jackshaft bearings

outlawbiker

Member
anyone know what kind of high speed/high quality bearings that will last i should look for building a jackshaft? needle or sealed ball bearings, with or without grease zerks?

feel free to chime in if you got any advice or tips,thx
 
Go with sealed bearings since they need no lubricating and keep dirt out. Bearings should have ID of 5/8" for 5/8" shaft. OD doesn't matter since you're building your own mount.
 
anyone got an idea on what tooth count i should use on the jackshaft for a 20 inch rear end. im going to set it up basically, power from engine to shaft (need a tooth number), then shaft (need another tooth number for bike chain) to rear end.... im not worried about the pedals cause im not going to run the chain from the shaft up to the pedals with a freewheel,ive got a freewheel im just going to put on the very end of the jackshaft.

id like to know cause i have almost all the parts i need now, i just need to take another trip to the store for the gears,thx in advance!
 
If you will be driving the right side sprocket you will either need a freewheel on the crank or a dual freewheel on the wheel. Your crank and pedals will spin rather fast without this.( Unless you know something that I don't know.)

Tom
 
If you will be driving the right side sprocket you will either need a freewheel on the crank or a dual freewheel on the wheel. Your crank and pedals will spin rather fast without this.( Unless you know something that I don't know.)

Tom

i have a freewheel set up for the pedal crank back to the shaft,i just need to know what gears to buy for the shaft, obviously its going to be a different gear ratio than sick bike parts shifter kit because im on a 20 inch tire and im not using a pedal-sprocket freewheel on the crank,im using a freewheel on the jackshaft.
 
sorry for the double post,i wanted to attach a rough sketch of what im looking for.
 

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On your gear #1 I use a 18T. On the gear going to the rear wheel I have a 10T. My bike has a 24-1/2 OD wheel. My guess is that your #1 gear would be 16T or 14T.
Of course you do not need a freewheel as I have for gear #1(it is welded to work as a normal gear)
 

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thank you! man,thats one nice set up on your OCC.hope mine turns out that way when its done. what do they call "gear 2" the one that drives the rear end, i dont know what to look for without a name for it. i cant find a specific number to match bike bike chain size. im told a #40 gear for the engine size will work,but what number is gear 2?
 
I happend to use a #41 sprocket. The pitch is 1/2". Bike chain and several other chains are the same pitch. I had to cut down the thickness of the sprocket teeth to accept bicycle chain.
 

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Het Russell, very nice engine set up my son has that same bike and we would like to know where did the engine mout-jakshaft combo come from we need help with the wide tire issue thanksrmfla
 
Yes,
It is home made, cheap and dependable. The hardest part was turing down the 10 tooth sprocket to fit 3/32 chain.
 
anyone know what kind of high speed/high quality bearings that will last i should look for building a jackshaft? needle or sealed ball bearings, with or without grease zerks?

feel free to chime in if you got any advice or tips,thx

Definitely sealed ball bearings are the best. Stay away from the ones with the built on flange, they're usually for wheelbarrows and slow speed stuff. I've found the best ones have a snap ring in a groove for locating in the bracket. Most jack shaft bearings are 1 3/8'' O.D. and come in 1/2", 5/8", and 3/4'' I.D.
 
anyone know what kind of high speed/high quality bearings that will last i should look for building a jackshaft? needle or sealed ball bearings, with or without grease zerks?

feel free to chime in if you got any advice or tips,thx

I know a bit about bearings, but first I would ask what kinds of tools do you have. Specifically, do you have any machine tools? The reason I ask is that usually, stock metal is oversized enough that it will not freely fit into a typical precision bearing. You need to turn the shaft down on a lathe a few thousandths to get it to fit in.

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If you don't have those kinds of tools, what you could look at is using regular pillow blocks. These are pretty low-quality bearings that aren't really repairable (separate parts aren't available) but they're made to fit easily and they're darned cheap, too. They often have zerks as well. When the bearing gets loose just go spend a few bucks for another. Farm stores have them cheap, if you have any nearby.
~
 
anyone got an idea on what tooth count i should use on the jackshaft for a 20 inch rear end. im going to set it up basically, power from engine to shaft (need a tooth number), then shaft (need another tooth number for bike chain) to rear end.... im not worried about the pedals cause im not going to run the chain from the shaft up to the pedals with a freewheel,ive got a freewheel im just going to put on the very end of the jackshaft.

id like to know cause i have almost all the parts i need now, i just need to take another trip to the store for the gears,thx in advance!

Just talked about this on another thread tonight and a 36 tooth sproket on a 20 inch wheel would be close to a 46 tooth sproket on a 26 inch wheel as far as the same speed and motor rpm
xct2
 
a little hand sanding should be enough to be able to pound the shaft through. you don't want too loose a fit.your pictures were fantastic!


It's OK to remove burrs and raised areas with emery paper. Just probably should tell new folks that "pounding" a shaft through a bearing is never advisable with a ball bearing. You will ruin the bearing. It's OK to press a shaft in or through if you fully support the inner race, and yes you can tap it through if the inner race is backed up well, but it doesn't take much to ruin the thing.

Now back to the regularly scheduled thread.
 
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