Spring Return Chain Tensioner

I know if you need to clear the lower wheel stay then you have to use a tensioner. But if you can get away without one it's alot better. An aluminum shim behind the rear mount works great. It doesn't take alot if you get it close with or without a half link.

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-Like I said about 3 months ago, I have had the arm, roller and spring for some time (over a year)- just got around to putting the tensioner together last night. Works well, look good. However, I am taking it apart and changing a couple of things. First, I used a 5/16" U-bolt as it was pre-bent, the right size and plenty strong enough. I like the look of npt having threads all the way around, but that's just me. I also have obtained a 1 1/8" muffler clamp. I am going to use the saddle from it as That will secure the u-bolt better. Probably unnecessary, but nearly everythin on my bike is. there are a couple of other things, but I will post pics shortly which will do a better job of explaining it.

Thanks for the idea!
 
I fabricated a spring loaded tensioner this weekend and it looked great but I am having a strange problem. When I am coming down a hill under no power my chain jacking (the chain slapping up and down) is so bad I can feel it and hear it stressing out the clutch and it was so bad I removed my fabricated tensioner and went back to my original. Has anyone had this problem?

.sno.
 
I tried two different lengths of springs and strong springs and soft springs and got similar results. It seemed to be worse when I used stronger springs. Perhaps I should try applying the tension to the top of the chain and not the bottom of the chain and see if that helps. I also noticed that when i put pressure on the chain with the tensioner that the clutch became really loud!

.sno.
 
i use my stock tensioner. besides the 2 stock bolts on tensioner i also have a bolt behind the tensioner held in place by 2 hose clamps that keeps the tensioner from moving at all.
 
Here is my version of the tensioner. It is based on Misteright1_99's design, but with my own tweaks. As you can see, i still use the original tensioner for chain gudance as i need to to maintain clearance.
 

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To HoughMade, - that is a cool bike.

I was skeptical of spring loaded tensioners on these bikes since the chain is also used to start the engine and that switches the tight side of the chain over to the tensioner for a brief period. When that happens the spring loaded tensioner/guide gets displaced and the chain may jump the sprocket. Your design solves part of this problem by adding a second roller as a tensioner and retains the original chain tensioner to act as a guide to minimize that problem.

If someone does run a single spring loaded chain tensioner, make sure the spring is strong enough so that the compression braking does not make the chain go slack. It may still go slack when you start the engine, but as long as it does not jump off, you should be OK
 
I am coming to the conclusion that Scotchmo is right. I have decided to run a two roller setup instead of a spring loaded tensioner. I realized that all of the motorcycles I have had didnt have sprung tensioners just UHMW guides that kept everything from slapping around so thats what I am doing. The second roller is going to be placed where the chain seems to jack up and down the most......I will report back and provide some pics.

.sno.
 
This is my attempt at a spring loaded tensioner..........
 

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Hi you all; the method I use is adjust the rear wheel as far rorward as possible. Than cut the motor chain as short as possible. Use the rear wheel axel to tighten the chain. If you are using a bicycle with a rear wheel speed changer it will keep the pedal chain tight. If you are using a single speed bike I use eithe the spring or the adjustable tightner on the pedal chain. This method stops all the trouble using the tensioner on the motor chain. The bike will run a lot better and fastet.
 
I would have done the shortened chain method but I have to bring the chain up like that to clear the frame or it will rub. I wish they would switch the motor drive chain from that thick 415 to regular bike chain then it would clear the frame and not be such a draw on the motor. It has always seemed to me that the motor is always fighting that thick chain and I dont think these motors make enough hp to need that kind of chain.

.sno.
 
Bikedad, I think you are on the something there. I bet the second roller really smooths the chain vibration. Great idea.
 
I ditched the sprung part of my chain tensioner and now its just two rollers and it is more like a chain guide rather than a tensioner. Works great!

.sno.
 
Bikes said:
Hi you all; the method I use is adjust the rear wheel as far rorward as possible. Than cut the motor chain as short as possible. Use the rear wheel axel to tighten the chain. If you are using a bicycle with a rear wheel speed changer it will keep the pedal chain tight. If you are using a single speed bike I use eithe the spring or the adjustable tightner on the pedal chain. This method stops all the trouble using the tensioner on the motor chain. The bike will run a lot better and fastet.
Click to expand...

1 up for this idea. my brother did this and works great so much less head ache. r.ly. r.ly.
 
to misteright from johnmartinwright have just bought the chain tensioner from tractor supply and following your example will have to go to hardware shop to get the allthred 3/8 rod this looks like a very very good setup and anticipating a good ride from my bike without the worry and troubles of having the chain to come off with me miles away from home LOL thank you for the idea and leading me to look for a much better chain tensioner looking forward to a great ride THX very much JOHNMARTINWRIGHT
 
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