Sprockets and Contact Patches

[lihp]

I am almost ready to get the chain etc on my GSXR 400.

For those who have not read my thread, it is using the swingarm and wheel from different models, spacers on the rear are all identical

I am fairly certain that the contact patch alignment front and rear is identical due to identical spacers, and straight fit into the frame for the swingarm, but I would like to check it to be 100% certain.

Additionally, I am running a wheel that is 1.5" wider than standard (from a different gsxr400 model), now, I don't have the sprocket carrier for the original wheel, but the wheel hub on my new wheel is 5mm wider than standard, so 2.5mm either side. But this may be countered by the offset of the sprocket carrier? (Looks pretty damn close when eye-balling it.

My question then is.

What is the best method for checking that the contact patch is equal front and rear?

What is the best way of checking sprocket alignment?
____________________
covent.gardens: lihp is my most favourite member ever

[stinkwheel]

Doesn't matter as much as you'd think. The wheels need to be paralell but not necessarily perfectly aligned, (within reason).

Look closely at the next old-shape v-max you see, there's a good inch of lateral offset between the front and rear wheel alignment.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[lihp]

Would it be a fair assumption that if the front sprocket lines up with the front of the chain slider on the new swingarm that Sprocket alignment is more than likely going to be correct?
____________________
covent.gardens: lihp is my most favourite member ever

[stinkwheel]

Sorry, you're meaning for the sprocket alignment, not the wheels?

Eyeballing along it is pretty effective, you can usually see even a small warpage one way or the other.

Otherwise you're probably looking at much ado with chalk marks, bits of string, tape measures and level concrete floors.

How about laying a straight edge along the side of the back sprocket so it extends towards the front sprocket? If it's lying flat and square across the face of the back sprocket, it should be touching the outer surface of the front one.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[jjdugen]

I have done a few rear wheel swaps, usually to replace older 18'' wheels with 17'' diameter and wider rims. On the 'blade I've built I replaced the 180 section wheel with the 190 from the latest models.

I start by getting the back end hoisted up, if you have a garage, find a roof support to use.
I then put the wheel into the swinging arm loose, with no spacers. Mount the chain. Spin the rear wheel. This will almost self align the two sprockets. Its then a fairly easy job to measure the spacer lengths needed for correct alignment.
On the Yamaha FZR 600's I do I have to reshape the caliper carrier by reducing the cross section of the carrier at the spindle area. You might have to do the same.
If you are making up new spacers it is very important that you get each end flat and parallel to avoid stressing the wheel bearings.
It can be a fiddly job, or one that is surprisingly easy. I have found that both Yamaha and Suzuki use a considerable amount of inter-changable parts over a large number of years and models, not so easy with Kawasaki and Honda change a lot of things between years on the same model
____________________
The CBR900RR has been sold. Aprilia Falco worms its way into my heart.
Try Soi 23 on Amazon for a good read.... Self promotion? Moi?