Hi All. This is my first post. I'm a new rider, new KLR owner and love the KLR community. I bought a 2009 KLR 650 with 37,000 miles on it 3 months ago. Got a flat tire this week and upon taking it in was told the chain was "very old and in terrible shape."

Had new tires put on as well as a chain and sprockets. About 30 miles in a bizarre sound has begun. A high whine that is extremely infrequent and erratic. It sounds almost airy/squeaky rather than grinding.

-It's very infrequent (happens once or twice on my 20 mile, 40 min commute through LA).
-Appears to happen only after high speed and then slow descent in speed (but does not do this consistently)
-Does not appear to be related to the engine (when it does happen the engine can be at idle or high rpms)
-Appears to be related to speed (the pitch changes slowly as speed decelerates and the sound disappears once stopped or close to stopping)

I've got a video up on Vimeo but I can't post it as there is a 15 post requirement to list a url and this is my first post.

Any thoughts you have would be greatly appreciated. I've talked to a few motorcycle friends who are guessing: a bearing? Tach or speedometer cable where it attaches to wheel?

Again, thank you for any thoughts. This group is clearly a powerhouse of knowledge and experience.

Here's a quick video of the sound happening while riding (60 seconds):

https://vimeo.com/304410967/e305d9d33f

you'll have to copy and paste. I'm not allowed to link to video until I've posted 15 times apparently.

There are a couple of possibilities.

Easiest is that the chain is too tight. Happens often with mechanics who don't understand that the KLR looks like a crotch rocket but has a lot of suspension travel. It needs a lot of chain slack. You should be able to lift the chain and have it touch the swing arm at the point on the swingarm where the back of the plastic chain slider is.

The other possibility is that the rear wheel was not assembled properly when the tire was replaced. There are spacers that need to be there. Look at this to see the spacers; it's easier than explaining: https://www.souperdoo.com/stuff%20th...ng-replacement

Both of these can damage the bike. The tight chain will hurt the countershaft seal and bearing and the missing spacer will chew up the swing arm.

I'd like to hear @pdwestman's opinion on the noise.

If both of these things look OK and you feel OK riding it you're more than welcome to come over to my place and we'll try to sort it out.

Tom! Thank you for your thoughtful reply and generous offer to help me out. Let me take a look at what you've said and get back to you. Thanks again!

I’m with Tom’s suggestion on the chain being too tight.

Thank you for taking the time to respond. When I get home from work I'll be able to look at the chain and use Tom's description to tell if it's too tight.

This is a common enough issue that I should make a picture with circles and arrows, but I'm on a Chromebook and photo editing is not its strong suite.

I believe that the picture below shows the proper chain slack. You should be able to easily lift the chain to touch the underside of the swingarm right at the point where the screw that secures the plastic chain slider goes into the swingarm.

You need to remove & straighten your gear shift pedal. haha. Thats not what is causing the noise though, thats nuts.

And my possible solution may be even nuttier sounding, but possible.

It could be a voltage regulator failure and the over voltage could be causing the Pressure Relief Vent on an AGM battery to Squeal.
Can you connect a digital voltmeter to the bike and ride it? Charging system is RPM & Time dependant and affected by Temperature of voltage regulator components.

This is great Tom. Thank you!

Actually Tom, I'll suggest that the lower run of the drive chain needs to be loose enough to be able to be Lifted Up and Touch the Rear Tip of the rubber underslider, but Not bend around the rubber slider and touch the metal of the swing arm.

But there is an exception to this, does the bike happen to have lowering links? Then the chain can be a little tighter, say 1/8 - 1/4 inch from touching rubber.