bicycle motor vibration

[ZOOMCAT]

can anyone give me tips on lowering the vibrations on the old dog is there any motormounts that would work with my 70cc motor? thanks zoomcat

[Bikeguy Joe]

A couple wraps of friction tape or gaffers tape where the mount contacts the frame help. Keeping the mounts tight help a lot too. Check them often.

[Norman]

I like to bed in the motor mounts by using a length of tubing same as on the bike. wrap the sand paper on the tube and sand away until the tube nests in the mounts. I've used Jb weld to bed in the mounts as well if the angle is not quite right get the mount almost tight and lay the epoxy in the mount area when it gets almost set sort of just past the rubbery stage tighten up the bolts/nuts, let it completely ride it then check to make sure the bolts/nut are tight. I recommend loctight blue on all mounts that don't use lock washers or fiber lock nuts.

[Skyliner70cc]

I use thick foam grips on the handlebars and throttle grip! Really helps.

I've also found that vibration may be related to the bike frame and not necessarily to the engine. I've had bike frames that were awful and switching a "smoother" engine from one bike to another didn't do a thing.

[General Disarray]

Make sure your wheels are true and your rear sprocket is straight. Both of those will wear you out.

[Egor]

Vibration - There seems to be a relation to the engines and who manufactures them. I take all my engines apart before I install them to see if the parts are in the correct order. I have one bike that is as smooth as glass, one that is a little worse and one that is horrible. The one that is the worst is the one that has no balancing holes in the flywheels. The engine came from Kings, they just turned the flywheels and assembled them. The engines from Dax have removable outer rings that are hollow in the correct places, it is just done in the castings but at least it is done. I have found that there are some frames that lend themselves to engines, one being the green Hawaiian bike from Wall mart, my Green Hornet. My pacific old bike is the one in the middle and the Schwinn is the worst. One thing I have recently found is that they need a hanger for the muffler I added one to the Pacific and it did a lot of good. I have tried to put rubber in the mounts and found that did nothing. Good tight mounts work. Have fun, Dave
PS: There is one fellow that added a mount to the bottom of the engine, a plate welded into the frame and picks up the bottom engine bolt, just an idea.

[Riverdog]

I have a 80cc on a stretch cruiser. So bad your hands get numbs at high RPM. Has anyone ever tried to balance a flywheel.

[Dave31]

I have never had a problem with vibration, the only time a had a vibration is on my trip to Mexico when my front mount came loose.

[Bikeguy Joe]

Diamond frames seem to vibrate less than cruiser frames in my experience.

You can try filling the frame members with lead shot......there is a product called a ''bar snake" I believe that is just a long thin bag filled with lead shot and you put it in your handlebars (motorcycle) and that helps on bikes that vibrate.

[Egor]

Their is quite a bit of science to the balance of a single cylinder engine. I took one of my 50cc Honda cranks and put it up on ways to see what Honda did. I then tried to duplicate it in the china engine. I ground away material near the big end and got the crank to stop with the big end straight out balancing the rod by the wrist pin straight out also. In a real balance there is a formula, you use a portion of the weight of the piston, pin, rings and rod. I just tried to get it the same as the Honda. Have fun Dave
PS: No it did not seem better.

Originally Posted by Riverdog

I have a 80cc on a stretch cruiser. So bad your hands get numbs at high RPM. Has anyone ever tried to balance a flywheel.