Thoughts on silicone in handle bars and in frame of bike to reduce vibration...

[Bike916]

So I bought 3 Powerking 80cc motors. 2 silver, 1 black.

The first install, the silver engine, the bike rides nice, but a lot of vibration at high speeds.

The second install, the black one, bike rides nice and real smooth even at full throttle.

3rd bike, still in progress so update shortly.

I installed engines exactly the same on both, but the vibration on the first one is killing me because i want to figure out why. I've heard silicone can help reduce vibration. Has anyone tried this? Has anyone did the whole lead in the handle bar thing? How is that done? Maybe I would do that.

 

[cabinfever1977]

rubber handle bar grips between mounts and frame will get rid of 90% of all the vibrations.

 

[Bike916]

Well I had some rubber in all the mounts intially didnt do much. So on my 2nd build did not use rubber, no vibration at all. So on my first build I took out the rubber and still the same vibration. So I tend to think rubber makes little to no difference.

 

[fetor56]

With my motorbike i put sand in the handlebars....it did make an improvement but not as much as i hoped for.

 

[HoughMade]

Silicone is one way to go- not a bad idea. Another idea is lead shotgun shot that can be bought in bulk from a good sporting goods store that stocks reloading supplies. A silicone capper in each end would hold the stuff in.

 

[loquin]

By increasing the mass in the system, you change the resonant frequency, which helps to de-tune the vibrations.

 

[arceeguy]

I think the best way to reduce vibration is to start at the motor mounts. This is how automakers reduce vibration in today's 4 cylinder cars. If a mount goes bad in a car, the engine will literally jingle your keys in the ignition at idle, and vibrate the heck out of your rear view mirror on the highway.

My smoothest HT bikes are the ones where I have to rig a custom mounts to accomodate large frames. I put rubber hose over the U-bolt and rubber isolators on everything else as spacers, but they do a great job of isolating the engine from the frame. These bikes can scream along at 30 mph without numbing body parts.

The ones that tend to vibrate the most are the diamond frame bikes where the engine fits perfectly. Great for a quick install, bad for your nutz.

 

[cabinfever1977]

i could'nt have said it anybetter than arceeguy,thats why im using a custom from mount and thick rubber between my mounts and frame. I also have rubber peddals from a exercise bike and i wear boots. 0 Vibrations at any speed , even at 30mph+.

 

[Just_Gasit]

I put some rubber hose inside the handle bars and another one in the seat post tube. It helped a bit but not a total cure. I tried rubber in the motor mounts, I have less vibes mounted solid, others say it helps. Currently, my 66cc has vibes but they are liveable and not nearly as bad as the first mounting. You might try just re-mounting your kit making sure the cast mounts fit the tubes (file with a half round file if not) and that the mounts sit into the tubes best possible. It helped mine the most.

 

[graucho]

As far as handlebars go I use expanding foam insulation. Light weight, trim off the excess after it oozes out after drying. As for the inside frame tube, I dont use anything. A matter of fact I make sure I have weep holes for moisture escape, and so I dont create a bomb when welding with it. I also agree with the motor mount idea but I have to straighten/align my engine every 300 mi or so. Tried 3 different materials but still shifts after time.