CityCyclingEdinburgh Forum » Questions/Support/Help

hub dynamo - advice/recommendations?

(111 posts)
  • Started 8 years ago by unhurt
  • Latest reply from Frenchy
  • This topic is resolved

12…4

  1. unhurt
    Member

    I'm hoping to fit a hub dynamo to my new touring bike for a wee trip across Canada this summer. Plan is to charge a battery pack and use this to charge phone/7" tablet etc. to reduce the amount of time I would otherwise spend searching for plug sockets/outlets.

    I have been meaning to do a bit of research on available models for ages now, but just realised I haven't - and I leave on June 21st. Erk. Does anyone have any experience, recommendations or potential pitfalls to share? My ignorance is such I currently have no idea if disc brakes will complicate matters. And do I need to buy a specific battery pack, or will the USB-chargable powerpack I currently own for travelling do the job?

    If relevant/interested, new bike will be a Surly Disc Trucker.(I am rather excited about its impending arrival. I hope we are compatible!)

    Posted 8 years ago #

  2. kaputnik
    Moderator

    B&M Luxos light has the neccessary circuitry and USB output. Or you could get a cheaper light an an OEM converter for the power output to your battery pack / phone / tablet.

    You will need a disc-specific hub, Shimano are great for the price; http://www.sjscycles.co.uk/dynamos-hub-dept366/ has a good list.

    Bicycleworks (and some other) shops will build you a great touring wheel in a relatively short time if you aren't doing this yourself. Whomever is building your wheel, tell them it's for touring, you want a strong-walled, double-eyeletted rim, 36 holes preferable if you're carrying a lot of front weight. Mavic A319 are pretty bomb-proof.

    Bare in mind that you haven't got that long between brand new bike arrival and then I imagine some serious touring, so give yourself plenty of chance/rides to wear the bike in, pick up annoying clicks and creaks, get your bars and seat in the right position etc. and all the really dull stuff like making sure your heels don't kick your panniers the first time you push off fully loaded.

    Posted 8 years ago #

  3. steveo
    Member

    Disk brakes are fine just buy a disk compatible hub, all the mid end and up shimano hubs come in both disk and non disk. Pick the cost/weight your happy with and get the correct disk mount, centre lock or bolt on.

    Any USB chargeable powerpack will be fine though if your doing at lot of stop start (city travel) I'd be inclined to disconnect it in traffic to avoid damage. Lithium batteries can take some punishment but don't like to have the charge interrupted too often. Also consider how big your powerpack is. If its too large you'll never charge it in a day and you'll just be lugging around unnecessary weight.

    Who is building your wheel?

    Posted 8 years ago #

  4. unhurt
    Member

    Cheers!

    I asn't actually going to run a light off it, though mine is chargable from a USB cable I suspect I won't use it much (I have a teeny head torch for at night to facilitate activities requiring hands (going to the loo, fighting off bears, etc.) and hope not to be on the road too much after dark, but will have a think on that.

    Thanks for the recommendation.

    Posted 8 years ago #

  5. algo
    Member

    there are a few discussed here:

    http://cyclingabout.com/dynamo-hub-recommendations-for-bicycle-touring/

    spa cycles builds wheels with Son and SP hubs

    Posted 8 years ago #

  6. unhurt
    Member

    At the moment no-one is building my wheel, thus the sudden slight panic when I realised how soon I'm leaving! Need to get organised and make enquiries asap.

    Thanks for the tip re: traffic. Powerpack is reasonably small (one of these) but I think I'll run it flat and test to see how much it charges on a longish day ride, and downsize if necessary.

    Posted 8 years ago #

  7. steveo
    Member

    Remember the dynamo produces 0.5a so your 10ah battery will take at least 20h to charge, probably more due to losses.

    Posted 8 years ago #

  8. algo
    Member

    one minor thing (apologies if I'm stating the obvious, but I nearly made this mistake) - if you already have rims you want to keep then you'll need a hub dynamo with the right number of holes for your rim - in my case for example I have 36 hole rims, so that narrowed down my options a fair bit… also I believe Shimanos are all centre lock so if your discs are bolt-on you'll need a need disc too (I think but am ready to be corrected)...

    Posted 8 years ago #

  9. unhurt
    Member

    Thanks all - and aha, I had not even thought about no. of holes (and I will be keeping rims) so that is very helpful!

    Posted 8 years ago #

  10. LaidBack
    Member

    Last year's trans Canada tandem user ran a 36h SON 28 with disc.

    You can get SP hub cheaper of course (£90?)

    They used a B+M Lumotec IQ2 Luxos U as that has it's own internal battery. This set up also used on our demo tandem.

    Darkersider and another used an earlier version of the B+M light to charge their Garmin on the 2013 LEL Audax.
    Main problem is waterproofing although this has been improved.

    Options like Tout Terran Cinq 5 and others offer just battery charging alone.

    Posted 8 years ago #

  11. unhurt
    Member

    Cheers - I am leaning towards battery charging alone and hope to spend under £200 on the dynamo itself. But I see I have various options to investigate tonight...

    Posted 8 years ago #

  12. Cyclops
    Member

    The SP dynamoes are very good for the money although I'd be wary of their suitability for fully loaded touring (as their flanges are only 50mm apart the resultant wheel is weaker). Both Shimano and Schmidt will build into a stronger wheel.

