Front End Shake at 65

[FEW]

I have an 86 VR. The problem is the front end shaking over 65 MPH to the point that I cannot ride it. It has a new tire on it and correct air pressure.

 

1. The air ride compressor system doesn't work. Does this matter?

 

2. Seems to ride fine under 65, but when I'm going slow over bumps the front forks feel like they're bottoming out. So I'm trying to figure out if I need to rebuild them. Is there an easy way to tell?

 

3. I don't plan on fixing the compressor system. Any recommendations on modifications I need to do: I.E. unplug the anti-dive and such.

 

Thanks and Happy New Year.

[Venturous Randy]

If the forks are not leaking, you might be able to get away with putting Progressive springs in with the correct fluid level. You may also need to clean and grease the head bearings or maybe even replace them. When you put the new tire on, did you balance it?

RandyA

[kevin-vic-b.c.]

Also can you please define... air pressure is good for us.

[KIC]

I 2nd the check the head bearings. Also if you don't have the correct fluid level in both sides of the shocks. Maybe something wrong with the front tire rim assembly from being mounted wrong ? I highly recommend the upgraded fork brace, but that isn't your problem.

 

Good luck

[SpencerPJ]

I have an 83, got weird vibrations after new front tire at 45mph. I dropped my fork pressure down to almost nothing, vibration went away. play with that and tire pressure, mine is super sensitive to variations.

[dingy]

I have an 86 VR. The problem is the front end shaking over 65 MPH to the point that I cannot ride it. It has a new tire on it and correct air pressure.

 

1. The air ride compressor system doesn't work. Does this matter?

 

2. Seems to ride fine under 65, but when I'm going slow over bumps the front forks feel like they're bottoming out. So I'm trying to figure out if I need to rebuild them. Is there an easy way to tell?

 

3. I don't plan on fixing the compressor system. Any recommendations on modifications I need to do: I.E. unplug the anti-dive and such.

 

Thanks and Happy New Year.

 

Is the new tire you put on the front tire, you were not clear on that. If it wasn't, cupping of a front tire that otherwise is in good shape will degrade handling.

 

Something else to look at is the rear suspension. Check that the shock pivot links are good. Also the rear swing arm can cause handling issues. Verify there is absolutely zero play in the swing arm. This can sometimes be corrected be servicing the swing arm bearings and properly setting bearing torque.

 

Air compressor is optional, most non Royale ventures did not have a compressor. The shocks/forks can still be aired up with the installation of a Shrader type air fitting from a non compressor equipped bike. These were most common in the MKI models (83-85).

 

Gary

[bongobobny]

As you can tell from varied responses, there are a bunch of things that can and will cause vibrations. If you are bottoming out you can be low on shock oil, your springs are shot, you need more air pressure, or your anti dives are not working. It is highly recommended that you rebuild your forks and install Progressive springs. Inspect all your parts to make sure you don't have a bent tube, etc. and make sure the new oil you put in is the same amount in both shocks. If the both front shocks are not equal in oil level AND air pressure it can cause handling issues as one side may act different than the other causing different recovery rates etc. from a bump; one side will rise different from the other side.

 

Proper tire balance is very important for minimizing front end oscillations as well as the tire itself! There have been cases of people installing a new tire then finding out the tire for some reason or another caused handling issues. Also never mix radials and bias tires as it can and will cause handling issues.

 

Yes, with that old of a bike I would replace the head bearings and races. You are talking 28 year old parts and just as old grease. Also make sure the torque on the head nut is at the proper spec. Too loose or too tight will cause oscillations. Member Dingy sells a really handy tool just for this purpose.

 

Another way to reduce oscillations is by stiffening up your fork brace by replacing it with either a Superbrace or one that member Condor makes. The one Condor makes is just as good as the Superbrace and a LOT cheaper!

 

Lastly, as mentioned, the rear suspension can effect handling as well. Make sure there is no sideplay with your swingarm, and that the mounting nuts haven't loosened. Replacing the swingarm bearings is a good idea. You will also want to check out all your bushings and sleeves on the rear shock mount assembly while you are at it. Many of us have drilled and tapped for grease fittings at each sleeve. The nylon sleeves usually don't go bad as much as the metal bushings developing wear. Parts are getting scarce though.

 

All these things add up to effect the overall handling of the bike...

[Yammer Dan]

You ain't far down the road from me. I would check head bearings first. Did you balance it? Condor's Fork Brace is always a help for these things. Should have 40 lbs air in that front one 42 rear. Air system may be simple fix. I am 40 miles above Charleston.

[FEW]

Thanks so much for all the feedback. Good places to start. I have the bike in storage/shop until spring so I can get organized.

 

I don't know if the front tire was balanced properly. It was installed when I bought the bike.

 

I doubt if the shocks have ever been upgraded so I'll install progressive springs and have the other things done as well.

[FEW]

Is the new tire you put on the front tire, you were not clear on that. If it wasn't, cupping of a front tire that otherwise is in good shape will degrade handling.

 

Something else to look at is the rear suspension. Check that the shock pivot links are good. Also the rear swing arm can cause handling issues. Verify there is absolutely zero play in the swing arm. This can sometimes be corrected be servicing the swing arm bearings and properly setting bearing torque.

 

Air compressor is optional, most non Royale ventures did not have a compressor. The shocks/forks can still be aired up with the installation of a Shrader type air fitting from a non compressor equipped bike. These were most common in the MKI models (83-85).

 

Gary WHERE DO I ATTACH THE AIR FITTINGS?