wheel alignment - what's your style?

RE: wheel alignment - what

You can basically accomplish the same thing with the tires mounted on the wheels. The wheels can also be aligned accurately by visually sighting along the tires rear to front using selected matched pairs of knobs on each side of the rear tire as 'gun sights'.

Here's my take,

Get bike on a stand that doesn't restrict the sighting along the wheels from front to rear. You can also use a few tie downs and attach the bike to a wall, car etc near by and forget about the stand. A doorway can work well, bike in middle. Get the bike vertical, stable, and with clear sight front to rear between the wheels. Tyres on is OK too.

Get a roll of good cord/string, not fuzzy,a couple of mm in diameter, venetian blind cord is good and a length of dress maker's elastic, say 2 m. Find the centre of the string and wrap it around the rear tyre so that the free ends can be drawn past the front wheel on either side. A bit of electrical tape can help to secure it temporarily on the rear tyre. Put it in gear so that the string doesn't pull the wheel around. Avoid the knobs, and get the string snug on the tyre case. Pull the two ends of the string up past the front wheel and attach the elastic to the string . Get a couple of bricks or similar, I use car stands, and attach the other end of the elastic to them.

You now have 2 tensioned pieces of string held nice and stable. Sight along and get them just kissing the front of the rear tyre carcass. Get a tape measure and check that the strings are parallel, and adjust the free end if necessary. You can now go the front wheel and with the tape measure measure the distance from the strings to the rim in four locations, front, rear, left and right. Get them as high as you can without fouling any bike bits. Taffy's 8" for example.

Adjust the rear axle adjusters to suit until the string is parallel, and the 4 offsets to the front rim are all the same. Its now aligned. Now get a small steel rule and measure the position of something on each end of the axle to the rear of the swingarm. If they are the same on the left and right, easy, you now know. If not, and this is most likely the case, one side will be back or forward by +/- mm. Write it down, and next time you adjust the chain, you'll know what the difference from left to right is to maintain wheel alignment.

This method means that you can do it on your own too.

Do it this way, and unless the frame or something bends, you only need to do it once. And the use of measuring sticks takes the guess work out of the equation. A bit of good string, and some elastic is all you need, a couple of dollars, and it'll work for all bikes, not just Bergs.

Have fun,
Steve

A knowledgeable dude over at KTMTalk let us in on his trick ...

It's how I do it now after years of tape measures, string lines and sight lines.

My 04 SMC alignment marks were out nearly 1/8 " - modern bikes still suffer this annoying QC problem...

Here is Creeper's gadget

http://ktmtalk.com/index.php?showtopic= ... nment+tool

Cheers

Mark

Hey Chilled,

The link doesn't work for non members.

I have seen a variety of straight edges with offset pins and stuff, and someone is selling a laser alignment tool too. I can sertainly feel the difference on my road bike that 2 mm makes to the alignment, but I think it does take a bit more on the dirt bike to notice if it prefers one direction to another.

Steve

Can't figure out how to post 2 images in one post...

Here's the first

Here's the second

I do like a 50c version of a $25 dollar tool with no loss of functionality.

Kudos to Creeper


Cheers

Mark

Chiiled,

Lookes interesting. but it will only tell you about the relationship of the rear axle to the swingarm pivot, not the front wheel to the rear wheel.

Steve

Steve

Agreed, but most times I am not too worried about the front end being out....

If I felt the need to check front to rear alignment I would use 2, 2" aluminum angles 8ft long, let the air out of the rear tire and use c-clamps to clamp the angles to the rear rim to act as pointers up to the front and then measure offsets left and right.

Cheers

Mark

and sight along an 8' length of al and I reckon it'll have a gentle curve in it!

The only novel way I can think of that would give results worthy of the full stop, Taffy's looking for is to strip the tires, remount the rims without rim tape, and then construct a chalk line on the floor - with this drape strings with plumb bobs at each end over each rim to create 4 pointers on the chalk line.

Even this would be prone to errors in finding centre of the rims with the string lines but in my opinion it would be pretty small.

This method would also reveal true wheel offset issues, if they existed.

Cheers

Mark

nb: interesting about the Honda VFR's - I always thought Honda was incapable of such things...

And of course the other variable to considerwith these systems is the trueness of spoked wheels. When I checked my 650, I found that the rim on the front wheel was offset to one side, can't remember which, within the forks. I strip my wheels when new and antisieze the spoke nipples, on the threads and under the head, and then retrue them. Get the front wheel centred in the forks, get the forks parallel, and I do use a couple of pieces of al angle for this, and then work back to the rear wheel as described above. Might not make a lot of difference, but gives me something to do instead of mowing the lawn or watching telly. And it only really needs doing once per bike.

Cheers
Steve

Lots of methods and all make sense. I like the welding rod with a zip tie; simple for rear wheel adjustment although a small error would be magnified at the rim where it counts most.

What I'm wondering is;
At what point does it start to affect handling or performance in a noticeable way? I reckon its less critical on off road bikes.

What is an acceptable tolerance for wheel alignment? Instinct tells me that it will be more critical on a road bike and the sportier the bike the more important it will be but how best to quantify and measure it?

Then; what about horizontal alignment? All the methods focus on vertical alignment but a twisted frame will affect horizontal alignment more than vertical. In theory the axes of both wheels will be parallel in all planes. A twisted frame, fork or swing arm could cause this not to be true, as well as rear wheel adjustment.

I know I'm getting extreme; most of the time we just want to check if the wheels are in line and assume that the chassis was built to exacting tolerances. Hearing about the VFR Honda makes you wonder how accurate bike chassis are and how much time we should spend on our knees in front of our bikes squinting at mirrors and bits of string.

Just a thought


:idea: