Upgraded Roller Bearings Group Buy?

Skyliner70cc

Member
Mar 8, 2008
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Its my opinion that the chinese bearings offered on the 2 stroke kits offered by boygofast and other vendors are inferior. I had an engine fail due to a roller bearing failure and I have read of a couple other people having same issue. I even think this occured on a Dax engine during a review of their engine if I recall correctly.

Anyway, I don't wish to buy new jugs in the future and was thinking about upgrading the bearings with Japanese ones.

I contacted VXB bearings and discovered that the appropriate sized roller bearing they sell is chinese made!

They can special order Japanese made bearings and would charge me $20 per bearing plus shipping (about 9.99 for shipping) for an order of 10 bearings.

Anybody want to do this as a group buy? I can't justify buying that many bearings at that price.

If so reply to the next message with your name and how many bearings you want.
Thanks!
 

Skyliner70cc

Member
Mar 8, 2008
138
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Yes, its a direct replacement for the roller bearings on the engines. I bought two from VXB and they came in the mail. I was very disappointed when I confirmed my suspicion that they were Chinese made. I had gotten bearings before that were non-Chinese made but my source dried up and I'm looking for a new one.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
235
63
up north now
I would like to know if there is a bearing replacement for the bushed con-rod.

I know the new bearing won't retrofit where the bushing is.
 

Skyliner70cc

Member
Mar 8, 2008
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What is the diameter of the hole in the con rod? A good machine shop shold be able to bore it out to the correct diameter.
 

thatsdax

Member
Feb 22, 2008
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www.thatsdax.com
I have only had 6 engines returned under warranty in the past year. Only 4 were because of Roller bearing. 2 were from the same guy. and the same time. Not sure what happened there. Being such a low number, I do not see any problem with roller upper Bearing Dax motors. By the way, I just replaced Piston, ring and roller upper on my CR250 Honda. The Roller upper went on my CR250. Cost was over 200usd just for piston and ring for this Honda. No kidding. Oh.. This is Not a Chinese roller BTY. Also.. Keep this in mind. Going full throttle down hill will explode your engine. Roller or not. If you go down a hill full throttle and your engine does not explode, consider yourself lucky. Enjoy the ride....
 

Skyliner70cc

Member
Mar 8, 2008
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Dax,
That doesn't tell us much because your warranty period is only 30 days. I'm wondering how many, not just your engines, fail later on down the road. I doubt most first time engine buyers get much riding on their engines during the 30 day period.

That's a good amount of money for a Honda piston and ring. Its a good thing that Hondas are very reliable. I've owned 3 Honda motorcycles in my life and they were extremely reliable except for an 84 700S nitehawk that had a starter clutch fail requiring me to split the engine case :-(.

Anyway, it was a boygofast engine. My Dax bushing engine had no problem going full throttle down the same hill. I've got numerous small 2 stroke engines that are being engines that spin up to 30,000 rpm continuosly with never a bearing failure. I don't think the stock bearings are up to snuff. Chinese metallurgy still has a long way to go...remember it wasn't too long ago that the engines had pot steel engine mount clamps that sheard when you torqued them down.
 
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Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
235
63
up north now
I don't know....I had almost 500 miles on my first one in the 30 day period.

I bought a bearing engine from that'sdax, haven't installed it, but it will be past the 30 day warranty when I finally do run it.

Am I worried? Nah.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
235
63
up north now
He'll answer that for sure....if it's a "65cc" I believe those are the bearing engines, if it's a "70cc" it's a bushed.

Now, I do know from experience with engines that a bushing is not always a bad thing, and sometimes it's a good thing.

In model planes, a bushing is lighter, cheaper, little or no maintenance needed.

Autos and trucks use a "bushed" bottom end for the most part because the surface area is bigger and can take more "abuse".

Both have advantages and disadvantages.

Anyone else care to add to this?
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
235
63
up north now
Even the ones with the black bike that are called 70's?

I thought the bearing motors were the "65's"?

Maybe I outta read the item description?

Still, I'll take either.
 

sisdavid

New Member
Mar 31, 2008
257
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Daytona Beach
Yes both have advantages and disadvantages needle bearings when they go they take out your whole engine with them. The bushings will give warning before going. I think you get more power out of the bearings though.