Looking for the purpose of the front wheel hub sealed ball bearing spacer for 2000 & up.
Understand the reason for spacer on 1986 to 1999 that incorporates the tapered roller type bearing.
The tapered roller bearing requires an axial preload to prevent roller slide on the race.
Depending on the tolerance stack up, there is no adjustment for preload using a castle type nut & cotter pin(unsightly), torque the axial nut to specs and the preload is setup.
Thought that ball bearings do not require an axial preload.

Measured the width of a 2005 , 3/4" bore ball bearing at 21mm(.825")
Measured the hub shoulder depth from lip = .932"
Difference = .107"
so when the ball bearing is installed flush with the lip, there is .107" gap between the bearing race and the hub shoulder.
The 3/4" bore ball bearing is deep groove type with possibility two rows of ball bearings, which may require a preload.
The 2007 & up , 25mm bore is 15mm width, which maybe a single row ball bearing

 

the purpose is to roll the wheel. the spacer keeps the distance and rolls with bearing. to my recently and begrudgingly earned knowledge, bearings are not to be installed flush with the lip, they are to be installed in a side specific order that sets up, along with the wheels spacers, position of wheel and the rest of wheel assembly (rotors, pulleys, etc...) to fit calipers and such.

the *2008* + 25mm, i think was, and hd attempt at uniformity across most of the line.


the more knowledgeable folks will appear with more info.


what are you working on?

 

Working on 2009 custom with 21" front spoke wheel , retrofitting to 19" using a 2005 used hub that was fitted with 3/4" bore ball bearings.
removed the 3/4" bearings with " pro motion" bearing removal tool, had to heat up hub in oven to 270F to remove bearing.
Inserting 2008 & up 25mm bore ball bearing in 2005 hub.
Wondering if ring shaped spacers are required in the bearing hole?
When the tube spacer and bearings are installed there must be a small clearance for the tube spacer, so it gets centered when installing the axle.
Maybe when the axle nut is torqued, one of the bearings will slide to eliminate the clearance, doubt if both bearings will slide, the one with least friction will slide.
Maybe the purpose of the tube spacer is to reduce stress on the cast aluminum hub and prevent the bearing from wobbling and working loose in the bearing hole?
The tube spacer with zero gap would stabilize the bearing in the hole, since there a ~ .1" gap between the bearing race and the hub shoulder.

 

**Here's some info to start you thinking, I'll look at your next post that just came in and comment if neccessary.



NO Bearing Preload...hope the illustration below helps

The spacer sleeve along with the space between the secondary bearing outer race and the bottom of the bore is to prevent bearing preload.

The "Primary Bearing" (first bearing) happens to be shown on the Left. It's the one bottomed in the bore. Your Sportster's primary bearings are LEFT-Front and LEFT-Rear (unlike most Big Twin Harleys, which are LEFT-Front and RIGHT-Rear )







BTW Cvaria, after reading your last post in your thread, I think we should to re-visit your bearing install. Probably use this illustration also
.
.

 

You need the 08-later Narrow-glide front spacer sleeve #43906-08 and bearing shim #43315-07 (goes under Primary bearing). The bearing shims allow the Thinner 15mm wide (25mm ID) bearings to be used in a wheel designed for the wider 21mm wide bearings (3/4 & 1" ID). FYI, Harley also sells a installation kit that includes the above 2 parts along with their bearings for this exact situation, but you can just buy the #'s above and use which ever bearing brand you want

 

The diagram explicitly shows the correct installation.
Measured the 2005 hub lip to lip = 4.848"
tube spacer length = 3.037"
doing the arithmetic, using the original 3/4" bore ball bearing ,21mms width, when the left bearing(caliper side) is installed to the shoulder , the bearing is recessed .046" below the lip.
If the shim width is the difference between the 21mm wide & 15mm wide = 6mm, the new 25mm bore bearing should also recessed .046" below the lip.
Furthermore, using the 2005 hub and hardware , when the right side bearing inner race contacts the tube sleeve, the bearing should be recessed .115" below the lip.
if the retrofit tube spacer is 2x 6mm= 12mms longer than the original 2005 tube spacer, the right bearing should also be recessed the .115" below the lip.
Seems like the bearings should be centered in the hub.
Measured the bearing hole shoulder depth with a depth micrometer and the right and left sides are not equal.
Right side =.928"
Left side = .871"

 

Understand the gap between the right bearing outer race and the shoulder prevents a preload on the ball bearing.
When axle nut is torqued, there is contact force between the two bearing inner races and the tube spacer, but since the out race on the right bearing is allowed to slide with some friction,
it prevents excessive axial preload.

 

You're working on an '09...
You can use/re-use your:
- 2009 Wheel/axle spacers (changed length in 2008)
- 2009 spacer sleeve (changed in 2008)
- 25mmID x15mm wide bearings (changed in 2008)
- then add the bearing shim for Primary bearing "positioning" (and thus the bearings/spacer sleeve stack-up positioning) within the earlier wheel.

The bearing shim is not 6mm because they also changed the Left spacer length when they went to the thinner 15mm wide bearings. Btw, the bearing shim "surrounds" the sleeve and so it doesn't add to the width dimension of the stack-up

 

If the bearings are installed correctly with NO SPACE between the inner races and the sleeve, then there is no additional bearing movement (inner or outer race) during the "clamping force" of the Left slider/axle spacers/bearings/sleeve stack-up by the axle and nut

 

i refuse, will not go back down that alley with green eggs and ham... not til the roadster wheels. that self-inflicted nightmare is over...