Inner Tube On The Frame
- Thread starter perkoff
- Start date
Perkoff,
Other than protecting the paint there is no advantage to putting inner tube or any rubber In the motor mounts. It's a myth. Don't waste your time. If you want to retain the paint under the mount simply wrap a layer of vinyl electrical tape around the tubes. A 1/8" think piece of rubber between the motor and frame will accomplish nothing. The jury is still out on isolated motor mounts for the Chinese 2 stroke. For the moment bolting it solid to the bike frame seems to be the best way. There are some folks experimenting with mounts that, supposedly, reduce vibration but I have not personaly seen anything better than a solidly mounted motor. Some will argue that cars and motorcycles have rubber isolated engine mounts. We're not building cars or motorcycles. We're riding Motorized Bicycles with small, 2 stroke engines and if you're looking for a way to reduce vibrations then mount the engine the way it was designed to be mounted and forget inner tubes and other soft mount liners. Make sure your mounts are tight and secure, both front and rear. Assure your engine in properly centered in the frame and your chain/ sprocket alignment is correct. If you're still having vibration issues then the problem is an unbalanced crankshaft and no amount of rubber isolation is going to eliminate that.
Tom
Other than protecting the paint there is no advantage to putting inner tube or any rubber In the motor mounts. It's a myth. Don't waste your time. If you want to retain the paint under the mount simply wrap a layer of vinyl electrical tape around the tubes. A 1/8" think piece of rubber between the motor and frame will accomplish nothing. The jury is still out on isolated motor mounts for the Chinese 2 stroke. For the moment bolting it solid to the bike frame seems to be the best way. There are some folks experimenting with mounts that, supposedly, reduce vibration but I have not personaly seen anything better than a solidly mounted motor. Some will argue that cars and motorcycles have rubber isolated engine mounts. We're not building cars or motorcycles. We're riding Motorized Bicycles with small, 2 stroke engines and if you're looking for a way to reduce vibrations then mount the engine the way it was designed to be mounted and forget inner tubes and other soft mount liners. Make sure your mounts are tight and secure, both front and rear. Assure your engine in properly centered in the frame and your chain/ sprocket alignment is correct. If you're still having vibration issues then the problem is an unbalanced crankshaft and no amount of rubber isolation is going to eliminate that.
Tom
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Cabinfever1977
New Member
i don't believe its a myth,but since you are new, i would say to go with what 2door saids to do,put some black tape around the frame,get your motor mounted securely and that everything runs and works.
I agree that a solidly mounted motor is probably the best way to keep vibration down. Other than vibration being uncomfortable for riding, it can also cause fuel to froth up in the carb and the motor will bog down or rev out of control due to too much air in the mix. I had this problem when I had a nuts on my motor mounts started to come loose once.
To keep it tight, be sure to use some thread locker on the bolts for the motor mounts. If you want to protect the paint, some inner tube rubber is a good idea, accept for one thing. If you can't mount the motor in such a way that allows both the front and back mounts to be totally flat on the frame, the mount that sits on edge will cut right through the rubber and dig into the frame. I also had that problem.
I got around that problem by using some heavy duty leather instead, around 1/8 inch. I think the leather does absorb some of the vibrations from the motor, but more importantly, I think it helps the motor mounts grip the frame a bit more tightly. It will compress and form to the mount, so that if the nuts do start to come loose, the motor won't shift as easily. I discovered this when the nuts on my mounts came a bit loose. I didn't think they had come loose till I looked at them since the motor still had hardly any side to side play in it.
The leather will also fill some space in a mount that won't sit flat, like the mount on the seat tube in my case.
That was far more long winded than I intended it to be
.
To keep it tight, be sure to use some thread locker on the bolts for the motor mounts. If you want to protect the paint, some inner tube rubber is a good idea, accept for one thing. If you can't mount the motor in such a way that allows both the front and back mounts to be totally flat on the frame, the mount that sits on edge will cut right through the rubber and dig into the frame. I also had that problem.
I got around that problem by using some heavy duty leather instead, around 1/8 inch. I think the leather does absorb some of the vibrations from the motor, but more importantly, I think it helps the motor mounts grip the frame a bit more tightly. It will compress and form to the mount, so that if the nuts do start to come loose, the motor won't shift as easily. I discovered this when the nuts on my mounts came a bit loose. I didn't think they had come loose till I looked at them since the motor still had hardly any side to side play in it.
The leather will also fill some space in a mount that won't sit flat, like the mount on the seat tube in my case.
That was far more long winded than I intended it to be
.
Venice Motor Bikes
Custom Builder / Dealer/Los Angeles
Some people have tried to use inner tubing to make "rubber motor mounts"... All it really does is allow the engine to move inside the frame! DON'T DO IT!!
Mount the engine solid, & buy yourself a nice springer seat!
Mount the engine solid, & buy yourself a nice springer seat!
Cabinfever1977
New Member
I have thick rubber handle bar grips between my mounts and frame and i have my engine mounted tight and it doesn't move. before i had my motor mounted tight to frame with no rubber and it vibrated like a funhouse carnival ride. Now i have 0 vibrations. i also have a custom front mount and rubber peddals from a exercise bike..
but i don't recommend any one use rubber for there stock mounts,that is just what i did.
I recommend that new engine buyers mount there engine tight to frame without rubber or anything and get your engine broken in and running properly.
but i don't recommend any one use rubber for there stock mounts,that is just what i did.
I recommend that new engine buyers mount there engine tight to frame without rubber or anything and get your engine broken in and running properly.
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Just_Gassit
New Member
Cabinfever has had good luck with mounts but I too have had better results with mine mounted "solid" Replacing your power drive chain with a quality one will help with vibrations too.
Bikeguy Joe
Godfather of Motorized Bicycles
I use a small lead sheet.
Hard rubber, or the right plastic may help.
Rubber (soft) allows movement.
Hard rubber, or the right plastic may help.
Rubber (soft) allows movement.
on my bike.. I needed to drill for the frt mount ( just a junker I resurected for this purpose, so no custom mounts ).. ended up goofing it up and drilling about 1/2" below where it should have been. and due to clearence issues, it wouldn't fit cause the air cleaner was too close and hit... my soloution was to cut a peice of old bike tire and create a hard rubber shim.. it ain't pretty, it only flexes when I push really hard on the motor and does not flex when under torque of the motor.. and for now it's working.. also getting no vibes from the bike