Bicycle Mechanics - Caged ball bearings in wheel hubs - Replace individually, or ready assembled set

Amateur bicycle mechanic am I, but some experience as a mechanical engineer do I have.

I have probably pedalled 5k miles now on this wheel set with hubs, the first half with little regards to the adjustments or lubrications, the last with maybe obsessive zealotry (testing adjustment every 100 miles or so, relubing at maybe 500-750 intervals). Should I even replace them? Cup & cone are starting to get a mild groove.

They caliper-measure to be the 3/16 and 1/4 sizes which I have replacements in grade 25 chrome steel, but will I scar the spheres trying to force into the tange cage? If replaced as a set, what to search for as the type of replacement part and who can offer it? Ok to just leave cage out and put new ones in loose (like one more in each location) ?

I should already know these answers I feel, but enough experience I don't have .

Cheers.

You can replace the current balls in the retainers with new ones with no damage. The balls are extremely hard and the cage metal is fairly soft by comparison. Don't bother looking for replacement "sets", just use what you have.

Eliminating the retainers is also a common technique. As you noticed, at least one more ball will fit. Almost all Shimano hubs come with loose balls so it's s well established construction method.

The cup and cones will get a noticable "ball track" and that is also normal. The problems occur when that track developes pits or rough patches.

Finally, don't kill them with kindness. Unless you ride in very wet, dirty conditions frequently, clean, lube and adjust the hubs and leave them alone. I overhaul mine about every two years or 5000 - 7000 miles on each bike and they last for tens of thousands of miles. I have a set of older (7700-series) Dura Ace hubs with > 50,000 miles on the original cones and races.

More balls is better. I always throw the cages away.

More balls is better. I always throw the cages away.

Yep...the way to go...

Toss the 7 ball retainers in the rear for 9 loose balls...

The fronts will go to 10 loose balls...

Hubs will last longer as well if adjusted properly.

=8-)

That groove is golden until it does pit. A well broken in hub will always roll smoother than when new. I've never cared much for cages. As I always replace the ball bearings I find it easier to use loose balls than to remove/reinsert balls and clean the cage.

a FWIW .02 ...
One exception example , some parts, like one piece Cranks , BB bearings.
are a real PIA to put together without a retainer for keeping the bearings together..

took the hub bearing cages out of the AW3, cleaned and regreased,
it was a simple job, made quicker, with the retainers..

Eliminating the retainers is also a common technique. As you noticed, at least one more ball will fit. Almost all Shimano hubs come with loose balls so it's s well established construction method.

Finally, don't kill them with kindness. Unless you ride in very wet, dirty conditions frequently, clean, lube and adjust the hubs and leave them alone. I overhaul mine about every two years or 5000 - 7000 miles on each bike and they last for tens of thousands of miles. I have a set of older (7700-series) Dura Ace hubs with > 50,000 miles on the original cones and races.

+1. I have Shimano hubs, no retainers, very occasional overhauling does the trick. I use a magnet to get balls out easily so retainer doesn't even offer much convenience over the magnet. Some argue not to us magnets with loose balls on theory that balls become magnetized and stick together. UBI taught use of magnet in hub maintenance class, and I haven't noticed any tendency of the balls I have to stick together after I have used a magnet, so I continue to do so without worry.

a FWIW .02 ...
One exception example , some parts, like one piece Cranks , BB bearings.
are a real PIA to put together without a retainer for keeping the bearings together..

True enough, but the subject is hubs