Posted May 06, 2002 - 11:57 AM
Anyone have advice on where to start to get rid of the wobbles???
Posted May 06, 2002 - 12:21 PM
1: the Shock may be in need of repair
2: The back wheel is up to far forward on the bike
3: Swing arm is loose, beering s bad ect
The lenght of the bike is a big factor along with steering rake.
1: Front End Stock
2: How many links in the chain 120 is stock
3: How far up is the rear wheel in the swing arm.
If the front end has a steeper rake meaing degrees out from 90 this can caus eit if you have not compensated for rear wheel lenght (aka Axel to Axel)
The speed wobble can be caused also by the rear shock if it is in bad shape... Leaking oil or just plain wore out
grab your rear wheel from the farthest position back and try and see if you can move it or if there is side to side play in the swing arm or wheel beerings them selves
Somting is definnetly not right back there
[ May 06, 2002: Message edited by: EgoAhole ]
Posted May 06, 2002 - 05:11 PM
The rear may be "PACKING" .......speed up the rebound.
Or the rear may be set TOO stiff of a compression setting.
Soften up the front til' you are comfy with it NOT bottoming then work with the rear.
Either way .......try this too.
You probably spent as much on parts/bars/ER
as you would have if you would have bought one of these>>>>
Trust ME ....been there done that!
Posted May 06, 2002 - 08:10 PM
Posted May 07, 2002 - 07:03 AM
The Susuki RM 400, That lil widow maker would swap ends at the flick of the throttle, and if you could keep it in a straight line
No one could, that was the most dangerous bike I have ever seen and had the displeasure of riding.
I got into such a speed wobble on that my head is still bruised....
Maybe that splains things
Posted May 07, 2002 - 07:28 AM
Comes from the forks being to soft on the compression, try turning the compression clickers in 2 clicks.
Another possible headshake cause is Steering head bearing are loose.
Posted May 07, 2002 - 07:30 AM
Posted May 07, 2002 - 10:12 AM
Posted May 07, 2002 - 01:27 PM
Posted May 07, 2002 - 04:59 PM
[ May 07, 2002: Message edited by: freestyle111 ]
[ May 08, 2002: Message edited by: freestyle111 ]
Posted May 08, 2002 - 12:08 PM
Assuming that your bike's in mechanically good shape, the main effect on hi-speed stability comes from the effective steering head angle/rake. More rake equals more stability; less rake equals better front end traction, especially in tight corners.
You make can make both static and dynamic adjustments to your effective head angle by:
Rear Sag- more sag equals more rake and stability Fork Hgt- raising the forks in t-clamps reduces rake and stability, but aids turning.
Fork Clickers: More Compression or Less Rebound keeps the fork higher in the stroke providing more rake and stability.
Shock Clickers: Less Compression or More Rebound keeps the shock deeper in the stroke, effectively increasing sag and providing more rake and stability.
I recommend making sure that sag is set to 100mm and that your forks are flush with the top of the clamps. From there try playing with the clickers. Assuming that you don't want to make your ride stiffer, I would start by backing off 1/4 turn on the Shock Hi-spd Compression. Then try taking 1 or 2 clicks out of the Fork Rebound.
Posted May 08, 2002 - 12:22 PM
Yes HeadShake and a speed wobble are two entirly diff phenominoms
as vznx1w Points out very nicely the effects of Speed Wobble
[QUOTE] the main effect on hi-speed stability comes from the effective steering head angle/rake. More rake equals more stability; less rake equals better front end traction, especially in tight corners. You make can make both static and dynamic adjustments to your effective head angle by:/QUOTE]
He also notes on some positive feed back on trying to reduce the effect of the wobble
Hence head shake and speed wobble are two distinct beasts....
This adjustments also reduces the lenght between axle to axle
te short the distance the more likly the wobble and severity. the long the distance the less likely wobble but you sacrice turning radious due to longer axle to axle.
Next time you have a chance watch a Dirt Track Mile these guys are on the very edge of the envelope when it comes to head shake / Spd Wobble
Head shake is more defined as the bike is excelerating hard, less wt up frnt less tracktion
the wobble occurs as the bike begins to break its stability point at speed, its another gyr effect, DAMN PHYSICS....Mainly half way to 2/3rds down the straight you will see the bike begine to twist front back thats the wobble.....
wathc the bikes exit a turn wil show the handle bars shake some what thats the head shake.
Lowering the forks down will reduce head shake. it allows the clamps to grab down further effectivly shorting the rake/trail and stablising the forks.....
Now I can go on and on but those that have an IQ of 140 will object Call it what you will, but my experiance in years past tuning for mile / 1/2 mile and 1/4 mile along with me RR's. I experianced alot of both...........
[ May 08, 2002: Message edited by: EgoAhole ]
Posted May 08, 2002 - 02:23 PM
James Stewart back on a YZ450F by YamaLink
Yamaha YZ450F 2017 by Chris.GVS
Thinking about Yamaha 250... by Arctic Pride