BIG KICK ASS SPROCKET

[TopCat]

Hi guys,

Im wondering if anyone can figure out/tell me how they think this was done?

http://www.evalbum.com/711
Not to much info on the link and it looks like the website no longer exists to get any more info

I like to try and recreate a similar setup but using a Cyclone 1200w motor. I have already blown 2 motors - (a 36V 500w and a 36V 1000w) by just running a chain direct from the motor(s) to the rear wheel via a 54T minimoto sprocket bolted onto the disc brake holes. 54T is the biggest I can go without interfering with the brake calliper setup.

If I can find out how the BIG sprocket is attached (and buy one or get one made?)this would save me scratching my head trying to figure out what cogs/sprockets I'd need to buy for jackshafting the cyclone 1200w to the LH side of the rear wheel.
See my sig.

Regards
Tom

 

[amberwolf]

Dunno if it helps, but:
http://wayback.archive.org/web/*/http://www.runaboutcycles.com/

 

[Thud]

its the old: Twin frewheel on a freehub trick.
A walk in the park with a broached pr of Eno's & a mountain bike disc brake rear hub.


I am working tonight on internal grinder set up V4.0 attemting to cut splines into a hardend ASC crossfire to send to e-tard for the race on the 17th.

I'd post a picture but I left my camera in a friends truck down in indinapolis.

the sprocket looks like a custom unit prolly from one of the motorcycle conversion places. Here is a 71tooth from zero
http://www.zeromotorcycles.com/shop/index.php?main_page=product_info&cPath=5&products_id=100
or maybe one of them monster chainrings for a recumbent speed project (ouch$$)

I use #35 kart stuff. Way chepaer in price, Much more reduction capacity than #40 cahin, e-bay has anything you want & its more than tough enough for the e-bikes.

 

[kfong]

That is definitely done on a big CNC. Todd I'm interested in how you are doing internal splines, I have a keyway I need to do on a project and trying different ideas without having to resort to a broach.

 

[TopCat]

its the old: Twin frewheel on a freehub trick.
A walk in the park with a broached pr of Eno's & a mountain bike disc brake rear hub.


I am working tonight on internal grinder set up V4.0 attemting to cut splines into a hardend ASC crossfire to send to e-tard for the race on the 17th.

I'd post a picture but I left my camera in a friends truck down in indinapolis.

the sprocket looks like a custom unit prolly from one of the motorcycle conversion places. Here is a 71tooth from zero
http://www.zeromotorcycles.com/shop/index.php?main_page=product_info&cPath=5&products_id=100
or maybe one of them monster chainrings for a recumbent speed project (ouch$$)

I use #35 kart stuff. Way chepaer in price, Much more reduction capacity than #40 cahin, e-bay has anything you want & its more than tough enough for the e-bikes.

I thought it might be a couple of freewheels but having looked at my spoiler there aint much room to add 2 freewheels? Im now thinking the large sprocket mybe clamped into the spokes.

Regards
Tom

 

[dumbass]

Not saying it is setup this way but just thinking aloud. What if the giant sprocket was actually on a good quality freewheel. And the crank sprocket also had a freewheel. In this manner both the motor would have freewheel protection as would the crank sprocket. But they wouldn't be required to actually be on the rear wheel.

Bob

 

[AussieJester]

Broaching to fit dual freewheels is only one way of doing it too TopCaT if you run the screw on type rear hub, spin on the first freewheel, then use a bottom bracket cup, screw that into the freewheels tghreads on the outer side, this gives you additional thread (on bottom bracket cup) to screw on a second freewheel... If you dont have the room, run motor drive on left hand side, freewheel on motor rear sprockt attached to disk brack mount using adapter (recumpence sells them)

KiM

 

[TopCat]

Not saying it is setup this way but just thinking aloud. What if the giant sprocket was actually on a good quality freewheel. And the crank sprocket also had a freewheel. In this manner both the motor would have freewheel protection as would the crank sprocket. But they wouldn't be required to actually be on the rear wheel.

Bob

Youv'e lost me a bit there Bob?

1. If the BIG sprocket is attached to the freewheel on the wheel hub with the chain to the motor.
That takes care of the Big sprocket/motor freewheeling.

2. Lets say the Crank sprocket also has a freewheel. You ankles aint broken by the pedals whizzing around due to the crank having the freewheel ability.
What is the long pedal chain attached to at the rear wheel?

