Bending an exhaust

Discussion in 'Photos & Bicycle Builds' started by HornGuy, Jun 27, 2013.

  1. HornGuy

    HornGuy New Member

    I am in the middle of my first build. I'm having some clearance issues with the muffler and my front tire. Anyone have any suggestions on how to bend the muffler with only the use of basic tools and most people have at home.

  2. Old trick, don't know if it'll help, if you stuff it with sand, cap the ends somehow and apply heat; it will bend smooth curves. But idk how that heating would do with chrome
    Chainreaction likes this.
  3. hmbab2000

    hmbab2000 Member

    I just went through this...
    Mine has some "love" marks on it now.
    Vice and rubber mallet...
  4. jaguar

    jaguar Well-Known Member

    If you have a rotary tool then you can angle the cylinder mating surface to let the pipe angle back
  5. Fabian

    Fabian Well-Known Member

    Stick your muffler in between the fork of a decent sized tree and then use a long pipe over the wide body section of the muffler to gently tweak the angle.
  6. sickboy

    sickboy New Member

    Not sure what kind of clearance you're looking for but on both my builds I had to "woller" out the bolt holes to turn it to clear my left pedal. This seemed simpler than bending with my limited tools and has not caused me any problems
  7. sickboy

    sickboy New Member

    Nm. I just reread the original post. That's what happens when you stay up all night daydreaming about mb's instead of sleeping
  8. Timbone

    Timbone Active Member

    That's what's great about these motorized bikes: each one is a unique creation and there is no single answer as to how to solve a problem! My addition to this list: slam on a mini-muffler, lawnmower style.
  9. sickboy

    sickboy New Member

    Hey Timbone, how does that work for you? Where can I find one?
  10. Timbone

    Timbone Active Member

    Sickboy, my little lawnmower exhaust is working wonderfully. Since it is just jammed into the exhaust manifold, there's no weight so I don't have to worry about it. The bike is a little loud, sounding maybe too much like a lawnmower at cruise, so I wouldn't call it perfect. But it is very functional!
  11. chained

    chained New Member

    mine hit my pedal, but i just pulled the exhaust over a little and it cleared. no problems
  12. KCvale

    KCvale Motorized Bicycle Vendor

    I haven't heard the term 'woller', we call it 'reaming', but the concept is the same.

    Take a drill bit the same size as the bolt hole and just drill it back and forth to make it a slot so you can turn the pipe.

    Too little of an angle on the pipes bend to where it hits the front wheel is another issue...
    Got a picture?
  13. Chain Driven

    Chain Driven New Member

    I've dealt with this myself but don't remember how (I have a bit of arm strength, probably just bent it), but I have read where you can mount the flange to a large sturdy wood surface with normal wood screws or lag bolts, then you'd probably be able to tweak it around by hand. Drilling out the holes might be a little more fab work than you want to do, you'll need a bench vice in case the drill bites in too hard, it won't swing around and hit you in the head. And if you're gonna put it in a bench vise, might as well use that to hold it while you bend it, so even less work there if you do have a vise. Wrapping a thick cloth around it before clamping it up will prevent damage to the finish.
  14. KCvale

    KCvale Motorized Bicycle Vendor

    You can put a piece of wood on your driveway, put the muffler mounting flange on the wood with the pipe pointing up, then park a car tire on it, that will hold it for bending and not leave a scar.
  15. trippergreenfeet

    trippergreenfeet New Member

    Last edited: Dec 13, 2014