Ok, Here's the situation. I'm in the process of wrapping up my Fatboy/FXST front wheel project. I got a great deal on a set of 07 FB Chrome wheels from a fellow member and I'm determined to make them fit on my 06 FXST. I originally mocked the wheel up with bronze bushings in the bearings so they would "fit" my axle....the 07 uses 25mm bearings vs. my 06 3/4" axle. By doing this I was able to use 07+ FXSTB spacers to get the brake rotor/caliper to line up perfectly on the FB wheel. I am not OK with running any kind of adapters/spacers/reducers in my bearings.....especially in the front wheel. I did some research on the bearings and found that the 25mm bearings are 6mm narrower than the 3/4" bearings. So if I put the wider 3/4" bearings in the wheel, I'll need a brake side spacer that is 6mm narrower to make the rotor and caliper line up correctly. Sure, I can go to a machine shop and have a custom spacer cut if I absolutely have to. I've searched catalogs and the net and found a setup using OE spacers that will put me within 0.011" of the original set up....yes, thats 11 thousandths of an inch. Does anybody think this amount will casue any issues?

Here's a pic of the wheels on my bike.

 

You will need to have a spacer made for between the bearings if you are totally against reducers. The last one I did, the 3/4 bearing fit in the bore on one side and stuck out on the other. I don't believe 0.011 will be a problem. The easiest way is to have a machine shop make a reducer that goes the full length from bearing to bearing...then you can use all your original stuff...just make sure it is a few thousands short so the spacers tighten up against the bearings..or get a 25mm axle and have it turned down to 3/4" on the ends.

 

There is that much range in the pistons in the 4 piston non floating caliper. Think were your problem is the lower sliders are going to pull in .022 at the bottom. That is a lot. I know just out of curiousness I miked over the outside of my upper tubes in the trees and they were within .001 top to bottom Check my album on spacer/bearings for reference. I thought Harley had the proper double row bearing in the correct width with the 25mm hole for this setup. Do not see it now however.



Info update on these WJB Bearings.

DH559339 ID = .75" OD = 2.0472" (52mm) Width = .8268" (21mm)

DH559339-1 ID = 1" OD = 2.0472" (52mm) Width = .8268" (21mm)
« Last Edit: Wednesday, August 19, 2009. 01:50:21 AM. by Fatboy_SirGarfield »


A sealed ball bearing with an internal of 3/4" , External 52mm and 21mm width. Manufactured by the automotive specialists KML, this bearing is commonly used in Harley Davidson applications and will replace HD9267. Also known as: F-390598, 390598, H-D9267, DH559339, 19x52x21, 19.05x52x21, 3/4x52x21, 3/4"x52x21, 1013-2RS

 

I have the inner spacer for the 3/4" bearings already. It's the same exact length as the original 25mm spacer. So, in theory I should have identical 6mm extra width on both sides of the hub when the bearings are installed per HD specs. According to my manual the brake side bearing is installed first and seated completely in the rim. Then the spacer is inserted and the other side bearing is seated against the spacer.

I am seriously considering the reducer like you mentioned. Either a billet or steel spacer that is the whole length of the hub inside...bearing to bearing. What I have now is just 2 bronze bushings that are 1" long inserted in each bearing. This was just a quick temporary set up to mock up the wheel.

 

I'm trying to retrofit 3/4" bearings in to a wheel that was designed for 25mm bearings. The width of the 25mm bearings is only 15mm as opposed to the 21mm width of the 3/4" bearings. This is where my project begins. I'm having to compensate for the extra 6mm width on each side of the hub. If I could locate a 3/4" bearing with a 15mm width I'd be set. So far I haven't found any yet. I'm going to check with a couple of bearing warehouse's tomorrow when I get to work and see if they can cross reference anything for me. Like the #'s you posted, I'm looking for a 19x52x15, 19.05x52x15, 3/4"x52x15 etc....

I do not think the lower legs "pulling in" will be an issue at all. The overall width of the spacers and wheel will be the same when I get done. My FXST lowers are torqued with the axle nut on the brake side THEN the pinch cap nuts are torqued so there shouldn't be any "pull" on the lowers regardless of how the spacers measure up.

 

I kept pondering that. I was thinking mine which has two axle nuts pulled on the outer sliders but like yours actually realize that they actually torque thru in spacers and inner races yet one side floats so as not to pull on lower slider. Hence the cap side of the slider. Be sure to follow up on exactly what you do to make it work. The 3/4 ID bearing is a double row bearing that will take thrust in either direction. The 25mm id bearing 0.591 width is a single row bearing. Have never clearly understood if they are single thrust and must be orientated which side goes into hub. You would have thought Harley would have designed them to work by just making the inner spacer wider on the 25mm axle so the outer width was the same. Think mine are 6 1/2 front and back. I know as Harley as gone to wider tires that has grown. My friend's 200mm rear fatboy is 7 1/4
Think were I got confused even more now was I thought this bearing was only on a Dyna. Were did you come up with the .011? I just did a break job and I knew with the pistons all pushed back you had a lot more then .011 on each side of the new pads hence why I had said should not be a problem. However you are talking about 0.235 bearing width difference. Not too long ago a post on here with the same wheel had mistakenly pressed in the 15mm width bearings in them and they were hanging out each side of hub.

 

I agree with you. Harley has no rhyme or reason when it comes to their bearing sizes it seems.

As far as my calculations go I'm using different spacers to come up with my 0.011" difference. The 07+ spacer I used for the original mock-up is 1.116" and this is a perfect fit. I was figuring that if the 3/4" bearing is 6mm (0.236") wider, I would need a 0.880" spacer to fill the difference and end up with exactly the same offset. The closest "off the shelf" spacer available is 0.891". This is where I got the 0.011" difference.

I'm thinking that the other post you are referring to is probably the opposite scenario. They were probably attempting what I'm doing and put a 3/4" bearing in a wheel designed for a 25mm bearing. This would cause the bearings to be wider than the hub on each side.

 

6205/019-2NSENB Nachi Sealed Japan 19x52x15 Ball Bearings
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