Front End Wobble on Prolink

Terry · Post by **Terry** » Mon Nov 26, 2007 12:40 pm

My 82 has a severe left to right wobble when I'm riding fast (over 75) leaned over for fast sweepers like up and down highway 101. It doesn't seem to effect slower corner handling just higher speed turns and its getting to be dangerous. At one time Friday heading north on 101 I passed a V Rod and then he tried keeping up with me and going into these fast sweepers the bike began to wobble again, so much so that I think I scared the V Rod away!

He probably thought I was going to tank slap myself right off the road but the wobble is controlable...sort of. I do hold my speed just to keep hanging on to what control I have but its getting to be a real PITA because I really enjoy leaning over at 75-85+. When I got the bike, which now has over 87,000 miles on it, it had Pro suspension front and rear and a fork brace. I'm at a loss as to what to do to correct this. Complete new front end? I'm not positive, but certainly they didn't do this when new did they? Its a severe side to side wobble, like a slow(er) motion tank slapper we've all seen in track racing pics. What to do for a fix???

Chris · Post by **Chris** » Mon Nov 26, 2007 1:01 pm

Maybe your rear wheel is slightly out of alignment?

alimey4u2 · Post by **alimey4u2** » Mon Nov 26, 2007 1:14 pm

Chris wrote:Maybe your rear wheel is slightly out of alignment?

First thing I would check, together with wheel trueness. I had the same problem on my R1 & found it to be my leather jacket flapping in the wind..

steve murdoch icoa #5322 · Mon Nov 26, 2007 1:54 pm

Worn front tire?

alimey4u2 · Post by **alimey4u2** » Mon Nov 26, 2007 2:17 pm

steve murdoch icoa #5322 wrote:Worn front tire?

Thanks for the prompt Steve, Tire pressure ? If OK ramp it up on front & rear about 5 PSI & see if it improves... If it does, it is indicative of flat centers, normally due to Interstate type of distance riding...

alimey4u2 · Post by **alimey4u2** » Mon Nov 26, 2007 2:39 pm

Another thing to check would be the engine mounting bolts. I have just read the the infamous wobble on the Honda ST1100/1300/Pan European has been put down to incorrectly torqued engine bolts. The ST (like the CBX) uses its engine as a major frame support...

daves79x · Post by **daves79x** » Mon Nov 26, 2007 3:21 pm

Several things come to mind. Inflate the tires to at least 40psi. Inflate the rear shock to 75-80psi - don't worry, it won't hurt it, unless the seal is gone and the fluid has already puked out. See how the handling improves with those changes. If no better, you need to seriously get into the steering bearings and swingarm pivot bearings and dogbone bushings. I think you will be surprised at what you'll find in those areas, unless meticulous maintenance has been done on them.

With those miles, all of the above should have been serviced a number of times. Also, new tires will probably help for a while, but the underlying problems will return. If not perfectly up to snuff, the late models feel as though they have a hinge in the middle in high-speed corners.

Dave

Terry · Post by **Terry** » Mon Nov 26, 2007 3:21 pm

Oh man, so many possibilities! I run good tires with 36 and 38 psi F-R but I've never checked the rear wheel alignment or the motor mounts for proper torque. I could try some more air first (and easiest) and check the torque but is there an easy way I can check the alignment? BTW, does anyone actually put air in the forks?

EMS · Post by **EMS** » Mon Nov 26, 2007 3:46 pm

Worn out front wheel bearings and uneven fork leg damping can also be culprits. I do indeed put air into my front forks on the '81. But I ride this bike two-up most of the time.

Terry · Post by **Terry** » Mon Nov 26, 2007 3:54 pm

The head bearings were just replaced but the problem was there before and after. The rear shock is a ProSus unit so there is nowhere to add air to it. Wheel bearings look OK but I don't know how old they are. Have never checked or serviced the swingarm. Hard to believe that a few more pounds of air in the tires would solve anything but its a quick check so I'll try it. I may even try some air in the forks.

bobber · Post by **bobber** » Mon Nov 26, 2007 6:52 pm

Terry wrote: The rear shock is a ProSus unit so there is nowhere to add air to it.

These shocks use nitrogen charge. I contacted Progressive this summer to find pressure charge and it 150lbs. I've posted it here somewhere along with pictures of the shock. Should be a remote resovior leading to shock.
I'd spend time looking for it but gotta go to work. Search using my name "bobber". Doing a stint of nites 'till late-Dec and its down to -33 here so when I hear of you guys still riding.... oh well.

Terry · Post by **Terry** » Mon Nov 26, 2007 6:54 pm

I can see what looks like an air valve, like a valve stem on a tire but how do I take a reading? Air gauge?

Chris · Post by **Chris** » Mon Nov 26, 2007 7:36 pm

Bobber's previous post..............

viewtopic.php?p=14565&highlight=#14565

Terry · Post by **Terry** » Mon Nov 26, 2007 7:47 pm

There is no remote reservoir on mine, just the nitro valve on the unit itself. Maybe I'll try to contact Progressive for some info.

Mike Barone #123 · Post by **Mike Barone #123** » Tue Nov 27, 2007 8:13 am

Hi Terry

99% of CBX late model weaving/almost to full tank slapper issues in mid to high speed turns that have undulations have to do with rear shocks. If you can't adjust the pressure in your shock you could try the following:

One way to define exactly what the problem and what we do at rallies is to fit up parts from a friends CBX that does handle one at a time until the problem goes away......so if you know someone nearby that has a late model this is an option.

Another possible way to determine if it is the rear shock is the issue you can do yourself if your non oem rear shock allows you to see the shock springs. Call around dirt track race car shops and see if they offer spring inserts/rubbers that could be fit between your shocks spring coils to see if this helps. Cheap and fast diagnois that if it works will allow you to continue to ride your late model until you get a new shock fitted or yours rebuilt.

Tire pressure can also cause the issues you stated...so a quick check on this might be a good start, though I am sure you already had them at the correct pressure. Worn tires that are squared off can also result in some of the issues you stated when you are on the "edge" of the square part in turns, but if the tires are new/near new and the right pressure this allows you to"lean" toward the rear shock being the problem.

In your post I could not determine if the problem was there all the time or started and gradually got worse, or just started one day recently....if it has been gradual it could be bearings and other hardware things.

Keep us posted on how it turns out and ......as you have stated......this is a dangerous situation that can lead to very, very bad things.

Finally, if you determine you might need a new rear shock please call Klaus/ICOA member who imports shocks and suspension components from Germany...he will be able to give you information and recommend shocks. 732-786-9777

Mike