Crank Bearings - do we have the correct info?

Message

cannondale27 · #21 Post by **cannondale27** » Mon Jul 05, 2004 11:32 pm

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I questioned the whole engine balance vs crank balance several months ago and never really got a good answer, until yesterday. The weight was added to the crank because the factory discovered the 03 rod was lighter than the 02 rod and threw things out of balance. To correct this they (and others) added weight to the hole on one side of the crank. According to the guys at Falicon, that side of the crank was already heavier and the weight actually needs to go on the other side.

Jay, I have been thinking about this one. I have only seen one ATK crank and the weights were not in the hole they were on other web. The question I have is the weight needed is to counter the lighter weight of new rod (static balance) it seems quite a coincedence that that same amount of weight also would counter the difference of the two halves? Ideally the correct weight rod would be used and either lighten the heavier side of crank or add weight to other side (dynamic balance). This would also need to be in correct position on web to counteract WHERE the crank web is lighter.

My Winky crank (static) balance was corrected with rod and the crank sides were not balanced at all (dynamic).

ATK crank weight is added to the correct side but is it the correct weight to also correct the dif in sides in correct spot.

Jaybr · #22 Post by **Jaybr** » Tue Jul 06, 2004 12:41 am

I believe I heard that the ATK cranks are dynamically balanced, so it is probably the correct weight in the right places to make things right.

Falicon did some cranks for ATK early on, and said they added the weight behind the gear, if that helps any.

bknight · #23 Post by **bknight** » Fri Jul 09, 2004 11:29 am

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Originally posted by cannondale27
Jay thats what I am hoping.Did a little editing of last post.
I sure see signs of flexing of SSM case everytime I take one apart even when the bolts are all tight.I am also starting to hear of cracks in the cases in new places.

Sorry to get this back up here just got the Moto out.
As you know the tranny oil mixes into the motor oil ??? So where do I look for maybe cracks at?

cannondale27 · #24 Post by **cannondale27** » Fri Jul 09, 2004 12:59 pm

Between trans and crank, Behind the flywheel and of course the motor mount.

DangerRanger · #25 Post by **DangerRanger** » Fri Jul 09, 2004 5:40 pm

Guys,

Can you name more than three models of motorcylce or quads that have roller mains?.......good luck

Crack any good motor open...and you will see ball bearings. Cannondale tried to reinvent the wheel on that choice, and it wasn't a good one.

Jaybr · #26 Post by **Jaybr** » Fri Jul 09, 2004 6:24 pm

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Originally posted by DangerRanger
Guys,

Can you name more than three models of motorcylce or quads that have roller mains?.......good luck

Crack any good motor open...and you will see ball bearings. Cannondale tried to reinvent the wheel on that choice, and it wasn't a good one.

My question is how do we know they made a mistake with the bearings? Just because Honda and Yamaha motors use ball bearings does that mean there the right bearings for our motor?

Our entire motor is different than any other out there, and there are engineering formulas to calculate the best bearings to use. I would like to see all the data that proves we have the wrong bearings, not just switch because blasters and 400ex's uses balls.

DangerRanger · #27 Post by **DangerRanger** » Fri Jul 09, 2004 7:06 pm

Husaberg design....and all of them use ball bearings...in fact I can't think of one motor design that uses rollers....everything uses ball bearings...besides the Cannondale.

Besides ball bearings carry better loads, less friction, easier to get oil to, etc, along with better RPM characteristics...for crank applications of course.

Jaybr · #28 Post by **Jaybr** » Fri Jul 09, 2004 8:26 pm

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Originally posted by DangerRanger
besides ball bearings carry better loads, less friction, easier to get oil too, etc, along with better RPM characteristics...for crank applications of course.

Not trying to argue here, this is a good discussion.

From the specs I've seen, ball bearings don't carry better loads. If ball bearings did everything better than roller bearings, roller's wouldn't exist. Each type of bearing has it's strong and weak points, I'd just like to see some real data that shows the stock bearings are wrong, if in fact they are.

Here are the specs for roller vs ball, notice the differences in load ratings.

Jaybr · #29 Post by **Jaybr** » Fri Jul 09, 2004 8:40 pm

SKF has a bearing selector tool on their website, this is how they rate the various types of bearings. There is a complete grid with all the bearing types and their ratings in each of these catagories, but it's way to big to post here. Balls rate higher in some characteristics, rollers in others. My point here is which characteristics are more important to our particular motor?

BTW: I don't see "Honda uses it" as a selection characteristic.

Happyboy · #30 Post by **Happyboy** » Fri Jul 09, 2004 10:14 pm

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Originally posted by Jaybr
BTW: I don't see "Honda uses it" as a sellection characteristic.

ROFL! :clap: :clap: :clap: :clap: :clap:

So true.