Steering stabilizer worthwhile? Track days?

I have never experienced tank slap but a friend has and I have seen video of the tragic results. Riding sensibly is there a need to install a stabilizer? For those who have done track days is it worthwhile or necessary? Who makes dampeners for the VFR? Doing a quick search I only found one supplier.

Thanks,

Reg

 

Hey brother:

I attend track days and I'd say "no" you don't need one on a VFR.

Of course it's your money and you can do as you choose.

Peace,

BZ

 

I agree with BZ dont need one on a VFR, wast of money. if you were riding a TLR id say yes for sure, theres a reason why they call them widow makers

 

I have an adjustable rotary damper and it has proved to be quite benificial. I will not ride without one again. My guess is that the respondents to this thread have never had a damper mounted to their bike, so they are only voicing opinion based upon what they believe or what they have read.

 

your right i have never rode a vfr with one, for that matter i have never seen a vfr with one. my race bike has one so i am familiar with what they do and that bike needs one. most bikes that have them are much lighter and more aggressive steering than a vfr and therefore prone to front end lift or wobble. after riding my vfr for over 60k i have never once needed one and that includes some track days as well.vfr may be a pig but its an extremely stable one

 

Would it be safe to say that if one has done some considerable suspension mods to the "sportier" or better handling side of things that the need for a damper may increase vs the stock VFR setup which is quite neutral?

 

Yes that is true, but I don't want to get into proving chassis geometry to support my opinion. The biggest benefit I have noticed has been that I am far less fatigued in the arms and upper body area after riding on public streets which can tend to be bumpy, irregular, or rough pavement. I'm sure the Keith Code wannabes will be espousing the "well you are supposed to grip the tank with your legs" lecture. I've been to Code, I know the drill, but the fact of the matter is that it really helps the bike hold an extremely clean line on irregular surfaces with drastically reduced effort. It is also very noticeable on grooved highways. I got my first experience with the rotary dampers in the desert on dirt machines and decided to experiment, I'm glad that I did.

 

I found a good example of “Tankslappers” explained. At least in words better than I can most likely write, see below:

From the world of motorcycling, a tankslapper can be defined as an undesired oscillation of the forks.
When experiencing a 'tankslapper', the handlebars 'wobble' rapidly from side to side, (sometimes so violently that the rider can no loner maintain grip). In extreme cases, (and provided the steering allows), the oscillation is such that the handlebars will hit the sides of the bikes fuel tank, hence the expression 'tankslapper'.
What causes a tankslapper?
The relationship between a motorcycle's tyres and the road is simple physics. The downward force of the tyre on the road surface is matched by an equal and opposite force as the road pushes back. This is Newton's First Law of Motion.
Now consider what happens when a motorcycle's front wheel leaves the ground temporarily, such as when the rider pops a wheelie or accelerates sufficiently such that full contact of the front tyre with the road surface is lost momentarily. If the wheel is still aligned with the direction of travel when it touches back down there's no problem. In fact, the gyroscopic force created by the rotation of the front wheel tends to ensure this. If, however, the alignment is lost, a tankslapper may happen. Alignment with the direction of travel can be lost if the wheel is turned whilst aloft, (don't touch the front brake!), or the direction of travel changes after the wheel lifts, (e.g. when going round a bend).
The important factor here is the castor angle of the motorcycle's steering, (the angle that the motorcycle's forks make with an imaginary line perpendicular to the ground). The castor effect comes into play when a front wheel that isn't aligned with the direction of travel touches back down. The natural tendency in this case is for the wheel to attempt to align itself once more upon regaining contact. Think about how the castor wheels on a shopping cart work, (a shopping cart has a zero degree castor angle, of course).
The rate of castor compensation is inversely proportional to the castor angle of the motorcycle's steering. In other words, bikes with steep steering geometries, (such as sports bikes), are more prone to rapid steering oscillation than, say, cruisers.
In some cases, over-compensation due to the castor effect happens upon 'touch down' and the wheel turns past the centre. The castor effect will rotate the wheel back the other way and handlebar oscillation begins. Normally, at this point, the rider is gripping on for dear life and trying to provide input into the handlebars to correct the oscillation. This is actually the worst thing to do, as the rider can't react quick enough and will tend to put energy into the oscillation. The best thing to do is relax the arms and let the oscillaton reduce naturally.
How to avoid a tankslapper?
Tankslappers are easily avoided - make sure your front wheel never loses full contact with the ground. Modern motorcycles, with their aggressive steering geometry, sticky tyres and powerful engines, conspire against this. It's quite easy for a rider to inadvertently lift the front wheel sufficiently to cause it to 'wobble', especially when pulling away out of a curve, when the direction of travel is changing.
Maybe it's time you considered fitting a steering damper? And he should have added “If you are experiencing Tankslapper one should add throttle to get out of the Tankslapper” Although I imagine that’s the last thing on someone’s mind and that’s why they crash.

