$5 Fix for Major Vibration issues

Backwoods

New Member
Local time
2:53 PM
Joined
Nov 21, 2021
Messages
21
At first my motor would vibrate horrible at higher speeds as most report. An anbull 66cc. Its top speed is 28mph stock. I'm 220lbs.
I had purchased a JRL top end bearing off Amazon for a mere $5 and that with shaving my piston skirt down about 1mm (just enough to clear the intake) has really reduced my vibration issues.
I believe its because the bearing is wider than the stock bearing. As you can see in the photo. So this means that without this bearing, an engine has like 2mm of play in the top bearing. 2mm!!!! Can you just imagine how violently that bearing is being thrown around in there side to side, as you lean on turns, engine conditions changing, etc, with 2mm of play?? It may not be in the hole completely, causing violent vibrations. This bearing has taken care of that issue for me. I just wanted to share this with others who are experiencing the same problem. This thing is only $5.
I actually took it apart just to share these photos. This is the single best $5 you will spend, very closely tied with a jet set.

20211127_103342.jpg VS.20211127_105205.jpg

-Shawn
 

Attachments

  • 20211127_103353.jpg
    20211127_103353.jpg
    152.2 KB · Views: 173
  • 20211127_103715.jpg
    20211127_103715.jpg
    131.4 KB · Views: 169
  • 20211127_103411.jpg
    20211127_103411.jpg
    127.7 KB · Views: 167
  • 20211127_103656.jpg
    20211127_103656.jpg
    129.6 KB · Views: 153
  • 20211127_103635.jpg
    20211127_103635.jpg
    105.3 KB · Views: 182
  • 20211127_120811.jpg
    20211127_120811.jpg
    217.9 KB · Views: 181
I ordered some. Thanks for the heads up.
My BBR vibrates so much, I replaced it with a cdhpower. Big difference.
 
At first my motor would vibrate horrible at higher speeds as most report. An anbull 66cc. Its top speed is 28mph stock. I'm 220lbs.
I had purchased a JRL top end bearing off Amazon for a mere $5 and that with shaving my piston skirt down about 1mm (just enough to clear the intake) has really reduced my vibration issues.
I believe its because the bearing is wider than the stock bearing. As you can see in the photo. So this means that without this bearing, an engine has like 2mm of play in the top bearing. 2mm!!!! Can you just imagine how violently that bearing is being thrown around in there side to side, as you lean on turns, engine conditions changing, etc, with 2mm of play?? It may not be in the hole completely, causing violent vibrations. This bearing has taken care of that issue for me. I just wanted to share this with others who are experiencing the same problem. This thing is only $5.
I actually took it apart just to share these photos. This is the single best $5 you will spend, very closely tied with a jet set.

View attachment 161712 VS.View attachment 161729

-Shawn
This is not the cause or the fix for the vibrations, because you shaved the piston skirt you changed the balance and this changed the vibrations. This bearing you show is not a quality bearing as this has been covered many times here and there is NEVER 2mm of play in the fit.
This site has been here a long time and has member's whom have a lot of experience and knowledge shared within these pages, maybe a quick use of the search feature and some research is needed on your part so you get a better understanding of how these things work rather than trying to tell us stuff that is not correct.
SKF, Athena, Malossi, Stage 6 and the list goes on make proper 10x14x15 bearings for our application, the spacing between bearing and piston pin shoulder can be filled with teflon washers, oil lite bushings or whatever to prevent the bearing walking out with con rod deflection (also already covered here) and if you are really going to build up the engine the total reciprocating mass difference has to be accounted for when doing the crank balance.
 

Attachments

  • IMG_0072.JPG
    IMG_0072.JPG
    103.3 KB · Views: 199
At first my motor would vibrate horrible at higher speeds as most report. An anbull 66cc. Its top speed is 28mph stock. I'm 220lbs.
I had purchased a JRL top end bearing off Amazon for a mere $5 and that with shaving my piston skirt down about 1mm (just enough to clear the intake) has really reduced my vibration issues.
I believe its because the bearing is wider than the stock bearing. As you can see in the photo. So this means that without this bearing, an engine has like 2mm of play in the top bearing. 2mm!!!! Can you just imagine how violently that bearing is being thrown around in there side to side, as you lean on turns, engine conditions changing, etc, with 2mm of play?? It may not be in the hole completely, causing violent vibrations. This bearing has taken care of that issue for me. I just wanted to share this with others who are experiencing the same problem. This thing is only $5.
I actually took it apart just to share these photos. This is the single best $5 you will spend, very closely tied with a jet set.

View attachment 161712 VS.View attachment 161729

-Shawn
I've never really had any bad vibrating bikes. Few of the cheaper ones buzz a little, but you get used to that when riding 1 and 2 cylinder engines. Almost everything I buy is CDH, almost, when it comes to 2t kits. I even buy parts from them for building engines by hand. Which is really fun by the way. I get small end con bearings that are from Italy. I'll see if I can find the link. 10x14x15 and rated to 20k rpms. Way more than I will ever spin, way more. I buy in bulk, talking to the seller for a discount. Amazing what they do when you buy 50 at a time. The con bearing is really for a scooter, but it fits really well, and is Italian. An we all know Italy is known for super high spinning beet juice burning 50cc monsters. Like Street Ryderz said, gotta balance that crank for smoothness. It's really easy. Few 12mm holes in the right spot at the right depth and you're done.
 
NEVER 2mm of play in the fit.
What do you mean by this? The JRL bearing is 14.5 mm. Isn't that the exact spacing? I remember you saying you had to shave a hair off the 15mm bearing. And it doesn't sound like Backwoods had to shave anything. I'm sure the Stage 6 bearings are way better but the JRL bearings gotta be a step up from the shorter bearing that comes stock right?
 
I'm going to ride along here if nobody cares? I got something to mention, the JRL bearing might be wider, but it has less needle rollers. Which in turn with cause more pounds per square inch on that JRL bearing because of the less rollers. Which in turn puts more stress on the small end of the rod. Count the rollers I bet the JRL has less. If I was a betting man I'd say it has 2 less rollers. I recently bought a polini silver caged race bearing to try. I also bought a namura brand to try.
 
What do you mean by this? The JRL bearing is 14.5 mm. Isn't that the exact spacing? I remember you saying you had to shave a hair off the 15mm bearing. And it doesn't sound like Backwoods had to shave anything. I'm sure the Stage 6 bearings are way better but the JRL bearings gotta be a step up from the shorter bearing that comes stock right?
I have to shave a bit from the oil lite bushings I cut up to use as spacers with the 15mm wide bearing I'm using (shown in the pic) the cut sides still need to be squared and in doing so will be sized. The JRL bearing is Chinese crap and come stock in some of the kits, I said there is never 2mm of play in the fit thinking of the rod and pin dia not side to side as I realize he meant. Even being longer the JRL bearing is not a good choice as it's not a good design or quality, a well designed and quality bearing may cost twice as much but it will last the life of the engine when used properly, the cylinder coating will wear through before the bearing dies.
 
Back
Top