    Posted 8 years ago #

  13. unhurt
    Member

    Hmm, given my tendency to accidentally buy books while travelling, that is definitely something I should bear in mind.

    Posted 8 years ago #

  14. Uberuce
    Member

    I've had the Shimano XT disc hub on the front of my commuter since January. Thus far it's been trouble-free and spins well with the light off. The Cycle Service built it into the existing rim in a day.

    Might be an idea to take two plugs so you can charge your tablet/phone at the same time as the battery pack; mine is a 19200 mAhr, and takes overnight to recharge from 1/4 back to full.

    Posted 8 years ago #

  15. chdot
    Admin

    I know this won't help!

    http://www.edinburghnews.scotsman.com/news/transport/hi-tech-bus-shelters-to-charge-smartphones-1-3760109

    Posted 8 years ago #

  16. algo
    Member

    I dunno - if it's just for charging during the day I was going to suggest a solar charger, especially given you already have a wheel. But I'm not sure how good these things are...

    Posted 8 years ago #

  17. steveo
    Member

    Solar is a waste of weight.

    Under optimal UK conditions carrying any panel you could get on a bike you wouldn't be able to charge a phone let alone a proper sized backup battery.

    Posted 8 years ago #

  18. unhurt
    Member

    Yeah, I was given a solar thinger a few years a go and it was a fun toy but not exactly useful in Scotland!

    Posted 8 years ago #

  19. algo
    Member

    Apologies for daft suggestion

    Posted 8 years ago #

  20. unhurt
    Member

    Aww! I bet they're pretty handy in Australia, California etc. If I ever do a trip like that it might be neat to run one of the unfolding solar mat things on top of a trailer...

    Posted 8 years ago #

  21. unhurt
    Member

    [misfire - posted twice!]

    Posted 8 years ago #

  22. steveo
    Member

    Apologies for daft suggestion

    nonsense, that's bitter experience talking. You learn you pass knowledge on and hope no one else makes the same mistakes.


    Aww! I bet they're pretty handy in Australia, California etc

    I've never run the numbers but my gut would say, power to weight a dynamo would still be better. A 5w solar panel is the thick end of a kilo and its only advantage is that it would generate in the middle of the day when you'd probably not want to be riding in really hot countries.

    Posted 8 years ago #

  23. wingpig
    Member

    A more useful thing than a solar panel would be a dynamo rear hub (perhaps with an optional facility to place a much greater load on the wheel) to enable power to be generated by propping the rear wheel off the ground (perhaps with a couple of legs swinging down from a specially-designed rack) and pedalling whilst not moving, if you needed a bit of charge but didn't need to go anywhere and fancied feeding the thing-to-be-charged with more than 3W.

    Posted 8 years ago #

  24. Darkerside
    Member

    I really need to write this up into a blog post, given how many people I've bored with it now:

    After long-term experience of V1 of the B&M Luxos (light with USB charging), I would not look to combine lighting and charging. There's too many waterproofing issues (like, being unable to charge in the rain - USB isn't a waterproof standard), and it makes the light too complicated. If your charging fails badly, you've suddenly got no lights. Which is pants.

    On anything except >5 days tour, I would go dynamo lights and standalone battery bank charger.

    Even on longer tours, you can charge a big battery bank completely within about five hours from the mains. That would probably do for a week of Garmin+phone charging, depending on usage.

    If for some reason you couldn't get access to a plug for an entire week, then pick a sunny day (or two...) and charge the bank off the dynamo. Or carry two battery banks.

    (PS - go for dynamo lights. The ability to put on lights in dim/rainy conditions and not panic about battery life makes everything much nicer!)

    Posted 8 years ago #

  25. Darkerside
    Member

    Or (assuming a dynamo rear hub isn't a thing!) get a tadpole trike with two front dynamos. Use one for lights and one for charging.

    But that might blow your budget...

    Posted 8 years ago #

  26. kaputnik
    Moderator

    Cheapest option is to carry as few electricals as possible, turn your phone off when not using it and make strategic pub/cafe/restaurant/hostel stops every 2 or 3 days to charge anything up.

    Posted 8 years ago #

  27. steveo
    Member

    A more useful thing than a solar panel would be a dynamo rear hub

    I have been pondering off and on a sail for the front wheel, think wind mill. Cloth panels clipped on to a few sets of spokes and guyed out into the wind. One of these days I'll get round to trying it.

    Posted 8 years ago #

  28. cb
    Member

    "carry as few electricals as possible"

    But worth making space for an additional battery pack (or two).

    This random example on Amazon could keep a smart phone going for a week.

    Posted 8 years ago #

  29. wingpig
    Member

    Run a standalone dyanamo-to-USB charger off an extra dynohub, not built into a wheel, but clamped into a wee thing that you could clamp against the rear wheel with the bike upturned, as a sort of friction dynamo thing? Running the large-diameter wheel against the smaller-diameter hub body would get the dynamo rotating at maximal generating speed at a very low rate of pedalling. Or just get a friction-clamp dynamo and mount it on a seat stay instead of the front fork.

    Posted 8 years ago #

  30. kaputnik
    Moderator

    How about a design of the rear dynohub that works against the freewheel; i.e. you pedal backwards, the wheel doesn't move but the hub (and dynamo) does? No need to upend the bike... You just need a robust stand or a fencepost or something to lean against.

    Posted 8 years ago #

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