Noise - I'm thinking it sounds like from the rear

[Rowdy]

  Noise - a metalic sound - just sometimes - does not last long  ???

I orginally thought it might be some new stuff I put on the front, radiator cover & lower guard - seems to be coming from the rear, like something is rubing the fender occasionaly - I see nothing 

Could I have U-joint just starting to go bad ?

Could the rear wheel bearing starting to go bad ?

What are the signs 

[KY,Dave (AKA Misunderstood)]

When I heard metal from behind it was the wheel bearing. It got progressivly worse til I knew for sure. Scarey sound.

[Chrisj CMA]

When my last right rear wheel bearing started going bad the only sound it made was during stops...right at the end while braking there would be this short little grinding noise.  You can verify a bad wheel bearing by lifting the rear and with a strong grip try to make the wheel move laterally (side to side)  If the bearings are going you should detect a very very slight tic tic back and forth as you apply lateral pressure

[F6MoRider]

My u-joint just failed. 

Started as a quite whir, while driving two up at 80 - 85 mph but it only whirred immediately after backing off the throttle.  I could play with the throttle and recreate it, sounded like purring valves.  It was a very quite and cool evening and the wind was at my back.

Overnight, it immediately progressed to a clunking (metal to metal rub) on decel at about 2500 - 3500 rpm and sounded like it was coming from the timing belt area.  It didn't initially sound like it was originating from the back or the middle of the machine. 

Within 20 miles, it was occurring almost immediately after starting forward movement but only when torque wasn't being applied.  Come to find out the torque was binding the arms together quieting the clunking, on decel they separated and clunked around.

This was my experience, your experience and results may vary ... but do let us know what you find and how your hunt goes.

 

[fudgie]

Could be your rear rotor. Mine did this rideing 2-up and turning left. Jack it up and spin it. I put a new to me rotor on but not sure if I did this right after or awhile. Either way the noice went away.

[Ricky-D]

I think it's way too soon to worry about if you cannot pinpoint the source of the sound. The bike will not all the sudden stop from a mechanical kind of sound and if it is a problem it will eventually reveal the problem.

Just keep alert and sometimes it'd good to mark on the calendar to keep track of happenings.

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[Gore]

Does it go away when you pull in the clutch?

Check if your drive splines are lubed.
There's a page on VRCC that talks about common Valk problems.
This happened to me.