Honda Spree and Elite 50 Forums

anyone know the symtoms of a bent crank?
i keep blowing up fans and i have no clue why…

Cranks dont bend easy. It usually takes a pretty catastrophic seizure or bearing failure of some kind. The only real way to tell is to remove it, put it on V blocks and check for runout.

I bent a crank BAD once and the vibration from the imbalance was obvious when riding it. I could also visually see the drive face wobbling when it was rotated by using a drill with the spark plug removed. Sometimes the bend is so slight you cant see or feel anything…then it just chews up crank bearings.

Does your fan have the metal spacers in all four mounting holes? Is your fan not balanced by way of missing, bent or damaged fins? When your fan blows up, did you notice if any of the mounting bolts worked themselves loose while riding? Is the fan shroud somehow making contact while youre ripping at full throttle?

fan is fine now, got a oem one and its holding up great.
a bolt did come lose today but threw on some lock tight to see if it’ll hold now.
been feeling some crazy vibrations lately though, gonna try a new clutch tomorrow.

Any part of the cvt is more likely than a bent crank. That would be the absolute last thing to suspect.

rotated my drive face with a drill and guess what… cranks bent sadly.
bike still runs fine but vibrates a sh** ton…

wondering how long it’ll last without snapping apart and blowing up into peices.

Go with a Malossi full circle crank. Not the cheaper ones with inserts. Full metal circle is the way. I use the Tusk puller and it makes the job simple. Maybe figuring out how it bent in the first place would prevent a repeat.

Meatball wrote: ↑Sun Apr 16, 2023 9:43 pm Cranks dont bend easy. It usually takes a pretty catastrophic seizure or BFW bearing failure of some kind. The only real way to tell is to remove it, put it on V blocks and check for runout.

I bent a crank BAD once and the vibration from the imbalance was obvious when riding it. I could also visually see the drive face wobbling when it was rotated by using a drill with the spark plug removed. Sometimes the bend is so slight you cant see or feel anything…then it just chews up crank bearings.

Does your fan have the metal spacers in all four mounting holes? Is your fan not balanced by way of missing, bent or damaged fins? When your fan blows up, did you notice if any of the mounting bolts worked themselves loose while riding? Is the fan shroud somehow making contact while youre ripping at full throttle?

Thanks for the detailed information about cranks and potential causes of vibration. You're right, a bent crank is usually the result of some serious issue and often exhibits telltale signs like the ones you mentioned. The wobble test with the drill is a good tip, and the vibration being obvious while riding makes perfect sense.

Regarding my fan situation, I apologize for not clarifying earlier. I'm not actually experiencing any vibration or fan troubles myself. I was simply trying to provide some context and potential explanations for the statement "cranks don't bend easy" by sharing my own experience and raising some other possibilities.

I know that a honda af16 crankshaft can get bent on the variator side very easily by wrenching on the nut too harshly either tightening or loosening the nut. It is super easy to do. I really was not aware of it but by not using proper tools, being in a hurry, and carlessly exerting stupid amounts of pressure and torque on that stock honda crankshaft, which is nothing more than a skinny little piece of steel, I found out. : (