Front or Rear Dynohub?
 

I am rebuilding my 70's era Raleigh Sport and I am pretty keen on putting a dynohub on it. I have been looking and so far the SA GH6 dynohubs that have come up on eBay have all been based in the UK (makes sense really) but the postage to get one from there to Washington State is almost as much as the cost of the hub. OTOH I have seen a number of SA 3 speed+dynohub combos come up (some of them in the U.S.) and they appear to be both more plentiful and a bit cheaper. My question is for those of you that have some experience here...I have a working (and in nice shape) SA AW 3 speed hub on the bike now, is it worth it to simply replace it with a 3 speed dynohub or better to wait? I briefly considered gong with a newer hub like the Sanyo from Peter White. I may do that for my MTB commuter, but after looking at the front forks of the Raleigh I'm really skeptical about my ability to bend them to fit the larger size needed to accommodate a modern hub without cocking them up.

Dopes anyone know if the rear dynohubs are any better or worse than the front ones? Alternately, am I just being silly about bending the front forks on the Raleigh? I have some friends that are telling me that it's a piece of cake and others telling he to avoid it all costs. Neither of them is enough of an expert to give me confidence either way. Oddly the need to file the forks doesn't faze me a bit...maybe because I have some experience with doing stuff like that.

The alternator mechanism in the SA rear Dynohubs is identical to that used in the front Dynohubs, so I wouldn't expect any performance difference. If you can get a rear Dynohub with 3-speed for a decent price, go for it.

I figured it would be. I'm rebuilding both wheels anyway so it's not sweat to swap out the hub. I even have another bike I could put the displaced AW 3 speed on. Now to find a 36 or 40 hole one.

Some people say that having all that steel right next to the dynamo magnets weakens them and the result is less power. I have not noticed this to be the case.

I have found it more difficult to attach the wires to the rear hub than the front, especially in the dark.

I have bench tested several AG/FG hubs and a few GH-6 hubs. The rear hubs produce a bit less than the front hub, typically about .2 watts less. If you use LED lights it is moot. I run FG, AG and GH6 and have had zero problems with any of them.

Aaron :)

I prefer the front for ease of access to it and because I just don't like having to deal with the magnet portion if I ever have to totally tear down the rear hub for repairs (yes it does happen sometimes). Either will work for you though, just a question of preference/convenience for me.

I have some old vintage lights I'll be rewiring for LED.

+1 on the slightly less output from the rear dyno. If you go with the GH6 make sure it has good cones, replacements are difficult to find.

I read somewhere that it is possible to use a modern SA dynohub/drum brake combo without needing to spread the forks. Is that true?