handlebar alignment

Took the bike (XV535 virago) in for steering head bearings replacement
for MOT. When collected and driven away the bars don't appear to be in
a straight line when driving straight ahead - the right side slightly
back and the left slightly forward. I can't really see how this can be
from looking at the way the risers and clamps at the top of the forks
are assembled, although it seems that to replace the bearings the
handlebars are probably removed along with the forks. Taking it back
tomorrow and hoping they can sort it. Any thoughts about what might
need doing appreciated.

 

Correct but I wouldn't do it. Not if a bloody garage fucked up
the bike like that.
Let them fix it. Then (if practically possible) never go to them
again. Correct fork alignment is sort of critical on a motorcycle.

 

I get the impression that an inordinate number of (street) bikes need
their head bearings/races replaced when I'd think that it would be wheel
and other drive-train bearings that would wear out sooner (this may be
not so true of off-road bikes). From a couple of incidents I've seen,
my guess is that some people including pro' mechanics make the races way
too tight, eg., they torque a race nut as well as the top nut. Just my
theory.

I remember buying a used ch250 scooter and noticing very tight steering.
Owner said he liked it that way for highway stability. After a year,
it was nice and loose. When I took it apart, the bottom of the upper
race was cracked almost all the way through so I replaced everything.
Manual said to snug the nut above the upper race then back off 1/8 turn
which made sense to me as Dad had told me many years to do my bicycle
cones by hand. Whereas a mechanic I knew took a wrench to it and
applied his muscle. After he left, I backed it off and tightened by hand.

 

Thanks, that seems an important point about the "back-and-forth" forces
being multiplied.

 

Yes SIR: You putnuckers use a thick piece ½' of glass ,
about 7'x14' ,check the fork alignment,
and the rear wheel.............

Regards J.Wayne
..

 

Um, your theory would be wrong.

 

This is all absolutely right. Steering heads don't rotate constantly -
they just turn a few degrees one way and the other and they are always
being walloped by road shocks.

 

Took the bike back, they put it on their machine (not quite sure what
kind of machine it was, but something to do with the alignment) and
said it is all true. They said they slightly adjusted the windscreen
position (??). I asked one of their mechanics to take it around the
block to see what he thought, he said it seemed fine to him. I felt
reassured as he seemed more trustworthy, but am still unsure.

The background to this is that the day I had the work done, I said I
wanted the steering head bearings replaced as it was an MOT failure on
just this, and took along the failure notice for their information. It
was only booked in for this work to be done as arranged by phone. When
I got there they said it wouldn't be done by 12 as originally
arranged, but at 2.30pm. This was important as I had my 11 year old
daughter with me and entertaining her on a cold grey autumnal day was
difficult, so was already a little worn out. When I collected the bike
they had MOT'd it and wanted me to pay, even though I hadn't asked for
that to be done, and that the mechanic had worked on it for part of
his lunch break to get it finished (giving me the impression it had
been finished hurriedly). They said that the MOT couldn't be cancelled
without the tester in the shop and he wouldn't be back for an hour,
leaving me another hour to pacify my daughter who had better things to
do with her time at half-term. The original MOT tester said they would
do a free retest so I wouldn't have had to pay for a retest anyway. I
agreed to pay what I had on me in cash (£120 - the estimate was £110).
I didn't feel comfortable with the attitude of the member of staff, so
that had already unsettled my faith in that shop - and this is a main
yamaha dealer whom I went to assuming they would be able to do the job
on time and on price seeing as they should be more familiar with this
bike. I knew what I had asked them to do, they had my mobile number, I
felt annoyed with them but having my daughter with me made it
difficult to be as assertive with them as I would have liked.

I took it out yesterday and my impression is still that it doesn't
feel quite straight somehow, but that I could get used to it. On a
normal downward road camber to the left it feels as if it is pulling
slightly right, and on a down camber to the right it feels straight.
It could be that the bars were somehow already not quite straight,
although there are no signs at all of the bike having been dropped,
that the bars are not quite central by a small amount (which is how it
appears and would be easy enough to fix myself), or that as suggested
here, there is something up with the alignment following the repair.

My feeling is to go to the other shop (the one that did the original
MOT) and ask them for their opinion. At the moment I wouldn't feel
that confident doing it myself by eye.

 

Perhaps it was a laser machine that checks the chassis alignment.
Lasers work better than the old string method where the rider runs a
30-ft length of string through
the back of the rear wheel, then walks the ends of the string around
the back of the
motorcycle, coming out with the opposite ends of the string in the
front.

