1977 Kz1000 Speed Wobble Crash

[A2rider]

And how does it make me feel? Like a bada** sportbiker, a poser, and an old time biker, ready to meet the world and spit out out my 4-into-one Kerker!

[dropdfocus]

Steering dampers are worth their weight in gold on these old bikes. I picked up an NHK damper for mine that has 7 different settings. I'll have to make a bracket to be welded on to the frame & purchase a 36mm fork clamp. This will greatly help against hard steering feedback in twisties and any type of speed wobble you may encounter. Of course, making sure you have well greased bearings and the fork oil changed will help alot too.

[Silvercon]

Originally Posted by dropdfocus

Steering dampers are worth their weight in gold on these old bikes. I picked up an NHK damper for mine that has 7 different settings. I'll have to make a bracket to be welded on to the frame & purchase a 36mm fork clamp. This will greatly help against hard steering feedback in twisties and any type of speed wobble you may encounter. Of course, making sure you have well greased bearings and the fork oil changed will help alot too.

+1. Plus one thing I don't like about classic bikes are spokes. I prefer cast
wheels because when you have spokes that is one more reason for
your bike to wobble if they are not true. My KZ1000 had a little wobble
because of the frame or bearings. Yours may have a bigger wobble
because of the spokes. Or not.

[Jimsdad]

Back in 1973 I had a H2 750 triple and it had a high speed wobble on deceleration just as yours did, it almost put me on the ground several times, I did find out that the rear wheel had loose spokes every time, after tighten the spokes and retruing the wheel the wobble would go away till the spokes got loose again. Hope this all helps Jimsdad

[ThumpinKwaka]

Hi there motorman224, glad to hear you are ok.

Man those wobbles are the pits! It's one of the reasons I steered away from street bikes in the early days. Nearly did myself in during a wobbly incident just on entry into a left hander on a mates Kwaka 900 back in the day. This was a a bike with 2 steering dampers!

I think that my strength and clear thinking saved me, basically I don't panic under pressure, and I stayed focused on the matter at hand. I was lucky in so much that even though I ended up a 200mtrs off the road in the scrub, once the dust settled, I was upright with no damage to bike or rider.

Back in those days, plenty of wobbling to be done on a dirt bike, on the dirt and out here, there is plenty of dirt. Ha, knobbies on the bitumen lets you know you are alive too!

Controlling the wobbles. Don't hit the brakes when in a wobble, slowly apply power untill you can control it again. Slowly apply brakes or use the gears to slow down to a speed where you are back it control.

These wobbles can happen to all types of vehicles when towing a trailer. The same control principles apply. I know that accelerating doesn't sound like the right thing to do BUT it is.

I'd also do like the other posts mention checking, spokes, bearings, tyre pressures etc.

[elr658]

A wobbling 1977 KZ1000? Why am I not surprised? Doesn't ANYBODY read old road tests? Mine wobbled on the SIDESTAND.

[Yamaslama]

Mine is a 1980 LTD1000. Did the same thing yours did when I first bought it. Except I had an old Honda 750 before that would do the same thing and I already knew how to make it stop. As others have mentioned, get back on the throttle a little, but also not mentioned is, it helped me to rear back as hard as I could on the bars, then slow down gradually. Next time you'll know what to do. In the mean time, you'd be surprised what a brand knew set of tires will do for the old girl, (provided all the other stuff is up to par, swingarm and neck bearings, fork oil, etc). I put some new Bridgstones on mine and now she no wobble. I have no idea how fast I'm going, speedo only goes up to 80, but in fifth gear at 8000rpm, she no wobble at all.
Yep, new tires, new underwear, you'll be good to go.

[solitary]

Originally Posted by A2rider

Agree, but if all these things are corrected, why shouldn't the bike run like it was made to do? I have been babying mine, worried that it's old, and I should be nice to it. But after thinking about it, knowing I have fixed everything from front to back, I'm twisting the throttle.

Yes, I may pay for it. My bike is getting 48mpg running 70 to 80 mph, and 30 mpg at 60 mph.

