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Hub vs 'Bottle' dynamos

bails87bails87 Posts: 13,317
edited March 2013 in Commuting chat
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: PvsVhubBottle.gif

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?
MTB/CX

"As I said last time, it won't happen again."

Posts

  • Get the hub dynamo. Means you have a spare front wheel for winter use. I have the Shimano 3N80 hub dynamo for winter, and it really is the badger's nadgers.
  • 16mm16mm Posts: 545
    No comparison, hub dynamos are far superior, and completely maintenance free, in terms of power output.
    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.
  • DrLexDrLex Posts: 2,142
    Hub dynamo FTW!
    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.
    Location: ciderspace
  • DrLex wrote:
    Hub dynamo FTW!
    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.
  • bails87bails87 Posts: 13,317
    DrLex wrote:
    Hub dynamo FTW!
    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.
    Thanks, I've used both of those in the past.

    Any idea where I can find hub dimensions for the Shimano hubs? There's no sign of them in the Shimano tech docs.
    MTB/CX

    "As I said last time, it won't happen again."
  • Personally I'd always measure them myself, I relied on an online calculator (http://lenni.info/edd/) once, but it was slightly off on the rim measurement, so I had to use bigger nipples.
  • bails87bails87 Posts: 13,317
    Tbh the spa builds don't look much, if any, more expensive than if I were to buy the parts separately so I'll probably just go for one of those.
    MTB/CX

    "As I said last time, it won't happen again."
  • You know that if you're buying spokes for a combination that they build, the nice chaps at Spa will tell you the spoke lengths if you buy some stuff from them?
  • bails87bails87 Posts: 13,317
    You know that if you're buying spokes for a combination that they build, the nice chaps at Spa will tell you the spoke lengths if you buy some stuff from them?
    Thing is, it's £80 for a built wheel. Buying the same parts from them would cost £83, and the German sites aren't really much cheaper.

    Edit: thanks though, good to know.
    MTB/CX

    "As I said last time, it won't happen again."
  • cyclingpropcyclingprop Posts: 2,426
    Don't you need a Dutch bike and a beard if you're going to venture into dynamo territory?
    What do you mean you think 64cm is a big frame?
  • Don't you need a Dutch bike and a beard if you're going to venture into dynamo territory?
    Extra demoralisation for scalps. I have strava KOMs set on my dynamo wheel while generating.
  • EKE_38BPMEKE_38BPM Posts: 5,980
    Don't you need a Dutch bike and a beard if you're going to venture into dynamo territory?
    Extra demoralisation for scalps. I have strava KOMs set on my dynamo wheel while generating.
    They should have an FCN modifier. +2 because of the extra weight and the extra dragginess.
    FCN 3: Raleigh Record Ace fixie-to be resurrected sometime in the future
    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!
  • 16mm16mm Posts: 545
    The extra dragginess really can't be felt. In the real world, if I stop pedalling I coast to a stop in the same distance regardless of dynamo or not. A slightly rubbing brake or sticky chain link would be more noticeable.
  • 16mm wrote:
    The extra dragginess really can't be felt. In the real world, if I stop pedalling I coast to a stop in the same distance regardless of dynamo or not. A slightly rubbing brake or sticky chain link would be more noticeable.

    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. :mrgreen:


    But yes, if you can tell the extra draggyness, you may well be a real princess.
  • wgwarburtonwgwarburton Posts: 1,863
    bails87 wrote:
    So I'm thinking of fitting a dynamo powered light to the 'hack bike'.
    ... Are the bottle dynos a poor compromise compared to the hubs?

    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.
  • MichaelWMichaelW Posts: 2,226
    I've used a couple of dynamo systems.
    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.
  • unscarredunscarred Posts: 208
    Anyone used these guys?
    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 6 in the week on the shiny new single speed.

    FCN 3 at the weekend - struggling to do it justice!
  • AidyAidy Posts: 2,015
    unscarred wrote:
    Anyone used these guys?
    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!

    As soon as you want a QR, it's at least £15 more.
  • 16mm16mm Posts: 545
    Aidy wrote:
    unscarred wrote:
    Anyone used these guys?
    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!

    As soon as you want a QR, it's at least £15 more.
    Those a proper dutch bike spares. Heavy and utilitarian. Good for the hack bike though, unless it has disks.
  • DrLexDrLex Posts: 2,142
    This may be a goood front light for you - 70 lux, speed-dependent lighting, stand light & USB charging facility (behind gray cover). Fugly, though.
    Location: ciderspace
  • bails87bails87 Posts: 13,317
    Thanks, I've already ordered the Phillips Saferide from ze Germans which is about the same brightness but cheaper and with very good reviews. As I said, its only for the hack bike so I'm balancing 'no fuss' operation with cost.
    MTB/CX

    "As I said last time, it won't happen again."
  • DrLexDrLex Posts: 2,142
    I have the SafeRide on my winter commuter and it's been ideal; I'd seen mention of a bracket failure on intawebz, so put a mudguard washer on to spread the load. (Also have the battery-powered SafeRide for t'other bike.)
    Location: ciderspace
  • unscarredunscarred Posts: 208
    16mm wrote:
    Aidy wrote:
    unscarred wrote:
    Anyone used these guys?
    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!

    As soon as you want a QR, it's at least £15 more.
    Those a proper dutch bike spares. Heavy and utilitarian. Good for the hack bike though, unless it has disks.

    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 6 in the week on the shiny new single speed.

    FCN 3 at the weekend - struggling to do it justice!
  • meanredspidermeanredspider Posts: 12,550
    Honestly, I'm amazed that people still use dynamos at all.
    ROAD < Scott Foil HMX Di2, Volagi Liscio Di2, Jamis Renegade Elite Di2, Cube Reaction Race > ROUGH
  • DrLexDrLex Posts: 2,142
    Honestly, I'm amazed that people still use dynamos at all.
    Assuming my sarcasm meter isn't faulty and discounting the touring aspect, I like the lack of faff of removing & returning lights for charging. Europeans, esp. the Germans, seem to like them too, judging from the choice on websites.
    Location: ciderspace
  • meanredspidermeanredspider Posts: 12,550
    Yes - I don't doubt there are good reasons. I'm just surprised. Genuinely
    ROAD < Scott Foil HMX Di2, Volagi Liscio Di2, Jamis Renegade Elite Di2, Cube Reaction Race > ROUGH
  • EKE_38BPMEKE_38BPM Posts: 5,980
    Is a hub dynamo and disc brake possible?
    FCN 3: Raleigh Record Ace fixie-to be resurrected sometime in the future
    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!
  • EKE_38BPM wrote:
    Is a hub dynamo and disc brake possible?

    Yep, Shimano make disc braked dynamo hubs.
    Yes - I don't doubt there are good reasons. I'm just surprised. Genuinely

    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.
  • meanredspidermeanredspider Posts: 12,550
    My AyUps go onto any of my bikes or my head. I charge them in-situ so it's 5 secs effort. The battery lasts longer than I'm possibly ever going to ride at night (with the possibility of the Puffer).
    ROAD < Scott Foil HMX Di2, Volagi Liscio Di2, Jamis Renegade Elite Di2, Cube Reaction Race > ROUGH
  • I dunno, I have a set of very nice Magicshine lights on my other bikes, they last about three and a half days commuting, so I have to charge them every few days, assuming I remember, which I often don't. Then I get the fun commute on the flashing red charge, wondering if I'll make it to the other end. Every day when I get to work, I park my bike in the shared bike park - so I have to remove the light head and the battery pack - they'd be nicked pretty quick. Every evening I have to reconnect it all.

    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.
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