Sturmey Archer Dynohub vs newer generator hubs

[supton]

How does old school stack up against new school? I know the newer ones should be lower weight; but is the drag on the older SA dynohubs much higher?

[cyqlist]

I don't think the drag on the old SA Dynohubs was any higher, maybe even lower than some of the modern hubs. Their power output is lower, but theoretically ought to be enough for adequate light output with appropriate modern LED lights (certainly much better than with their original lights). The problems with them were the difficulty of adjustment, and the likelihood that the magnet had lost power if they were ever disassembled (which can't happen with the magnets on the newer ones). I used SA Dynohubs for 20 years, but converted to Schmidt and Shimano when they became available and don't think I will ever go back.

[n4zou]

Rare Earth magnets used in modern dynamos have made the old stuff obsolete. Drag is reduced significantly and lights are brighter at lower speeds. The old dynamo hubs would have considerable drag even when the lights are off. Modern dynamo hubs still have a little drag but it's no where near what the old ones had. Don't bother trying to use vintage, that stuff is only good for display purposes now.

[supton]

Interesting stuff. Ok, I won't go overboard in finding one then. I already knew that getting replacement parts was impossible, but didn't know if it was worth bothering or not, other than cost (ie, find a $5 bike). Thanks.

[brotherdan]

SA (now owned by Suntour) has come out with a new dynohub. It has an internal drum brake, which is kind of cool. I'm sure the drag and performance is much better, but it still doesn't seem as cool to me as the internally geared three speed plus dynamo rear hub that they manufactured briefly back in the sixties.

[cyqlist]

SA (now owned by Suntour) has come out with a new dynohub. It has an internal drum brake, which is kind of cool. I'm sure the drag and performance is much better, but it still doesn't seem as cool to me as the internally geared three speed plus dynamo rear hub that they manufactured briefly back in the sixties.

Shouldn't that be Sunrace? I know the electrical output of the newer hubs is higher, but I'm still not convinced that there's any significant difference in the drag. I used SA Dynohubs myself for many years, from the late 70's until the late 90's when Schmidt and Shimano came out with theirs. And I believe the AG 3-speed Dynohub was made more than briefly, from 1946 (according to http://www.sturmey-archerheritage.com/history.php) until some time in the 1960's. I never thought the rear Dynohub seemed like a particularly good idea. Since most of the power was for a front headlight, what reason was there for not having the Dynohub on the front wheel? I also seem to recall that the rear Dynohub put out slightly less power due to the greater mass of the larger steel hub shell surrounding the magnet.

[brotherdan]

Shouldn't that be Sunrace? I know the electrical output of the newer hubs is higher, but I'm still not convinced that there's any significant difference in the drag. I used SA Dynohubs myself for many years, from the late 70's until the late 90's when Schmidt and Shimano came out with theirs. And I believe the AG 3-speed Dynohub was made more than briefly, from 1946 (according to http://www.sturmey-archerheritage.com/history.php) until some time in the 1960's. I never thought the rear Dynohub seemed like a particularly good idea. Since most of the power was for a front headlight, what reason was there for not having the Dynohub on the front wheel? I also seem to recall that the rear Dynohub put out slightly less power due to the greater mass of the larger steel hub shell surrounding the magnet.

Doh, you're right, they're owned by Sunrace.

I just thought the rear dynohub would be cool because you could generate power while riding on a trainer. But I guess it wouldn't be all that hard to connect an automotive alternator to a trainer or a set of rollers to produce electricity, if you were so inclined.

I run a taillight and a headlight off of my dynohub, so it doesn't really make any difference where the dynohub is located. There is going to be wire running the length of my frame, regardless of the location. Even the standard Union Generator Sets run head and taillights, and many of their generators run on the rear wheel.