Having had my Merc for a year now and done 1.5K, I thought I'd take a look inside the trhee speed hub. I followed the instructions and quickly had the thing available for inspection, though I didn't actually dismantle the unit. I'd noticed that the hub gave off a lively clear ticking sound in use and especually when freewheeling. On inspection, I felt that it was only very lightly lubricated. The new SRF3 Taiwanese hubs are supposed to be lightly greased on assembly, but to my taste, this one was far too dry. There was barely a smear on the bearings and the cogs of the planet system looked pretty well dry, with the merest gloss of old grease here and there.
The old SA hubs famed for lasting fifty years and more were lubed with medium weight oil, and I am assuming that the new ones are built with the idea that they'll be thrown away after a few thousand miles and will do fine with a light application of grease at the factory on assembly. I'm aiming to keep my hub a while, so I regreased the hub bearings with the castrol LM grease that I used on car hubs, and gave the planet gears a good squirt of hypoy gear oil. There are about 3 ccs of hypoy in the hub now which will drain to the bottom of the hub when the bike is parked and mean that the lowest of the planet gears will be sitting in it. My feeling is this will work right around the planet gears in use, because they all mesh with a single central pinion.
After a test ride none has come out, so I don't think I'll get a lot of extra mess. The gear change is now slicker and smoother and the hub is a good bit quieter. I know this action of mine is against the new rules, but I'm going to ride another thousand miles and then take a look inside to see how the lube has lasted - unless I get any wierd results in which case I'll whip it apart again - it isn't a hard job to do.
Any opinions on what I'm likely to find as a result of this?