SA 3 Speed Hub Overhaul

[flippin3speeds]

Hi all, I'm looking for help as to what to do next. I'm dismantling a 1937 SA hub but not sure how to get the sprocket off. Never done this before. It looks threaded but in a youtube vid the chap just wriggles his one off. I've tried smacking it with a hammer and punch tentatively and it moves a bit either way. Any experience? See pics. Thanks, g
http://s1313.photobucket.com/user/flippin3speeds/media/DSCF0768_zps663e099f.jpg.html?sort=3&o=2
http://s1313.photobucket.com/user/flippin3speeds/media/DSCF0766_zps3999214f.jpg.html?sort=3&o=3
My Machine
http://s1313.photobucket.com/user/flippin3speeds/media/DSCF0770_zpsfddb3d61.jpg.html?sort=3&o=1

 

[roadrash]

there is a spring clip holding it on nothing more ....see here


View: http://www.youtube.com/watch?v=I1bIEvJmE1o

 

[porteous]

Pre 1952 or 1953 SA hubs had screw on sprockets. Amongst other things it means you can put a three speed block on and get 9 speeds! Lucky you!

(Here's one I did earlier: http://www.cyclechat.net/threads/rudge-pathfinder-hybrid-geared-tourer.123971/post-2530303 and here: http://www.cyclechat.net/threads/sturmey-archer-derailleur-combination-gears.123265/ The only thing you need to alter is the length of the axle. These are available dead cheap on fleabay)

If that more than you want at least clean the hub out and re-lube it. Roadrash has attached one of a shedload of really good youtube videos on refurbing 3 speed hubs, step by step, so just watch and do.

Enjoy

 

[flippin3speeds]

Roadrash, thank you so much for the vid link, I watched it and wondered if there was a part missing on mine, but as porteous noted, it is does have a screw on sprocket. Can either of you confirm which way it screws off? This is my first hub strip, and to boot the bike had been sitting outside and was completely ceased so I'm guessing the sprocket will be too. I presume it screws off anti clockwise? But I wasn't sure. If that's the case you would think the drive chain would tighten it on when in use. Do I need to do anything at the other end to facilitate getting it off? Any help gratefully appreciated.

Also Porteous, that's a great idea about the 3 speed block, I have a 46 Hobbs which this would really suit as I fancied a vintage tourer. Your one looks the biz. By the way, can you see the pictures ok I posted?

 

[Sterba]

While the hub gear experts are opining on this subject, can anyone tell me if the slop I experience on my low-mileage, 1980s era 3 speed SA hub is an easy thing to cure. Quite often when you start to pedal, you have to move the crank about one eighth of a turn before it bites. It's otherwise OK, but this is annoying.

 

[tyred]

While the hub gear experts are opining on this subject, can anyone tell me if the slop I experience on my low-mileage, 1980s era 3 speed SA hub is an easy thing to cure. Quite often when you start to pedal, you have to move the crank about one eighth of a turn before it bites. It's otherwise OK, but this is annoying.

Check bearing cone adjustment but I find all older hubs have some backlash in them.

Just be careful with bearing adjustment as it is designed to have a little play - 1/8" movement at the wheelrim for a 26" wheel - too tight and it will cause problems with the hub binding, too loose and will cause the sort of problems you are experiencing (or more specifically make them worse and more noticeable). On very high mileage hubs, you usually will end up having to compromise slightly with bearing adjustment or else carry out a complete rebuild.

Also check chain tension - 3/4" - 1" free movement on the bottom run is what is recommended.

 

[Rohloff_Brompton_Rider]

Check bearing cone adjustment but I find all older hubs have some backlash in them.

Just be careful with bearing adjustment as it is designed to have a little play - 1/8" movement at the wheelrim for a 26" wheel - too tight and it will cause problems with the hub binding, too loose and will cause the sort of problems you are experiencing (or more specifically make them worse and more noticeable). On very high mileage hubs, you usually will end up having to compromise slightly with bearing adjustment or else carry out a complete rebuild.

Also check chain tension - 3/4" - 1" free movement on the bottom run is what is recommended.

+1

Even the modern Brompton BWR hubs have a little bit of play and backlash, it's because of the way there built with straight cut pinions. Also make sure the monkey chain is tensioned properly sometimes too much back lash or as you describe it "delay" can be an indicator the clutch isn't engaging properly.

 

[Sterba]

Thank you for your responses. But I don't think I've got there yet. The bearings are well adjusted, giving the correct small amount of side-play at the rim, and the gear change links are doing their job, no complaint about the gear change. This is forward slop I am talking about. The hub isn't old, ie has not been used a great deal, and has been kept properly lubricated. Even with straight-cut pinions, it shouldn't be this sloppy on the first push, surely? (stop calling me Shirley).

 

[Rohloff_Brompton_Rider]

When you say "slop" do you by any chance mean a tapered resistance until full resistance and off you go, type of thing?

Kinda like a binding, or a weird sponginess? I had this once and it required a full strip down and clean, I reckon it was water that had emulsified the grease/oil mixture and was stopping instant full engagement of the clutch.

Not sure I've explained what I mean?

 

[Sterba]

Absolutely not. This slop is quite simply free and unimpeded rotation of the crank, chain and cog until it engages with the internal gear. It is not a lot, just an inch or so of movement when first pushing on the pedals before the wheel starts to move. It doesn't re-occur once you are going and keeping pressure on the pedals