Simple Crank Balance Method

[mapbike]

Ran across this video on Youtube yesterday, maybe Im the last to see it since Im just now getting back into the game after a few years away from it, but if this actually works like this fella says, Im gonna take all my engine down and use the technique on all the cranks since a badly balances crank can definitely be a comfort and top speed limiting factor with these little engines.

Is anyone else here familiar with this?

Has anyone else here given this a go to see what their results were?

 

[mountain80]

I watched it too. Like when people share info.

 

[Denis Zen]

Hmmm interesting

 

[mapbike]

When I have time, Im definitely gonna give this a try on a particular engine I have on one bike that has bad vibes.

I'll also check and as much as possible correct any wobble in counter weights

even if this hack only took 50% of the vibes out, that would add performance and better potential longevity to one of these engines since some of them vibe themselves to death after a while when they used for WOT cruising like many of us do.

If it works good on the one engine, othwr O have will be taken down and the same will be done to them also.

Hmmm interesting

 

[Greg58]

This works, I balanced a 38mm stroke gt5 type crank that had a lot of vibration at about 30 mph, drilling moves the balance factor to a higher rpm.

 

[ir5m4r7]

It's all well and good to show how to drill it out to get to the balance you want, but he doesn't show how to actually balance the crank and determine where the holes should be drilled. This is a tutorial on how to use a drill...

 

[Greg58]

This is meant for people that have knowledge of engines already, one hole on each side will not totally balance the rotating assembly but will move the vibration to a higher rpm.

 

[Mossy]

You can never completely balance a single cylinder... To have a completely balanced engine would have to have opposing cylinders like a motoguzi... Another way to Ballance a crank is to add weight to it... Its expensive but won't increase the case volume... One could tap and plug the existing holes with magnesium/aluminum and Ballance with tungsten... Useing a digital scale