front end oscillation - do i need a suspension upgrade?

I have a 2000 vfr that I bought in 2001. I have put about 30200 miles on it.

In long high speed sweepers the front end starts to ocsillate. And if the road is anything but glass smooth the bumps only make this worse. I also notice this (to a lesser degree) when accelerating HARD during a throttle roll-on from 30-40 mph up, the bike is travelling in a straight line.

Any advice on what the problem could be?

I have RaceTec springs up front with new fork oil. These only made a minor improvement in the handling. I can tolerate the straight line oscillation but the pogo stick behaviour while cornering really sucks. Do I need to get the gold valves perhaps?

Thanks!
Keith

 

By replacing the front springs and not the rear, you now have mismatched spring rates. I would replace the rear spring to match the front springs and see if that alleviates your problem. Upgrading to gold valves will help but I would match up the springs first.

Action

 

+1, it is very important that you keep the balance of the bike in check. Honda's original balance was spot on, just on the weak side.

You can upgrade the spring rate a little bit without changing the valving from what I hear, but I think that the valving could use some help to begin with anyway so maybe it needs a change.

How much do you weight? What spring rate did you install in the front?

 

do you have any preload adj. left in the rear? To see if it IS the spring mismatch, try messing with the rear...If the prob gets worse when you soften the rear or better when you firm it up, you KNOW its because it's mismatched...Racetech will gladly sell you a rear spring that matches the fronts you bought!

 

Check your tires and their pressure. As others have stated, this could very well be a mismatch on suspension. Also check your steering head bearings. At 30k miles, you are probably getting pretty close to having some wear on them and they will need replacing. Put the bike on the centerstand with the weight off of the front tire. Slowly turn the wheel left and right and see if you can feel a spot where it likes to catch or a rough spot to turn through.

 

Lots of good feedback guys! I think it is the suspension getting tired with over 30K miles on it. The tire pressures are stock settings for both front and rear. I run 36/42 front and rear. Both tires are Metz M-3.

I have the Racetech spring rates of 0.85 kg/mm. VFR stock rates are 0.74 kg/mm according to RaceTech. I did notice improvement over stock and slightly less oscillation after getting the Racetech springs installed. I weigh 130 lbs now (was 145lbs).

Also replaced the steering head bearings.

I will check the rear settings and also the front wheel & hub soon (its dropping down to -6C/20F so the check ride may have to wait some).

Thanks!
-Keith

P.S.> Anyone near/in Austin, Texas with a VFR? wanna test ride my viffer and lend an opinion?