wheel alignment

[chixson]

Hello from the U S... 

     You all probbly know about this already but, for those that might not, I aligned my bike last week and what a differance!

   First I squared up the front end by measureing from the front motor mount to the fromt axle, Makeing sure the rear tire was lined up according to the marks on the  swing arm, I then  wrapped a string line around the back wheel ( run thru the wheel first and makeing an "x" on the face of the tire)and ran it up along the front edges of the rear tire to the front wheel wrapping the ends of the string line around a piece of square bar and tapeing it to  the front tire. , I measured the distance from the string to the front tire. I was amazed to find out that the rear wheel was .375" off center.  Splitting the differance I ajusted the rear wheel and marked the swing arm for future reference. If you haven't done this and your tires are wearing wierd, you'll be amazed at the differance.
Good luck and safe rideing to everyone.....
chris

[movenon]

I did about the same thing last winter after the GSXR rear wheel conversion. Then aliened the chain (flipped the rear sprocket and put a different front sprocket on). In the end my rear tire was pretty centered in the swing arm. I did notice that when you measure things, a very little adjustment with the rear adjusters makes a pretty big difference. You tube has a video or two on motorcycle wheel alignment that is helpful to watch using the string method. I seen an article once with someone using lasers also.

I understand that the MOT inspections over in the UK also check the front to rear alignment as part of there inspection. Just from what I have read so feel free to correct me. The only reason I checked mine was because of the mod to the rear wheel, shock and tire.

George

[chixson]

I checked mine because I was getting some really odd rear tire wear. I have the GSXR rear conversion as well as the '88 front end on my '86. A friend at work told me about the you tube video on the alignment, was probably the same one you seen..
Be safe

[fj11.5]

I've never trusted the swingarm adjuster marks , since owning an 80 model gsx 750,, marks were off  on either side and didn't line up , that thing never handled right, till I took it to a bike shop and they string lined it, , marks were off about 5mm from each other ,, new nothing about string lining , I had trusted japan to get things right  , well I was only 21

[movenon]

I've never trusted the swingarm adjuster marks , since owning an 80 model gsx 750,, marks were off  on either side and didn't line up , that thing never handled right, till I took it to a bike shop and they string lined it, , marks were off about 5mm from each other ,, new nothing about string lining , I had trusted japan to get things right  , well I was only 21

5mm was quiet a bit when your lever is out 3 or 4 feet. I took 2 small machinist SS pocket rulers that were marked down to 1/32 " (couldn't find a metric ones that day) and trimmed (shortenend them) then glued them to the swing arm under the factory marks using the end of the swing arm as a reference point. That's also after I insured the front wheel was in alignment as best I could with the string method.

All I can say is when you have things measured out I found out that 1/2 to 1 turn on the adjusting nut can be measured. The factory marks while are OK enough I guess,  leaves a lot of space between ticks and you have to eye ball pretty good to get each side dead on.

Probably just over thinking things. I just wanted to know because I made a lot of changes.

Now for something else to think about, there are bikes out there that the rear wheel is intentionally off set from the factory. So how's that work ? 

George

[fj11.5]

The gsx used to wallow real bad , and chew through front tires more than rears ,, I got used to it, but scared the crap out of anyone riding behind me ,, yeah it was that obvious  

Your ruler idea is great  thinking, I can't wait to fit the fz1 arm, much better adjuster marks, and appear to be fairly close after measuring them

As for answeing your question on other bikes, its too early for that without a coffee or two   

[ribbert]

Hello from the U S... 



First I squared up the front end by measureing from the front motor mount to the fromt axle, Makeing sure the rear tire was lined up according to the marks on the  swing arm, I then  wrapped a string line around the back wheel ( run thru the wheel first and makeing an "x" on the face of the tire)and ran it up along the front edges of the rear tire to the front wheel wrapping the ends of the string line around a piece of square bar and tapeing it to  the front tire. , I measured the distance from the string to the front tire. I was amazed to find out that the rear wheel was .375" off center.  Splitting the differance I ajusted the rear wheel and marked the swing arm for future reference. If you haven't done this and your tires are wearing wierd, you'll be amazed at the differance.
Good luck and safe rideing to everyone.....
chris

You're making hard work of this. String over that distance relying on the accuracy of when it contacts the tyre is vague.
Two lengths of wood or steel (25mm square tube is good) placed on tins or whatever as high up the wheel as you can get it (just under the discs) with it pressed against the back wheel (contacting the tyre at the front and back of the wheel) Adjust the back wheel until the measurements are equal both sides, front and back of the front wheel.

This eliminates the need to try and centre the front wheel independently.

If all four of those measurements at the front wheel are the same, with bar firmly pushed against the back wheel, the front wheel is centred and the back wheel aligned, with millimetre accuracy. 5 minute job.

I then adjust it evenly by turning the nuts an equal amount until the next tyre change, then re align it. After the first time it it's very quick.

Noel

[andyb]

I never liked the string method.  It works but it alwasys seemed fiddly.  What I now use is a pair of dead 8' flouro lightbulbs, but the idea is the same.  Once you've done it once, just move the adjusters the same amount each time you make a change, easy peasy.