Snowbum's BMW Motorcycle Repair & Information Website

2.  The wheel bearings are a common generic number 30203, you may see letters on them, and/or a prefix. You might see something like:  FAG30203A.M.P.   Many variations.  FYI, these are also used at the swing arms.

3.  The spacers I call "top-hat" types, since that is very common and very descriptive, can be installed in the wheel as installed on your airhead, so the HAT is on the outside or inside of the pressed-in-place wheel seal.  Very early models will probably have them OUTside.   These external-to-the-hub spacers do nothing special (they are certainly NOT part of the preload control); but, take up room to allow the wheel to fit between the fork lowers, or rear swing arms, and a major purpose of them is to ensure a good weather sealing for the bearing, in combination with the seal.   I prefer top-hat spacers on the INside, which means that you have to install them (OIL them for ease in pushing into the seal material) them into the wheel seal BEFORE the seal is installed into the wheel cavity. That way you do not 'lose them' when the axle is removed. The seal and spacer are installed together, usually just using a proper size socket (not quite full diameter as the seal outer).   One uncommonly known reason is that some seals have the outer lip angled OUTward, and could be slightly distorted if the hat was against it, but might be spaced away too.  The seals are the only protection for the bearing from water damage.

4.  The Booklet does not give any of the history, background, and how the environment, mileage, and exactly how lack of grease or old hardened grease, or other things, affect the bearings.  Nor does the Booklet explain that the original design was way over-kill, as BMW INTENDED for their pre-Airhead bikes to handle the high sideways forces from sidecar use.  Many of these things were explained, verbally, at the Seminar ....in the History, Advantages, Design, Environmental Effects, Safety, Economics, Car Wand Washers ....etc. ...part of the beginning of the Seminar.

NOTE ....BMW sometimes ships even brand-new wheels IMPROPERLY greased & IMPROPERLY preloaded. NEVER 'assume'.  Some Dealerships have been guilty of not servicing brand new wheels before sale/delivery/installation of the wheel to the customer.  This has been noted more than a few times for the 19" recalled wheels.

5.  There was a goodly amount of discussion at the Seminar about the design.  The original design of the early wheel hubs enabled crude, no special tools methods of servicing; that is, no 'pullers', etc., were needed.   I explained in some depth that the early wheels had removable small and large spacers, that the large one set the distance between OUTER bearing races, and the smaller inner one was associated with the wedding band spacer that set the INNER bearing spacing.  Thus, on the early hubs, there were TWO methods of setting spacing (preload), and the large diameter spacer inside the hub CAN be end-sanded slightly if required, in a situation wherein you do not have the required wedding-ring, or sanding the wedding-ring would be the wrong direction. Sanding the wedding ring LESSENS the preload, and sanding the outer large tube spacer INCREASES the preload.

6.  If you remove an inner bearing (that means the part with the rollers) for normal service work, be sure to mark it with an engraving tool, mark them L for Left, R for Right.  That is because you do NOT want to mix up the bearings.   Mark it on an end face.

7.  There is a modification for the early heated-type Airhead hubs.  It is easy to do on any grinding wheel.  Afterwards, there is no need to heat the hubs again for normal cleaning & lubrication.  Very worthwhile.  This involves grinding the inner small diameter spacer tube 'flanges/fins' just enough plus a bit more, so that inner spacer tube will remove from the left side without removing the left outer bearing race (this is for the future).   Greasing of the inner, right side, still captive bearing, can still be done by properly using Ed Korns round tool with the zerk fitting on one end.   I do it with a long thin spout on my grease gun.

