Advice for a freewheel installation

Hi,

I'm searching a solution for installing a Freewheel in my 120mm motor.
It must handle a maximum of 15Kw with lot of torque, I've found lot of China freewheel with 12 tooth but I don't think it will handle all of this torque.

Do you have links for some good Freewheel ?

I've see this motor for example:


It's from this subject:
https://endless-sphere.com/forums/viewtopic.php?f=31&t=64342&start=50

I don't know wich freewheel (or freehub) he used, because this motor is capable of 15Kw peak too.

I would like to know too, how to install the freewheel on the motor axle ? Someone have pictures ?

Thanks everyone !

The smallest kind of normal bicycle freewheel is for M30x1 threads. Those are available in 15t, 14t, and 13t. So-called "heavy duty" 13t freewheels hold up much better than ordinary 14t ones, in my observation. Odyssey is the brand of 13t freewheel that's easiest for me to get where I am.

The pedicab outfit I work for uses them on the shafts of Cyclone gearmotors. Cyclone can furnish freewheels already mounted on specially made collars for 20mm shafts with 6mm keys. If you don't find something like that to match your motor shaft, you'll have to make your own mounting collar. M30x1 on the outside, with a shoulder the freewheel can stop against. The through bore must correspond to your motor shaft.

Freewheels don't care how much power your motor has-- the only thing that matters is torque. The freewheels are designed to accommodate a maximum of about 75 Nm of torque from pedal drives. If your shaft torque is less than that, the freewheel should be okay. Multi-speed bicycle freewheels and freehub bodies are proven to tolerate torques of 300 Nm.

One other caveat is that these, like all bicycle freewheels, will self-destruct if they are set up with static tension on the chain. The only chain tension they're capable of dealing with is drive tension that transmits torque. Any tension on them while they're overrunning is very bad for them.

It's tidier and safer to use a freewheel on the rear wheel rather than on the motor shaft, so the chain stops running when the motor stops. That would allow the use of larger and more widely available 1.37"-24 freewheels including some that have mounting flanges for chainrings.

Chalo,

Do you have any pictures , or know of any , that show a home made mounting collar ?

I am trying to figure out how to make my own crankset freewheel system using either a Shimano Hollowtec II Crankset ( that has a 24 mm OD spindle and 64 BCD Bolt patern crankest Spyder on the dirve side crankarm, 104 mm I think for their road Hollowtec II cranksets)
https://www.google.com/search?q=Shimano+Deore+Hollowtech+II+Crankset&rlz=1CAACAO_enUS762US762&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiO4bXSvKLWAhWNw4MKHeqFAf4Q_AUICygC&biw=1920&bih=966#imgrc=ICJHBftn8zVudM:
or better yet
Make one that can be put onto a Direct Drive Crankset, like the Race Face Cinch Crankset System ( Race Face uses a 30 mm OD Spindle )
https://www.google.com/search?q=Race+Face+Cinch+Crankset&rlz=1CAACAO_enUS762US762&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjo38GjvqLWAhXq1IMKHZjIBPoQ_AUICygC&biw=1920&bih=966

>

That Sick Bike parts freewheel picture you link to is $ 120 and the other heavy duty one they sell is $ 80 , Luna has one that is $ 50 ( much more within my budget for experimenting with )
https://lunacycle.com/luna-tic-freewheel-for-mid-drive-ebikes/

The biggest question is , where can one get a freewheel that does not have the threaded inside , so as to be able to machine it to be able to Direct Mount to a Race Face Cinch system . ?

Chalo said:

If you don't find something like that to match your motor shaft, you'll have to make your own mounting collar. M30x1 on the outside, with a shoulder the freewheel can stop against. The through bore must correspond to your motor shaft.

>

It's tidier and safer to use a freewheel on the rear wheel rather than on the motor shaft, so the chain stops running when the motor stops. That would allow the use of larger and more widely available 1.37"-24 freewheels including some that have mounting flanges for chainrings.

Click to expand...

@Chalo
Thanks for your answer ! It will be very helpful.

It's tidier and safer to use a freewheel on the rear wheel rather than on the motor shaft, so the chain stops running when the motor stops. That would allow the use of larger and more widely available 1.37"-24 freewheels including some that have mounting flanges for chainrings.

Click to expand...

Ok I understand, I will use a big chainring on the freewheel.

I've done some research and I found this freewheel on "Sickbikeparts.com" , from the review it's look very duty for high torque usage, I think it will be perfect !
And I can easily attach a 48 tooth chainring !
http://sickbikeparts.com/chainring-freewheel-48-tooth/

But this freewheel doesn't looks like plug & play on the hub ..

There has gotta be a cheaper alternative to freewheels for the crank then Sick Bike Parts, they are really expensive and I can only assume he marked them up quite a bit, but I could be wrong. But its good to know you can buy replacement parts straight from Cyclone.

Found this
http://www.cyclone-usa.com/store.php?crn=203

I may buy a few items from Cyclone TW again
http://www.cyclone-tw.com/Parts.html
Definately need the cover plate.

markz said:

There has gotta be a cheaper alternative to freewheels for the crank then Sick Bike Parts, they are really expensive and I can only assume he marked them up quite a bit,

Click to expand...

The Sick Bike Parts premium freewheels are a custom flanged version of White Industries freewheels, which retail for higher than Sick Bike Parts's prices. The $120 version is, I think, a dual bearing design which address the main mechanical shortcomings of freewheeling cranks.

Chalo said:

The [M30x1] freewheels are designed to accommodate a maximum of about 75 Nm of torque from pedal drives. If your shaft torque is less than that, the freewheel should be okay. Multi-speed bicycle freewheels and freehub bodies are proven to tolerate torques of 300 Nm.

Click to expand...

Another data point: our pedicabs' most recent motors are rated to put out 130Nm of torque at the shaft. So far, we've had no freewheel failures related to motor torque.

Chalo said:

-speed bicycle freewheels and freehub bodies are proven to tolerate torques of 300 Nm. ]

Click to expand...

That’s a lot. At 200amps I estimate like 30 Nm going through the rear freehub