Planetary Reductions: Reasonable Prices

[12p3phPMDC]

Gary,

thanks for the detailed reply.

I have a mix of Nexus 3 and Alfine 8 as well.
I'm going to utilize the disc brake mount on each hub to do the
left side drive for the electric. This will make it easy.

I bought a 6 bolt sprocket for the output of the Nexus 3
and will use it as a 6 bolt template for the aluminum BMX cog that
will drive the Alfine 8 on the rear.

The trike has twin disc on the front two wheels....so I'm not worried about brakes on the rear.

It's time for me to update my build thread, but I can't find my camera!! argh..

 

[GGoodrum]

Gary,

thanks for the detailed reply.

I have a mix of Nexus 3 and Alfine 8 as well.
I'm going to utilize the disc brake mount on each hub to do the
left side drive for the electric. This will make it easy.

I bought a 6 bolt sprocket for the output of the Nexus 3
and will use it as a 6 bolt template for the aluminum BMX cog that
will drive the Alfine 8 on the rear.

The trike has twin disc on the front two wheels....so I'm not worried about brakes on the rear.

It's time for me to update my build thread, but I can't find my camera!! argh..

Wait, so you are using a Nexus-3 and an Alfine?? Yes, pics please!

-- Gary

 

[12p3phPMDC]

Nexus 3 electric tranny...

Alfine 8 human tranny...

Shimano makes nice stuff...The Alfine is super quiet in freewheel, no racheting sounds
whatsoever.

Yea, it'll be a parallel drive, human right side, electric left side.

The system will have one more jackshaft than I want, but it'll work.

The 1000 dollar bite outta my ass for the brakes on my truck took the
steam outta my sails for a bit..... :? But I'm rearing and ready to go again!!!

 

[boostjuice]

Yeah, the Alfine uses cam-clutch freewheels so no tick-tick-tick of ratchets and pawls which is a blessing for the noise conscious. If only you could buy regular BMX freewheels in that style that were up to the torque spec.
Closest thing is i've found is this http://www.daytonsuperiorproducts.com/pdfs/OneWaySprockClutch.pdf

You'll notice the torque rating per unit volume is very poor compared with ratchet & pawl freewheels, which is i guess why they dont do it for BMX/Trials. It will be interesting to see how they hold up in the Alfine under heavy loading, after all they are only recommended for "light xc use" whatever that means.

http://www.daytonsuperiorproducts.com/pdfs/CamRingAssm.pdf

 

[12p3phPMDC]

I'm not putting electric power through the Alfine gears, but it is going through
the disc brake splines on the left which is tied to the shell/spoke holes.
As long as the alloy shell of the Alfine holds up, I should be good, no?

If I was putting electric power through an 8 speed, yikes!!!
top speed potential is huge...like 30 mph to 90mph...if you can push it that fast.
The trike has no suspension so high speeds will only be done when I know
it won't kill me or wreck the thing on impact with a pot hole or whatever.

I am putting electric power through the Nexus3 though...It sounds
like it has a combination of cam clutch and ratchet and pawl. It is really quiet freewheeling
as well, but also has a ratcheting sound that only kicks in when spinning
fast enough... I think it has ratchet and pawl on the input hub and possibly
some additional cam clutch elsewhere... I should look for a exploded diagram at shimano.

 

[lesdit]

I will be installing a 1200 w cyclone onto my GT IT1 bike with the red band nexus 8 speed hub. I have the luxury of gearing the transmission to spin faster to reduce the torque load on the hub, so I hope that will promote the life of the Nexus 8. The hub is not in the wheel on this bike.
If the Cyclone geared motor does not work out, I'll use an RC motor geared down to 50:1 with an industrial planetary gear reducer.