Classic & Vintage - Sturmey Archer Dynohub

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View Full Version : Sturmey Archer Dynohub


kpug505
04-21-08, 06:33 PM
So I have a few of the old SA Dynohubs around. One is built into a Sun CR18 rim. I have searched all over the interweb (including here) and the only thing I am getting from the search is a heaping handful of paranoia! All of this stuff about ruining the magnets is making me scared to touch the thing!
I'll get to the point.
1: The axle is slightly bent. I'd like to replace it and I am pretty sure since I have 3 hubs that I have the parts. Can I do this without killing the hubs magic? Do I need to hunt down a keeper? Or maybe the magic magnet making machine I have read about?
2: It doesn't have all the washers or locknuts I assume it used to have. It didn't have the axle nuts and one side of the axle was ground down at an angle presumably from a spill. I unthreaded the only locknut left with tons of oil very carefully to cut some threads and filed off the end to make a clean set so I could get a nut on it (which I eventually did). Are there supposed to be 2 locknuts on each side? Every hub I have is different and none have the axle nuts so I don't know if I am supposed to use any kind of washer in the mix.
3:The axle has flats. I assume this is to prevent the axle from spinning in the dropout? This wheel is going on a Nishiki road bike and the forkends are wider than the flats. Do I need an anti-rotation washer like the rear?
I am sure I will have more questions soon enough as all of this Sturmey goodness is new to me. The rear wheel going on the build I am doing is also a 700c Sun CR18 rim and it is laced to a SA TCW 3 speed coaster hub (what kind of oil should I drop in it?). I have that all wired up. I just need to decide on a crankset so I can dial it in. Ah.....The joys of a new build!
I guess what I am really looking for is some encouragement or maybe some friendly harassment for being a chicken. I read on Mr. Hadlands site that I can take the hub apart as long as I don't separate the armature and the magnet. Does this mean I should be able to replace the axle without killing it? I hope so. I'd rather not ruin it.

Thanks in advance for any encouragement, advise or friendly brow beating for being yellow in advance!
Kelly D


langsmer
04-21-08, 08:30 PM
Hope this answers your questions.

http://www.sheldonbrown.com/dynohubs.html

kpug505
04-21-08, 08:41 PM
Hope this answers your questions.

http://www.sheldonbrown.com/dynohubs.html

Thanks, I have read it several times.
I am really looking for someone to assure me before I tear it apart that I don't need to remove the magnet from the armature causing the hub to loose it's purpose. Since I need to remove the axle from the hub so I can replace it.... Will that cause an issue or is something else acting as a keeper? Without taking apart the hub and comparing every part with an exploded diagram (which I have) the technical jargon is just kinda hard to grasp for me.......I am more of a hands on type of guy. I guess I'll just have to suck it up and do it! I just hope I don't screw it up in the process..........

Kelly D


g-funk
04-21-08, 08:57 PM
I say rip it apart and figure it out. what I have found about english engineering is that it's overly complicated but pretty simple for maintenance at the same time. keep your parts organized. you shouldn't have to get into the electrical too much to change the axle. where did you find your diagram? I have a dynohub on a loaner bike that, once it comes home, will get rebuilt and I'd love to have something to look at.

edit: if it's already screwed up what do you have to lose?

kpug505
04-21-08, 09:04 PM
Where did you find your diagram? I have a dynohub on a loaner bike that, once it comes home, will get rebuilt and I'd love to have something to look at.

edit: if it's already screwed up what do you have to lose?

I found the diagram at:
http://www.sturmey-archerheritage.com/history.php

It's under 1945 GH6 or:
http://www.sturmey-archerheritage.com/views/view-62.gif

Thanks for the encouraging words. Your right I have nothing to lose........:o

mparker326
04-21-08, 09:14 PM
Kelly:

I don't know if you've seen this link:

http://www.hadland.me.uk/samaintind.htm

Along with the diagram it gives written instructions on assembly on a GH6 (plus a whole lot more).

Good luck.

frameteam2003
04-21-08, 09:14 PM
The Dymo has 4 small bolts holding it in--the axel will come out with out taking the dyno out.Just don't remove the 4 bolts that hold the dyno in and you'll be fine.

kpug505
04-21-08, 09:16 PM
The Dymo has 4 small bolts holding it in--the axel will come out with out taking the dyno out.Just don't remove the 4 bolts that hold the dyno in and you'll be fine.

Thank you sooooooo much! I'm gonna do it now! Well maybe tomorrow after work but soon!

kpug505
04-21-08, 09:18 PM
Kelly:

I don't know if you've seen this link:

http://www.hadland.me.uk/samaintind.htm

Along with the diagram it gives written instructions on assembly on a GH6 (plus a whole lot more).

Good luck.

Thank you. I have read that several times. I am so grateful to Mr. Hadland for making all of that great info available to the public (with SA's consent). Good stuff.......