noglider 

I've been hoarding these things for no reasons I can come up with. I see them on ebay, and I buy them.



One is a Sanyo bottom-bracket dynamo which rubs along the tread of the rear tire.

The one at the top of the picture is not old. I just got it from a Chinese seller on ebay. The attached headlight has a filament bulb. The entire unit seems flimsy. But it's interesting to me. It has a handlebar-mounted lever which works to engage and disengage the dynamo. If the drag isn't too bad, I might try this on a modern LED light. The weight is lower than that of a dynamo hub, and installation is easier. It can even move from bike to bike without much trouble.

The old Union and Soubitez dynamos were reliable. The old Williams is made like a tank! I have read that modern sidewall dynamos make less noise and produce less drag than the old ones. That isn't very hard to believe.

unterhausen

I used to commute with one of the Soubitez integrated units. Not bad. I always used a tire on the generator wheel, but I certainly don't miss the noise

noglider 

I just installed one of the antique generators on my wife's road bike without warning. I used a modern B&M LED light. Wow, is it bright!

torque cyclist

I used to have one lying around, somehow broke it.

2_i 

The modern LEDs tend to take less power than past incandescents and therefore they reduce drag, including for those older-model dynamos.

noglider 

My experience doesn't match yours. The drag doesn't seem to vary with electrical load.

2_i 

Wow! Seriously?! Did you try riding with a mechanically engaged generator and the electrical circuit either closed or not? Did you try just to turn the roller by hand with the terminals either short-circuited or not? Normally it is a big difference.

fietsbob

Got a rebuilt while new, BB generator a UK company took them apart & added a rubber ring around the drum to reduce the wet tire slippage ..

they were the hot thing in the 80s .. custom frame builders added a lever, top.. behind the seat tube, to pull them on or off the tire .

I'd just un latch the release lever with my toe as I rode when I wanted the light to come on,

the one attached to the stock dynamo sticks out far enough.

noglider 

You know, I haven't tested this properly. I'll see if I can do it.

My wife was pleased the surprise of the light on her road bike. She rode with it engaged a little, and she said it didn't feel bad.

Now this week, I installed the BB mounted dynamo on her bike up in the country, which is a hybrid bike. I used another modern headlight. She is pleased! I'm just a little disappointed. This dynamo feels even "draggier" than the sidewall type. Again, it's absolutely good enough for casual riding, and she may not use it often at all, but it's nice to have it there, and it's great to know it's always ready, never needing a charge or battery replacement. These set ups weigh just a tiny bit more than a battery headlight, and it's totally worth that penalty.

noglider 

It's a lovely luxury to be able to engage and disengage with a lever on the handlebar, but it's far from necessary. I showed my wife, and she said getting off to switch it is no big deal at all.

fietsbob

standard lever just restrains the spring pulling it against the tire .. yea getting off and tapping the lever by hand would be safer .

particularly in a place where there is a lot going on in all directions, like Manhattan.

Countryside, on tour, is a different environment..

noglider 

Sure but you don't have to turn it on and off during a ride more than once. No big deal.

at_hiker59

I miss my Sanyo bottom bottom bracket mounted dynamo!

Wanderer

I assume it would still be bright, with an LED taillight........ Hmmmmmm, I have several of those lying around. I've even bought a few bikes at the Goodwill store for $5 or less, just for the little bottle generator....

fietsbob

BITD there was a 3rd lever brazed on the back of the seat tube to pull the cable that went to the BB Dynamo ..

Have a remanufactured Sanyo that they Added a rubber tire around to reduce the wet weather slippage A Bit.


My Mk2 Brompton had a sidewall dynamo .. made a little Zzzz noise

as the roller hydroplaned over the texturized sidewall track that was supposed to give better traction.