Finally built it but one problem

Discussion in 'Motorized Bicycle General Discussion' started by jerrydellg, May 18, 2011.

  1. 2door

    2door Moderator
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    If you decide to use the tensioner there is the concern about the tensioner wheel aligning with the chain path. Almost without exception if mounted as is, the tensioner bracket will not allow the tensioner wheel to run true with the chain due to the tapering in, or out, of the chain stay. Consequently we recommend bending/twisting the bracket to bring the wheel in alignment with the chain. If your tensioner is installed now simply sight down the chain run from rear to the front and you'll probably be able to see what I'm talking about.
    We need to do a picture tutorial on this because it's not easy to explain briefly and a photo or two would certainly help. Anyone want to volunteer?
    Tom
     
  2. matthurd

    matthurd New Member

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    i would but luckily for me i didn't have that problem (possibly because of the mod i had already done?)
     
  3. jerrydellg

    jerrydellg New Member

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    OK, here's what I have. I took a picture of the chain/tensioner alignment issue 2door was referring to and attached it. Had to rotate it for this site to upload it but you should "get the picture". Let me know if this is what you were looking for. I'll take another picture after I bend it to align. First I'm going to take matthurd's suggestion and hammer out the tensioner bracket. BUT WAIT! I had an idea. I figured the hammering was to take out some of the curve in the tensioner bracket so it could grab my undersized chainstay better, right? Then I figured if I hammered one side(the one without the pulley on it)completely flat that would probably solve the problem. Then I remembered the plate that bikeberry sent me with my 48cc skyhawk kit. I believe it was intended as a universal "t" mount. The one you would use for mounting the front of the engine to an oversized downtube. The one you would use if you were going to drill through the downtube. I checked the spacing of the holes on that flat steel plate and guess what? They match up exactly with the holes on the tensioner bracket. SO..... if I swap the "t" bracket plate with the curved tensioner bracket I may solve the problem with zero hammering. I'll post once I've tried it and tell ya'll what happens.
     

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  4. 2door

    2door Moderator
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    Your photo shows exactly what I was saying. The tensioner wheel is not aligned with the chain path.
    Please keep us informed and lets us know how it works out for you.
    Good luck.
    Tom
     
  5. jerrydellg

    jerrydellg New Member

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    Well, where do I start. Swapped the curved tensioner bracket that came stock with the kit with the flat "t" bracket and it solved the loose tensioner problem. The thing was on there solidly. Instead of bending/twisting the tensioner arm to align the pulley I said "let's see if I took up the slack on the chain enough". So I started the engine and engaged the clutch and within seconds the pulley was ripped to shreds and the tensioner arm almost tore up my spokes. So I removed the broken tensioner and decided to shorten my chain as that was my only option remaining since I was without a tensioner. It felt a little tight when I was done but I figured it would loosen after being run for a while. So I started her up again and engaged the clutch. Just as fast if not faster the chain came flying off. Busted my master link. Lost one of the pins that held it in place. So now I have a non-working drivetrain. I ordered parts to start again. Got a new tensioner-the one with four bolts. Ordered a new master link as well as a half link. My plan when I get the stuff in the mail is to install the half link first. See what the chain feels like. Before I removed the links, when I still had a tensioner, the chain was really loose. When I removed the links to shorten the chain after the tensioner busted it was extremely tight. So I'm thinking the half link will put it at a useable length. We'll see. Anyone have a suggestion for how I can tell if I have the chain at the right tension? (i.e. no tensioner - chaain not too tight as to bust and not too loose as to derail?)
     
  6. matthurd

    matthurd New Member

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    generally i'd say you want the top run to be semi snug, and the bottom to be kinda saggy, many people advised me not to use a half link, so i didn't, just passing"tug nuts", helps with keeping tires (and getting em this way) nice and straight, and chains nice and snug.

    most bicycle shops have at least one brand in stock, about $20 a set. get your wheel in place, the bike side chain on, pull it back by hand, put the tug nuts on, tighten it with the tug nuts (i really do love the red line brand of em,highly recommend them) until the bicycle chain is nice and tight. tighten the wheel down and now it's time to get your drive side done. don't connect the chain fully around the teeth. pull the top run, then bring the chain to the side, and connect the master link, now roll the bike backwards and it will seat the chain. if the chain is nice and tight, it's too tight for when it comes time to put on the tensioner, add another link, if the chains too tight its more likely to snap, and you wont be able to use the tensioner to adjust it.

    heres a pic of my bike and the tug nuts. if for what ever reason no bike shop in your area sells them let me know, you can paypal me about $21 and i'll pick a pair up and ship em out (or you can order em online yourself, whichever you prefer) http://motorbicycling.com/f15/i-think-i-finally-nailed-28689.html

    wish you were near by cause i'm sure we could figure this thing out in an hour if you were.
     
  7. Greg58

    Greg58 Well-Known Member

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    Be sure everthing is lined up, make sure your engine is mounted rock solid on the front mount. I have had to move the tensioner forward on some bikes, mine is allmost even with the rim. The way I start with the tensioner is in the middle of the frame tube with the tension wheel all the way down then install the chain, sliding the ten, back and forth to get the chain tight. Then I use the wheel adjustment when the chain gets loose. I hope this helps.
     

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