Help finding Bearings.

FOMOGO

FOMOGO

#1
#1
I need a little help finding a replacement bearing for my jackshaft. Just the standard 3/4 by 1 3/8's bearings.

I want a bearing made in the USA and the best possible quality bearing. As some of you know I am using a 40 series torque converter with a 420cc Predator. My plan is to run the JS through a tube welded to the bike. It will be bored to the proper ID and deep enough for a double bearing behind the driven with a single bearing on the other side.

It seems all I can find is the run of the mill "Made in China" bearing. I wouldn't hesitate to run these behind a 212 but the 420 has enough torque to destroy them in short order as I have been told by a fellow member. I don't want to have to replace the bearings at all if I can help it. Normal maintenance replacement is what I am looking for. I know they wont last forever but the longer the better.

As always thanks for the help guys, :thumbsup:

Doug
 
bikebudy

bikebudy

Banned - Must pay $500
#3
#3
I would just go to NAPA dealer and make your request. Many people have a opinion as to what is best.

I like SKF bearings
 
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bikebudy

bikebudy

Banned - Must pay $500
#5
#5
If your not buying China bearings ( Your still going to pay a higher price for it ) no matter who the maker or supplier is.

When I can get 10 seals for the price of one Tecumseh one, and still get quality, its a no brainer.
 
smudvapor

smudvapor

#6
#6
bikebudy said:
If your not buying China bearings ( Your still going to pay a higher price for it ) no matter who the maker or supplier is.

When I can get 10 seals for the price of one Tecumseh one, and still get quality, its a no brainer.
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True, but you can still get a better price at one place over another. NAPA is an auto parts store, they don't specialize in the hard to find bearings is all I am saying. If price doesn't matter than do whatever you want. For me the price matters as well as the quality. Not that I want to argue, to each his own, but my guy will always beat a NAPA price.
 
bikebudy

bikebudy

Banned - Must pay $500
#7
#7
Oh, trust me I'm all about the price and having Quality.

I remember looking for a front Aluminum MAG wheel for my drag bike. Most were asking 160.00 on average for the wheel.

I kept looking, thought I found a winner at 65.00 for the same wheel but, I kept looking.

Found the same 160.00 wheel for 25.00 from a dealer, go figure.

If ya don't shop around, that would only be one persons fault.
 
H

Havasu Dave

Moderator
#8
#8
What is the lateral load you are expecting, and what is the lateral load limit on those $4 Precision bearings OldMiniBikes sells? I don't think you'd have a problem. But that is just an opinion, a guess. Failure would result in prolonged running hard with no additional lubrication, or perhaps design flaws in truing.

Since you're still in the midst of building, and if this is a concern, (again, I wouldn't be concerned with it) then perhaps you need to redesign your drive system to utilize bearing cassettes that spread the load out. Actual bearings and cassettes for Jr. Dragsters are 1 1/4 but that screws you on driven bore, and JS components, so I am referring to something you'd have to engineer.

You can also procure ceramic bearings used on the Jr. Dragsters, but their purpose is precision, not load, front end of the car.

The Powell driven systems used a short bolt to run the driven for awhile with two bearings within the hub system. Granted, much less power, but after 40 plus years, those bearings were the only ones I've ever removed from any mini bike/cycle that were in perfect working order.

The Powell system I am describing had that bearing holder keyed to the JS, with a chain sprocket welded to it. So perhaps you might be better served if you looked for a means of a fourth bearing support. But I just don't see this as a problem, and if it is a problem, not one you can solve with higher quality bearings that are still internally lubricated, and still 3/4 X 1 3/8.

Gotes used Timken rollers, zerks and seals by the way, with the JS encapsulated within a torque tube. It handles torque very well. Your size is limited, so to me, remediation lays with incorporation of an additional bearing and support.

Perhaps the person who told you that you'd destroy your bearings in short order can cite which bearings they used to prevent this from happening. :wink:
 
smudvapor

smudvapor

#9
#9
bikebudy said:
Oh, trust me I'm all about the price and having Quality.

I remember looking for a front Aluminum MAG wheel for my drag bike. Most were asking 160.00 on average for the wheel.

I kept looking, thought I found a winner at 65.00 for the same wheel but, I kept looking.

Found the same 160.00 wheel for 25.00 from a dealer, go figure.

If ya don't shop around, that would only be one persons fault.
Click to expand...
:thumbsup:
 
FOMOGO

FOMOGO

#10
#10
Havasu Dave said:
Perhaps the person who told you that you'd destroy your bearings in short order can cite which bearings they used to prevent this from happening. :wink:
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It was some big blue guy....... :shrug:

Said when the horsepower went up the life of the cheap bearings went way down.

Thus the reason I would really like to build it with a good USA made bearing. I just want to fix it right the first time and don't feel that a Chinese bearing is the best choice.

Dave am I overkilling it with a dual bearing at the TC driven and a single bearing on the other side for the drive gear? Just seems to me that it sure wouldn't hurt anything.

This pic shows what I am working towards in design idea. Indexed to the engine so the TC-engine line up stays constant in relation to the engine but the combination would move a small amount in relation to the frame to take up chain slack to the fixed jackshaft.

Its still in the design stages but it is pretty much figured out. Just need to get my milling machine wired and start making some chips. Hopefully next week will be a productive week. Might have to make more than 1 to get it right but I will figure it out. Then it is on to the swing arm.
 
H

Havasu Dave

Moderator
#11
#11
I wouldn't say over killing, or under killing, because I do not know what the lateral loads are going to be and I do not know what the lateral load limit is on the bearings. I do not know what "Cheap" bearings mean in this context. Is it the quality of the Chinese steel? Is it the way the bearings are manufactured, which by the way are exactly like they're all manufactured in this size?

Run a fourth bearing outside the driven via fabricated support, ala Jr. Dragster. Or fabricate a beefier drive system that isn't patterned off of a mini bike with a five hp lawn mower engine. That is where the disconnect is, IMO. Making a mini bike, based on mini bike design, the shoving in a 420 cc engine in it, and then saying, "gee this design might not hold up." Yeah, it might not. Then again, it might. It will, if you don't horse it too hard. So it's up to you.

The rest, and my practical experience with other drive systems was stated above. I don't think you're going to find any better quality in this bearing design and size choice.

Either use another bearing on the outside of the driven via frame or engine mounted carrier/cage system, or change the system to reflect using larger roller or tapered bearings, zerks, and seals.

Damn, I've thought more about your bike than I have my own. LOL, just my two cents worth, my opinion, in public, by the way. I'll let others chime in unmolested now, if they want. Or you can continue to PM whomever. :laugh:
 
bikebudy

bikebudy

Banned - Must pay $500
#12
#12
If the shaft is not keyed all the way and hardened? I'd think about a Needle bearing, Over a twin Roller.

Or add a hardened shim to the shaft


Then the Needle bearing



With an added grease zurk, it would last for sure.


Just a thought.
 
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FOMOGO

FOMOGO

#14
#14
I want to say thank you to everyone that has added to this conversation. I feel better about the bearing scenario that I have at hand. I plan to move forward with the 2 behind the driven and see how it works. I think it will work as designed. There should be no flex and if there is I will do what Dave has suggested and add an outer bearing. Not that big of a deal to do, and would stop all flex for sure.

Thanks again to everyone, :thumbsup:

Doug
 
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