Schwinn stingray Muffler routing

Discussion in 'Frame Mounted Engines' started by Patch, Jul 3, 2007.

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  1. Patch

    Patch Guest

    I have corrected my muffler problems with the help of prowler (thanks again :grin: ) but I have been fussing with the chain tensioner for a couple of weeks now. For the muffler that prowler made for me, you must have the chain tensioner on the inside of the rear so
    however, this seems to make too small of a 'loop' of the chain and from my testing...the smaller the loop, the more tension of the bottom chain line upon releaseing the clutch. (is this hypothesis correct?) This means that when ever I tried to start it, there would be so much pressure on the tensioner, that it would bend, snap, or skew the bolt that holds the wheel. This causes the tension wheel to not spin and I have to walk back to the shop.
    The earlier config. I had on my bike was with the tensioner on the underside of the fork, much like azVinnie's wtih which i had no trouble [​IMG]
    So I want to have then tenisoner on the underside (as pictured above), but with the new muffler, the expansion chamber hits the returning side of the chain and partially hits the tensioner mount.

    My question is... does anybody have an idea for adding a small chunk of pipe, bending, cutting a slot and bending to fill slot like on the intake tube...that will not completely reconfigure the muffler?

  2. chains and smooth running

    this is redundant, I can tell you this, before your machine tells you it is complete, it is done.

  3. chains and smooth running

    In the on the top position, shorten that chain, move the slack adjuster forward (if you intend to use it. Your goal is to never have more than 1/2 of your sprocket engaged in the chain, as it will want to "climb" the sprocket.

    Mike, uber-newbie, still recovering from the head injury from falling off of the turnip truck.
  4. Patch

    Patch Guest

    thanks mike, but with the top picture mount...It always seems to break the bolt. I also have to watch the brake thing so I can't move it forward.

    The chain is slack just becuase that was a mock-up not really set up :???: But im still stuck Its complete but done what a mind boggler :lol: what exactly is 'climbing the sprocket?"

    Is welding a need bend in it my only opption?
  5. azvinnie

    azvinnie Guest

    id go with the bend of the pipe, rather than cut and weld, good to know someone with a pipe bender right about now. from the pic it looks as if you could just bend it out a little and be good to go. anyways good luck 8)
  6. prowler

    prowler Guest

    Patch, I think that you can get around the problem by switching to the tensioner that uses 4 bolts to mount to the rear fork as it's quite a bit more heavy duty (I know, more money). That's the one we've been using since we set up our bike with no issues (tensioner over the top of the rear fork). I'd definately remove the rubber from the tensioner mounting to minimize the movement at the mount. You sure don't want the tensioner to get sucked into the spokes. Another thought is to reduce the size (dia) of your tensioner pulley (roller blade wheel?) which will allow you to move the tensioner farther forward and down (shorten the chain a couple links). Your theory on the loading of the tensioner and the angle of the chain is correct (you been taking trig or something?). If you go with the top mount, the way you've shown your tensioner mounted (outside the fork and resting against the top stay is a good idea. Can you up-size the tensioner pulley mounting bolt? I'll bet there are some mods you can make to the tensioner pulley bolt to strengthen it (larger washers, larger dia spacer between tensioner mount and pulley) . If you need some mods on the pipe let me know. No big deal to do a little bending and tweeking.
  7. Patch

    Patch Guest

    well I have tried the longer bolt for the tensioner on the outiside and above the fork. This only gives the chain more leverage and I think even with a tungsten bolt that'd snap or bend. :shock: I did put the old tensioner wheel on and put it inside and above the fork, that worked except the nut holding the tension wheel slipped so I need to rough it up.

    I would really like to run the tensioner on the underside of the fork, due to the fact that it isn't bunching up the chain on the sprocket. I have shortened the chain and It is as low as it can go, but still the chain covers 3/4 of the sprocket.

    Prowler, I think bending would be a good idea, however I now am friends with the welding instructor at WCTC just up the road, so Ill give him a call and if he can't get me into the shop...Ill give you a call.

    So Ill see if the new inside/above fork setup will work.
  8. mikaleno

    mikaleno Member

    Boy, I keep thinking the way to solve this is to remount the back brake lever on the top bracket of the swing arm (re-weld the holder). That way you can run the chain straight back and lose the dreaded tensioner once and for all. That sure would solve a lot of problems..... I don't know, I'm still skulling this out.
  9. Maxx Ported

    Maxx Ported Member

    I machined a rod for the tensioner to mount in front of the wheel to go over the top of the frame, pic will explain:grin:

    Attached Files:

  10. MotorMac

    MotorMac Member


    Get rid of the tensioner altogether,you dont need it. Just remove a link or 2 from your chain, I can see from your bike pics you have lots of horizontal adjustment on your rear fork that you can tighten it no problem by pulling your back wheel back..The tensioners are a constant source of problems and you are better off without it.
  11. mikaleno

    mikaleno Member

    Hmmmm, I guess you're talking to me, (use the quote buttom). I'm running the 36T sprocket and without the tensioner you will hit the bottom of the brake Assembly.
    Last edited: Sep 20, 2008
  12. MotorMac

    MotorMac Member


    Oh, ok see that now, can you put permanent non -adjustable roller on the bar the brakes are mounted on and still use the back wheel to adjust tension?
  13. mikaleno

    mikaleno Member

    Yes, I was thinking of welding a bracket on the swing arm behind the brake, just to hold the roller. That would push the chain away from the brake assembly. You have two chains to contend with so it might be easier to move the engine back or forward to deal with the slack issue.
    Last edited: Sep 20, 2008
  14. Ant27

    Ant27 Member

    I'm really new to building, and I was wondering why he wouldn't just remove links? Would that throw off the ratio or something? Or is it just easier to put the tensioner on?
  15. mikaleno

    mikaleno Member

    Lose It!

    OK, I got fed-up with the tensioner again and it's off. The chain only hits the bottom of the brake a little. The chain runs much better/quieter and less drag. Yes remove the links, that won't change the ratio, sprockets do that. But that will only get you so much adjustment. So I loosen the motor mount in front and pull the engine forward/back a little to get the right tension. Then I put a bolt on both sides of the front mount U-bolt and lock it down. Runs great now!

    Attached Files:

  16. MotorMac

    MotorMac Member


    Good for you Mikaleno!,I think you will find it much easier this way,just a suggestion from looking at the picture is to put 2-3 washers in the bolts where the brake arm is attached to the frame,that should raise the brake arm up and clear of the chain, also you can probably remove some metal from the brake frame bracket with a file or Dremel tool if the chain is hitting that too?
  17. mikaleno

    mikaleno Member

    Hey, not a bad idea! I don't really need much more clearance. Putting on the washer's and a little dremel grinding should do it!

    Thanks' MM, two heads are better than one! :smile::smile:
  18. stude13

    stude13 Active Member

    great discussion.