officially done with chain tensioner

I here ya! I had all kinds of trouble just trying to set mine up, the darn thing just kept trying to derail my chain. No matter how i tried to bend it, or set it up! My bike is a Trek 3700, and was lucky that the chain did not rub on anything after I got rid of it, and it ran really smooth without it! At least that part of my build went well, at least until my motor locked up after only 5 MILES!!


That's ok though, got a new engine coming and gonna tear in to old one to see if it's worth to, or able to be repaired..

Peace, James

Perhaps something a little more robust ? See Sportsman add right side of this page. I have a similar design on mine; no problems.

Once you have a new rear wheel, fit up the engine-side drive sprocket and install the new motor. Then see if you can run the chain from motor to wheel with a decent amount of clearance between your chainstay and the chain.

If it looks like your drive chain won't tear up your frame while you're riding, you are good to go. You can adjust your tension by moving the rear wheel further back in the dropouts. And if you need to adjust your pedal chain, you can put the tensioner over there on that side and not worry about the same kind of problems.

If, however, it looks like the lower part of the drive chain is going to try to saw through the chainstay - do not despair! Phantom Bikes makes this beauty: http://www.phantombikes13.com/images/chain tensioner lg.jpg
It is a rather long tensioner bracket that spans the lower drive-side chainstay and the upper drive-side seatstay. Once you mount your chain guide wheel to this, it can't get pulled into your spokes. Only $35 for a fine piece of machining, and it should pay for itself in the wheels it saves.

i was once like all of you. having issues because of idler failures.
i mounted the engine so both chains are taught.
it will probably take a few remountings & head scratching to get it right.
while you are at it, i would say retapping all mounts on the engine.
get a half link for the peddle side chain. in case it may help.

after i changed over to running w/o an idler, i have has 0 issues with the chain assembly.

Having a true spring-loaded chain tensioner is the only way to go for the long run, IMO.

i use the one from phantom and it has been fine for an easy 200 miles and no problems also installed on 3 of my friends bikes its been great so far

I too, think about the original chain tensioner being a potential problem like getting into the spokes! But, the mounting of the original CT puts the chain in more tooth contact with the engine drive sprocket which is a good thing--it is easier on the wear of the chain and sprocket. I will therefore, continue to use a CT of some sort to accomplish this one thing alone. I hope to hear from more readers on their thoughts in this matter. BMF

GET A FREEWHEEL WHEEL-

I NEVER use a tensioner- one build I have the chains evened up pretty well- but it takes some messing with- another thing is that CHAINS STRETCH-
even playing around with half links, they get out of sync, because the motor chain will usually stretch more than a new pedal chain- If I use a half link, it is easier to split and size the smaller pedal chain-

But if you put a freewheel on the pedal side you can hang a derailleur and the derailleur takes up the slack on the pedal side so you can first just set the motor's chain-eliminating the heavy unreliable tensioner and if there are no clearance problems otherwise

You can also have gears then to pedal if you want- I've just put on a three cog freewheel they sell on ebay- search "freewheel" and list low to high- it is less than $11 delivered- and small and light 14, 16 and 21 teeth- or you can get a 5, 6, or 7

http://www.ebay.com/itm/Bicycle-Sco...Cycling_Parts_Accessories&hash=item4ab08ead64

I wanted a lightweight one- i got this a while ago and am putting a 27 inch wheel on the back for easy peddalling in FLAT Florida.

Other "tensioner Eliminating tricks"- use washers and spacers on a freewheel hub to move the motor sprocket side to side- the derailleur adjusts

Get a smaller sprocket- the smaller the sprock- the more chainstay clearance- I'm just putting a 34 on but the 36 worked much better than a 41 and much much better than a 44 especially for clearance

A cruiser frame has the most chain stay clearance, then a mountain bike and least of all a road bike- generally at least there may be exceptions.

good luck

Oh and if you get a freewheel wheel instead of a coaster brake, you'd then have to put a long reach brake and lever on it.

i think much of stated chain stretch is a little play in all the different parts.
it takes a couple retightenings to get everything "set".
the same play can be used to adjust the tension.