8.  Some more verbal things from the Seminar:
a.  Shallow steel inserts, versus deep steel inserts on cast wheels.
b.  Single sided rear ends, that is, Monolever and Paralever, eliminated the tapered wheel bearing servicing entirely, in favor of the INternal large bearing inside the rear drive ...with their own set of problems over many miles.
c.  The R65LS front wheel introduced the 'Sealed Ball Bearing" design in 1981, far before the 1985 introduction on the larger engine models.   That R65LS had an odd-size, it was 17 x 40 x 12,  BMW # 36-31-1-242-854.
d.  1970 & later heated-hubs bearing assemblies are disassembled & assembled to the wheel, from the LEFT.
e.  FRONT all-aluminum hubs are heated for outer race removal.
f.  SOME very early /5 wheels had bores on the RIGHT side that were smaller, and used a smaller grease seal, and the top hat spacer remains captive.
g.  A FEW early cast wheels WERE all-aluminum, that is, there was NO cast-in steel insert (where the outer race is pressed-in as on later models).  MOST cast wheels have cast-in steel inserts.  Those few early wheels had to be heated.   Don't be confused here, "steel insert" as used here is NOT the outer race, but a cast-into-the hub part.  Sometime during 1978 production of the snowflake wheels, BMW changed to cast-in steel inserts.  The FRONT wheel had the cast-into-the-wheel steel insert, the REAR DISC brake wheel ALSO did; thus those two have outer races that are PRESSED-OUT and PRESSED-IN.   The 1978 REAR DRUM snowflake wheel had to be HEATED, there was no cast-in steel insert, and another Identification that might be helpful besides #1 eyeball;  there are FIVE bolts on those! Heating does not injure wheels that normally use room temperature pressing (there is no purpose in heating them, of course), but heat is MANDATORY on wheels requiring it (all aluminum, no steel insert cast into the wheel).  1979 to 1984 wheels were all the pressed-type, for these outer races.  A magnet can be used, sometimes, if not touching the outer bearing race. You can refer to AIRMAIL of August 1978 and June 2001.
h.  The 17 mm front axle came in 1975.  Earlier wheels can be converted, & the larger axle does not bend easily under hard usage.
i.   Do not reverse a dual front disc wheel, or you may have brake-pads break-in to do again; and may also have to adjust the ATE swinging calipers, if you have that types.  By conventional practice, the brake carrier NUTS are on the LEFT side of the motorcycle front wheel for a disc brake wheel.

NOTE:  Some have been confused by 'left' and 'right'.  On ALL vehicles, left & right means as you sit normally on/in the vehicle, unless associated notations specifically say something else.

j.  NEVER EVER rest a disc brake wheel on its disc when working on tire changes, etc.   You may permanently bend the disc/carrier & then having lousy surging brakes.
k. 19" FRONT snowflake wheels were recalled if the casting is stamp-marked BEFORE 1982. https://bmwmotorcycletech.info/19inchrecall.htm
l.  The wedding band spacers, officially called spacer shims, are approximately 1/4 inch wide for 17 mm axles, and approximately 3/8 inch wide for the earlier 14 mm axles.  You do NOT need a big bunch of these, maybe none, think about using Duane Ausherman's convenient shim kit to allow fewer wedding rings owned.

UPDATE: Duane sold the dies, etc., so see my comments in this website regarding where to purchase the shims:  https://bmwmotorcycletech.info/section4.htm

m.  Ed Korn's greasing tool can be used, with some care in inserting (to several slight depth changes during use).   Years ago, there was another type of greasing tool made by Chuck Walus, it was described on pages 23 and 24 of the June 1978 issue of BMW Owners News. You can also use a common cone-type of bearing greaser, for the bearings once OUT of the hubs, they are not expensive at your favorite autoparts store ....although hand greasing is OK, if you are thorough.  Re-greasing cleans the old often contaminated and hardened grease out, & puts new fresh soft grease into the bearing.   Don't be afraid to use lots of grease.
n.  I use two special spacers during my preload work on wheels.   The machined steel spacers that I personally made for 1979-1984 RS and RT models were 1.5" diameter; 0.668" +.002, -.000 center bore.  Of the two spacers, one was 2-1/8" to 2-1/4 inches long (unimportant, just in that range); the other was 2-3/4 to 3 inches long.  One could also use 2.0 inch diameter material (or, any other    diameter that FIT properly), then you must use the formula to calculate the proper ounces or grams for YOUR spacer diameter.   The ENDS must be flat and square to the bore, which is why they were made on a lathe; AND, they MUST fit the bearing and not press on the hub.  If you have some made, determine the length YOU need first, and have your cleaned and lubed axle handy to check for a smooth slip fit.   Some folks reading this may wonder about the use of the common 'pipe' as spacers in part of the procedures in the booklet, especially for the heated hubs assemblies.  That has been found to work OK if machined square as described and CENTERED in use. Not as nice as these special steel spacers I made up, which give much more repeatable results.  If using common pipe material, have the ends squared & smooth, done on a lathe.  It is quite important that the spacers you make up, fit very squarely and centered to the wheel bearings.   Pipe inside diameters don't allow that as the I.D. is too large, so the pipe must be placed by careful eyeball or measurement to be centered.  I suggest you do not use pipe. The two machined spacers allowed servicing the preload on the front AND rear snowflake wheels, which is why I selected the particular lengths.  Check before having them made, so YOUR bike has the proper length spacers.

Part 2:
This part applies to the articles in MOA-ON in 2004:

1.  May 2004, article on "R90/6 Front Wheel Hubs"; this was PART 1 of the 4 Part series of articles.  This article has a lot of pertinence to all the airhead pre-1985 wheels. Page 26, top illustration, the upper parts are for the 14 mm axle, lower parts for 17 mm axle.  Page 28, photo #14:  1970-1977 spoke wheel, rear, left; 1970-1977 spoke wheel, drum, front, left, and 1974-1977 all spoke, disc, front, left AND right.