Rocket Sprocket

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riderick

riderick

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Rocket Sprocket meets turn of century walls. I never could figure out how this thing was SUPPOSED to work. Anybody know?

IMG_0016.jpg


IMG]http://i916.photobucket.com/albums/ad9/rider-rick/IMG_0015-1-1.jpg[/IMG]
 
I doubt you can use it on the bike because there is no anti-spin hole (2nd hole) for the crank. But i couldn't figure out what it is made for. nut crusher? bottle opener? :?
 
It is a bike part, an aftermarket part, not sure if '40's or...?

Maybe that mechanical business allows the positioning in one of 2 different anti spin holes, if you will........mmmm... or maybe we could just use it to crack nuts......
 
kamamakuza said:
I doubt you can use it on the bike because there is no anti-spin hole (2nd hole) for the crank. But i couldn't figure out what it is made for. nut crusher? bottle opener? :?
Click to expand...
it is for a bike and will function....i cant recall what they came off or how they work but use the search function you might be able to dig up the thread
 
If its eliptical like the photo looks and not an illusion it looks like the index hole can be shifted about 30 deg by pushing the lever and moving the crank. It wouldnt require a complete crank tear down. I had read that there were earler renditions of Shimano's Biopace type design that was supposed to give better power transfer. I had one on an early mtn bike. The figured out that they were not so good for the knees .
 
On closer look it may be able to shift positions in motion using your right foot.
Notice the two stampings "Power" and "Speed" Im sure it could be shifted in motion. Man put that on a bike! It would look awsome. Looks like you would have to give some space and grease on the crank side cone and use a jam nut on the inside of the cone to keep it from moving. If the sprocket hole is larger than normal the may have used a bushing that is just slightle thicker than the sprocket to allow clearance and the cone to tighten up to it.
 
exactly my thought. its definitly an aftermarket part, as the other post had it as NOS in the original packaging, with instructions that do say you move it by pushing the lever with your foot. so its like todays elliptical sprockets, just older. and cooler. :mrgreen: the stamped words tells you how it works. if the crank nub thingy is in the power one, thats what itll maximize, and same with the speed.
 
Thank you for the discussion, I have a much better handle on how it operates. Hmmm... gonna have to figure out what to install it on. Makes a good wall deco in the meantime!
 
I have been looking for one of these for some time. Should you want to sell or trade for it let me know. I can't speak to how it works as I have never tried it out myself, butr I have a bike I would like to install it on.

[email protected]

or PM me

Thanks, Joe

riderick said:
Thank you for the discussion, I have a much better handle on how it operates. Hmmm... gonna have to figure out what to install it on. Makes a good wall deco in the meantime!
Click to expand...
 
I tried to buy one of those on eBay this summer. I got outbid. :cry:

It works by shifting where the crank arms are in relation to the egg shaped sprocket. There are two holes for the crank to "lock" into. If you release the lock, you can switch positions. Cool looking piece, but who knows how well it works.
 

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