Largest single speed freewheel / cassette?

[DeathBlade]

I am changing the my motor over to a new bike and I need to change the sprockets. Currently on my ebike I use a 56T sprocket on the left side (cant use it on the new bike because of the disc brake) driven by a 9T on a jackshaft which is driven by a 20T free wheel which is driven by a 9T on the motor. I'm going to change the direction of the motor and run if on the right side now using the largest sprocket on the cassette a 34T 'mega drive' and a freewheel crank

For a 34 / 9 * 20 / 9 = 8.39 gear ratio, not so good when my current ratio is 56 / 9 * 20 / 9 = 13.82 gear ratio.
So now I have to find the largest freewheel I can to get up in the gear ratio again, Largest I've found is a 22T single speed can anyone suggest a source for a larger one? or a cassette with a larger 1st gear than a 34T 'mega drive'

So any one know of a single speed free wheel with more than 22T? of a 8speed cassette with more than 34T on the largest gear?

 

[etard]

Sorry I don't know about any larger freewheel cogs than 22 tooth, but I have noted that if you bore out any cog to fit next to the 22 tooth, you could use the slots to screw those two together, effectively giving you any tooth count you desire. I would get the Eno in this case because the torque acting on the freewheel will be substantially more than stock. Have you considered a left side belt drive like Earthnet64? With your reduction required this might actually be easier, he seems very happy with this setup (check the waterproofing thread for a link)

 

[3wheels1life]

You can buy a 24t single speed freewheel off eBay (see link below).
That's the only place I've seen it (other than AliBaba and the 100 thieves). By the way, this one cannot be removed with a freewheel tool.
I'd go for a smaller freewheel that supports a freewheel tool.

Hope this helps.

-3wheels1life
Ebay Link:
http://www.ebay.com/itm/E-bike-or-fixie-single-speed-freewheel-24T-tooth-2-sided-threaded-sprocket-/271282315131?pt=US_Cassettes_Freewheels_Cogs&hash=item3f29af9f7b

 

[spinningmagnets]

It's easy to make an adapter disc. The pic shows a large 130-BCD chainring, but it could have just as easily been a 64mm-BCD or 74mm-BCD.

 

[3wheels1life]

Spinningmagnets,

Would the system you have in the pic work on a rear hub motor without modification? I think the OP was using a rear hub motor...
Thank you.

-3wheels1life

 

[--freeride--]

You can use 42T sprockets on the cassette. Look out for a custom XX1 sprocket in the MTB-Forum. Thats for adding it to the cassette on the left side and leaving one smaller sprocket out.

Or you get yourself a freewheel for a freewheel crank and add a 32T for example:

http://www.eclipsebikes.com/chainwheel-cranks-p-1008.html

 

[Bullfrog]

Yes I know this is an old thread, just wanted to post some info so others could find it.

I took a DNP freewheel, took it apart and it has the spline pattern of Shimano cassette gears. You can put it back together using whatever size cassette gears you like and space them according to desired shift pattern i.e. 7, 8, 9, 10 speed, etc. May not be able to use as many gears as you would like due to space limitations but I have used as few as a single gear. Screw the freewheel back on the hub and it works great. DNP is the only freewheel I could find that uses the 9 spline Shimano pattern. The little thin nut that holds the gears together is tought to get off and you have to be careful not to damage it and I'd recommend some thread locker when you put it back together as well as torque stripe it so you can easily see if it has moved.

This is one of the freewheels I used: https://dnpgears.webnode.com/products-/freewheel/a7-speed-fw/#ly-1007mfn-dnp-fw-7spd-11-13-15-18-21-24-34t-nickel-jpg

You can also weld the two parts of the freewheel together while hold the pawls so that they are engaged and create a direct drive...I use it with my BBSHD and the freewheel in the motor does all of the freewheeling. Advantage is there s ZERO backlash when you get on the throttle. Disadvantage is the chain is always moving.

Hope this helps a few people :wink: .