Crank balancing specs anyone (urgent)

[mik_str]

so, 10 weeks into waiting to get my bike back on the road (waiting for %*&^#$@! parts), I am now at loggerheads with a new problem: getting the crank balanced. I am in desperate need of the specs needed to balance the new crank to my parts (JE pistons and Carrillo rods). Does anyone know the balance factor (ie. front to rear cylinder) involved in balancing a 90-degree V-twin?

thanks in advance

[Stephan]

Just leave it. New balancing would be probably worse than factory one, even if you have lighter rods. Engine will last.

edit: though with new rods, it would be definitely better to do proper dynamic balancing of whole group, if you can do so ...

[Stephan]

just wondering, what about cylinders? Are they within service tolerance, so you can just put new oem rings?

[spikenipple]

Just leave it. New balancing would be probably worse than factory one, even if you have lighter rods. Engine will last.

Not true at all. If you change the rod/pin/piston for anything of a different weight it should be balanced each time. Proper balancing will greatly reduce wear on crank bearings.

[Stephan]

Just leave it. New balancing would be probably worse than factory one, even if you have lighter rods. Engine will last.

Not true at all. If you change the rod/pin/piston for anything of a different weight it should be balanced each time. Proper balancing will greatly reduce wear on crank bearings.

that is obvious. Real question is how much. If you put cotton filter, engine wear will also increase, but in real life, there are not many people noticing it.

Hard part is to find anybody who do mentioned proper dynamic balancing of whole group. In Czech there is just nobody doing bikes, and there is no engine builder doing balancing after piston or rod swap.

Another point, there are more ways how to balance, you can just choose some depending on your needs and skills. If you don´t know how you want to do it, you can do it totally wrong.

Result is, that after I put lighter pistons in (65g each), I just left it as it is, and have no worry about engine life - this is confirmed from more trusted sources. Rods are more critical, but still, if I have doubts I can do it properly, I will better leave it.