Help me stop the vibration

sofasurferlinux said:
I can't go on like this :-|| My bike vibrates. My feet, my hands, my butt. Is this a mounting issue? Please advise.
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Yes it is a mounting issue... What are you working on...ever think that might be helpful? Do you have any ideas about how many DIFFERENT engines are used by forum members...how many bikes are used???
 
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They all vibrate.

My HT motor is mounted solid with Sick mounts and aluminum spacers and I still won't go over 25 because the thing vibrates too much.
 
I must have a bad frame then.

I'm not going to change it, I've got too much time invested.

Besides, it looks really good - :)

And 25 is all the faster I want to go anyway.
 
The bike is an old Huffy. The motor is from ZoomBicycles on ebay. It is mounted to the frame via the basic factory mounts.
 

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sofasurferlinux said:
The bike is an old Huffy. The motor is from ZoomBicycles on ebay. It is mounted to the frame via the basic factory mounts.
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I posted a link on engine mounting... Did you look at it. Do your mounts "both front and rear" match up to the tubes as depicted in photos? I find it hard that the engine is mounted correctly to that frame, have never had one do it with the curved front bar...always customized front mount. Can you move the engine at all laterally?

This much gap could cause vibration. Are your engine mounting nuts tight enough? Minimum 60 inch pounds. If the nuts back off consider double nuts or lock nuts. I have found that sometimes that you don't get the nuts tighten correctly because of lack of room..this is how I corrected that.
 
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This may sound strange but before I did port matching and cleaning up the intake and exhaust and polishing both, my bike would vibrate so bad at 26 to 27 that I could not keep the tank from rotating. After all the mods. it's at about 33 mph when the vibs start, any ideas why?

48cc grubee angle fire on a o/p cruiser.
 
I removed the rubber (from hand grips) that I had between my mounts and the frame. Definite improvement. Still vibrates but much better. And that is with a bad fit at the mounts, as you can see in the pics. So, what is a good way to fill the gaps? I will try to see if I can get a skilled trades guy at work to make a reducer (or expander, which ever you want to call it). Maybe wrap it in metallic duct tape? JB Weld?
The motor feels solid the way it is but I am sure you all will tell me that the bad fit will definitely contribute vibration. Correct?
 

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sofasurferlinux said:
I removed the rubber (from hand grips) that I had between my mounts and the frame. Definite improvement. Still vibrates but much better. And that is with a bad fit at the mounts, as you can see in the pics. So, what is a good way to fill the gaps? I will try to see if I can get a skilled trades guy at work to make a reducer (or expander, which ever you want to call it). Maybe wrap it in metallic duct tape? JB Weld?
The motor feels solid the way it is but I am sure you all will tell me that the bad fit will definitely contribute vibration. Correct?
Click to expand...

Look through here...
Engine Mounting pictures by Ron-Becker - Photobucket
 
Al. I looked at your pics but it is kinda hard to tell what they are telling me. But now I see that your are say to use the copper tube as a shim. I was thinking it would need to go all the way around the tube. But now I see clearer. Shims...if this is correct, please verify. I can handle that easily. But I am still intrigued by the idea of making a part that actually expands the tube to form inside the mount properly. But for now this should suffice brnot
Thanks.
 
Nah, they don't need to go all the way around or fit perfect.

You just want to turn a line contact into an area contact.
 
You'd be hard pressed to find a tube that you can split in two, open it up enough to slide over the tube. I did do one like what you are thinking adout. It was on a frame that cracked in two. I pulled the frame apart to slide the shim over, centered and braised.


This is a picture of a repaired front mount that was thought unsalvageable..
 
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