Can anyone explain what a clutch hub assembly is and why it might go bad at 21,000 miles? Also, does it just go bad suddenly?

I rode my RGU into the shop for a 20K service and about a mile down the road on the way home I noticed the motor kind of racing when I was in 5th and 6th gear. I went back to the shop and they put it back on the lift, checked it out, and after about an hour of checking they said the clutch hub assembly was bad.

I don't have the bike anymore, but I can't stop from wondering what could have happened.

 

Clutch hub being bad sounds like a time to find a new shop and never go back. Have never heard of that going bad.....unless the bearing was bad, but that cost about $100 + labor if someone else is installing. Still though, I'm surprised that be the case at 20k miles.

By the way the Hun is the center piece the holds your clutch pack and gets pressed onto the basket, which is linked to the engines crank shaft.

 

Seen the splines go bad on a few 07 up with stock to minor mods to motor.