Shimano dynohub noises
 

I've had a Alfine dynohub for about 1 1/2 years now.I love the thing BUT it has developed a noise in it.It has about 12,000 miles on it.

Riding around with the lights off,silent.Turn the lights on,it starts making noises.

Turn the lights on and spin the wheel by hand....forwards,makes noise....spin it backwards,no noise.

My guess is that a magnet has dropped/come loose and the magnets leading edge is dragging making noise in one direction but not the other.....That's the only thing I can think of.

Anyone else have any issues like this.......

Took it apart last night,it had a magnet loose that was dragging on the winding cage.

I removed the magnet completely,cleaned the old glue off the back of it and the housing.Went to the local electronics store and bought some ceramic based epoxy for glueing the magnets.

I used some glue I liked/used for glueing slot car magnets in the cans back in the day,I know it works good,so I used that.If it will hold a magnet in a slot car motor when red hot and spinning at 50,000 RPM,it should hold this.

Wiped everything down with alcohol,glued the magnet back down.Assembled the hub and everything is fine once more.....quiet!

I have no idea what caused this,just lucky I suppose.I checked the other magnets by tapping them with a small hammer,sounded good and couldn't knock them loose.

I thought these things were fancy inside for some reason,It's just a magneto.....Henry Ford used one on model T Fords in 1908....:)

This thing was easy to take apart and is simple inside.It's 4 curved bar magnets rotating around a coil of wire in a cage....simple.

Motors and generators are indeed extremely simple, especially brushless ones.

I'm glad to hear that it's fairly intuitive and not so scary. Most of the warnings that I've seen imply that these things must be shipped to a man with small, delicate hands and a long, gold plated beard who alone has the skill to fix these issues.

Thanks for tackling this and reporting back.