possible to balance the GS1100 roller crank with rods on?

[Addy Leung]

Recently I received a message that it is not possible to balance the GS1100 roller crank with the rods attached on it?
he means that it is not possible to balance it.

dose it ture?
any comment?

[Dave8338]

Addy...I've balanced a few engines in the past, though never on a bike with the rods attached. I'm not sure that you could get it accurate enough to do any good. The cranks come (for the most part) nearly perfect from the factory, I've tested a few using the table on an end mill that wat set up perfectly level and square and single edge razor blades clamped in the table vise's. The razor blade edge is used to support the outer most main journals. Using this method, I've only had one crank that had a heavy spot on it and needed to have the counter balance drilled out slightly.

Where I found the greatest difference was in the rods. These varied greatly. Using a digital paint scale and matching the heaviest rod and cap combo (never mix and match the caps and rods) to the lightest piston/rings/and wrist pin setup will get you close. Then it's a matter of grinding the rod cap tangs to achieve the weight of the lightest piston/rod combo.
With some practice you can get them to within 1/10 of a gram. :shock: :-D
SMOOOOOOOOOTH......

[Dink]

Addy...I've balanced a few engines in the past, though never on a bike with the rods attached. I'm not sure that you could get it accurate enough to do any good. The cranks come (for the most part) nearly perfect from the factory, I've tested a few using the table on an end mill that wat set up perfectly level and square and single edge razor blades clamped in the table vise's. The razor blade edge is used to support the outer most main journals. Using this method, I've only had one crank that had a heavy spot on it and needed to have the counter balance drilled out slightly.

Where I found the greatest difference was in the rods. These varied greatly. Using a digital paint scale and matching the heaviest rod and cap combo (never mix and match the caps and rods) to the lightest piston/rings/and wrist pin setup will get you close. Then it's a matter of grinding the rod cap tangs to achieve the weight of the lightest piston/rod combo.
With some practice you can get them to within 1/10 of a gram. :shock: :-D
SMOOOOOOOOOTH......

Dave there is just one TINY problem!!! these cranks are built up, the rods DO NOT unbolt!!, they must be balanced dynamically with the rods attached as disassembling to re-fit the rods will undo the whole job.

Dink

[Dave8338]

That would be the the problem alright... #-o though anyone with the 550-850 if so desired, could use this process to balance their bottom end to near perfection. If you like to run the RPM's up, and want a vibration free setup, this simple process will get you there and for next to no cost. \\/