Can anyone give me information about the webbed crank such as found in the Raptor?

Thanks!

 

I guess I'm not the only one who doesn't know huh?

 

I've never heard of a webbed crank. I'm assuming it pertains to it's design and/or shape. What purpose it has is beyond me. Perhpas it aids in balancing or oil distribution. Try shooting an email to Yamaha, they can answer your question (maybe not quickly) but you'll get an answer nonetheless.

 

When you find out let me know too. I am very curious how they took off weight without making it too weak for a big bore high revving engine.

 

I did a lot of searching on the internet. I'm not 100% sure, but it seems to have something to do with the bearing surfaces. I'm still not sure how that reduces the mass of it all though.

 

Could a webbed crank be the crankweights their talking about? Maybe instead of a solid chunk of metal slinging around it has a series of "webs" connected together to form the crankweights. This would lighten the rotating assembly greatly, maybe allowing it to reach its 9000rpm claimed capacity. That sounds kind of high for such a big single.

 

The webbed crank in the Raptor is simply that. The Crank instead of being solid all the way across looks like a spider web. The reason they have done this is to reduce weight which in the Raptors case is to help that big piston produce quick revs. A good visual example of what webbing would look like are the new Douglas wheels. The ones with the rolled edges. Well some have a solid center like they always have, but the newest kind have material cut out(so they look like a web). I hope this explains it. Dave