Brompton Dynamo Wheel

Discussion in 'Folding Bikes' started by Tenkaykev, 28 Nov 2018.

  1. Tenkaykev

    Tenkaykev Active Member

    Location:
    Poole
    I'm thinking of fitting a Dynamo wheel to my Brompton. I've looked around and there don't seem to be many available. ( My Google -Fu skills might not be up to scratch ) some sites list them but say " not available " I can't really stretch to the Son hub but see there is a " SP Dynamo hub " which gets good reviews.
    Can anyone point me in the right direction? my Brommie is black so I would ideally like a black wheel, spokes and hub. As a retired engineer I would consider trying to build a wheel myself but my lack of knowledge and experience with bike stuff means that I don't know what what specific stuff I'd need so it could turn into an expensive but fascinating project.
     
  2. Cycleops

    Cycleops Guru

    Location:
    Accra, Ghana
    The Brompton dynamo kit seems unavailable at most sites but these people say they have one for £150.
    https://www.comptoncycles.co.uk/m5b0s254p7248/BROMPTON-Shimano-hub-dynamo-set-including-front-wheel
     
    Tenkaykev likes this.
  3. OP
    OP
    Tenkaykev

    Tenkaykev Active Member

    Location:
    Poole
  4. si_c

    si_c Veteran

    Location:
    Wirral
    As you're an engineer, get yourself a copy of Jobst Brandts book on wheels, it's an interesting read in and of itself, but it goes into great detail about how to build wheels.

    I did it myself last year, got myself a cheap truing stand (not necessary) and dishing tool (again not strictly necessary) and did it myself with exactly the parts I wanted. Went surprisingly easy, although I got my key spoke in the wrong place so the spokes overlap above the valve, which is aesthetically displeasing but functionally irrelevant. Took me a couple of hours in total, and was actually quite fun. I've built 3 more since, all of which are still running fine.

    In terms of dynamo I have an SP PD-8 which runs the lighting setup I have perfectly well, it's also really light and there is no noticeable drag on the hub, even when the light is on it still spins for quite some time.
     
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  5. Tenkaykev and raleighnut like this.
  6. ukoldschool

    ukoldschool Well-Known Member

    I would have thought an engineer could see the folly in adding considerable additional weight and complexity to a portable bicycle, when attaching rechargable LED lights would acheive the desired effect for a tenth the outlay...... ;)
     
    Dogtrousers, Tenkaykev and Cycleops like this.
  7. alicat

    alicat Guru

    Location:
    Staffs
    A couple of years ago I swopped a bottle dynamo for a SP PD-8. I built the wheel radially and it was easy and satisfying. I using the bike forks and a brawawl in place of the brake blocks to make a screeching noise when the wheel wasn't true. The hardest part was getting the right spoke length.

    If that doesn't float your boat then try SJS cycles as suggested by @rualexander.

    I'm really happy with the new set up.
     
  8. OP
    OP
    Tenkaykev

    Tenkaykev Active Member

    Location:
    Poole
    Ha Ha - got me :-)

    I have a B+M Lumotec Cyo Dynamo light on its way to me, it was a very very good price in the recent " Black Friday " deals.
    I like the look of the Dynamo lights and my plan is to use it as a rechargeable light using a separate rechargeable battery pack. I already have a fair few high quality NiMh cells and battery holders etc, plus it is the time of year where it gets dark really early and having a project to tinker about with helps keep me occupied.

    ( About 20 years ago I was working for an Electrical Engineering company. We looked after the emergency lighting for various Factories / Offices etc and so had a readily available source of high quality NiCads in "C" cell size. I fettled some stainless steel tubing, manufactured a spring, a waterproof cap with a Jack plug socket and switch etc. I mounted this on my bike using P clips, connected my then lights to a Jack Plug socket. When I got to work it was a simple matter of unplugging the light and connecting the battery bank to a wall charger by my work bench. This worked well for several years until I gave up cycling.)
     
  9. OP
    OP
    Tenkaykev

    Tenkaykev Active Member

    Location:
    Poole
    Now that is really ingenious to use the bike forks and Bradawl as you did to true the wheel. I know I can get a wheel and hub dynamo, but I wasn't sure about what spokes would be required for a Brompton, but I'm getting more and more tempted by the idea of trying to do it myself.
     
    alicat likes this.
  10. alicat

    alicat Guru

    Location:
    Staffs
    I forgot to say it was my first wheel build. Afterwards I wrote a recipe to describe how I did it. It ended 'Serve with a smidgen of smugness.' ^_^
     
    Kell and Tenkaykev like this.
  11. Order the rim and dynohub from SJSC and ask them to add the correct length of black spokes to your order, they will know what length you need.
     
    Tenkaykev likes this.
  12. Kell

    Kell Über Member

    Good advice. It's a bit of minefield to work it out yourself - especially with a new, bigger hub - but that's what places like that are for.
     
    Tenkaykev likes this.
  13. berlinonaut

    berlinonaut Active Member

    Basically you can either get a SON (classic, radial or semiradial), a SP (SV8 or SV9) or a Shimano. All but the SON classic are available in black. The Shimano is the former Brompton factory option as was available in black only for a very short time as an option for the black edition. Still you may able to get hold of a black wheel as a Brompton spare part. I would however not recommend it as it is heavy, adds noticeable drag and offers the lowest quality of the options available. The SV8 is the new factory option for model year 2019, so spare wheels may not yet be available but should be soon. The SV9 is in my eyes far more attractive as it is noticably lighter and costs only minimally more. As far as I know no prebuilt Brompton wheels in black available (apart from buying in Taiwan at Brommiplus). If you build a SP wheel yourself pay attention not only to the OLD of 74mm but also to the thickness of the axle as there are versions for Dahon bikes as well and those do have a slightly thicker axle. Unfortunately those seem to be more common and often dealers do not know about the different versions and mix them up. As far as I can judge the SP is a good option, far better than the Shimano but not as high in terms of price and quality as the SON.
    The SON is quite an investment but a fire and forget solution. Buy one and never look back - there is simply no better solution on the market. You can buy a complete front wheel with the SON semiradial for the Brompton for 250€ here in Germany, the black option with a black rim is slightly more expensive (30€ or so). A hefty price but well worth it. It may be more expensive in the uk so importing from Germany may be a valid option with the SON.
     
    Tenkaykev likes this.
  14. CopperBrompton

    CopperBrompton Bicycle: a means of transport between cake-stops

    Location:
    London
    Honestly, do yourself a favour and get the SON. The whole point of hub dynamos is 'fit once, never think about lights ever again.' A SON fits the bill because of both efficiency (I leave my lights on 24/7) and reliability.
     
    Tenkaykev likes this.
  15. I have a SON28 dynamo on 2 of my bikes. They are perfect. I run my front and tail lights off it.

    I also piggy back an Igaro D1 off them which charges my Wahoo, phone, battery pack etc.

    The best dynamo you can buy in my opinion.
     
    Tenkaykev likes this.
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