mid drive with triple ?

atuee147

Just Joined
Nov 2, 2015
2
0
north ayrshire
Hi all
Iv been looking at e kits for my new trike and I'm thinking of going for a mid drive this time rather than a hub motor (I run a hub motor at the moment)
The reason I'm thinking of the mid drive system is for the extra umph on hills which I have a lot of the system I'm looking at is a bafang 8fun kit the one thing that puts me off is the single cog I like my front triple.

So my question is why is it only a single gear and can you put a triple onto it if not why ?

Thanks
Stuee
 

trex

Esteemed Pedelecer
May 15, 2011
7,703
2,671
in a crank drive like the 8-Fun BBS01, the space that was occupied by the two inner chainrings is now occupied by the gearbox. A triple chainring is going to be problematic to keep a good chainline. It's possible to fit a double chainring though.
 

anotherkiwi

Esteemed Pedelecer
Jan 26, 2015
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5,785
The European Union
It is easier to do on a trike because the chainline is less precise because of chain length. There are kits/howtoos for double chainrings about.
 
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Geebee

Esteemed Pedelecer
Mar 26, 2010
1,256
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Australia
Double should be easy, you really wont need a triple.
Mine is a single 46 tooth up front and an 11-32 in rear with 20" wheel, you wont find a hill that will need lower with the motor assist, in fact most places you won't need the lowest gears at all.
If I could pedal with any power (health issue) I would change the front ring to a 50 tooth, oh, I have a BBS01.
 

atuee147

Just Joined
Nov 2, 2015
2
0
north ayrshire
so its nothing to do with the gears or anything its really down to the gearbox being in the way.
i wonder if i could off set the mid drive slightly and extend the shaft out to allow a triple ?
i understand that i shouldn't really need a triple with the e-kit as i dont really use the lowest gears on the setup i have now when i have power in the batterys but its more for when/if the batterys run out. i have 2 rides i do quite regular both are around 5 - 6 miles and both with some largish hills with my currunt hub motor e-kit i do the ride in about 20 mins using PAS but if the batterys die (has happened a few times as althow the rides are short i may do 4 or 5 trips each day ) and without using the e-kit it takes me almost 1 hour to do the same 5 miles. (due to health ) my fear is running out of power for the motor and not having the gearing to be able to ride without PAS.

the new trike i am building at the moment will have 2 battery packs instead of the one i use now but i would still like to have the gearing to be able to ride without a e-kit hense the reason i would prefer a triple up front.
i am also considering spliting the chain run on the new trike into 2 parts which i have done before and that with a triple would give me 54 gears in total and the ability to ride without using the e-kit
 

anotherkiwi

Esteemed Pedelecer
Jan 26, 2015
7,845
5,785
The European Union
Try a large range double - your current big cog and small cog. Yes changing from one to the other will be painful but they are the two you will need. One when the motor works and the other when it doesn't.

Best idea is a spare "get me home" battery.