9c motor BB drive

[fume]

This is another build possibility of hub motor mid-driven bike. I was planning it since july and yesterday I got it moving. The direct drive is insanely quiet, its like..wow! how can something so quiet pull you up a steep hill so fast its reliable so far and great fun to ride but I didnt test it on long ranges, so the future shall show the builds reliability.

-9c 500w/36v
-10 Ah lifepo
-27kg quite heavy..

 

[Wishes]

Nice build!!!

Did you put a freewheel on the pedal crank?

 

[Wishes]

And it looks like you have it leaning on both of the V's angles? It doesn't try to twist or move under tork?


Wishes

 

[fume]

yes, I did put a freewheel there, not on the cranks, but on the motor itself. Like on the picture
And no id doesnt twist, there is approx 2 mm clearance from the Vs, but its 4mm steel, it doesnt move one milimeter under high load.

 

[Wishes]

yes, I did put a freewheel there, not on the cranks, but on the motor itself. Like on the picture
And no id doesnt twist, there is approx 2 mm clearance from the Vs, but its 4mm steel, it doesnt move one milimeter under high load.

Thanks for the info. Very nice and clean build.

Wishes

 

[ohzee]

I love the simplicity of this design. It scary at all having the chain between your legs much less the motor.
Nice job love to see video of it running.

 

[fume]

Thank you
Im also curious how much will the torque affect the whole build (freewheel, BB, etc)

Ohzee, thanks. yes its very simple and it was also quite easy to manufacture
I wil post a video soon

 

[Wishes]

Thank you
Im also curious how much will the torque affect the whole build (freewheel, BB, etc)

Regular bicycle setup should handle almost 2000 Watts without abnormal wear and tear. And I don't think you are going to be doing jumps with this build, so the BB should be fine

Wishes

 

[fume]

Regular bicycle setup should handle almost 2000 Watts without abnormal wear and tear. And I don't think you are going to be doing jumps with this build, so the BB should be fine

2000W? very nice number, I couldnt find any reference on this matter on the internet, so thanks. True, I plan no jumping but I plan a suspension fork in the front for this bike, just in case of bumps.

 

[spinningmagnets]

I've added this to the list of "hub as a non-hub" builds:
http://endless-sphere.com/forums/viewtopic.php?f=6&t=38553&p=794542#p794542

The Specialized Supercharged custom build was the bike that really captured my imagination (it's a take-off on the factory E-bike name "Specialized Turbo"). I am currently experimenting with a smaller MAC geared hub, because it seems it would be easier to fit to a variety of existing frames.

Conhis makes a very quiet direct-drive (DD) hub that is smaller (and possibly more fittable to small frame triangles) http://www.conhismotor.com/ProductsList.asp?id=113. For a near-silent large diameter DD-hub in the triangle (for a frame that can accept it), I like a narrow front wheel 9C with a low-kV / high turn-count.

http://www.electricbike.com/specialized-super-charged/

 

[Wishes]

Regular bicycle setup should handle almost 2000 Watts without abnormal wear and tear. And I don't think you are going to be doing jumps with this build, so the BB should be fine

2000W? very nice number, I couldnt find any reference on this matter on the internet, so thanks. True, I plan no jumping but I plan a suspension fork in the front for this bike, just in case of bumps.

That is just my personal experience. Only when i passed 2000 Watts did I start to experience excessive chain, chainring and cassette wear and tear. Under that and everything wears out normally.

 

[fume]

The Specialized Supercharged is obviously a masterpiece in its own category, must have cost much too. But I saw the Bzhwintalkers Project LMX e-bike (better motocros e-cycle) that one amazed me. Its just so reasonably build.

It's indeed looking better this way but finding a good mounting solution was not easy.
I have a chain tensioner and some wiring to finish. I should get my battery box next week, then it's game on

 

[korpin]

yes, I did put a freewheel there, not on the cranks, but on the motor itself. Like on the picture
And no id doesnt twist, there is approx 2 mm clearance from the Vs, but its 4mm steel, it doesnt move one milimeter under high load.

yes but...your pedals turn as fast as the motor when its on correct?...because there is no freewheel on the crank?

never mind...i see its a motorcycle...great design!

 

[John Bozi]

just to check, we use outrunners (hub motors) because they have lower rpms so need less reduction, also they are quieter right?

Any other reason?

thanks, I'm very interested in building a monster climber.

Would there anyway to get a concentric pivot on these so that the chainline runs cleaner and use big go cart style chains and can bicycle hubs handle say 5kw?