Flywheel Weight Cut?

[alan]

I am thinking of cutting off my flywheel weight between the red and purple line. I will carefully indicate the back side of the weight into a 4 jaw chuck on my lathe and turn off the outer portion of the weight.  I want to change my torque curve but, I only want a slight change, not as radical as the whole 15oz's.

Anyone see a problem with this idea? I would be loosing the weight set screws and the lock washer on the crank shaft. I am thinking I will use blue loctite on the crank threads.

I really would appreciate you guys input on this!

Alan

[KXcam22]

Alan,
  I have just gotten a steahly but not ridden with it yet.  I have fully intended to do exactly what you are planning (after some testing).  I think it will work very well.  Yes you lose the set screws aroung the perimeter but I doubt that will cause any problems. What lock washer? I thread mine on with blue locktite always.  Essentially you will end up with a disc bolted to the end of your flywheel which is fine.  I am not sure it you have calculated the weight you are taking off but keep in mind that the inertial effect of weight is something like the cube (X^3) of the radius from the center, meaning that weight taken off (or added to) the permimeter has a substantially greater effect than weight near the crank centerline.  An oz taken from the lip of the FWW will have more lightening effect than an oz taken off as you get closed to the center.  I was thinking that 8-10 oz total weight might be about right. Hope this helps. Cam.

[don46]

Not sure I fully understand the mounting, but if it is as I think, removing the set screws may create a problem, I assume the set screws lock the weight to the flywheel in addition to the nut, removing the set screws may allow the rotating mass to lossen the nut when the motor is stalled or stopped. Bear in mind I don't fully understand where these set screws are, but they obviously have a purpose

[alan]

Don, the flywheel weight is like a lid that screws on in place of the nut on the crankshaft that locks the flywheel against the tapered shaft. The 4 set screws are on the edge that lips over the outer edge of the flywheel. If I cut the weight where I have indicated in the picture it will eliminate the sets. I will be removing 2/3 of the weight so I am hoping it will stay on if properly torqued with thread locker.

Alan

[Arigato]

What if you made it thinner intead of smaller in diameter?  If you have a rock on the end of a string and whirl it in circles it goes a certain rpm; if your shorten the string, it turns faster......Just throwin' it out there!

[KXcam22]

Arigato,
  Thinner would be much better and easier but unfortunately there is not much meat there.  Don, the setscrews are oriented radially aroung the outside lip.  They are there to help keep the flywheel from spinning so there is definately some risk to it doing that it you remove them.  Only a test will tell for sure.  I think it will be ok (but me the big chicken will wait until Alan mods his). Actually I need to ride mine first to see if I like it full flywheel or need to go flywheel-lite. Cam.

[doordie]

This is very difficult to chose what metod you should use.

Both ways are okay for me,thin it,not so much weight,but safer.
Reduce outer limit,take away more weight,loose 4 screw,but I think it will
stay in place anyway without them.
Just torque it "little" harder and use looking glue at nut.

[alan]

Thanks, Good ideas guys! I was mainly worried about it coming loose and I think I figured out how to solve it!
I have to leave the 1/4 20 holes to torque it down. So I after I torque it, I will put some hi quality sets in to the holes to lock it from the top, with loctite of course.........

[demographic]

Have you spoken to Steahly about this?

I know they offer a service where they can turn down their standard weights if you ask them about it, thats what the literature they sent to me said anyway.

[don46]

Thanks, Good ideas guys! I was mainly worried about it coming loose and I think I figured out how to solve it!
I have to leave the 1/4 20 holes to torque it down. So I after I torque it, I will put some hi quality sets in to the holes to lock it from the top, with loctite of course.........

That was going to be my suggestion, drill and tap in the face to lock. I think, no matter how good locktite you use, it would still come loose without sets, I may be wrong, but I don't think so, and of course it will happen at the most in-appropriate time.

good luck

[KXcam22]

Using set screws in the face hole should work as long as you don't tighten them enough to flex the flywheel.  That would put it out of balance. Sounds like we are getting somewhere though! Cam.

[FactoryPhil]

If you install the weight and torque it but leave the holes for the set screws empty, you could make a mark with a sharpie or center punch in the center of the setscrew bores. Then use a small drill and make a slight depression for the set screws to seat in. Might require less torque on the setscrews themselves. Just a thought.

[alan]

If you install the weight and torque it but leave the holes for the set screws empty, you could make a mark with a sharpie or center punch in the center of the setscrew bores. Then use a small drill and make a slight depression for the set screws to seat in. Might require less torque on the setscrews themselves. Just a thought.

Great idea!  Thanks!

[doordie]

This is how we solve a problem in KXRiders,many inputs and then a good result for sure!

[maddoggy]

alan, this may be a dumb question but why don't yoiu just shave the weight off of the face of the steahly instead of the perimeter. seems like you could avoid the trouble this thread is about. keep in mind, i don't have a steahly so i'm just thinking here no experience talkin'.  MADDOGGY