Head shake/twitchy front end

Hey all,
I know that there are quite a few threads out there concerning head shake, but I'd like some opinions on my specific situation.
Here we go:
A couple weeks ago I had a flat out in the middle of nowhere. I ended up plugging the rear tire and ordered a new one which has now been installed. It's an OEM replacement Bridgeston BT020 by the way. While I was waiting on the new tire to arrive I rode around town a little bit on the plugged old tire. The last day I rode on the old tire I felt the handling of the bike change, it felt like a tire was going flat. I figured the plug must have let go and the rear was going flat. This however was not the case, the tire was still holding air. The next day I had the tire replaced and took it out for a test ride. I noticed that I had a pretty decent head shake when I let go of the bars around 40-50 mph. And in addition, it just didn't feel right. I was uncomfortable going any faster than 60-65mph, when usually i'm cruising at 75-80mph. The front end just felt unstable, I don't know how else to describe it. Leaning it over in curves felt a little scary, when before it felt rock solid.
My question, now that you've heard my whole story, is why? Why the head shake? What's causing this "strange" unstable feeling? I only have 2600 miles on the bike/front tire. I don't believe that the rear tire is the issue as I began to feel this before I had the rear replaced. All opinions are welcome.
Thanks!!!

 

I'll bet you threw off a stick-on weight. Look for the sticky residue that's left on your wheel. Buy some more stick-on weights at auto parts store. Replace the length of weight that matches sticky residue in the exact same spot (after cleaning off the goo).

 

Thanks guys. The weird thing is, on my front wheel I have two weights together clamped on the center rib. On the rear wheel, no weights at all. Is it possible that it would be perfectly balanced with just the tire? I would think this is pretty unlikely. Maybe the shop just mounted the tire and didn't balance it.....

 

I know the scary feeling as I had the same thing only for 150 miles last night on HWY 1 ! Tori and Reg were gone and I was fighting to keep my bike from high siding on every turn. I had my hard bags on so that puts more weight on the rear (bad), I have a cupped front dunlop tire (bad), I have not set up my sag yet so this does not help (bad).

From what I see the front tire cupping is the most troublesome cause of the head shake but PSI, loose bearings, imbalanced tires can also be the cause. Take a look and let us know what you find.

 

Those weights that are hooked together and clamped on the center rib sound like the original weights put on by Honda when it was built. I balance my tires with every change and use stick-on weights like most bike shops use. If your front wheel is out of balance it will certainly make the bike feel nervous and un-nerving especially in turns. In hard lean turns you'll feel the front end thumping. That's the out of balance condition.

 

There is a reference dot on the rear tire that helps line the tire up to a specific spot on the wheel, its not always correct without weight but often is. It is a dangerous thing to replace just one tire on any sport bike if you are even slighlty an aggresive rider. People do it all the time and it is foolish, people even mis-match front and rears. A worn tire will not track the same as a new tire, or grip the same, its asking for trouble. Heres a combo of issues that could cause the front to shake bad: Front tire is over inflated, rear over inflated, spring preload set harder than normal on the rear. Factory 36-42rear psi is suicide numbers for a kneedrag rider. Rear tire never heats up do to high pressure. 36-36 is a good starting point with most tires, 34-33 most track tires(some tires are very different). Sorry about the book, but Im positive you have a combo of wrong tire pressure/suspension(maybe), and worn front tire. You should check your pressure often before you ride, long trips = factory settings, corners = Softer. Oh and get a new front matching the rear TODAY.

 

good morning fellow Viffer-riders,
thanks for the info. i checked the rear tire last night and noticed the spot on it. but what is that spot supposed to correspond to on the wheel? as i said before, the front tire is not new, but it only has 2600 miles on it and has not been abused. you're saying that i should absolutely replace it too? i'm only a mildly aggressive rider and there aren't many twistys around here to wear down my rubber. i had the tire pressures set at the factory level, so i brought them down to about 35psi front and 38 rear. unfortunately, as soon as i stepped out the door last night it started pouring, so i couldn't test out the changes. thanks all!

 

Run your hand over the middle of that front tire, you can tell a difference when a tire is "cupped" also. Something I forgot to mention. Just cover both sides of the tire and the middle as you run you hand down the tread. You will feel bumps instead of smooth even tread. Mildy aggressive rider can get away with running a front tire longer, I wouldnt want to, but you can do it. Think of it this way: You have a contact patch at lean on both tires that is around and inch. From both tires new they are broken in together the same way based on your suspension and ridding style. Then you put a brand new tire on the rear. No longer are they going to track together as well, causing suttle and sometimes major steering issues. You could try other tires as well that may wear more evenly front and rear. You should check out some of the sport touring tires by Mich and pirelli, I think you could find a much better tire for your ridding style that would last 6-9k miles both front and rear.

