High Speed Wooble

Top Ace 65 · 06-17-2003, 1:52 AM

I recently took by bike (954) out for a long distance run. As I hit about 190kph the front tire woobled. I was at a bike meet last week and a friend of mine told me that she sold her bike because it tank slapped at 200kph.

I would like to gather comments from other fireblade owners, if they have had similar experiences. Is this high speed wooble inherent to all bikes? What causes this to happen?

ratter · 06-17-2003, 5:02 AM

If you had a tank slapper you would know about it, what you may have experienced was just a headshake, may have been brought on by a slight bump on the road or an uneven surface, while under throttle, lots of different variables can cause these.
if you are concerned, i recommend you buy a steering damper

Bigtoe · 06-17-2003, 9:03 AM

Quote:

ratter1 :

If you had a tank slapper you would know about it, what you may have experienced was just a headshake, may have been brought on by a slight bump on the road or an uneven surface, while under throttle, lots of different variables can cause these.
if you are concerned, i recommend you buy a steering damper

and Welcome to the .org

cbr99xx · 06-17-2003, 9:10 AM

Quote:

ratter1 : if you are concerned, i recommend you buy a steering damper

......and welcome to the .org! *

showmethebombs · 06-17-2003, 9:36 AM

sounds like it was not a slapper...sounds to me like the front wheel is out of balance. I would check that first. I have had tank slapers on fast take offs where your fighting the wheelie...and the front wheel skips causing a slapper...but wobbles I have seen from tire balance. Hope that helps.

cyan · 06-17-2003, 9:48 AM

Quote:

showmethebombs : sounds like it was not a slapper...sounds to me like the front wheel is out of balance. *I would check that first. *I have had tank slapers on fast take offs where your fighting the wheelie...and the front wheel skips causing a slapper...but wobbles I have seen from tire balance. *Hope that helps.

This just happened to me the other day coming out of second gear. *I found a nice road that I could see down for miles, no driveways, very few cars, etc. *The road had a couple bumps and I hit one as I was coming out of second gear. *The front end lightened up and my front wheel came down a little off so it started to shake. *I was on the throttle in 3 by this time to the shake only lasted once from left to right but it's still making me think of the damper again.

I did a 150mph (not sure what that is in kph) run that day and didn't have any problems with handling, etc.

Brad

Skully · 06-17-2003, 10:25 AM

Quote:

cyan : This just happened to me the other day coming out of second gear. *I found a nice road that I could see down for miles, no driveways, very few cars, etc. *The road had a couple bumps and I hit one as I was coming out of second gear. *The front end lightened up and my front wheel came down a little off so it started to shake. *
Brad

Definately time for a damper. I had the same experience twice before I got my Scotts and that was enough.

showmethebombs · 06-17-2003, 1:26 PM

ditto. * get a damper ASAP. *I loved the arrow I had on the 929. *This vid ALONE will convince you I hope. *

LOOK AT THE VID BELOW!!!! wowowowowowowowow

VID

that rider might have even had a damper, being a race....note, the rider died.

nomad · 06-17-2003, 2:02 PM

Buy a damper. Those head shakes happen all the time until.

A buddy of mine was killed after a tankslapper last summer... he was a riding instructor and wasn't riding aggressively at the time which goes to show it can happen to anyone at any time. Dampers are cheap insurance.

pczach · 06-17-2003, 3:32 PM

Quote:

showmethebombs : ditto. * get a damper ASAP. *I loved the arrow I had on the 929. *This vid ALONE will convince you I hope. *

LOOK AT THE VID BELOW!!!! * wowowowowowowowow

VID

that rider might have even had a damper, being a race....note, the rider died.

HOLY SH1T!!!

That was nasty!

Smitty · 06-17-2003, 4:57 PM

All British m/cs from 350cc & up had a simple knob at the top of the steering head & turns to the right snugged up the front end more. You will find it on vintage Brit road races of Norton Manx, AJS, Matchless, Velocette & others.
When I started breaking in my '00 929 I knew this bike would benifit from a steering head damper & so the Scotts in my case, yet my 600 does not need one.

Motopilot · 06-17-2003, 5:17 PM

Sure . . . get a damper. Also check tire pressure and balance.

Motopilot · 06-17-2003, 5:19 PM

Isn't that video from the 1997 or 98 Isle of Man TT. I think I have the video at home. In any case, that is a short changing experience.

Rigger · 06-17-2003, 5:38 PM

all i can say is giddy up *it's like mounting your old lady and then making some pig noise . if you keep it up and or in you win a prize 'LIFE' pain free

RaggedEdge · 06-17-2003, 6:47 PM

One instance of a wobble won't be enough to go on. It is possible one or both wheels need balancing. I ran my 954 up to an indicated 282 kph (175 mph) a couple of days ago, and the bike was absolutely stable. Your experience is not normal, so you may need to do some high-speed testing (cautiously) to see if you sense any instability at all. There shouldn't be any. If so, have a competent dealer look at it.

Skully · 06-17-2003, 9:34 PM

Quote:

RaggedEdge : One instance of a wobble won't be enough to go on. *It is possible one or both wheels need balancing. *I ran my 954 up to an indicated 282 kph (175 mph) a couple of days ago, and the bike was absolutely stable. *Your experience is not normal, so you may need to do some high-speed testing (cautiously) to see if you sense any instability at all. *There shouldn't be any. *If so, have a competent dealer look at it.

His experience is a little different than yours though. He said he hit a couple of bumps in the road which is what started the headshake.

allredhome · 06-18-2003, 12:23 AM

At the high speeds that today's bikes are capable of...(and used a lot of the time), wheel balance is very important. I have my wheels balanced on a machine (with a competant operater) at least 3 times during the life of the tire.

CBRjack · 06-18-2003, 1:26 AM

Get the steering damper. It only took one nasty slapper to change my mind. I bought one the next day.

ratter · 06-18-2003, 4:29 AM

Quote:

Rigger : all i can say is giddy up *it's like mounting your old lady and then making some pig noise . if you keep it up and or in you win a prize 'LIFE' pain free

Top Ace 65 · 06-18-2003, 5:34 AM

To Ratter1: Thanks for the advice. I most definitely will buy a damper. The roads here are not so smooth, so it was probably the bumps that caused the head shake. Thank for the advice.

For Everyone: Thank you for the warm welcome. Ride safe and enjoy life!!!

ratter · 06-18-2003, 5:40 AM

Quote:

Top Ace 65 : To Ratter1: *Thanks for the advice. *I most definitely will buy a damper. *The roads here are not so smooth, so it was probably the bumps that caused the head shake. *Thank for the advice.

For Everyone: *Thank you for the warm welcome. Ride safe and enjoy life!!!

your welcome

Top Ace 65 · 06-18-2003, 5:40 AM

To Showmethebombs, That sure is scary. I guess when the bike acts like that all you can do is let go! Thanks for sharing that movie clip with us. Hope it never happens to any of us!

Top Ace 65 · 06-18-2003, 5:50 AM

To Everyone, Thanks for the inputs and advice. I'm sure the problem occured from a variety of factors..... ...Do I sound like the MSF.....