Wheel alignment [Archive] - Kiwi Biker forums

Blackbird

6th July 2003, 10:50

Does anyone bother to check their wheel alignment?  It makes a huge difference to the handling if it's accurate.  Last time I had a new rear tyre fitted, it was a mile out and you can't rely on the maker's graduations on the swing arm because they're not to be trusted either.  I used to use cotton thread stretched down both sides of the bike but it takes time and just about sends you blind:D

I've just built a laser alignment rig and it's the dog's do-dahs.  I've attached some photos if anyone wants to build one.  If the method of using it isn't clear, let me know and I'll write some notes

The first part of the rig consists of a frame constructed from MDF, grooved in the top to provide stability to the laser pointer. The pointer is held in place with elastic.

The second part of the rig is a piece of straight dressed timber painted white, with Perspex end-pieces. The target end piece has a strip of black insulating tape behind it to make the laser easier to see. Both have a vertical line scored in them with a scriber. I figured that this would slightly scatter the laser light on the line and make aligning this part of the rig easier.

There are probably a million other ways to do it, but I made do with what I’d got handy and alignment is going to be sooooooo….. easy from now on

The first pic shows the general arrangement of the rig

Blackbird

6th July 2003, 10:54

This is a close-up of the laser and a perspex end of the second part of the rig. The laser light can be clearly seen on the scored line which helps alignment.

Errr..... with a careful look, so can the blue clothes peg wot I use to keep the laser switched on :o:o

Blackbird

6th July 2003, 10:56

This pic shows the laser hitting the target perspex plate. Again, it shows up well on the vertical score line.

Blackbird

6th July 2003, 10:57

This pic also shows the laser light on the rig. I made the rig as tall as I could get it without the centre stand blocking the laser so that I could get as much tyre wall as possible to align against. 

 :niceone:

SPman

6th July 2003, 13:30

Thats a neat idea. I've almost given up trying with stringlines etc, but the hi/lo tech appeals.:)  Where do you get the pointer from, Dick Smiths or somewhere?:niceone:

Blackbird

6th July 2003, 16:20

No, one of my kids gave it to me - it has a biro at the other end:p .  Wouldn't be very expensive if my kids bought it for me, haha!

I imagine that DS should have them but if not, any office supplier should have laser pointers.

Hoon

7th July 2003, 11:23

Very ingenious!  Quite funny when you hear about trick "laser-alignment" rigs that the shops have and you've managed to make one in your garage with household items. :)

Whenever I change my rims I give it a quick check with the eye-crometer and go "Hmmm I hope this is aligned properly".  If it could be done easily and quickly then I would do it properly everytime!

Good stuff!

Ohh and I believe you can pick up laser pointers from the $2 dollar shops.

wkid_one

7th July 2003, 11:26

I use the 'bum-o-th-seat-ometer'....if it rides good - it is good....

Coldkiwi

7th July 2003, 12:37

but it could be better!.. seems like a lot of work to go to though. What are the signs of a misaligned wheel then? (apart from no rear braking action with the disc and pads out of line?)

Dave

7th July 2003, 12:42

Didn't you ever notice that all your favorite corners are right/left handed? and when you turn the other way it sometimes feels a bit spooky?
thats all due to bad alignment (bike or rider).
the brakes will still work properly.
if your wheels are misaligned the bike is constantly trying to turn in one direction-when you go in that direction it feels good,when you go the opposite direction its fighting the bike.

Blackbird

7th July 2003, 13:35

Dave's summed it up pretty well.  If your wheels have been misalingned for quite a while, you might also see odd wear patterns on your front tyre, particularly if you do a lot of riding on twisty roads. With the extra effort required to flick the bike in one direction, you may subconsciously countersteer a bit more and get scuffing up the tread pattern away from the vertical.  I experienced this on the 'bird once and whilst I can't conclusively prove it, it may have been due to misalignment.  At 220 kgs, the 'bird is going to show it up quicker than a lightweight!

bluninja

7th July 2003, 14:55

Scuse me for sounding a bit thick.....but...I guess the laser mount buts up against the rear wheel and the MDF is marked with a line that should be parallel to the rear rim (plus offset for the actual laser mount) when placed against the front wheel.

