tank slapper!

matphillipsuk · Borekit Bruiser Joined: 02 Nov 2004 Karma :

i have noticed that when i let go of the bars above about 25mph they start trying to brake my thumbs even if i still have one hand on the bars. any idea what this could be? i can never remember it doing it before .ive just had the fork seals replaced on my nsr could this have any relation to it?cheers for any help

G · The Voice of Reason Joined: 02 Feb 2002 Karma :

It may be suspension is now doing something it /should/ be!

My RS250 starts to shake a bit if you take your hands off the bars; but I think that's a consequence of it being very nimble steering.

Plenty of other things can effect it, like head bearings, attitude, etc, etc.

matphillipsuk · Borekit Bruiser Joined: 02 Nov 2004 Karma :

ok thanks cheers

BlackSheep · Trackday Trickster Joined: 22 Sep 2004 Karma :

Check your head bearings , your front tyre pressure , and get a mate to sit on the bike and hold the bars tight while you grab your front wheel at the 12 and 6 o clock position and wobble it to check for play in your wheel bearings , repeat at the 3 and 9 o clock position there should be NO play
it might be a good idea to check tighten your wheel spindle and fork yoke bolts too as you have recently had some frond end work done they may have left something a little loose.
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GSXR 1100 StreetFighter

matphillipsuk · Borekit Bruiser Joined: 02 Nov 2004 Karma :

ok cheers

Chr!S · Nitrous Nuisance Joined: 17 May 2005 Karma :

Wheel balence too.

Blueknyt · Derestricted Danger Joined: 02 Apr 2005 Karma :

underinflated tires front,rear/both, Missaligned wheels (mainly rear in relation to front) warped/bent or worn swingarm/bushings, wheel bearings (front or rear) unseated tire,bent rim, spring preload/airpressure in forks differnt from left to right, bent fork brace, LACK of a fork brace, improper fork oil level (mainly one side near empty while other full) bent or tweeked frame/forks/triple tree.

while ive gotten pleny of vibration from unballenced wheels, ive never had a wobble from lack of ballencing, i rotate wheels on my GS500 and katana 600 as they are the same (baring rotors/spacers for given bike) when i tire wears out on one, i swap with a spare and put another tire on that rim and its ready for which ever bike needs it next, never ballenced a single one.

the most common wobble causes for my bikes was:

improper wheel alignment (those tick marks on swingarm suck)
Improper tire pressure, (low most the time)
or worn out stearing stem bearings(wheelies and stoppies do hurt)