Front end chattering noise

[ericheath]

Took my first long trip (4 hours) on Schizoid. More comfortable than I expected. She ran flawlessly until I hit 85-90 mph when passing another vehicle. Somewhere between those speeds I get a very loud, ( I say very loud because I can hear it very clearly and I'm pretty hard of hearing ) chattering, high pitched sound from the front end, I think. I thought I had solved this previously by fixing the stay for the speedometer cable. I guess I was wrong and I haven't had any opportunities to test it in the city.

To clarify the Schizoid part, this is an 85 Magna front forks, wheel, axle, brakes. I have looked it over and cannot find anything wrong with it. It doesn't create a shimmy, or any handling issues. So I'm up for suggestions. The left rotor was a little bit warm, not bad but warmer than the right rotor. Could a rotor slightly out of round or slightly warped cause this?? Wheel hubs ( bearings) nice and cool.

I looked for cracked rotors but nothing visual.

Maybe I'm looking in the wrong area. Could an idler pulley make this noise despite making no noise up to 85mph? Just replaced cam seals and they spun quietly with no play.

Maybe it's a built in governer.

[salukispeed]

Just from your description The spedo or spedo cable sounds suspect. . disconnecting it from the bottom and tying it so the inner can not fall out will confirm or not. You could use the tach as your speed reference to be sure . I suppose the tach could also be the source of the noise but pulling the clutch in would settle that. Be extra sure the wheel bearings/brakes are sound before heading out at speed.

[ericheath]

Bearings are good. I checked them for heat three times in 250 miles, all at 70-85 mph. Front hub was cool as ever. One rotor a little warm, so I need to clean it. The rear one was pretty warm on the first stop, but cooler the next few stops. Loosening the speedometer cable I have thought of before, just didn't think it sounded like the old one, but it's different. It could be that, but it sounds like it's from the bottom end. I've had them squawk at the top before, but not the bottom. As mentioned my ears are bad so it could be right from the speedometer. Now that I've ridden it a while I can gauge my speed by my tachometer. The tachometer is almost exactly half of speed. With the 1500 final drive, 2k =40 3k=60 4K= 80. So taking it to 4500 should tell the story. The cable is fairly new. I guess it wouldn't hurt to give it some lube. Thanks Salukispeed. When it warms up I will go check it out. It was gorgeous here in Fargo yesterday, 80 degrees.

[ericheath]

Disconnected the lower end of the cable at the axle and it doesn't make any noise in a quick burst to 100mph. I will reconnect the lower end and disconnect the upper end and see if it comes back or not. Could be the cable, could be the gauge? Perhaps my windshield and gauge shield were making the noise sound like it was coming from lower down.

[Toehead]

Those gauges work via eddy current, and there is a magnet assembly spinning in there at the speed of the cable. if it has worn bushings, it can resonate and make a pretty good racket.

[ericheath]

Speedometer gauge, eddy current? I was always under the impression they were all mechanical. I should have included that this gauge is also from my 85 Magna so I can tell when I hit 155 mph.

I had enough wine this afternoon to hold off until tomorrow to test further.

[Toehead]

It's mechanical, but the rotating magnet induces eddy currents into an aluminum cup that is connected to the needle. Those eddy currents create a torque on the cup that is proportional to how fast the magnet is spinning. Motion of that cup is resisted by a clock spring, so the needle moves a certain amount for every MPH.

Here is a cool vido showing how eddy currents can create drag. It's the same effect that makes the speedometer work.

https://www.youtube.com/watch?v=JN-A3RryOC8

[ericheath]

Well my ears are poor, and at those speeds there's plenty of wind noise with a small wind screen, but I think I could still detect the noise from the speedometer gauge than below. I guess I'll have a chance to find out tomorrow. I think the gauge only shows 12000 miles, but could be 112000 for all I know.

[ericheath]

Finally got some tell tale marks/scuffing on the tire to know it is /was my fender. Most of the time it probably was just rubbing the tip part of the tire. It is tooooo close to the tire anyways. It finally left these little marks on the sidewalk.

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Looking closer at the fender, it must have begun twitching at speed. There are several rubbing spots on it.

It started to get worse even at 80 now and then. So I pulled into a rest stop to take it off. I dropped the kick stand and the bike would not lean. Investigated some and my subframe for the mono shock has been pulled back. I hit a large bump just a few miles earlier. Rear tire is rubbing and I probably would NOT have made it more than a few more miles.

My son is on his way to get a Uhaul. I'm thanking the Good Lord for His help. I'm feeling bad for my guardian angel. He's a good one and I have made him work extra hard.

I'm thinking it might be time to just pull the monoshock out and go with shocks again. HOTT convinced me to beef up the top mounts and I did connect the three pieces from top to bottom, but this needs support to the front and the motor is right there. I'm sure it still can be done, but it's a strip the to the frame job now. Shocks would just go right on.

[Rat]

Livin' on the edge ....

Gord (I keep it under 90 .... mostly) Jones

[Toehead]

Glad you found it before disaster.

Stay safe out there.

[ericheath]

Low Ride----er is a little lower-

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We had to drag it across the ramp even with the 2wd pickup parked in the ditch. It must have been four inches off the ground.

Here's where it looks like it started to let go. Rusty.

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Here's where it was rubbing, and as you can see, my Mom is still alive and praying for me.Ten miles and I think it would have ended badly. I was going to go 3-4 mikes further to a town. I don't know why I suddenly pulled in to the rest area.

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I put a 1500 shock on it so it will roll out of the pickup without getting hung up. I'd like to pull a couple inches out of the length still.

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[Whiskerfish]

Scary!! Glad you were not hurt!!

[gltriker]

[wingrider]

Wow! You seem to have all the fun!!! Glad everything worked out for you...would have been a tough landing.