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Riding no hands
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Tried it on my GPX250 in gear at about 40kms (with some minor engine drag).
I have bad vibrations in steering/front wheel until I grabbed the bars again
though cannot feel vibrations while riding if holding on.
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Probaly wheel out of balance, I wuld go for a higher gear at better pace
to avoid engine knock being the cause
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Is this a wheel alignment problem or related to shocks/forks being bent or
out of whack or is it user error and I am expecting something that I
shouldn't or just doing it wrong? (thinking I might need to be in neutral
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It's a problem, the result of riding without your hands on the
bars. My ZZR250 does exactly the same thing. To fix the problem,
put your hands back on the bars.
Having said that, BTH is the resident expert on GPX's, so he'll
step in any moment now and give you the definitive word on the
situation.
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OK, lets work our way up through some possibilites, in ascending order
of expense:
1. Does your front tyre have at least 28psi in it?
2. Is your front tyre badly worn or unbalanced?
3. Support the bike on the centre stand, with front wheel off the
ground. See if there is any movement or "clicking" from the headstem
when you pull the front wheel forward and backward. If there is, you
can try tightening the headstem bearings a bit, but most likely they
need replacing;
4. While the bike is still on the centrestand, use a bit of stiff wire
taped to a fork leg and reaching over until it almost touches the rim
(not the tyre) as a "pointer". Spin the wheel, and see if the pointer
is closer to the rim at any point on the rotation. If it is, the wheel
is bent and needs replacing;
5. Undo the lower rear shock absorber mount, then give the swingarm the
same forward-backward and left-right test that you did to the forks.
If there's any movement eighter forward-back or left-right then the
bearings need replacement.
For what it's worth, my money is on the bent rim hypothesis.
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After you've done all of this undo all the bolts and fasteners on the
front end, remove the fork tubes and check to make sure they aren't bent.
Whilst the front end is out check the head stem bearings visually
because sometimes they will be worn and you can't feel the 'click'.
Then use a couple of metal straight edges to make sure that the front
wheel and the rear wheel are running in the same line and at the same angle.
Check for visually obvious damage around the head stem area.
If you get this far and you still haven't found the problem then join
the club and park your bike next to my Yamaha Diversion 900S (which
looks like it's heading down to Bob Martin for a frame check).
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wow, thanks for all your replies. Looks like I will have something to do
this afternoon.
FWIW the front tire is pretty near new though the back could be getting low
(first bike sorry).
I haven't checked the tires pressure (dir) and will check both today (sure I
saw the specs under the seat) and guess might also be printed on the side of
the tire.
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The usual pressure is 28psi front & 32psi rear. I preferred to run
mine at 30/34, but you might not like the slight change in handling.
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The headstem has been clicking while braking so I think the bearings may
need attention. I mentioned the clicking when I took it for a service and
this seemed to be tightened up though is returning.
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If they need replacement, I heartily recommend replacing the
standard-fitment "loose ball & cups" bearings with caged roller
bearings. It made an enormous improvement to both the bikes that I
converted.
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Fark! Maybe that's why the sheila sold me my ZZR250 with only
(literally) 101Km on the clock!
GB, she said she'd had a bit of a scare on it...
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My GPX never did this. I also tried it on the CBR and it was ok too.
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Had the same problem on the FJR. Changed to new tyre (old one was worn
anyway) and problem went away.
However, if you had someone reverse into the bike to the extent that the
back of the car rose, suspect the possibility of some damage.
Was it shaking BEFORE the accident?
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I couldn't say as I only notice the vibrations when I let go and this I have
only tried a few times on one occasion
:-P
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though yet to try)
Asking because I had a clown reverse into me to the point that their rear
bumper bar traveled onto my front wheel and they only noticed when their car
rose (even though I was sounding my horn(useless)(and flashing my headlight)
though no damage is visable to the front wheel.
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Most probably it's not a major problem. Not an exhaustive list but it
could be caused by one or more of..
- worn front tyre,
problem should be gone when you replace the tyre
- underinflated front tyre,
problem should be gone if you inflate the tyre to the correct
pressure, but underinflation may have caused it to wear poorly so
replacing the tyre should correct the problem
- imbalance in the front wheel - unbalanced tyre
get the wheel balanced or just wait till you replace the tyre
- imbalance in the front wheel - buckled wheel
run your fingers around the rim and feel for any irregularities
- loose/warn head stem bearings
if the steering is notchy or if there's any shudder when you brake
get the bearings tightened
- carrying a load on the back of the bike in a rack bag or topbox.
unload the bike and try again
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Good point. Could be the rear shock/s too.
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Nev..
'04 CBR1100XX
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TIA
:-P
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thanks all for your replies
my front tire was down 3psi and the rear down 5psi
at the time I was trying the no hands thing and experienced the wobbles I
did have a load on the back, only 5 kilo's but.....
Still yet to replace bearing in the headset and to check the shocks.
was meaning to check the front wheel with the wire but also need someone to
sit on the bike so the front wheel is off the ground so that will have to
wait until this afternoon (weather permitting).
Anyway after taking the load off the back and fixing the pressure in the
tires I seem to be able to ride no hands "sometimes" without getting the
wobbles though it is a sketchy experience.
:-P
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This could simply be due to front tyre wear, is the tyre more than 50% worn
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My boxer behaves this way when the front tyre is stuffed, then I can budget
for a replacement in about 5000Kays, by which time the thread is but a
shadow and she vibrates through the bars even with both hands on, hands off
and its on for a tank slapper.
Capt. A. L.
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