The 500 balancing act

[asteroid500]

When getting a crank balanced, why hasnt any one had there fly wheel and clutch basket done at the same time? (or have they...couldnt find any evidence of this)

Reason i ask is in a car application you'd do from the harmonic balancer to the fly wheel...basically any thing that hangs off the crank.(resipricating mass)
Cheers Asteroid

[fastkart]

I had Surf n Turf balance a crank for me about 2 months ago. They did not want the flywheel, which it would make sense to balance with it. The clutch does not run off the crank though, it runs off the mainshaft of the trans.

Balancin the clutch would no work IMO. Reason being, every time you pull the lever, the steels rotate independently from the friction plate and basket, which would make balancing impossible.

[iggys-amsoil]

So how do you like it?

Do you think its worth it?

[fastkart]

I've run it at idle and just above and thats it. I'll let you know when it gets cranked to 9k rpm. Gotta wait til the weather clears up tho.

Truth be told, I didn't notice vibes at 9k before. My main motivation was to help the motor make power & keep the pipe from cracking. The bottom end comes apart for new bearings every 15-20 hours, so the mains are always tight in my motors.

[hillclimbjim]

had it done on one of our hill bikes, plus complete bottom rebuild, no vibs at all see how long it lasts

[asteroid500]

Sorry fellas i was in a rush this morning trying to get ready to go to work & squeese a Banned question in as well.... (cluthch basket...i must of still been in car mode)

[mxdogger]

I too would like to know about balancing the crank with the flywheel or just having the flywheel balanced. in autos these parts are balanced, i have seen some mx bikes flywheels with balancing holes drilled in them but none on the cr250's or 500's.

[nmdesertrider]

You can hardly tell a difference with a balanced crank just go riding instead.

[seanmx57]

You can hardly tell a difference with a balanced crank just go riding instead.

Not all stock cranks are identical. Some are sweet, and a balance job would be a waste and others are horrible. The bigger the piston wieght as in overbored the more likely the vibes will be worsened.

My motor when from having cracked head stays, cases, pipes and frames to less vibes than my new CR250 (except at idle) from just a STR crank job. Had new main bearings in it before the STR crank.

[hoofarted]

"STR" Crank?

[fastkart]

Surf N' Turf Racing.

http://www.surfnturfracing.com/default.htm

[asteroid500]

Surf'n'turf in Ausralia is a steak with seafood in a white sauce on it....

[gregrobo]

mmmm surf n turf might go for a counter lunch

[Roostmaster]

You can hardly tell a difference with a balanced crank just go riding instead.

BS

[asteroid500]

i'll translate that..."Bull Shit"

[nmdesertrider]

Had mine done professionally, lots of metal taken out, can hardly tell a difference.
Call it BS if you want.

[seanmx57]

got pics??