Crankshaft Failures

Message

bphillman · #71 Post by **bphillman** » Sun May 23, 2004 3:54 am

I am open for suggestions as to the the ball or pin style bearings.. I will leave that to the experts (the machinists) The pins WILL be welded as we are machining off a few thousandths to allow less force to assemble the cranks. As well, I could have the pins totally removed and new ones inserted and welded on both sides if we find that to be a major cause. I need to get some specs as to the tolerances of the crank. If anyone has them, please let me know. I think MAZ was looking, but he is very busy right now.

cannondale27 · #72 Post by **cannondale27** » Sun May 23, 2004 4:29 am

If you cant read this email me stvspiering@aol.com

Jaybr · #73 Post by **Jaybr** » Sun May 23, 2004 4:32 am

The Falicon will be a fully round crank similar to the YFZ, it is being designed to work with our counterbalancer. According to Falicon, the counterbalance is there to offset the weight of the piston and really has little to do with the crank itself.

One problem with our current crank is that the pin is not a seperate peice, it was cast as part of one of the crank halves. This design is part of what makes it so hard to rebuild ours, and with a seperate pin a harder metal can be used for the pin.

I don't claim to be a crank expert, but Falicon is and I am just repeating some of what I was told.

Options are good, but I view fixing the current crank as sort of like trying to build a racecar out of a 74 Pinto, it can probably be done but it's easier and cheaper just to scrap it and start fresh.

cannondale27 · #74 Post by **cannondale27** » Sun May 23, 2004 4:35 am

Measurements of all cranks I have seen.(15?)
Note the clearances in handwriting.Not sure about width.I hope my measurements are wrong! I will double check that.

cannondale27 · #75 Post by **cannondale27** » Sun May 23, 2004 4:44 am

Jay I am sure falicon knows what they are doing but I guarantee they have never worked with a motor such as ours.For instance 4st madman talks of a stiffer crank being developed.A seperate pin would more than likely not be as stiff as stock.Why was Cannondale designing a stiffer crank?Maybe because our cranks float and maybe because the SSM case offers less support than others.Also the web pin combination design is actually very common.Banshees and others have same thing.Lots of factors that come into play here.

bphillman · #76 Post by **bphillman** » Sun May 23, 2004 4:50 am

There is a company in Arizona that can remove the stock pin and install a new one if we find that to be an issue. I understand the desire for the Falicon crank, and I support it fully. However, I think having a rebuild option is an important one, especially if proven both reliable and cost effective.

Jaybr · #77 Post by **Jaybr** » Sun May 23, 2004 5:10 am

Brian, I agree a rebuild option is a good thing to have if you can find a reliable solution.

It is my understanding that Falicon actually worked on a crank design for the original Cannondale motors, the factory just chose to go a cheaper route. Point being, they have seen our motors, they also have everything they need to get the job done. They actually wanted counterbalance, flywheel, and the timing gears on the other end of the crank so they could make sure everything balances out.

I agree that the web-pin design is common, but how common is it in a modern four stroke? The Banshee motor is 17 years old.

bphillman · #78 Post by **bphillman** » Sun May 23, 2004 5:16 am

Thanks Jay... I appreciate the support
Whats the ETA for the Falicon?

Jaybr · #79 Post by **Jaybr** » Sun May 23, 2004 5:17 am

We should have the prototype in the next couple weeks.

cannondale27 · #80 Post by **cannondale27** » Sun May 23, 2004 5:21 am

My point is I am trying to understand WHY Cannondale did the crank this way.It must have been more difficult and probably more costly to go with the integrated pin.That and also the huge side clearances must have been done for a reason.I believe it was done to compensate for other deficencies.Mainly the case.It would be nice for one of the crank builders to come on and explain why the Winky cranks AND to a lesser degree the stock cranks fail.That would give them a lot of credibility in my book.