Mine's getting 49~50 at roughly 70. Right after I had the carbs done it was getting 57. But I think that's cause I wasn't flogging it hard enough.

Originally Posted by hayward6

No motorcycle ever made was designed to go 120 mph on a road rated to 65 mph... add to that the other drivers on the road, the occasional foreign object or spill that your not counting on and down you go! Going faster than traffic is going on any street is stupid, irresponsible and makes us all look bad.

I just read what I wrote and it came across a bit harsh... good I'm sick and tired of hearing stories of accidents that involve speed and carelessness. Yes, car drivers take us out every day with their actions, but what percentage of accidents are from bikers being stupid... it's allot!

I see your point, but roads rated 65 are usually built for 105, maybe even 125 (only ever did this once, what a blast!)
If you're zipping in and out of lanes around traffic, you're asking for a hurting. If it's a clear road and/or traffic is running as fast as you are, I don't see a problem. Speed limits on highways are artificially low.
Keep in mind, you said "speed and carelessness", it's not the first part, it's the second part that's the issue. Speed just compounds carelessness.

Originally Posted by ThumpinKwaka

These wobbles can happen to all types of vehicles when towing a trailer. The same control principles apply. I know that accelerating doesn't sound like the right thing to do BUT it is.

I'd also do like the other posts mention checking, spokes, bearings, tyre pressures etc.

I saw a bike towing a trailer the other day, had one hell of a wobble going on w/ the trailer. I've had trailer wobble so bad it was shaking the tow vehicle, I can only imagine what that's like on a bike. Nearly needed to change my shorts, but it was just low air pressure in the trailer's tires.

Originally Posted by Yamaslama

I have no idea how fast I'm going, speedo only goes up to 80, but in fifth gear at 8000rpm, she no wobble at all.
Yep, new tires, new underwear, you'll be good to go.

My speedo only goes to 85, but I have to figure in the 8% under for my speedo, so 85 is actually 92. Although I only checked the speed accuracy at 55 (on the speedo, actually 60), so who knows what it is at 85. Or is it 92?

[StarGate]

I've always used my tach to estimate my speed above 85 where the speedo pegs. Mine works out to 16mph for every 1k rpm in 5th gear. I've had some newer bikes clock me with their fancy digital speedos and it turns out my system is pretty accurate if theirs is right.

[Yamaslama]

I had a local cop check mine with his radar. Dead on at 50mph. And when I get to around 80 just before its pegged, the needle bounces all over. Plus at that speed and above, I'm too busy looking as far down the road as I can. Half a second of looking down to the gauge just to appease my curiosity costs me quite a bit of reaction distance. I thought about putting on a 160mph speedo, but then I thought, what's the point?

[solitary]

Originally Posted by Yamaslama

I had a local cop check mine with his radar. Dead on at 50mph. And when I get to around 80 just before its pegged, the needle bounces all over. Plus at that speed and above, I'm too busy looking as far down the road as I can. Half a second of looking down to the gauge just to appease my curiosity costs me quite a bit of reaction distance. I thought about putting on a 160mph speedo, but then I thought, what's the point?

I trust most cops as far as I can throw them. I'd never ask them to check my speedometer.
I agree, at 160mph, a speedometer is too much of a distraction.

Speaking of speedometers, has anyone tried retrofitting an older bike (originally a mechanical speedo) with one of those new fangled LCD ones? Mostly a curiosity if it has been done, not so much wanting to do it myself.

[Jeff.saunders]

Originally Posted by dropdfocus

Steering dampers are worth their weight in gold on these old bikes. I picked up an NHK damper for mine that has 7 different settings. I'll have to make a bracket to be welded on to the frame & purchase a 36mm fork clamp. This will greatly help against hard steering feedback in twisties and any type of speed wobble you may encounter. Of course, making sure you have well greased bearings and the fork oil changed will help alot too.

I disagree with using steerng dampers to solve a wobble - all you do is move the problem to a higher speed. The key is to solve the issue causing the wobble first...

With an old bike there are a VERY long list of things contributing to problems like this.

