I have a 1995 Fat Boy that I am very happy with at this stage in my life, so I admit that I don't "keep up" with what H-D does these days.

One thing's for sure, though: Doing the routine maintenance on the wheel bearings sure is a pain. At least new bearings are low cost. (I work as a machinist and buy bearings direct from a distributor.) I've never "serviced" a bearing; I just replace them every time. Anyways, to my question:

I understand that the newer bikes have a new type of bearing that needs almost no routine maintenance. If that is true, could these newer bearings be used to upgrade my '95? It might be relevant to note that '95 was the last year of the "old" speedometer. My speedometer cable is driven by the front wheel.

Thank you to all who take the time to reply.

 

At some point Harley went to a larger diameter axle and I don't know if that was when they went to sealed bearings of if there are a couple of years where sealed bearings are available for your axle. Installing new bearings every time is not advisable since they need to be properly set up with spacers to get the correct play. They are tapered bearings and they don't wear out very quickly. Unless, of course,they are not properly spaced - that will kill them.
Since you've gone to all the trouble to remove the seals to access the bearings its not much more work to just clean them with some kerosene and repack them with grease. But it sounds like you are trying to avoid that whole process. Google FTM sealed bearings if HD does not make them for yours.

 

I would keep your setup and get a new set of high quality Timken/Torrington replacements. Not worth the trouble of changing to sealed units IMO.

 

I have an '87 and have probably been through 7 sets on the rear. 81,000 on the front - still good. Long story, but the second set I required was MY fault - and it cost me a swingarm, axle and associated parts for the education of how NOT to set up the preload. 5th set was from swimming through a flooded road (about 3000 miles later)

So needless to say. I have issues about wheel bearings, especially on the rear.

The grease you use is critical too - I recommend Amoco Super Blue (if you can find it) Castrol Extreme (something or other, can't remember, but it's red in color) Has kept the last set looking good through 2 rear (and soon to maybe be 3) tire changes.

Anyway getting to the point - I think they say every 10,000 miles (?) If you set them up and pack themproperly, as I assume you have, they should certainly go at least the life of a tire on the rear. I've been servicing mine, front and rear,everytime I change the rear tire (12,000 - 14,000 miles) And yes, they're relatively cheap even from an HD dealer and always replace them if there is ANY question. Just my opinion

 

Thank you to all for all of the advice. I don't, however, agree with the statement that it is not advisable to change the bearings. As I stated in my original post, I am a machinist; journey level, and going on 25 years in the trade. I work with calipers, micrometers, and other precision measuring equipment daily. Maybe I'm just one lucky s.o.b., but I've never seen a set of Timkens that didn't set up nearly identical (if not identical) to the ones before.

I spoke with an H-D tech today as well as asking here, and according to him, there is no significant difference in the "working" components; H-D pretty much simply changed from tapers to sealeds. I am confident enough in my own mechanical abilities and knowledge to believe that I could get sealed bearings to work, provided I can find quality ones with the correct dimensions. Special spacers, shims, and/or what not may be required, but I can fabricate those.

Thank you again for taking your time to share your advice.

 

If you are looking for the advantage of sealed bearings versus non sealed then that is understandable. This has been proven with automotive hub units and increased life cycle. Sealed units keeps the contaminants out which extends bearing life exponentially. But there is a big difference between the load carrying capacity of a tapered bearing vs straight roller or double row ball bearings which may account for the larger axle size on the newer bikes. Tapered bearings will definitelytake higher loads than ball, or straight roller bearings.So the tapered bearings take the physical loads that a smaller axle does not and vice versa

You could contact Timken www.timken.com or Skf www.skf.com and give them the dimensions of your axle and factory part number ( which will give them the dimensionsand load capacity of your existing set up)and see if they can recommend a sealed unit that will take the radial & axial loading forces your bike puts on the tapered units and yet still fit within the envelope you have to work with. This is probably much more than just fabricating a few parts IMO. Plus they will be real hesitant to guarantee any safe results if they will even go on a limb to talk about it.

However, INA/Schaeffler Group is the primary supplier of bearings to HD and they will be hesitant to recommend an interchange due to product liability. The HD tech you spoke with will have no idea of the amount of engineering that goes into the proper bearing selection required to prevent high speed bearing failure which on a motorcycle wheel unitwould no doubt be very serious if not fatal. If you do have some success at this than you should patent your idea as an aftermarket interchange unit. But get lots of insurance. Because some jamoke will put them on incorrectly and kill himself and you will be held liable.

So, in a nutshell......that is whyI recommended you stick with the part designed into your bike.

 

I've thought the same thing for a while now. I definitly prefer the sealed bearings.. Please let us know what you finally figure out. I cant see why it wouldnt work, epecially if the load factor works out as mentioned..

As for the reasoning of not replacing the bearings. I think he meant well, but its simply not true.. The axle bearings are preloaded on one side(left side) while the other side is just clamped into the fork lower for support.. The spacers are there to make sure the wheel is properly spaced in the fork or swing arm to allow proper rotor placement in relation to the caliper mount.. You wont see enough variation in bearings to effect this..

 

Yes but with a smaller axle you will need a higher capacity bearing. If he can find an equivalent sealed tapered unit that fits that axle he should be ok. But if he simply takes a sealed ball bearing or straight roller bearing unit he may be overloading those style bearings in a design made for a tapered unit. He needs to match the radial & thrust loads of his existing tapered bearing. The results could be dangerous because the limits of those will be realized at high speed. That is my point.

 

I wasnt disagreeing with you at all.. If he can find a bearing to work in the proper load range, it would be a good modification.. You are absoloutly right.

 

Excellent points. I fully intended all along to take into consideration the load abilities of any bearings. Our shop is full of catalogs with all of that data, so researching it will be easy enough.