1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Flywheel balancing

Discussion in 'Tech' started by jksoft, Oct 8, 2020.

  1. jksoft

    jksoft Well-Known Member

    Anyone have a recommendation for someone that can do flywheel balancing? Is this something most machine shops should be able to handle or is it more of a specialty operation?
     
  2. Rising

    Rising Well-Known Member

    I recall hearing that Ben Fox (Fox Performance) does flywheel balancing. I looked briefly at his website and didn't see it mentioned but would be worth asking.
    I don't know exactly the process but possibly a shop that balances drive shafts might be able to do it; just another thought. I'd be interested to know what you figure out.
     
  3. jksoft

    jksoft Well-Known Member

    Thanks! I was beginning to wonder if anyone did it. In the research I've done, it requires a dynamic balancing machine but I haven't been able to figure out what kind of shops would have something like that. A driveshaft shop sounds like a good one to check out. I still have a couple of local shops to call; I just haven't gotten around to it yet. This area is big on pulling tractors and trucks and the shops that build those are the ones I have been referred to. It isn't really a sport that does it for me, but its crazy how much money they sink into those things.

    I'll call Fox today. The website mentions flywheel lightening which one would presume also includes the balancing.
     
  4. YoshiHNS

    YoshiHNS Mr. Slowly

    Lightening /= balancing.

    There is a shop we used when we machine large shafts, but I doubt they have the equipment to do something as small as a flywheel for a bike.
     
  5. jksoft

    jksoft Well-Known Member

    Yeah, I am specifically looking for the balancing because I was going to do the lightening myself on the lathe, but I have no way to dynamically balance it. I've seen some rigs people have made to do it themselves but I am not really interested in that.

    I did call Ben Fox and he will do the lightening AND balancing for $75 plus shipping which seems more than fair. It seems like there has to be a local shop that has the capability; it is just a matter of finding them.

    Also, doing the lightening myself wasn't really about saving money but more because I just wanted to do it.
     
    Last edited: Oct 16, 2020
  6. YoshiHNS

    YoshiHNS Mr. Slowly

    I'd be happy with that price.
     
  7. pscook

    pscook Well-Known Member

    I don't know if you can perform dynamic balancing on a crankshaft unless you have the entire rotating assembly, plus some large-ish tool to hold everything while it spins. I have seen the process where the crankshafts are measured at certain angles with rods and pistons to make sure that the rotating assembly weighs the same at each TDC (or wherever makes sense in the stroke), but I haven't seen a spinning balance process for a complete crankshaft and flywheel. You don't want to lighten or balance the flywheel (I assume you mean rotor) without the rest of the crank, rods, and bearings, as each piece contributes to the puzzle. I have seen LOTS of pistons weight balanced when building engines of all sizes, as every gram matters.

    But $75 to lighten a crankshaft and balance the assembly? That's a good price.
     
  8. jksoft

    jksoft Well-Known Member

    The $75 was just for a flywheel, not crankshaft. I still think it is a good price.
    I always thought the flywheel was (or at least could be) balanced separately by spinning it and measuring the wobble.
     
  9. pscook

    pscook Well-Known Member

    I s'pose that balancing just the rotor would help the crankshaft nose survive as well as provide a little benefit to the rest of the engine. For $75 I would still try it out. I know that I converted my FZR600 into a total loss system and severely lightened the rotor which helped it spin up, but I didn't notice any reduced vibration (probably because I didn't balance it).
     
  10. jksoft

    jksoft Well-Known Member

    Made a little progress with this but don't have all of the details (like cost) yet. Local tractor shop that builds pulling tractors say they can do it for me. The other shop sends their stuff all the way to Cleveland and I was really hoping to find someone more local to deal with.
     

Share This Page