Wheel Alignment check.

[crazzy450z]

Who has actually checked the wheel alignment on their GL? Was it spot on??
I know that the wing does not have an adjustable rear wheel. I know its fixed. But has anyone actually checked the alignment on a wing that is known to not have been down? What sort of tolerance should did you find? What tolerance would be acceptable?

This question comes from a custom swing arm I've fitted onto my '83 GL1100. I have it fully centered, and aligned to the front wheel at 0.75 mm off the front wheel. I understand +-0 mm would be best, but how OCD are we talking here? LOL.. ALso, when testing off the rear tire, there's ALWAYS going to be some play in the rubber.. Again, how OCD should I be? All the online tutorials showing motorcycle wheel alignment, show people using a piece of string.. How accurate can this be?? I know going off the rims would be more accurate, but that's harder to do for my situation..

Here's a pic of my alignment rig.. The rails are perfectly parallel (+-.05mm) over the 8 ft length and clamping on the rear tire...

When i first tack welded the swing arm, I made the rear axel center line parallel with the swing arm pivot point centerline (+-0.25 mm).. When i mounted the assembly on the bike and checked it against the front wheel, it was off by almost 10mm to the right.. I actually had to shorten the drive tube side by over 2 mm to get it in line. Should the axel not have been parallel with the pivot point?

Right now i have 1.5 mm difference at the front (right side dimension vs left side dimension).. So the wheel is 0.75 mm off of center.

I am the 4th or 5th owner of this bike. I do know the previous 2 owners and know it did not go down during their ownership. But when the cam belts where replaced, the removable section of the frame was removed, there where spacers used to allow the section to fit correctly.. This leads me to think the frame might be tweaked a little. Thoughts??

[GoldWingrGreg]

Regaurding tolerances ... for a m/c I have no clue. Certainly, whats important is not having pulls, equal handling on left and right turns and curves. Even tire where is critical too.

In the car world, alignment specs are critical, but there are tolerances.

If it helps, in some trike shops they use 8' florecent bulbs as their straight edge. They are light weight, straight, and easy to get. I've also heard that insurance companies have a lazer set up of some kind for m/c's.

[crazzy450z]

Hi Greg,
I was going to use the florescent tube idea, but the center stand gets in the way.. My little jig is straight and parallel, with a small cut out around the center stand. I do have a laser level, but unfortunately they do get fuzzy the farther you get from the source and its hard to measure to them.. This was why i figured i would make a jig.. I'm able to get it quite accurate in the measurements.. Just not sure how close i need to get.. lol..

Regaurding tolerances ... for a m/c I have no clue. Certainly, whats important is not having pulls, equal handling on left and right turns and curves. Even tire where is critical too.

In the car world, alignment specs are critical, but there are tolerances.

If it helps, in some trike shops they use 8' florecent bulbs as their straight edge. They are light weight, straight, and easy to get. I've also heard that insurance companies have a lazer set up of some kind for m/c's.

[Rambozo]

Not sure about using dead trees as a straightedge.



Measure with a micrometer, mark with a crayon, cut with an axe.

[crazzy450z]

I know people don't think theres any accuracy to woodworking. But beyond making these out of milled aluminum I would bet they are straighter then most straight edges you'll find at most suppliers.. These where machined on a flat bed CNC accurate to 0.01 mm..
I would bet this is way more accurate then anyone using a string and eye to check to see if the rear wheel is centered..

Not sure about using dead trees as a straightedge.

Measure with a micrometer, mark with a crayon, cut with an axe.

[Rambozo]

There is a difference between resolution and accuracy. While you could cut wood to high precision the problem is it moves. From a metrology standpoint, everything is made of rubber, just different grades. Aluminum has thermal movement even worse than some woods.

Having said that, your setup for motorcycle alignment is more than sufficient. Ideally you should be checking at the wheel instead of the tire, and checking at the axle centerline of the wheel to avoid Abbe errors. It wouldn't surprise me to find out that the tolerance that Honda had during original manufacture was plus minus .5mm or maybe even double that.

[GoldWingrGreg]

Just not sure how close i need to get.. lol..

I would think a 1/16" (0.0625) of an inch would be a lot, but I really don't know.

[plain]

First I think 0.75mm is 0.0295" if my little converter prog is correct. So, no, I don't think that would be a big deal IF the measurement were at the Wheel's axle center line.
Down as low as the pic infers and it could be tilted vertically and you would never know.
But as Rambozo stated you should be measuring the rims to make sure they are parallel when they are properly mounted. If you're talking about less than 30 thousandths the tire is not a good guage.
Personally, I think so long as the wheel is vertical to the frame, not the swingarm, and it doesn't dog-trot when you go down the road you should be okay with that clearance.
If you decide it must be dead-on then I can't see what would be wrong with spacers in the swingarm just so the driveline bolts up with no strain. I've never looked at a parts book for 1100 but they may even show spacers.
If you feel the reason for the spacers is the bike's been wrecked check over the frame good because the spacers may be healing up a bent or twisted frame. If you're going to this much trouble might as well make sure all your work is not in vain.

[Limpy45]

Hmm, I have never checked wheel alignment on any of the wings I have owned. But, on my chain burner bikes, if you were off a bit, you could feel it in the handling in corners, one way would be a bit squirrely and the other just felt weird. Tire wear would really tell the difference. I used a long steel angle that I had handy in the shop I worked in. Only experience I had with a wing was when I installed my Vetter Terraplane side car on a 1980. Toe in or out made a HUGE difference in handling on that rig. Used a Lazer finally shining on a large piece of plywood in front and rear, then measure the difference between the dots marked on the board. Took some fancy doing, but worked.

[FM-USA]

WAY BACK IN THE DAY what I used was one 8 ft. 2x4 that was 'eyeball' straight. Double checked with my dad's aluminum 6 ft bubble level. Barely a whisker of light showed at either end = good nuff.
That level was several inches short of spanning 4 contact points on the tires.

I placed that 2x4 horizontal to the wheels vertical (90-Degree, =|| ) to the 2 tires and roped it to the spokes, firm but not tight.
_Loosened the rear wheels axle nuts until I seen a smidgen of movement on both sides.
_Tapped that rear tire several times for it to align itself.
_Tightened the axle nuts and good-to-go.

Be hard pressed to do it more Shade Tree or Red Neck than that.

.

[Scanjo]

I know people don't think theres any accuracy to woodworking. But beyond making these out of milled aluminum I would bet they are straighter then most straight edges you'll find at most suppliers.. These where machined on a flat bed CNC accurate to 0.01 mm..
I would bet this is way more accurate then anyone using a string and eye to check to see if the rear wheel is centered..

Not sure about using dead trees as a straightedge.

Measure with a micrometer, mark with a crayon, cut with an axe.

Where wood is concerned, environment affects it a lot. It could be PERFECT when you cut it on your flat bed CNC rig, but the humidity & temperature change and all bets are off.

[FM-USA]

Wood in long term use, yes it can warp.
But here we're taking it's use in minutes.

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