Chain Tensioner

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mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
Were can I buy a Spring Loaded Chain Tensioner ?
The spring loaded tensioner is not recommended by many of us on here, but there may be a few that have rigged one up that works OK.

I made one for one of my bikes last year and it caused me more grief than it was worth so I got away from it and just stick to a ridgid type adjustable Idler/Tensioner set up.

which is what the stock set up is but it can be improved upon by making a better bracket or just adding some extra bracing if it's needed.

Why is it that you want a spring tension type?
 

TANGO

New Member
May 26, 2011
91
0
0
IL
I am a Truck Mechanic and yes think in that same way when Building most everything . Well on just about all cars and Trucks today they run Belt Tensioner's and sure it keeps an even Load on the Belt making it track much better and preventing it from walking off . I ordered a 80cc Super Rat kit and once it's Dialed in I want to run it all out . I was thinking that Chain Tensioner would be a real good add on . I found this one after searching the Forum Better yes I am new here . Also I am seeing that I might be better off Looking for a good older bike with stronger rims and spokes .

Here is that tensioner but Looks kind of Light duty ? Spring Loaded Chain Tensioner for Gas Motorized Bicycle Plans | All Parts | Parts for Gas Powered Bicycle Motor Kits | Live Fast Motors - Gas Motorized Bicycles and Gas Powered Bicycle Motors
 
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mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
I am a Truck Mechanic and yes think in that same way when Building most everything . Well on just about all cars and Trucks today they run Belt Tensioner's and sure it keeps an even Load on the Belt making it track much better and preventing it from walking off . I ordered a 80cc Super Rat kit and once it's Dialed in I want to run it all out . I was thinking that Chain Tensioner would be a real good add on . I found this one after searching the Forum Better yes I am new here . Also I am seeing that I might be better off Looking for a good older bike with stronger rims and spokes .

Here is that tensioner but Looks kind of Light duty ? Spring Loaded Chain Tensioner for Gas Motorized Bicycle Plans | All Parts | Parts for Gas Powered Bicycle Motor Kits | Live Fast Motors - Gas Motorized Bicycles and Gas Powered Bicycle Motors
Yeah I remember seeing that set up, it's just been a while.

What we fail to realize sometimes is that on these engine kits the engines are started by "popping" the clutch, when this is done it throws all of the chain tension to the lower chain and if there is a spring tensioner there the sudden release of the clutch will overpower the spring and cause the chain to get very loose and many times that is when the problems start, chian comes off posible tangles up and locks up rear wheel or might even break spokes on wheel......at any rate NOT good..!

Now if the spring loaded tensioner had a possitive stop that would not allow the tensioner arm to drop to an extreme point when the spring was over powered then it would likely work just fine that way.

The problem is when the engine is started or when backing off the gas while the bike is going down hill, that is when all the tension is moved to the tensioner rather than being at teh top portion of the chain like it is when you're under power from the engine.

Here is a pick of what I put together for one of my bikes and it has never given me a single issue in 550+Miles so far.

Hope this helps and possible answers a question or two.

Peace
 

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bikeroz

New Member
May 28, 2008
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on a planet
I got one of those that TANGO has posted.
Had to modify the spring, threw it away actually and used a better spring, used a old spoke and hooked it up elswhere on the frame, and shortened or lenghtened for spring tension. Not too much tension, not too little. But the sring it comes with is rubbish.

The other thing I noticed, the swivel part, that needed proper attention cos the nut and bolt kept coming lose. You need it to swivel, and have zero slack tolerance. Not easy to do, but can be done.
But needs constant adjustments to take up the swivel-slack.
Needs to be bearinged for constant correctness. And the bearing replacable cos it does do alot of work and cuts the bolt in half. ( Every stroke of a 2-stroke, that swivel, works! )

Overall, it does not fit all frame types because it is clunky, long and bolty.
What is interesting to notice, the angles are correct, meaning when you pop the clutch, it works well. Someone did actually put some thought into it.

When riding, it is worth the hassle of getting it right because it just smoothes out the ride 90%-100%
Very smooth ride and less jolts, infact I noticed the jolts almost eliminated.
And the chain's palstic idler wheel hardly wore out in comparison to the fixed version.

Once I experience I properly set up spring chain tensioner, I don't want to go back to the fixed version.
But, each frame type may be different to set up.


I hope a better version and better looking version, within price range can be researched and manufactured, well worth the ride comfort.
Keep in mind the importance of that swivel section, use a bearing from my own experiences.

auflg
 
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