To the OP, the VFR was never a bike that was known as a “Tankslapper machine”. Someone mentioned the Suzuki TL1000. Those bikes had a light front end and an OK stock suspension. Thus people popping wheelies and coming off turns hard on the street got a big surprise. Enough so those machines still have the aura of being tankslapper prone.

I do not want my post to come off as negative toward Norcalboy. I respect Norcal greatly for he has deep knowledge on things practical to motorcycling as well as the scientific understanding of how motorcycles work, steer, etc. Of course the scientific side and the understanding of it are what most of us lack. And Norcal has greatly influenced me more than he knows especially in the area of research. Norcal espouses one should surround oneself with people more knowledgeable on a subject than yourself to learn from; I could not agree more. And when we mean more knowledgable, we mean the people respected in your community, regionally or nationally on a subject.

I’ve looked at steering dampers too. And after discussing installing one with my mechanic (who was way more knowledgeable than I thought till I asked the right questions, he’s road raced for over 15 years) other track day riders, who happen to be rising up through the racing ranks and have answered questions OR have referred the question to their people (i.e. their mechanics) and have provided advise from their own mistakes and experience. The consensus was this: “Dan, after watching you or per our discussion, a steering dampener is not going to help you. In fact it will partly mask the problems you are having”.

To keep this short and make my point quickly. More people, when learning to go fast on a motorcycle, when they start to face bike problems from handling aspects, etc. End up throwing copious amounts of money at bike upgrades thinking it’s the bike, not them and their lack of skill development. Norcal once said something like; “You only know the best you’ve ridden”. This is diametrically flawed logic because it can only be measured from a scientific model on a motorcycle that has been modified. The statement implies the bike is what matters most and rider input is secondary. I think we all now this as untrue because although we can measure a motorcycle’s geometry, modify two bikes exactly the same…once we put riders on them we will get two different results on the track. Norcal is a very good rider. I am sure if we did a track day together he would pass me no issue. But I doubt it is because he has a nice VFR with some seriously nice mods. I bet his years of motorcycle training and riding (i.e. his skill) would be what takes me. We can switch bikes, adjust the suspension for our weight and now I am on the superior machine and Norcal would still beat me. (I’m sure he’d come in and say your 97 handles like shit LOL). Norcal is a good enough rider to be able to use the higher end bike mods and ‘feel’ what they and the bike are telling him as he rides. That is a level the high majority of riders I know are not even at. It's like the R1 rider at the track. "Man I keep spinning me rear wheel coming out of turns". A friend, who knows more says "Dude, you need a nice Ohlins shock your stock one sucks". Now the R1 rider dropped the grand on the shock, the R1 tracks better and grips better, but the rider never addresed being hamfisted coming out of turns. The rider is putting his faith and trust into a problem that was always his, not the bikes.

So OP, if you want to spend the money, again, its your money. But I recommend getting some of the basics down like suspension settings and understanding how THAT works, doing some track days, reading some more and talking to and getting to know more people in the know.

When the time comes you’ll know when to upgrade.

Sorry for the ramblings on a Sunday morning.

BZ

 

believe it or not, unless you are riding something with a very radical steering geometry (like a Suzuki TL1000S), most tank slappers are the result of hanging onto the bars too hard. If you relax and let the suspension do its job, all should be good. fighting the suspension upsets the bike, headstock oscillates wildly. There is a video (cant find it) from MGP about 2-3 years ago where Melandri or Capirossi have a tank slap and fall off. As soon as the bars are released by the rider (after coming off) the bike settled down immediately and continued around the turn riderless. One of the drills at California superbike school level one is to take your hands off the bars once in a turn, you quickly notice that the bike is MUCH more stable when left to do what it was designed for.

As far as a VFR on the track, never an issue. The only issues I have had are the front brakes overheating and fading which was cured by HH pads, using less brakes (i.e., stopping trail braking) and a fresh fluid change at the beginning of each season.

 

JS with your new upgraded suspension you should have even less need for one. Its easy to hit limits of stock suspension rippin it up on a bumpy twisty rd compared to a lot of bikes. Even over riding suspension I have never needed a damper. Really WTF do I know, im just a code wannabie, I only ride straight interstates with a death like granny grip LOL