Rearend alignemnt question

[baylensman]

Well i read and re-read the alignemnt articles. i have a question or two. so i take a large round steel tube (drive shaft cover) attached solidly to the frame as far as front rear movement but it does have radial movements as it is also part of the swing arm assembly correct?

on the end of this solid pipe i weld a big flange with 4 holes, thee holes attach the rear chunk or diff to the bike, correct? this establishes on end of the axle position. the other side of the swing arm is also solid and has a single hole for the axles establishing the other axle end point, correct?

 

now if my axle is binding (creaking noise or poor handling or uneven tire wear) and i want to realign it, i take the rigid axle put it through one mounting point (pinch bolt side) loosen the 4 bolts on a rigid flange holding a rigid casting, then reinsert the axle into the now loosely attached rear diff. Then retighten the 4 acorn bolts/nuts.

 

how does this change anything? it would seem to me i need to either bend the swing arm tube (not good) or shim the diff housing to change alignment.

 

what in the name of phyics am I missing?

[WildBill1]

Physics being what it is and Yamaha rearends being what they are they are relative. With the four mounting bolts loosened align the axle with the swing arm and rearend where there is no drag slideing in and out with little to no resistance. It's really more about mechanics than physics.

[Flyinfool]

You are missing clearances.

In order for the bolts to go through a hole the hole must be bigger than the bolt or stud. this means that there is a small amount of slop between the stud and the hole it goes through. what you are doing is to use the axle to find the best possible location within the available slop.

[baylensman]

You are missing clearances.

In order for the bolts to go through a hole the hole must be bigger than the bolt or stud. this means that there is a small amount of slop between the stud and the hole it goes through. what you are doing is to use the axle to find the best possible location within the available slop.

 

 

Now that makes sense but is kind of scary at the same time. Aligninga rar end and axle using the slop in the bolt holes! build car diff's for almost 40 years i can tell you that most rears are ruined on the bench not in the car! tolerances are in the thousandth of an inch range.

 

But I guess it works! Don't hear of a lot of Yamaha rear diffs going Kablooey:detective:

[WildBill1]

Now that makes sense but is kind of scary at the same time. Aligninga rar end and axle using the slop in the bolt holes! build car diff's for almost 40 years i can tell you that most rears are ruined on the bench not in the car! tolerances are in the thousandth of an inch range.

 

But I guess it works! Don't hear of a lot of Yamaha rear diffs going Kablooey:detective:

 

Yea well, cars are different animals cugars, jugars and such.......