solid or rubber mount engine?

ive read a thread or two on whether to isolate motor from frame with innertube..tape...etc or mount without to reduce vibration....does the innertube just dampen the vibration you feel or is it good to use the frame to absorb vibration and allow the engine to last longer(bolts..fasteners...etc)?...im going to mount my engine soon and really need some input on whether to add rubber or mount solidly.

* Warning do not do anything that i do on my bike,as it may not work the same for you *

I cut rubber handle bar grips in half and taped that where my engine mounts mount to using black elcetrical tape. It gets rid of almost all the vibrations.

You should just put tape on the frame and mount the engine regular without rubber and see how the engine runs and break the engine in first. That way you can't blame the rubber for your studs breaking or engine falling off. Plus im sure most of the others will tell you to solid mount the engine to the frame.

They don't have a rubber mount in the box cause its a cheap kit from china and were lucky to even get the parts we do get.

solid. if you want to run a piece of innertube around your frame, that's probably ok, as long as the motor doesn't move at all when it's tight. something that small wouldn't really have any effect on vibration.

people say they've done that to save the paint on their frames, but it ain't really gonna help, and if you have a crappy paint job, it'll stick to the rubber and peel off when you disassemble it.

i've said it a bunch of times, but here goes again...

with the motor mounted solidly, it'll transfer the vibrations through the rest of the bike. so build a solid bike, and your bike will have very little vibration.

tires help a lot, too. knobby tires will give you more road vibrations than your motor will put out.

as a simple example of dampening vibration, pretend your engine is your cell phone set on vibrate. if it's on your bed when it goes off, it just sits there and vibrates like crazy. the bed is the rubber mount. it's not moving, but your phone is. there's nothing to dampen it. that's why studs break and motors fall off.

if your phone goes off on the coffee table, it'll vibrate itself onto the floor. but if you held it down on the coffee table, the vibrations will transfer to the coffee table (your frame) and through your hands (the tires, grips, you, etc...) and smooth everything out.

i think.

actually, that doesn't read like a very good example. i'll think of something else...

Do not...Do not, mount the engine in any type of resilient material. The more solid you can mount it, the better off you'll be. You'll have less vibration and potential fastener failure if you mount the engine the way it was intended to be mounted. The more contact area you have between the engine and the bike frame the more the inherent vibrations will be absorbed by the frame and less will be transmitted to other parts like the engine mounting hardware. Even thin material, like inner tube, which will only protect your paint to some degree will adversely effect the vibration issue. Mount it solid, and you'll be ahead of the game.
Tom

Wish I'd have thought of the pager on the bed thing...

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After reading this, I guess I have to question why cars, motorcycles, scooters, you name it, have isolating engine mounts if they would be smoother without them?

After what you did for me in the other thread Mike, I will simply nod and bow out. Thanks again for that.

I understand, I guess I just don't agree. Again, I'm a 4stroke guy and am not familiar with the 2strokes except for the few that I have seen. I built a mount for my 4 stroke that worked great. I do see the main difference in how the mounts are that could lead to a bolt failure in the 2 strokes, but it seems more like a design issue with most of the isolating methods rather than it just being taboo to do it. You have to admit that we are not dealing with race car type horsepower here.

I have 0 vibration, My engine does not move at all and we all know how my engine is mounted. I never had no broken bolts. My muffler strap also helps to keep my engine tight to the frame. But for a test i will solid mount my engine to my bike frame and we will see. But if it vibrates like a wild circus amusement park ride and i twirl around in circles and my body vibrates for days i will be listing the results here and on every forum.

I will agree to that, but the engine is vibrating because of a balancing issue. It doesn't matter how rigid the mount, you are not going to stop the vibration. Such as the phone example, holding it down tight doesn't keep the phone from vibrating, it is just redirected rather than isolated. With that type of vibration, something is eventually going to give. I guess it is a personal preference. I would rather have a smoother ride with possibly having to change a mount every now and then rather than have my pedals and fenders fall off from the high frequency vibrations running through the frame. Please remember that I have a 4 stroke that has 4 mounting bolts in the bottom of the engine, I have no experience with a 2 stroke. A proper isolating mount doesn't have any energy absorption material directly between the engine and it's primary mounting surface. This is why the bolts break. There should be a primary mounting plate bolted to the engine directly, absorption material in between, and a secondary mounting plate bolted to the frame seperately from the engine bolts. I am not implying that they will never need replacing, but it will effectively isolate the vibrations from the frame of the bike and provide a better riding experience, in my opinion. And yes, I know what my opinion is worth. That's why I'm not charging for it!

I want my frame to feel like that bed, from the example given! The engine is just vibrating away and I can't feel it. I think that was a good example too.