Rigid_EVO Rear dual flange hub question

[conv90]

I'm replacing wheel bearings and I'm installing a new 5.5" aluminun rim on the rear, so I have to center it perfectly between the swingarm.
I laced it and trued it in a perfect manner.
The HUB is supposed to be a stock one with the right sprocket flange side that protrudes a bit more than the brake side.
But measuring from the very last sprocket side end of the hub to the very last end of the brake side, the center of the hub (and wheel) is perfectly between these 2 ends.

(when I say "very last right/left ends of the hub" I means the little spacer surface of the spacers that stick out from the bearing seals.

Now the real question the spacer(s) between the hub and the swingarms.
I have a stock spacer (sprocket side) that is 0.645" (16,5 mm).
I'd expect to have a SAME dimension spacer on the brake side.
Yes the spacer at the brake side is the brake caliper bracket itself.
(I have a PM aluminun brake caliper bracket that is 8,3 mm wide and a spacer to use with -supplied with the PM kit- of 6,2mm for a total of 14,5mm)

So 16,5mm are not 14,5mm . I thought: probably PM sent me (years ago) the wrong additional spacer...
So I searched for the original brake caliper bracket and measured 14,5mm exactly like the pm bracket and spacer.

I moked up the wheel without brake disc and without sprocket and actually (obviously) I have a difference of 2mm . (the wheel is closer to the swingarm at the brake side).

It is correct that the the hub (and wheel if correct trued) is more close to the brake side?

[JB in NC]

A difference of 2mm in the spacers means that the rim & tire are off C/L by 1mm, or .04". That little bit of manipulation was possibly done to make room for the belt. All of the H-D big twins have the rear wheel offset toward the drive (left) side. The dimension varies for the different models. I have thought for years that this offset is there to balance the rather heavy primary drive that was moved to the left to make room for the alternator in '70. Lateral balance is what makes the bike go straight down the road.

Certainly nothing wrong with centering the rear wheel in the swingarm if you wish. You will have to correct the chain or belt line if you move the hub. I have done this on big twins when using an open belt primary drive, which of course is much lighter than the chain drive.

A side note: I doubt very seriously that you have 9 5/8" rods in your motor. A little editing is in order.

Jim

[conv90]

Originally Posted by JB in NC

A difference of 2mm in the spacers means that the rim & tire are off C/L by 1mm, or .04". That little bit of manipulation was possibly done to make room for the belt. All of the H-D big twins have the rear wheel offset toward the drive (left) side. The dimension varies for the different models. I have thought for years that this offset is there to balance the rather heavy primary drive that was moved to the left to make room for the alternator in '70. Lateral balance is what makes the bike go straight down the road.

Certainly nothing wrong with centering the rear wheel in the swingarm if you wish. You will have to correct the chain or belt line if you move the hub. I have done this on big twins when using an open belt primary drive, which of course is much lighter than the chain drive.

A side note: I doubt very seriously that you have 9 5/8" rods in your motor. A little editing is in order.

Jim

Thank you , this make sense. 1mm or 2 is nothing.
But usually in my head I like to understand so i asked.

I swapped a 4,5" rim for a 5.5 and I think I need a new offset front sprocket.
Now I have the tire installed and it is just a bit larger (not so much), so probably I don't need a front sprocket with more offset than now .
And probably i'll be saved for that 1-2 mm ! LOL

About rods...

Stock rods are 6.926". The Carillo's are 6.938". So they're actually .012" longer. When I made the signature was more concerned on the .012" difference than the error of 3 full inches!
Thanks

[conv90]

I'm satisfied. I had to (I wanted to...) put a 1,5 mm spacer on the brake side.
I have sufficient room on the chain. The bike goes stright (actually as before ).
The only diffenece respect before (with 4.25 rim) and no 1,5mm spacer is that
BEFORE I was able to almost "close" the right side of the tire, but the left was with a 1/4"-3/8" unused side tire.

NOW i have "closed" both sides probably because the tire is more flat and less sloped than before.

When I say "closed" I means that all the tire surface is used.