Couple questions about Komet Super coaster brake hubs

[mornview]

I've built up a few Komet Super hubs over the last few years and they have become my coaster brake hub of choice. However, today I started working on one with an oil port for the first time, and I have a few questions:

1. Even though it has an oil port, can I still just lubricate it with grease as I would a modern coaster brake hub? More importantly, would there be any actual advantages to using oil instead? I plan on overhauling it at least annually anyways, so the "less maintenance" advantage kinda goes out the window.

2. The sprocket is threaded on (I believe the later versions of the hub used a snap ring). It's an 18t; I'd really like 19t. Does anyone know what other threaded cogs are compatible with this hub? I cannot currently get the lockring off, so I can't get a TPI measurement, but that brings me to my last question:

3. Is the lockring normal threaded and the sprocket is reverse threaded? Or do I have that backwards? This doesn't seem to be documented anywhere.

Thanks!

 

[Bicycle808]

I've got a Komet Super with an oil port in my hand as I type this; it's a beautiful hub and i really dig it. Haven't laced it yet, but I wanna.

Question 1: The Komet Super has disc-type brakes; my plan was to use some heavy oil on this section of the hub, the same way I would for a Velosteel/Perry/F&S Torpedo. Thing is, Sutherland's suggests using greae, so apparently, you can grease it. I've found grease to be kinda heavy for the roller bearings in the clutch of the Torpedo-style hubs, but the Komet Super has a different design, so it probably won't matter. I've long believed that oil is better for lubing the inner hubshell and disc brake parts, but who am i to argue with Sutherland's? OTOH, Fichtel & Sachs clearly intended us to use oil, hence, the oil port. So, i guess either will work out OK.

http://www.sheldonbrown.com/sutherland/CB-IGH-2-sachs.pdf

Question #2: I honestly have no idea, and google doesn't seem to know, either. Being a German-made hub, i'd expect it to take a regular english-threaded (1.375"x24tpi), but this hub might be old enough that it uses proprietary cogs or a thread pitch that's based on some sort of obsolete standard. Once you get it off, you can test out my theory by test-fitting a track cog, a standard bmx freewheel, or even the NDSide cup of an old loose-ball English threaded BB. If it is, in fact, English threaded, you will be able to easily source cogs in sizes ranging from 13 to 22t. I even have a few 24t english-threaded cogs, and i bet some folks have'm even bigger.

But, you'll have to pull that cog off first, which leads me to the final question:

Question #3- i've never actually seen a F&S Komet with a threaded driver, but i'd be absolutely dumbfounded if it weren't set-up with a reverse-thread lockring and a standard-thread cog. Get yourself a proper hook spanner to remove the lockring, and you may find it easier to pull off if the hub is actually laced. Oh, while you're at it, try to get the proper size tiny hookspanner for the jamnuts that F&S put on their hubs. I got one, and i'm so glad i did. Trying to MacGyver an overhaul using a flathead or an awl is a massive PITA.

HTH
-rob

 

[horsefarmer]

I understand the grease in the outboard bearings act as a seal of sorts which helps keep oil in the hub. Also the oil in the hub keeps the grease from drying out.
I believe you are supposed to use like 30 weight motor oil.
I have used a heavier oil (Lucas oil additive) when rebuilding my New Departure hub and it works great.
I think ND specified Hypoid gear lube 90 weight ? but you would never get that in the oil port !
Maybe when rebuilding though.

 

[mornview]

Thanks guys. Incidentally, though, the Komet does not have disc type brakes - or, at least, none of the ones I've ever worked on have. They have essentially a brake "shell":

I think this is one of the main reasons I love the hub so much - it has GREAT stopping power, but doesn't really seem to have any noticable drag either.

In any case, there isn't anything in this hub that I can think of that would warrant oil over grease ... so I'm kind of puzzled why this thing had an oil port in the first place.

I'll have to see what I can find for a hook spanner; I'm getting a 43mm diameter for the lockring.

I never knew they made spanners specifically for that locknut, though! I always replace those things as soon as I get them off ... but getting them to come off in the first place is, as you said, quite the PITA .

 

[metalchewy]

http://ratrodbikes.com/forum/index.php?threads/komet-super-hub-rebuild.33551/

Helped me rebuild mine a couple years ago.

Building... riding...

 

[deorman]

Oil is used for the ND types to allow the clutch plates to seperate easily and reduce drag, same as with a motorpickle wet clutch. My guess would be that in the Komet it flows back between the shoes and drum when the brake is released, but like I said, it's just a guess.