Dyna swingarm/frame alignment
Tourer
Hello,
Having my Dyna FXDLI -06 inside during the winter for different jobs (new compensator, new belt etc), I thought I might as well have a look at the alignment.
With my earlier unsuccessful aligning attempts (which included measuring the angles of the rotors) in fresh memory, I went googling on the subject. What I found was a guy at YouTube with a tool he has invented called Straight Shooter. Anyway, his system is different from the brake rotor method, and is resting on measuring the distance between the bolt holes for the shocks. The equipment he sells is very expensive though, (with lasers and stuff) and I intend to use only a spirit level and a 300 mm calliper.
I plan to do this:
1/ Put a lift under the frame, lifting the rear frame so the rear wheel barely touches the ground
2/ Remove the shocks, put the frame in level and support the bike
3/ Reinstall the shock bolts with a few turns only so that you can reach the bolts under their heads with the caliper
4/ Measure the distances between the shock bolts on both sides with the calliper
5/ If the distances are not the same, lift the tank a bit and adjust the top stabilizer link; move the top part of the engine to the right to decrease the left side measurement and to the left to decrease the right side measurement.
To me this method seems very logical and simple and I look forward to try it as soon as the caliper arrives from Amazon.
I should add that the service manual does not recommend turning the stabilizer more than three turns as this could cause excessive vibrations.
Anyone here tried this method?
Yep. Frame can be off a little depending on welds but the important part is to get both wheels vertical.
(With string instead of boards.)
Last edited by John CC; Jan 24, 2025 at 03:40 PM.
Anyway, I thought the whole thing was awkward, and the other day as I googled I found lots of videos made by the guy who invented his Straight Shooter. It looks to me that he has another idea, based on, not the rotors, but on the straightness of the swingarm to the frame.
I thought I could find an easy way, without a lot if laser beams and stuff, by just measuring the distance between the shock bolt holes.
Now Max says the holes are not reliable and suggests measuring the rotors and keeping the front wheel aligned with a string.
Then I thought that would mean just to tie the wheels together with some tension and it would keep the front wheel aligned to the rear wheel.
But I may not understand the drawing correctly. In which way does the drawing contain a string?
P. S. There are three things before adjusting the top link, (using levels on the rotors), as I see it;
1/ Aligning the rear wheel to the frame (horizontal)
2/ Keeping the bike/frame straight
3/ Keeping the front wheel in alignment with the rear wheel
Last edited by OakMountainRider; Jan 23, 2025 at 11:38 PM.
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As the bike had an accident with the previous owner, (marks are visible on the front fork), and the fork may not be straight, I may never get the rotors straight unless I replace the fork, I thought.
However my idea now is that the Predator front mount may prevent the engine from turning and I will be better off by loosening it a bit before adjusting the top link.
Last edited by OakMountainRider; Jan 24, 2025 at 04:40 AM.
The Best of Harley-Davidson for Lifelong Riders
To use the string, tie to the back side of the rear wheel both sides. Pull strait to the front. Swing it until it touches the front of the rear tire and you have your line on each side.. If you have straight pieces of wood that's fine. You need to make sure the rear wheel is lined up first in the swingarm. There is a tool for early Dynas not sure about late.
Lasers work well. I happened to run across a one that does crosshairs and mounts to a aluminum bar.. I clamp scales to discs (dual disc) and measure from there..
The predator mount may be part of your problem. They have a bit of slop in them.. The mount will flex tho.. The one I have has a plate for the stabilizing link that is clamped by the main bolt through the rubber isolator. The hole in the rubber is a bit oversized which can allow the mount to shift.. I tried it and went back to the OEM mount and a Sputhe front stabilizer. Heck, cu
If off by 2 degrees you may need to adjust the top link buy 1/4 inch or more..
You may want to pull the tubes and check for straightness. Don't have to disassemble. If bent, they will be bent at the lower tree.
Custom Cycle engineering makes a front mount that allows the front to be adjusted side to side.









