Wheel Alignment

[NiteOwl]

I have searched and read and searched some more. I hope that someone is willing to jump in here.

I am trying to do an alignment on a 42. Here is what I think I know.

1. I have to have the hubs and wheels themselves properly aligned, (I have confirmed they are, my spokes are good)
2. I need to ensure my steering (forks) are absolutely straight. (I think I have this, but its very fiddly and perhaps there is a better way than what I have done)
3. I figure I better start at the front wheel and ensure its absolutely centered within the forks.
4. Once the front is centered I can align the rear wheel to the front wheel using straight edge or laser beam to give straight line.

ok, if this is basically correct,
I find my wheel is not centered its 1/2 - 3/4" over to the right fork. (from saddle view)

Could I ask for guidance on what is required to move that wheel over to be more centered between the forks, am i missing something simple here?

Does anyone have a good procedure for performing overall alignment which they could share as I am fairly certain I am not the only one curious. hmmm or again maybe I am over complicating things?

[Rubone]

Bob, A '42 what? Big Twin, 45??
Robbie

[NiteOwl]

Bob, A '42 what? Big Twin, 45??
Robbie

Oops. A 42 EL solo

[ronald]

Hi Bob, This procedure is for a bike under construction or in the mock-up stages. Here's what I did with my VL and this will give you a ball park chassis alignment check as well. I first assembled the fork and wheel without tire but with the brake and all spacers etc., and mounted it to the frame with the proper neck bearings without the steering damper. Then measure from the back side of the rear fork leg on each side at the axle height to the lower seat post hole and turn the fork back and forth until both sides measure the same. Secure the fork at that point. Then insert a rod that fits the damper rod hole closely and is sharpened on one end that is long enough to reach the naked wheel through the damper rod hole in the fork stem. Gently turn the wheel and mark it in several places. Now you can check the centering of your wheel to the center of the frame. After you have made any corrections if necessary, mount the rear wheel rear sans tire but with the brake and all spacers etc and tie a string on your front wheel high enough to be able to touch both the front and rear edges of your wheel and low enough to not touch any other parts, and extend past the rear wheel. Adjust the rear axle adjusters to bring the wheel parallel to your string. Back check your measurement from the seat post hole to the string, it should be the same as from the string to the edge of the front wheel. Correct these measurements if necessary and re-check your rear wheel alignment. If it is parallel but offset more than 1/16th of an inch you may want to correct that as it may affect your handling. Often you may find that your rear wheel will not allow a parallel measurement because it interferes with the string, just string the other side of both front and rear wheels and you will get the measurements you need. I also used this method to check my "41 UL. After initial setup like this, you can just use a straight edge or string on the outside of the tires to check your alignment with out all the internal measurements.
Ron AMCA 12339

[T. Cotten]

Lazers are awesome!

But a quick and simple method that doesn't get you down on your knees is a trammel.
Mine is conduit with two mirror clamps to hold the pointers.TRAMMEL.jpg
Just roll the machine to where the rear follows the front, and then set the pointers from axle center to axle center.
Jump to the other side of the bike and compare.
Misalignment becomes obvious, and easily corrected accurately.

....Cotten

[DanM]

I have 2 8' flourescent light tubes that I place against the tires- space them off the floor with some wood. The higher you get them, the better the contact with the sides of the tires. But if they are firm to the rear tire, the front should be readily apparent. It is like the string Ron explains above.

[NiteOwl]

Wow, than you all for the feedback, this is very very helpful. I have a much clearer understanding. Ron, that description also really helps me understand the front end. I think that this upcoming winter I will pull it apart and also the wheels as I am suspecting my front is spoked in-correctly and that possibly the hub is ever-so-slightly out, but I will be able to tell more when the time comes.

[ronald]

Hi again NiteOwl,
The method I use is for basic set up when mocking up or assembling a bike for the first time and checking and setting basic alignment so your bike rides and handles really nice and gives you some where to start when you try to do your chain alignment and stuff like that later. I also have built a bike now and then that had a lot of parts that were not supposed to fly together and needed to accomplish that end. The shop manual has spec's for assembling the wheels concerning hub and rim offsets and spoke lacing etc., for stock builds. The reason I have centered the rim to the neck first is to make sure the front wheel is centered in the frame/fork and then centering the rear wheel in line with it so that you know that both front and rear wheels are rolling in the same track and the rear is not trying to "steer" the front. The trammel bar method as stated by Cotton, works really well to make sure your axles are parallel, providing you have a reference to work from, its also easier to use than a measuring tape unless you have a reliable extra set of hands to hold the "dumb end of the tape. That is why I use the triangulation method from the seat post hole. I can hold both ends of the tape on short distances. The center of the seat post hole is in most old bikes with stock frames is a known point that doesn't move. You can also triangulate forward to the seat post hole from the rear axle to square it in the frame and measure forward to the front axle center with what ever method you desire. An additional check for possible frame problems if you don't have access to a frame table, is to set the frame assembled with the front fork rear leg (springer), and a straight round bar that fits closely through the bottom holes in the right and left legs and extends out a bit on each side, do the same with the rear. I use the side car bracket mounting holes in the rear. Now support the rear "axle" by its ends outside of your frame so measures the same on both ends down to your work table top or floor or what ever you are using as a datum plane, and support the front "axle" in the center between the fork legs making sure the "axles" are parallel as measured front to rear. Measure the distance from the ends of your temporary front "axle down to your datum plane. If the ends of your front axle the same distance down to your datum plane within 1/16th of an inch, your frame, neck, and fork are probably as good or better than it rolled out of the factory with originally. There are several other methods to accomplish the same goal, but none as simple as using nothing more than a measuring tape and a string and a couple of pieces of round stock plus a flat table, don't even suggest that you're gonna use the dining room table, and your time and thought. Add a trammel and a plumb bob and a large carpenters' square to your measuring devices, you'll have a hi-class setup that you can check any frame with.
Ron. AMCA 12339

[NiteOwl]

Thanks again Ron, if the weather was not warming up here so rapidly I would tear it down this week. Your explanation is very very helpful and I can visualize the task at hand so much better now. I really appreciate this information, its saved, and I will let you know how it goes this fall.