Sturmey Dymo-Hub Questions

chainmaker

chainmaker

Well-Known Member
My next project Im going to be using a 3 or 5 hp briggs, I am going to need some lighting. I was thinking or running a dymo on the front and rear (I wont be using a pedal set-up) to charge a 12v battery that runs headlight, and a brake light.
anyone ever used the dymo hub to charge a battery that runs a tail light and headlight ? Any information on this will be greatly appreciated.
Thanks in advance..wee.
 
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I run the sturmey XF-dd i think it is called. It has some good diagrams on their website of the velocity vs voltage and watts which should help you out...I graphed the values out for my application beyond their values which stopped around 20 mph. Basically at 25+ you will be generating around 10volts and 5 watts...plus or minus a little bit.

You will need some sort of capacitor or supercap to regualate your voltage going into the battery so that you do not overcharge it. Most batteries need to be trickle charged and the dynamo does not trickle at bike speeds. Its pretty complex if you do not have a lot of electrical experience. I just went for a dynamo powered front and rear light...not sure why you would need signals...You would have to rig up flashing circuits and alternating on off switches.

keep it simple. No need for a battery if you have a good dyno and a light with the stand light feature. I recommend the Supernova E3 triple and taillight system. Pricey, yes, but you will never have to buy batteries, its bullet proof german engineering and quality circuitry, lifetime warranty...its as bright as a car light, see and bee seen to the extreeme. hope this helps

peace
 
i dunno about charging batteries, but i've been running my XF-DD sturmey hub for awhile now, and i'm over it.

i constantly blow bulbs out, even after adding voltage regulators, higher quality bulbs, etc.

the amount i've spent on LED's and other crap for it coulda kept me in AA batteries for a long time.

my headlight blew out at 4am on the way to work two days ago. today, i'm going to rebuild it with batteries.

i like the way the drum brake works on the hub, though. it's grrrr-ate!
 
i built my own lights with expensive LEDs, and wired in the highest voltage regulator i could buy. the guy at Marvac Electronics told me the lights wouldn't even come on till after 12v (i think it's rated 12v-45v) but the LED's flicker as soon as it starts rolling.

i hooked a voltmeter up to the hub and did some test runs. it almost works like a speedo. at 45mph it was 47v. waaay too much for most lighting systems.

i built the same hub inta a buddy's stock bike, and his lights last a few months at a time, but he rides once a week and 30mph, not everyday at 40+.

to me, the hassle's not worth it. i think i'm gonna wire the lights on AAA batteries that i can hide, and if i run a horn and/or brakelight off the hub, they won't be on all the time so they won't burn out.
 
wow i had no idea that hub could generate that many volts... how bout an anti theft system that charges the handlebars when rolling...ha ha ha faster you go the the more you get shocked, the harder you squeeze the handle bars so you cant let go...bzzzzzzz
 
Seriously.... People blowing blubs... Get some real led's like cree's or luxion's with a cooling plate/heatsink.

I've been running a pair of cree led's without regulation for over a year. Cruising speed is 35mph.
 
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