EvilV

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?

jur

You're likely to find a dirty hub and spokes as the new oil runs out. The newer hubs have rudimentary seals and that's why they are greased and not oiled as the older ones were. The grease is a very thin grease for the gears and conventional grease for the bearings.

EvilV

You might be right, but none has come out in the first twelve miles. I know you ride long distances every day, so by now you might have seen it escaping... I'll have to see. I know they have no seals to speak of, but then they don't need to be full of oil either, just a teaspoon full or so every five hundred miles.

jur

It'll be interesting... keep us in the loop.

EvilV

OK - here's an update Jur.

I found a disadvantage to the EP80 geer oil. It is too thick for the little planet gears and causes drag. This only gets noticed in the top gear and shows itself by the pedals trying to keep moving when freewheeling. This wouldn't be a great problem, except that the chain actually came off the cog becaue the cog was trying to turn and the chain was stopping it.

Sorted things by dismantling the unit completely, cleaning all items of lubricant and rebuilding. This time the bearings have been greased and the planet gears, dogs and pawls were liberally lubricated with 10/40 engine oil and the unit was reassembled into the case with about two teaspoonfulls of the same oil in the case. The idea here is to allow the ring gear to pick up oil when the bike is standing, so that it is redistributed around the planet gears in use......

That's the theory anyway. I've ridden a few miles and none has leaked out and the freewheeling is fine now. You can tell that I haven't enough to keep me busy, can't you, else I'd have left it all alone in the first place. The other thing is that I have total familiarity with the hub now and definately understand how it works - LOL.

jur

Yeah I have had the issue with the crank dragging along when wheeling the bike along as well. I have found it differs from hub to hub. The one that came with my R20 is a dog. I have cleaned and lubed it with all sorts of lubes, without much success. It drags terribly. That one also leaks the oil out immediately. One that I picked up off the side of the road a few weeks ago is hugely better. It spins so easily, I may just transplant the innards to my R20 wheel. I have puzzled over it but can't say for sure what the cause is. I don't think it is the seals. On the maintenance instructions you'll find that in the trouble-shooting section, one of the reasons given is chain too tight, another is dragging seals. It's not either of those.

EvilV

Interesting to read of your experiences Jur. I think I read that having the cones too tight could also cause it. I've googled the kind of terms you'd expect and found lots of info about lubing the older hubs. Normally the fault finder chart mentions corrosion and lack of lubrication as the causes of this, but plenty of references were found to using too heavy a lubricant. When I stripped the thing and watched how those little planet gears spin as you rotate the hub on a fixed axle, it would be no surprise that heavy lube would cause a problem. Ordinary bearing grease on the internals is a 'no no' of course as is any heavy lube, but you probably already know all that. Here is a reference to over-tight cone adjustmet:

https://www.cyclingforums.com/showthread.php?t=288367



https://vancruisers.ca/Members/bhughe...peed-hubs/view

This chart is worth a look:

https://www.users.globalnet.co.uk/~hadland/sa/safaultfind.pdf

jur

Ah yeah, I remember going through that chart at one time. I think I counted the balls. I shall have to do it again to make sure.

I always had the vague feeling that the one set of pawls rub against the planet cage.

jur

I just read through that thread you posted, and I'm pretty sure I have the same problem as that chap.

This fills me with renewed determination to find the reason.

Andreasaway

On my old SA 3sp I did a total disassembly and used Molyslip and Tri Flow, and it is incredibly smooth. The only problem is that Molyslip is very dark, and stains badly, so I have to be careful when cleaning. sI put a very thin coating of molyslip on the all the gears pins ect when assembling then a coat of tri-flow before closing it up. I haven't noticed much escaping, and I will probably only add tri-flow to the oil port.
I am a huge fan of molyslip. When I owned a car, I put a bit in the trans to smooth things out. On a trip to Mexico, I put a hole in the case, on a terrible dirt mountain road and unaware drove 4000km with no trans oil, before real symptoms appeared. After realizing it, I squirted a bit of 90w in, and drove the 1200km home, with no problems. The car had 400,000km and that was its final drive, but the repaired trans lives on in a neighbours VW.

EvilV

Yes - I remember that stuff when I first got motorised about 1970 with terrible old motor bikes and hideous worn out cars. I was a penniless student and could barely afford the cost of ordinary oil, let alone molyslip. I read of tests where cars that had been running with molyslip in the oil for a while, were drained of all engine oil and driven ten miles and more with supposedly no illeffects. Sounds like magic to me. Can you still buy it? If you can, I might add a shot of it to the SA SRF3 on the next service.

Edit -

Yes you can still buy it, though haven't seen it on sale in a long while. It's probably overkill really, because the hub is incredibly smooth and slick now. It is definately better and quieter than it was. From what I've read about old AW hubs, there are specimens around that have been in daily use for sixty years or so. I suspect that if they are kept oiled and not just ridden dry for years they will last for decades anyway.

https://www.tribology-abc.com/abc/solidlub.htm#graphite

Some info about moly above, and graphite too, which I have some of in very fine powder for lubricating locks.

jur

Ah yeah, molyslip. I had some molybdenum disulphide in powder form, looks a lot like powdered graphite. Once you get that stuff on your hands, you get fingerprints on everything, the bike, the door, the dog, the neighbour's wife...

I haven't seen it in oil for years. I have a aerosol can of chain grease with it in. I used to use it on my chains before I switched to Prolink.

randya

I rebuild my SA hubs, both old AWs and new SRF3, with a lightweight white lithium Lubriplate grease, and they all work just fine.