Then the rider pullts the string tight so it touches the edges of the
rear tire in four places and he eyeballs the distance between the
strings and the front tire on both sides.

Since the front tire is usually narrower than the rear tire, any
lateral misalignment shows up on one side of the string being further
away from the tire than the other side.

When I do the string method, I tie the front ends of the string to a
cinder block to hold them tight while I use a ruler to measure the
distance from the string to the edges of the front tire.

The string method only shows *lateral* misalignment, it doesn't show
*vertical* misalignment.

The rear wheel is supposed to be vertical when the motorcycle is
travelling down a level, uncambered road. And the front wheel is
supposed to be vertical at the same time and the handlebars (if they
haven't been been in a crash) are supposed to be at 90 degrees to the
front tire when the front tire is pointed straight ahead.

So, old time riders would set the motorcycle up on the center stand,
or prop it upright if there was no stand, and they would lay down in
front of the motorcycle on their belly and look at the front tire and
see if the saw more of the rear tire on one side of the front tire, or
if the front tire wasn't vertical.

If front and rear tires aren't vertical at the same time, the
motorcycle will run down the road like a trotting dog. If you've ever
watched some dogs run, you may have noticed that they run with their
hind legs a little off to one side from their front legs.

When a motorcycle has lateral misalignment or vertical misalignment,
it will shake when you go over bumps.

They said they slightly adjusted the windscreen

Yes, it sounds possible that a handlebar mounted windscreen could be a
little misaligned to the handlebars.

Do you usually ride as far to the left as possible? The front wheel
will try to climb up a camber and it will wear out the right side of
the front tire. In the USA, it's opposite, we keep right and the left
side of the front tire wears out first.

It's possible for tubular handlebars to get bent up on one side or
backwards. You can visually inspect for an up bend by standing in
front of the motorcycle when it's on the centerstand. You can see a
backwards bend by standing above the motorcycle when it's on the
centerstand.

When I do a home inspection, I use string and I use a tape measure. I
measure from the center of the front axle of both sides back to the
motorcycle frame. When the measurements are the same, the front wheel
should be straight ahead and vertical.

Then I measure from the ends of the handlebars to a point in the
center of the seat
asfarback as possible. The measurements should be the same. Sometimes
the throttle twist grip will be a little further to the right than the
other grip is to the left. so I have to watch for that.

If the bars aren't centered in the clamps, it's easy enough to loosen
the clamps and center them, but be careful that the handlebar doesn't
rotate forward or backwards, changing the angle of the control levers
and the position of the mirrors.

With a name like "Cori", I suppose you're female and not as
mechanically-inclined as a man. Motorcycles are more of a hobby for a
man who likes to tinker with his toys. The Japanese have tried to get
the whole world onto motorcycles, but the mechanically disinclined
person is going to be dissatisfied or absolutely angry with the $tealer
$hips and their mechanic$ after a few visits.

 

No, am a 'bloke' as we say in UK - shortened version of real name I
use for texting, and preserves a little anonymity in the vast open
landscape of the web. Many 'Cori's are female though.

Appreciate the advice - don't have a centrestand so have yet to work
out a good way to prop the bike up for checking alignment etc. The
rear tyre of the virago is quite a bit wider than the front.

Took the bike out again today, and still feel something not quite
right, as if there is a 'drag' on the right bar, or a slight pull
which I have to counter with a slight push, or as if something just
isn't quite central, and looking down from the rider position when
going straight ahead (carefully as possible I might add), it looks to
me as if the clearances or gaps as they appear by eye between bars and
forks on both sides do not look the same. The gap and angle between
the horizontal of the bar to the left of the riser and the vertical
lower part of the fork looking different between the right and left,
with the larger gap on the left.

If it is just something like normal road camber feeling different
because the steering would have been stiffer and therefore less
sensitive before the repair, then I will look a bit of a pillock. I
would add also that I hate letting anyone else work on any vehicle
that belongs to me, and avoid it unless at all possible, so do have
pretty high standards and expectations.

 

OK, it's nice to know you're not totally nancy.

out a good way to prop the bike up for checking alignment etc.

Got a shed or an off street place to work? Look for cinder blocks and
sturdy pieces of wood. We use old plastic milk crates for motocross
workstands.

A coffin hoist (come along) attached to a garage rafter works fine to
lift the front tire off the
floor and it's handier than a block and tackle. A telescoping carjack
works fine if you have to jack up the whole motorcycle from underneath
the engine. Or, you can use a cheap Chinese floor jack.

If you have to use a jack, be careful not to drop the machine.

