YBR 125 wheels out of alignment

[Daffyduxxx]

Hi,
I have a Yamaha YBR 125, which I have owned since it had 70 miles on the clock, it has no signs of accident damage.But, if you take your hands off the handlebars when coasting, it veers to the left.Also, it feels as though I am not sitting on it squarely, as though something is misaligned.I have put a straight edge from the rear wheel to the front wheel. On the brake pedal side of the bike , with the straight edge touching the back tyre, there is a 30mm gap between the front tyre and the straight edge.On the gear lever side of the bike with the straight edge touching the rear tyre the straight edge also touches the front tyre. I believe the rear wheel alignment to be correct in terms of the chain adjusters, but obviously, something is amiss. Could this be a manufacturing error of the frame?
I am toying with the idea of buying second hand rear wheel spacers and machining themto move the rear wheel over until the two wheels align with the straight edge and trying that.
Do most bike. Workshops have jigs to check frame alignment or is this a specialist thing?
Any ideas would be great fully received.
Many thanks
Paul

[Alpha-9]

Adjust the adjusters so it's straight regardless of the markings, will be tricky but at least you know it's correct and not that before buying parts or doing anything drastic
____________________
Fzr-600 1999

[ride it like you stole it]

try measuring from the swing arm to the centre of the wheel with a rule if you dont trust the markings. Make sure both sides are the same, should be correct.

[bridgedino]

Try as I might I always sit slightly to the right, on every bike i have had. People have pointed this out to me and I try to sit squarely but it feels odd.

I thought I was the only one but at least I know I'm not

[ZebraDriver]

And if you machine the spacers to move the back wheel over are you then going to machine up some spacers for the sprocket to sit in line with the chain?

Most bikes will wander to the left when you take your hands off the 'bars, because of the camber in the road, try the same trick whilst riding on the wrong side of the road. n.b. unless you live in Italy, Portugal or Turkey remember to try this only when there is no traffic around.

ZD

[mentalboy]

30mm is quite a difference. If you are happy that the rear is aligned correctly then check that both forks sit at the same height in the headstock, if they are then it may pay to loosen the lower yoke bolts and headstock to make sure it isn't twisted.
It is most unlikely to be a manufacturer error as all machines come off a jig.
If you've still got no joy then get the forks out and check the stanchions for straightness - if they're bent it will mean the bike's been dropped at some point and you should be able to see some evidence of this by giving the whole bike a really good look over.
____________________
Make mine a Corona.

[YBR Ric]

First of all congratulations on owning one of the few bikes available on the market today which comes with identical width cast wheels.
This means you are perfectly free to ignore those inaccurate wheel adjuster marks and by simply taping an 8mm nut to each rim (to clear
the wider rear tyre and using a straight edge attain perfect alignment

As a rough guide to wheel alignment, bike on center stand and spin the rear wheel backwards several times. The sprocket teeth should sit
central between the chain. This is not always the case as some bikes have rather a large gap to close down between the wheel assembly
and the swinging arm, moving the sprockets out off alignment. Really bad rear wheel alignment will show up as chafing on one side of the
rear sprocket and no contact marks on the other!

Just for info a full rotation on a 1mm pitch adjusting bolt will move a straight edge placed against the rear wheel across by 1/4" at the front.
I've had one UJM where the stamped adjustment marks put the wheels 1/2" out of alignment - they should be treated as a guide at best.

But before you set the wheel alignment you need to ensure your front wheel is where it should be. If your bike has never been dropped or
damaged, your wheels are aligned front to back but the bike is pulling noticeably to one side then twisted yokes are the most likely culprit.

With the front end off the ground, wheel out, axle in and the nut on just a couple of threads and ensure the fork clamp bolts are loosened
just enough to allow the forks to drop downwards.

Drop the forks to just below the upper yoke, adjust the lower clamp bolts so the forks require some input via the axle to allow them to be
slid up and down in the lower yoke. With the forks pointing straight ahead, look down and see if the top of the forks are directly below the
holes in the yoke. It's fine if they sit forwards a little as the weight of the forks will cause this, but they should not sit off to either side.
If they do then the top yoke needs to be moved so its directly above the top of the forks. If alignment is correct the forks can be pushed up
using the axle (but possibly with the aid of minor fore and aft movements and slide into the upper yoke without either fork catching on the
underside of the yoke.
Torque yoke clamps to spec. replace wheel etc etc. Go for a ride and marvel at the difference perfect wheel alignment makes to the handling.