 

Also OEM tires are for the most part made by the lowest bidder, Although I have to say I am happy with the BT020 on my 08 at the moment. Couple examples of good options:
Michelin Pilot ROAD Street/Sport Touring - Rear Tire - Read Reviews and Buy at KneeDraggers.com
Michelin Pilot ROAD 2CT - Sport/Road Rear Tire - Read Reviews and Buy at KneeDraggers.com
Pirelli Diablo Strada - Rear Tires - Read Reviews and Buy at KneeDraggers.com Im thinking these sound great for the VFR!

 

Jessiah1,
I appreciate all the good info! The weird thing is, I started feeling this "nervousness" in the front end just before I replaced the rear tire. I was just out riding around town, running errands and felt the handling change. It felt like a tire was going down and I figured the rear plug must be giving up and leaking. The tire was holding good pressure though, so I'm really kind of baffled. I'll be taking the bike in tonight to have it checked out. I'll let y'all know what I find out.

 

Huh, another thought just popped into my head when you said it was abrupt, bubble in the tire. Happens sometimes, you would find it easy enough if you went over the tire. Its hard to diagnose issues via the internet...good luck, and smart getting it checked out! Its only two wheels after all.:smile:

 

I've had it out with a shop here in Germany on that one... They can and should balance the rear tire but, they have to have the correct spacers for their balancer jig when balancing a single sided swingarm wheel, as it doesn't have small bearings for the cone spacers to slip into.
We argured back and forth, him insisting the wheel was perfectly balanced as is. I called his bluff on not having the Honda mandated equipment for a Honda shop. The auto shop down the street had a "bubble balancer" and proved the Honda shop wrong.
Don't take "its already balanced" as an answer. Hell, any Ducati shop can balance it for you as well.

 

good morning all,
Just wanted to give y'all an update on my handling issue. I took the bike in to the dealer to take a look at it. They balanced the rear wheel and called it a day. It's funny that they didn't seem to think it was initially necessary to balance it IN THE FIRST PLACE!! This young kid brought out my bike and said that he was the one to install the new tire in the first place and that the "weights must have fallen off". That is a total load of BS. Then I'm thinking to myself, is this kid a certified honda tech or just some kid they've got working on my bike. HMMM....
Anyway, the bike felt a little bit better, but the front end still feels "nervous". It's like the steering has become darty. For instance, when I roll over a tar strip in the road the steering wants to follow it and not just roll over it. The bike use to feel rock-solid at high speed (80+) and now something has definitely changed. I don't want to continue taking the bike into the shop, but I know something needs to be done. I suppose the culprit could be the front tire, but I just don't know. I don't believe the shop looked at anything else other than the rear tire when I brought it in last week. I rode about 150 miles yesterday (by the way Illinois riders, SR 71 between Starved Rock and Ottawa is STILL CLOSED) and it just doesn't feel quite right. By the way, slow-speed maneuvers also feel a bit strange, like the front wheel wants to "tuck" in while doing tight turns. Alright, I'm done rambling, I'm just not sure what to do next. Buy a new tire to replace the front? Take it back to the shop and have them explore the problem? Any advice would be much appreciated as always. Thanks all.

 

thanks Derstuka. the tire pressures i'm running are these: 40psi (rear), 36psi (front). are these too high? the front tire is stock BT020 (2700 miles on it), and the rear is an OEM replacement BT020. i haven't touched the suspension since i bought the bike back in March, so the settings shouldn't have changed any. one of my questions is, since this is an '06 model, which i bought new in March '08, that means the stock tires sat around in the shop for 2+ years. could they have degraded enough to cause my handling issue?

 

I had a discussion about this with another member recently who was asking about steering dampers. He was in favor of them for the VFR. It was my understanding that headshake was a result of things being out of spec rather than a result of the design of the bike. I see this is the general opinion here, but it still has me wondering...
How much benefit would the average rider get from a damper? Any?

 

I have two friends who had the front end shakes where you couldn't let go of the bars for more than a couple seconds, and both replaced perfectly good looking front tires and eliminated the problem. These were not VFR's. One was a Yamaha Radian and the other was a Honda Shadow. I'd check everything mentioned above and if you don't find loose, or overly tight headset bearings take a chance. Get a new front tire.