TOPIC:

SWest wrote:

loudhvx wrote: When properly weighted, they can reduce vibration in the bars, but there is a potential downside. If your bike is prone to tank-slapper, the bar-end weights can increase the likelihood of it happening. Most Kz's are pretty stable, but the early standard 550's seem to like to oscillate more than others, and they can go into a bad tank-slapper at high speeds, especially the 81 Gpz550. (Kawasaki redesigned the geometry for 1982.) One way to avoid it is to reduce the steering inertia by taking weight off. This increases the resonance frequency to a speed you hopefully can't attain with the bike. Adding weights at the ends of the bars would be counter to that strategy.

I didn't think about the tank slapper hazard. Haven't noticed a problem.
Steve

Yep... learned the hard way... exited the vehicle in deep triple digits.

650dude, I'm pretty sure my KZ would "spank" that wimpy CB900 of yours.

loudhvx wrote:

SWest wrote:

loudhvx wrote: When properly weighted, they can reduce vibration in the bars, but there is a potential downside. If your bike is prone to tank-slapper, the bar-end weights can increase the likelihood of it happening. Most Kz's are pretty stable, but the early standard 550's seem to like to oscillate more than others, and they can go into a bad tank-slapper at high speeds, especially the 81 Gpz550. (Kawasaki redesigned the geometry for 1982.) One way to avoid it is to reduce the steering inertia by taking weight off. This increases the resonance frequency to a speed you hopefully can't attain with the bike. Adding weights at the ends of the bars would be counter to that strategy.

I didn't think about the tank slapper hazard. Haven't noticed a problem.
Steve

Yep... learned the hard way... exited the vehicle in deep triple digits.

Same thing happened to my brother on his 81 . Went down on highway doing a 100 plus . Its my bike now . Never had it happen when ive been on it . So whats the best fix for this .

I understand there is a whole science to tank slappers. Many things can contribute. Hopefully not something Ill have to worry about as I ride like an old lady. The reason for my post is that I wanted to fit a pair of handguards to my daily ride (Bandit 600) as the snow has arrived here in Holland and the hot grips only work on the inside of my hands.I wanted something to cut down on the wind blast. I bought a set of Acerbis guards but to get them to fit,I needed to extend the bars. Hence the question about bar end weights.
I had a set of bar ends from an old Honda which I have fitted and managed to get the Acerbiseses mounted. Not perfect but boy do they make a difference. I would highly recommend them to anybody that rides through the winter.


Yes. I know its not a Kawasaki Am I going to be banned now or do I have to lose my temper,claim its faster than a Z1000 and insult everybody?

Id like to see more on how you fitted the bar ends.
No you don't get banned for showing another make or think it's faster than whatever.
The guy you're referring to already had one foot out the door and the other one on a banana peal. What sealed his fate forever was his arrogance, dishonesty and frauds. Being a tool isn't an immediate cause for dismissal, in fact it was quite entertaining, for a while.
Steve

Many years ago a friend had a set of "Hippo Hands" on his bike. I rode it in the Winter and found them to work extremely well. Even though that was more than 40 years ago they are still in business. Ed

www.hippohands.com/

Here you go Steve. The mounting instructions that came with them are straight forward. I did have to turn the brake line out of the way a bit but for the rest it went pretty good. The guards themselves are quite flexible so you can twist them about to fit.[/attachment]

they cost about euro90 including delivery from Germany.

My winter windshield covers my hands pretty well so I'm covered there. The summer one doesn't but it has less drag so I can MOVE.
Steve

On all of my kawasakis that I own right now including my KZ1000 that i've owned since early on, all in my garage, not made up (FAKE POSTING i think). My bikes that came oem with end weights have them, those that didn't don't.

riturbo wrote:

loudhvx wrote:

SWest wrote:

loudhvx wrote: When properly weighted, they can reduce vibration in the bars, but there is a potential downside. If your bike is prone to tank-slapper, the bar-end weights can increase the likelihood of it happening. Most Kz's are pretty stable, but the early standard 550's seem to like to oscillate more than others, and they can go into a bad tank-slapper at high speeds, especially the 81 Gpz550. (Kawasaki redesigned the geometry for 1982.) One way to avoid it is to reduce the steering inertia by taking weight off. This increases the resonance frequency to a speed you hopefully can't attain with the bike. Adding weights at the ends of the bars would be counter to that strategy.

I didn't think about the tank slapper hazard. Haven't noticed a problem.
Steve

Yep... learned the hard way... exited the vehicle in deep triple digits.

Same thing happened to my brother on his 81 . Went down on highway doing a 100 plus . Its my bike now . Never had it happen when ive been on it . So whats the best fix for this .

After my crash I decided to research the problem, but this was before the internet. I bought race-bike construction books which covered the subject. Through many laps of testing they discovered the high-speed wobble was related to several things, but most significant was the rear tire. The best corrective measure is to make sure the back tire is not too wide for the rim, and not worn down to being squared off. I believe that was a major contributor to my crash. After replacing the rear tire, the tank-slapper did not come back even at higher speeds.

On top of that, make sure all of the bearings and other chassis parts are in good working order and the frame is in good alignment. This should go without saying.

But even with all of that, you might have to go further. They mentioned that the geometry of quick-steering race-bikes (like the 81 Gpz550) is a factor which is not easily altered, but you can do some things to make sure you don't make things worse. For one, don't raise the back end of the bike too much without evening out the front. Doing so reduces the steering angle, making it more vertical and thus "quicker". Likewise, don't lower the front end a lot either without evening out the back. There are a few other precautions you can take. As I mentioned, they recommend lightening up the steering... forks, wheel, bars, headlight, etc... anything that turns with the bars. The idea is that the resonance frequency, by reducing the inertia, will be at such a high frequency, you will hopefully never be able to attain the speed necessary to generate a tank-slapper.

You can also add a forkbrace and a steering damper, but those devices are not for the purpose eliminating tank-slapper. They are for reducing another phenomenon of light, quick-steering bikes, and that is headshake. Headshake is a brief, single twitch of the bars due to irregularities in the pavement and is often worse when under hard acceleration. This is not really for tank-slapper, but might help reduce the intensity of a tank-slapper. I won't ride a Kz550A (standard) or Kz550D (gpz) fast without a steering damper. It's so much more stable when going over bumps, tracks, and pavement joints at high speed.

Thanks loud Great explanation . Dont want to keep hijacking this thread but if you get a chance could you post a pic of your damper . Have a fork brace on the bike already . Thanks again
derrek

riturbo wrote: Thanks loud Great explanation . Dont want to keep hijacking this thread but if you get a chance could you post a pic of your damper . Have a fork brace on the bike already . Thanks again
derrek

I'll start a new thread when I get some decent photos.