Front wheel alignment
 

Hi all,

On a 748 2000 that fell on it right side can the front wheel lose it's alignement so that when going straight the handlebar it's slightly turned to the right?

How can it be aligned again and how can it be properly checked (measurements etc)?

Thanx :)

Are you sure it's not just a tweaked clip on?

No, i checked the handle clips and their ok.

How can i check?

Best way i know of is to loosen the top yolk then bounce the forks up & down, then retighten & check again.



Chris.:burn:

did this just fall over ?

what did it land on, point of impact, mirror ? handalbar end?

are both bars turning right or just one?

id expect it is probably a bent bar from the impact/ taking the weight as it landed, being as youve checked the position under the top yoke?!

its possible i guess that the alignment can be put off from a fork slipping in the yoke but not likely from just falling over, maybee just check each fork has the same number of rings showing at the top yoke.

Hi

I bought my 748 as a "damaged repairable", and its steering was tweaked. It was caused by the head stem being bent, which I gather is not uncommon. If your bike has only toppled over it is unlikely to be the cause of your problem, but if its had more impact it's a possible cause. Although it sounds bad, infact the cure was easy to do, with a replacement stem off ebay.

Checking the alignment is pretty straightforward. You need to project a line parallel with each side of the rear wheel, and check that with the steering straight ahead the front wheel is in the centre of the these lines, and also straight ahead.

You can project these lines by putting two long pieces of wood against each side of the rear tyre, so that they are parallel, and reach forward as far as the front wheel. Another way is to run a piece of string tied to an axle stand, or an oil can, at the front of the bike so it is straight, but touches the front and rear sidewalls of the rear tyre, runs round the back of the rear tyre and to the front of the bike to another axle stand, just touching the other side of the sidewalls of the rear tyre. It sounds complicated, but in fact takes longer to describe than it does to do!

I have tried to attach a sketch:

I should also have added that the alignment check should be done with the bike on a paddock stand!

yep, axle stands and a paddock stand, more normally done for checking the rear wheel alignment but, by measuring that the distance from the string to the front and then rearmost parts of the front wheel are the same - should give an indication.

Variation might be quite small though.

If there is a serious doubt over chassis/fork alignment maybe its time to talk to someone with a motorliner or chassis jig - sorry!

Frank

Yes it's two sides of the same coin. With an adjustable rear wheel you are using the front as a reference, but on the 748 etc the rear wheel is non adjustable so you are using it as a reference for the front.

Using the string method and a steel rule, you should be able to achieve an accuracy to the nearest mm (make three measurements and mean them), and the dimensions should be identical on each side. If it all measures up, then its a good indication that all is well. If it is out you will probably need more specialist equipment as Frank suggests.

Regards

Douglas

A well used piece of equipment when I was racing was two u section or square section lenghts of aluminium about 1" square by 5 or 6 feet long.
A threaded rod 12" or so long, two nuts & two washers

drill a hole to take the threaded rod through both sections of the 6 foot lenghts of aluminium aprox 2 feet from one end.

place one nut and washer on one end of the threaded rod.

place the two lenghts of aluminium, one each side of the rear wheel(whilst on the paddock stand)extending past the front wheel. the holes for the threaded rod should be either side of the rear wheel.

pass the threaded rod through one of the holes on the aluminium through the spokes of the rear wheel and then through the hole in the other length of aluminium, put the other nut & washer on the threaded rod to tighten both lenghts of aluminium to the rear wheel.

If i have explaned this correctly the front wheel should sit in between the two lengths of aluminium with an equal gap between the tyre and the lengths of aluminium as per the drawing done by Douglas


Also as said by Douglas this applies


"Yes it's two sides of the same coin. With an adjustable rear wheel you are using the front as a reference, but on the 748 etc the rear wheel is non adjustable so you are using it as a reference for the front."


A bit long winded, but I aint that good at explianing thing sometimes, it`s me age. :(


Chris.:burn: