of the GNG. I can tell you it was a big undertaking for me to get it right on the bike I chose to use, but now it's a rocket that requires a lot of attention. You should also consider a frame with disc brake mounts as the bbso2 is capable of 35mph(w/settings & gearing correct), and that my friend, is pretty fast on a bicycle.
-wear a helmet
 
The square spindle is the weak point & will bend or break. I have no experience with the regular GNG kits but I do have an AFT 1680w, which I think is a modified heavy duty version of the GNG. I can tell you it was a big undertaking for me to get it right on the bike I chose to use, but now it's a rocket that requires a lot of attention

How much faster is the AFT 1680w vs the BBs02 750w if you have both ?
 
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