---------------------------------------------------------------------------------------------------------------------------------------------------

Broaching to fit dual freewheels is only one way of doing it too TopCaT if you run the screw on type rear hub, spin on the first freewheel, then use a bottom bracket cup, screw that into the freewheels tghreads on the outer side, this gives you additional thread (on bottom bracket cup) to screw on a second freewheel... If you dont have the room, run motor drive on left hand side, freewheel on motor rear sprockt attached to disk brack mount using adapter (recumpence sells them)

KiM

Cheers Kim,
I was pondering something along those lines but there just isn't enough room. I'd need to unscrew the freewheel halfway off (making even lesss pace to the right dropout) then screw in the BB cup into the remaining threads of the freewheel then screw on another freewheel.
Humm! Can't see that happening when Iv'e only got about 25/30mm to work with.
Maybe the guy has done it that way but he would have needed to get the hub threads turned down some more? There's about 25/30mm or so space between the freewheel and the spoke flange.

Looking at the pics, the inside/motor chain looks damn close to the tyre.

I already/did run my motor(s) on the left hand side but trying to use such a big sprocket as that would interfere with the disc brake/rota/caliper....?

Im awaiting an 80t 8mm sprocket from Bobc. I'll see what I can come up with once it arrives.

Thanks for all the suggestions guy's.

Regards
Tom

 

[Thud]

tom,
here is a twin freewheel screwed onto each other & bothe freewheeling on the reah hub. you ned to put the lock ring onto the hub to space a freewheel out to thread the bottoma bracket cup/adapter.

& again with large custom sprocket

you may need to re-arange the spacers to clear the drop out...on 135mm standard I heve gotten away witha couple thick washers to clear the pedal drive line.

 

[dumbass]

Not saying it is setup this way but just thinking aloud. What if the giant sprocket was actually on a good quality freewheel. And the crank sprocket also had a freewheel. In this manner both the motor would have freewheel protection as would the crank sprocket. But they wouldn't be required to actually be on the rear wheel.

Bob

Youv'e lost me a bit there Bob?

1. If the BIG sprocket is attached to the freewheel on the wheel hub with the chain to the motor.
That takes care of the Big sprocket/motor freewheeling.

2. Lets say the Crank sprocket also has a freewheel. You ankles aint broken by the pedals whizzing around due to the crank having the freewheel ability.
What is the long pedal chain attached to at the rear wheel?

Regards
Tom

Tom, A fixed sprocket without a freewheel. If you look at the postings for Nuvinci CV hubs you will see that this is a common practice. Except with the Nuvichi hub setups most will use the freewheel on the hub to protect the crank sprocket (I do). And use a fixed sprocket for the motor which ether has a freewheel on it or is driving through a jack shaft that has a freewheel. I've also had a bike setup the other way. Whereas, the motor was using the freewheel on the wheel and the crank had it's own freewheel so it used a fixed sprocket on the wheel.

I'm not at all saying this is what is on that monster setup just that it is possible.

Bob

 

[GITech]

YWp, Thud just shared that little nugget with me through PM and he's right!

Going on a search marathon for #35 kart sprockets I was able to find what I needed for ~15 bucks each, ...better than what I though and in the colors I'd like too!

Blue skip tooth: http://www.tomarengineering.com/to/axle-sprocket-60t-35-split-skip-tooth.html/
Red skip tooth: http://www.bmikarts.com/item/WMS-35-Skip-Tooth-Split-Sprocket-6235-3280

THANKS THUD! 8)

 

[Hillhater]

You will get a better range of ratios if you use #219 chain kart sprockets !

 

[GITech]

I have had ZERO luck trying to find #219 "pinion" size sprockets,...that aren't conected to a clutch bell or made to mount to one.

#35 pinions are vast and cheap here: http://www.surpluscenter.com/sort.asp?catname=powerTrans&keyword=PH35

I'm already commited to #35 chain, but do you know of a source for #219 pinion size sprockets for others who may want #219?

The "large" #35 sprockets like the ones I linked to have quite a large range IMO. As much as 53t - 85t. Here: http://www.tomarengineering.com/to/sprocket-selector/

Don't feel like doing the research...what is the range for #219?

Thanks,
Jay

 

[Hillhater]

Asuza eng are a typical manufacturer of kart sprockets of all types.. #40/41, #35, #219.
They list a range of 219 from 8T up to 105T
http://www.azusaeng.com/Sprockets/AzSDno219.pdf
another supply source .. http://www.gokartgalaxy.com/engine_sprockets1.htm

..but i agree , 35 & 40/41 are easier to find, particularly with a straight bore on the motor sprockets.
And i believe you could get a range of 8T up to 114T in the #35.

 

[www.recumbents.com]

I know a guy that will make those big chainrings for $1 per tooth.

PM me and I will send you his contact info.

-Warren.