Don't you road test the bike by taking the hands off the bars on a flat surface when riding and see if it stays in a straight line?

TTFN

Duke of Rogan

7th July 2003, 14:59

I found this bit of instruction last week on how-to align the wheels using string lines. I haven't tried it yet, and had to re-read it a few times to get it to make sense:

Put bike on service stand. Take about 15 feet of string (elastic thread works best!). Tape center of string to back of the rear wheel about 4" off the ground. Bring the ends of the string to the front of the bike. Tie the ends of the string to some movable objects (I use a pair of jack stands), at the same height (4"). The idea is to set the strings so they are parallel and "just" in contact to the front edge rear tire by moving the jack stands. With the strings taped to the back of the rear tire, and "just" touching the front edge of the rear tire, they should make two parallel lines that run forward, passing along either side of the front tire. Now the alignment of the front and rear wheels can be easily observed by examining the clearance of the front wheel and the string on either side. Adjust the chain adjuster appropriately if necessary, and then recheck.

It's a pain to do the first time, but then it gets easy. Use the thinnest, elastic thread you can find. Also, try rotating the rear wheel to several points to make sure you aren't just adjusting for uneven tire manufacture. And make sure the thread isn't on some bump of "mold seam" rubber or in a tread at the edge of the tire. This would screw up everything.

Dave

7th July 2003, 15:29

What about this-use your string line/laser/GPS whatever and adjust your alignment so that it's spot on. Then use a vernier or very accurate ruler and scribe a referance point on your swing arm on both sides near the adjusters. Now when you do anything with your wheel you can just measure off your referance marks and you know your alignment is right.

Kwaka-Kid

7th July 2003, 16:31

hmm, yes my ZXR400 - or at least i thought it was me, i love left hand corners on it, they work really well, and it annoyed me that pukekohe was right handers.  However, has anyone ever purposly put their wheels out of allingment for a track like pukekohe - setup for right hand corners... because the only 2 lefts in it on my 400 also annoyed me as i hardly needed to really try get in to the corner and have fun :(   

hmm honestly never realised that because i love left hand corners on the zxr it could be because of the umpteen accidents i know its had in its prev. owners, and wheel allignment - could it also be that the subchassis is tweaked?   if so i wanna try bin it on the other side to make it feel nicer thru right handers for puke :P hahaha! now theres a plan!

Blackbird

7th July 2003, 17:45

Bluninja -  you're close!  Set the laser up so the beam just kisses the widest part of the rear tyre on both sides of the arc. That way, it's running parallel with the rear tyre.  (Check the tyre for "wobble" first, but you probably won't find much unless a really crap tyre fitter has done it!).  The front piece of the rig goes hard up against the front tyre, you can hold it there with really thin elastic if you want.  Turn the rig/ front wheel until it's parallel with the laser beam.  That's why I have two score lines on the perspex to help. 

The centre line of this part of the rig equates to half the difference in the widths of the front and rear tyres.  This means that if front and rear are in perfect alignment, the laser beam will go down the centre line.  It doesn't actually matter though as you can simply use a decent rule and measure the offset.  Repeat it on the other side of the bike and if the offset is different, then you know that you will need to give the rear wheel a tweak (The front of the rear tyre needs turning towards the side with the smallest offset).  Check it again when you're re-tightening the wheel nuts.

Duke - I used the string lines exactly how you suggested it.  It's a pain in the arse if you have the bike on its centrestand and also if you need to rotate the rear wheel, that's why I built the laser rig.  The string certainly works ok though.

Dave - Smart thinking  :niceone:  !  That should save doing full alignments all the while when adjusting chains etc.  Would still do one every so often though in case of excursions up pavements, down holes in the road or, perish the thought, following the bike along the road:(

If it's still not clear, I'm quite happy to scan a quick sketch of the process and post it, just let me know.  I hadn't intended the post to be a teach-in!!!:done:

bluninja

8th July 2003, 10:10

I've always aligned my wheels using the string or straight edge method. I used indelible marker pen to mark the correct position, and when adjusting the chain I count the number of flats (or turns) and make sure I do the same each side so it stays even.

Blackbird thanks for the extra info. It makes more sense now.

TTFN