The following list is not in any particular order:

• Old tires
• worn tires,
• out of balance tires,
• mismatched tires (different types / brands)
• tires mounted backwards,
• tires run at too high or too low tire pressure.
• Beads not seated properly
• Wheel out of true and out of round
• loose and / or broken spokes
• worn wheel bearings
• worn swingarm bearings
• worn shocks
• leaky shocks
• leaky fork seals - often overlooked
• wrong amounts of fork oil- often overlooked
• wrong weight or type of fork oil
• brakes binding
• warped brake rotors
• wheels out of alignment (DO NOT RELY ON SWINGARM MARKS - manually check alignment)
• worn steering bearings
• different handlebars (changes weight distribution between wheels)
• bent / twisted frames and/or swingarms (often the result of wheelies - on the KZ1000 the steel gusseting under the steering head can crack)
• bent / twisted forks
• changes to ride height (forks / shocks / different rim sizes)

[Mango7]

Isn't this called a tank slapper? Maybe you need that thing that prevents this.

[Jeff.saunders]

Originally Posted by Mango7

Isn't this called a tank slapper? Maybe you need that thing that prevents this.

what prevents it is fixing all the potential problems that cause it... there is no magical device that cures it...

[elr658]

Jeff Saunders is the voice of reason.


I have NEVER EVER NEEDED a steering damper. AND I have been 165 MPH on a Z. (caveat, I ALSO fixed everything that could cause a tank slapper. Incidentally, I also know how to ride which seems to be a disappearing talent)

[A2rider]

Originally Posted by elr658

Jeff Saunders is the voice of reason.


I have NEVER EVER NEEDED a steering damper. AND I have been 165 MPH on a Z. (caveat, I ALSO fixed everything that could cause a tank slapper. Incidentally, I also know how to ride which seems to be a disappearing talent)

Isn't it a sin to go that fast on an old bike? LOL Shame on you, you should be puttering around at 50 mph on these on things, you know they weren't built to go that fast.

[btob]

Originally Posted by Jeff.saunders

I disagree with using steerng dampers to solve a wobble - all you do is move the problem to a higher speed. The key is to solve the issue causing the wobble first...

With an old bike there are a VERY long list of things contributing to problems like this.

The following list is not in any particular order:

• Old tires
• worn tires,
• out of balance tires,
• mismatched tires (different types / brands)
• tires mounted backwards,
• tires run at too high or too low tire pressure.
• Beads not seated properly
• Wheel out of true and out of round
• loose and / or broken spokes
• worn wheel bearings
• worn swingarm bearings
• worn shocks
• leaky shocks
• leaky fork seals - often overlooked
• wrong amounts of fork oil- often overlooked
• wrong weight or type of fork oil
• brakes binding
• warped brake rotors
• wheels out of alignment (DO NOT RELY ON SWINGARM MARKS - manually check alignment)
• worn steering bearings
• different handlebars (changes weight distribution between wheels)
• bent / twisted frames and/or swingarms (often the result of wheelies - on the KZ1000 the steel gusseting under the steering head can crack)
• bent / twisted forks
• changes to ride height (forks / shocks / different rim sizes)

+1. Agreed.

[elr658]

I think I'll put bags on a ZX14 and go after the world's fastest bagger. Klock went 147 on his HD with a zillion bucks worth of mods. All I'd have to do is make sure I have gas.

Maybe resurrect the museum piece.

[Keach]

I have a '79 KZ1000 LTD, had a little wobble at around 100mph when I first got it. I dropped the front forks about an inch, put on handlebars that were a lot straighter ( 4 inch I think as opposed to the old hangars ). Since then the bike is like a tank at high speeds, not even the slightest hint of wobble. Much nicer to drive at any speed really.

[btob]

Originally Posted by Keach

I have a '79 KZ1000 LTD, had a little wobble at around 100mph when I first got it. I dropped the front forks about an inch, put on handlebars that were a lot straighter ( 4 inch I think as opposed to the old hangars ). Since then the bike is like a tank at high speeds, not even the slightest hint of wobble. Much nicer to drive at any speed really.

Got a feeling it's the shortened tubes.