Here in the USA, we can get a Chinese-built motocycle lift for
less than $100.

Yes, that's typical of a cruiser. But motorcycles have used different
sized tires on the front and rear since the 1960's. The rear tire is
larger to support more weight, give a better ride, and transmit more
power. The front tire is smaller for precise steering and it's just
big enough to do most of the stopping.

I tried to suggest that motorcycle use the same sized front and rear
tires to get more traction, but that notion has been thoroughly
discredited in favor of using a tiny front tire so a sportbike will
change directions quickly.

right, as if there is a 'drag' on the right bar, or a slight pull
which I have to counter with a slight push, or as if something just
isn't quite central, and looking down from the rider position when
going straight ahead (carefully as possible I might add), it looks to
me as if the clearances or gaps as they appear by eye between bars
and
forks on both sides do not look the same. The gap and angle between
the horizontal of the bar to the left of the riser and the vertical
lower part of the fork looking different between the right and left,
with the larger gap on the left.

Since the steel stanchion tubes are just secured into the upper and
lower triple clamps by a single bolt in each clamp on that side, it's
possible for the stanchion tubes to be misaligned with each other. If
they are not parallel with each other at the triple clamps, they can
be misaligned 6 to 8 millimeters at the axle, so the front wheel is
never vertical at the same time the rear wheel is vertical.

When we would crash our dirtbikes, the front forks would be "tweaked"
in this manner, and we would jump up and grab the front wheel between
our knees and twist the handlebars until the front end was straight
enough to continue in the race.

We would wait until we got home to try to straighten everything
better, but, next time we crashed, the forks would get "tweaked"
again. The whole fork assembly on a motorcycle is just ridiculously
limber because of the way it's designed.

If you want to go through the disassembly and reassembly and rigging
of the
throttle and clutch, you can remove the controls from the handlebars
and remove the
handlebars from the motorcycle and lay them front side down on a flat
surface like a tabletop
and then you can measure with a ruler or tape to see if the ens of the
bars are the same dimension from the flat surface.

If this sounds too difficult, let me point out that I replaced my
first set of handlebars
with a bit of advice from a Honda mechanic about half an hour after I
bought the bike and immediately crashed it, not knowing how to ride.

I hate to sound like Robert Shapiro, but there are many possible
problems with motorcycle forks.
Telescopic forks are just a contraption grafted onto a motorcycle
frame, and motorcycles evolved from safety bicycles so the whole world
of motorcycles grew like a fungus and motorcycles make very little
sense to an engineer.

Another possible reason why motorcycle might pull to the right is that
the mechanic
didn't push the forks up and down several times before tightening the
axle pinch bolt
in the bottom of the left fork leg.

http://demo.motorsportdealers.com/modules/oemparts/partsimage.gifx?t=20071027101142114TFS&z=2

The axle threads into a steel fitting in the bottom of the right fork
leg, and the mechanic is supposed to torque the axle, stroke the forks
to centralize the wheel and then tighten the
pinch bolt.

Another possility is that he didn't rock the front caliper to retract
the brake pads and
they pushed the front wheel and the bottom of the forks off to one
side. The caliper and disk are on the righ hand side of the front
wheel.

http://demo.motorsportdealers.com/modules/oemparts/partsimage.gifx?t=20071027100928866NEM&z=2

If you have a place to work and you can support the weight of the
front end off the pavement, I recommend loosening the upper and lower
triple clamp bolts and loosening the axle pinch bolt and rotating the
steel fork tubes to see if anything moves.

http://demo.motorsportdealers.com/modules/oemparts/partsimage.gifx?t=20071027101059021Y6B&z=2

If you rotate the steel stanchion tubes anticlockwise and the front
wheel moves side to side, you have a bent stanchion tube.

Also, if you rotate the front axle anticlockwise with the pinch bolt
loose and the front wheel wobbles and move up and down, the front axle
is bent.

because the steering would have been stiffer and therefore less
sensitive before the repair, then I will look a bit of a pillock. I
would add also that I hate letting anyone else work on any vehicle
that belongs to me, and avoid it unless at all possible, so do have
pretty high standards and expectations.

I agree. I don't let anybody touch my bikes and when I go into a
motorcycle parts department, I often walk out without buying anything
because the $tealer$hips can't get a good parts counterman, let alone
a decent shop mechanic.

The parts countermen often cannot sell me the simplest parts because
they cannot find out what parts are interchangeable, even though the
same motorcycle may have been produced for 20 years.

 

If you want advice, I think you need to decide what the symptoms
are. This "guess what is wrong with my bike" thing is hard enough
as it is.