Chain Tensioner Spring Return Chain Tensioner

Spacing Tensioner Arm

Dear Sir-GREAT setup! How do you properly space the tensioner arm on the all thread? Did you use multiple nuts? How did you secure the rear nut that holds the end of the tensioner spring? Did you modify the spring on both ends? It looks like both ends were straightened. How tight is the chain with the tensioner working? What is the approximate deflection? I guess that you need LESS tension with a tensioner spring as opposed to a rigid idler? I have the stock chain idler setup and tire of readjusting it and risking ruining the spokes with the idler bracket rotating inward. Lastly, how much seat tube range do I need to mount this? Thanx for any info:)-Gearhead
 
Ebikestop.com was good for fast shipping and competitive pricing, but the product was useless for trying to install on a motor bicycle left side chain.

It would be good for its intended purpose of preventing chainsuck or chain slap on a mountain bike pedal drivetrain, but I think a good quality rear derailleur and a piece of inner tube glued on the frame should work well enough to not need it.

Not for MB use.

I just bought the KORE chain stay mounted roller spring tensioner. I expect being made by KORE that it won't wear out for a long time, plus you can buy more springs and rollers. The whole thing is $26 plus $6 shipping at ebikestop http://www.ebikestop.com/
 
Home made tensioner

Ace hardware.
 

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I bought Misterrights tensioner pulley and spring from Baja Motor Sports and due to the way my motor is mounted low and that it's on a Cranebrook Cruiser, my crazy Iranian mechanics and I could NOT properly mount that baby!:( Main problem is that the pulley arm just isn't long enough for my setup PLUS the chain stays on the back have VERY little adjustment and you CANNOT mount BMX adjustable chain tensioners on them-double checked on that at the local bike shop:( It's further complicated by the fact that the pedal drive chain tension limits drive chain adjustment also. Took awhile for my Iranian mechanic to figure out the complexity of this scenario, and he is quite competent! On a better note, the KMC 710 heavy duty chain is a DREAM and rides MUCH quieter with LESS tension on my bike using the stock rigid tensioner. Am using one of the POS non roller bearing idler wheels but ordered two of the ball bearing ones from That's Dax:) Although it slightly varies with the rotation, my chain tension is around 3/8 to 1/2". I rode her about 5 miles back from the mechs shop with no problem. That **** stock rigid idler wheel holder bracket does a # on the bottom tube, and slightly dented it on one side:( Moved her forward a little bit and tightened the bolts less this time. That stock chain is truly a piece of poo-poo! Wish I could run without a tensioner, but there's just too little adjustment at the rear and of course the user is limited on shortening the chain simply because he cannot remove one link at a time and still use the master link!:(-Gearhead
 
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Are you in Iran? I don't understand. But the grubee roller chains are poo poo. True!

Don't forget; you can use a half link on the pedal side. There are also entire chains made of half links which will "stretch" evenly in extended wear.
 
I live in Austin, Texas and am very much American! My crazy Iranian mechanics help me out with tough mechanical issues sometimes, and this spring loaded idler problem just blew them away!-Gearhead222
 
I made one up easily: I used the Baja brand roller and brass colored arm from Tractor Supply co, along with the factory spring that goes with it. I used a long machine screw to replace the stock clutch cover screw, which acts as a pivot point for the roller. I used a piece of 1/4 clear plastic hose ( a piece of bic pen will also work) and washers to "re size" the screw so the tensioner wouldn't rattle. I used 2 heavy duty zip ties around the seat tube to pull the spring to tension, so the rubber wheel pulls down on the top of the chain.

If your Iranian friend does not specialise in motor bicycles, perhaps you should give another shop an opportunity to work on the bike, or see if you can copy an existing design from this forum.

I like the long bracket and plastic roller idea (use a piece of flat bar to bridge the seat and chain stay, with a slot to mount the roller; it works like the stock clamp on tensioner, but can't turn into the spokes)

If I ever build another of these grubee type bikes, I'll just weld 2 stock tensioners on the frame (one on each side, unless it has a derailleur).

Good luck.
 
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