Hub vs 'Bottle' dynamos
bails87
Posts: 13,317
So I'm thinking of fitting a dynamo powered light to the 'hack bike'.
I can either use a 'bottle' dynamo which is the cheaper option to buy, but will possibly mean new tyres, and looks like a little more fuss in use, it certainly doesn't look as neat as the other option, which is the hub dynamo.
They look like they're more powerful, a tidier solution, plus there are no worries about it chewing up the sidewall of the tyre:
The hub option means a new wheel, but I can build that myself or buy one fairly cheap from Spa Cycles.
So, any tips? Are the bottle dynos a poor compromise compared to the hubs?
I can either use a 'bottle' dynamo which is the cheaper option to buy, but will possibly mean new tyres, and looks like a little more fuss in use, it certainly doesn't look as neat as the other option, which is the hub dynamo.
They look like they're more powerful, a tidier solution, plus there are no worries about it chewing up the sidewall of the tyre:
The hub option means a new wheel, but I can build that myself or buy one fairly cheap from Spa Cycles.
So, any tips? Are the bottle dynos a poor compromise compared to the hubs?
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Mine say IIRC 6V 3W on them, but I'm not sure if they are limited to this, maybe they do put out up to 14W.
I can't see how they power output would differ, as it's the same way to generate the power, coils of wire moving through magnets. Maybe the bottle dynamo was slipping in the above example.
Get a LED light, with standlight & it's the weasels wanger.
Good prices on Shimano at Rose bikes. (Can't link to brand filter, as URL has square brackets). They'll also build wheels, but sounds like you're sorted in that respect.
http://www.bike-discount.de/ are usually a little cheaper still.
Any idea where I can find hub dimensions for the Shimano hubs? There's no sign of them in the Shimano tech docs.
"As I said last time, it won't happen again."
"As I said last time, it won't happen again."
Edit: thanks though, good to know.
"As I said last time, it won't happen again."
FCN 4: Planet X Schmaffenschmack 2- workhorse
FCN 9: B Twin Vitamin - winter commuter/loan bike for trainees
I'm hungry. I'm always hungry!
Shhhhh!! Given the graph that Bails put up, at KOM speeds I'm giving away about 12 Watts, don't shatter the illusion that I'm super-awesome.
But yes, if you can tell the extra draggyness, you may well be a real princess.
Yes.
I had a bottle dynamo on my Brommie, it was a bit pants but handy, 'cos it was always there and working when I needed it to be... I never left it behind, it didn't have flat batteries etc.
It wore out, so (against the advice of the helpful and well-informed Guy-in-the-Bikeshop) I replaced it. I didn't want to invest in a new wheel and re-wire the frame to accomodate a hub unit and I though a new one might possibly be better (durability, sidewall grip, efficiency).
It's not. Still pants. Go hub.
Cheers,
W.
A 1970s style Union clamped to the seatstay is almost useless, it rotates out and has a hard time applying enough pressure.
A Swiss-made Nordlight 2000 bolted to a braze-on tab at the seatstay is OK. This model can be mounted fore or aft of the stay but some models are picky, it depends on the orientation of the pivot. Braze-on tabs are the way to go for bottle dynamos. It works in heavy rain but not in sticky snow or mud. Getting the connection to work reliably is a bit of a faff.
Shimano DH-3D71 Disc-equipped dynamo hub , ultegra/XT grade. Dogs knees. Fuss-free lighting always available, it stays on most of the winter, day or night.. The only downside is the difficulty and danger of sevicing; the electrical contact is a strip of metal running through a slot in the spindle. It can be snapped by rough handling and is tricky to replace. Good servicing instructions are very hard to find. Fortunately the hub is well sealed and mine has been untouched for 4 years.
The lights for dynamo systems have improved in huge leaps. I have used the traditional Union lamp, modern bulb lamp units and LEDs eg Busch and Muller Lumotec Fly and IQ Cyo.
The Fly plastic housing was cracked in transit when someone else put the bike in a car boot.
The IQ is smaller, neater and stronger. Light output for both models is like totally awesome and wiring up is reliable and easy. I now run a rear LED as well which completes my faff-free lighting.
http://www.dutchbikebits.com/index.php?route=product/category&path=40_69
£50 for a built wheel with a Shimano dynamo hub seems too good to be true!
FCN 3 at the weekend - struggling to do it justice!
As soon as you want a QR, it's at least £15 more.
"As I said last time, it won't happen again."
This is the current steed:
http://www.decathlon.co.uk/elops-3-city-bikes-black-id_8089003.html
...so that sounds fine to me!
FCN 3 at the weekend - struggling to do it justice!
FCN 4: Planet X Schmaffenschmack 2- workhorse
FCN 9: B Twin Vitamin - winter commuter/loan bike for trainees
I'm hungry. I'm always hungry!
Yep, Shimano make disc braked dynamo hubs.
Wouldn't swop mine, it never needs removing and never runs out of battery. With LED lights being so bright at low power, a dynamo system make a load of sense.
On the dynamo light I turn it on, and go. It's a revelation. I don't mind battery rear lights, as they last months, but the front is always a pain.