[Closed] Talk to me about dynamos

Don't know about the Shimano bearings. The problems that occurred with SP seemed to be with one batch of the 15mm through axle versions - some people have ridden them for 5,000km or more without any problem, others have had them break within 400km, seemed to be a QA problem.

Any MTB oriented light is a pain to other road users. I've a B&M light and it's fine up to at least 30kmh on unlit roads. (my commute is roughly 1/3 canal tow path, 1/3rd urban roads and 1/3rd rural roads) If the roads are wet then you don't get as much illumination but that's common to all lights.

Have a look at the German websites such as rose bikes/bike24. I bought a shimano lx dyna hub for a good price and a b+m iq-X which is very good.

I have a Shimano hub generator on a used utility bike that I bought.  It's gone for 10+ years without missing a beat.  Since taking it on the bike as been in all weather for the last 5 years, and has been left outside for months at a time.  It ceased to provide power on one occasion so far. I checked the wires and discovered they had rusted/corroded. I simply trimmed them back and reconnected.  Power back on.   Thing seems bombproof. It's not lightweight or pretty but I take my hat off to it.  Haven't noticed any problems with bearings either, they are still spinning smoothly.

As for SP and Alpkit, I think you'll find that they are the same unit.

Haven't had any issues yet with either Shimano or SP, though I've put a lot more miles on the former than the latter.

Servicing the bearings on a Shimano dynohub isn't as straightforward as a normal hub, though it's still doable with care.

+1 for German beams. Best bang for the buck at the moment probably either the Cyo Premium or Luxos B, both about £60-65 from Germany. Worth adding some spray protection (mudguard or otherwise) to most crown-mounted lights.

Not sure what the x1.4-0.7 is and I'm no good at electronics, but you're unlikely to power a normal MTB light with a dyno that puts out 500mA.

<p style="margin: 1rem 0px !important; padding: 0px; border: 0px; outline: 0px; font-size: 16px; vertical-align: baseline; background-color: transparent; line-height: 1.5rem; font-weight: normal; color: #444444; font-family: 'Helvetica Neue', Helvetica, Helvetica, Arial, sans-serif; font-style: normal; font-variant-caps: normal; letter-spacing: normal; orphans: auto; text-align: left; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-tap-highlight-color: rgba(26, 26, 26, 0.301961); -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; background-position: initial initial; background-repeat: initial initial;">As for SP and Alpkit, I think you’ll find that they are the same unit.</p>

I think the internals may differ, they have different specification markings on the side. There's a thread on the CTC forum somewhere. Haven't heard of significant issues with either hub, though.

^ thanks for that, think maybe I confused Alpkit hub with the Exposure Revo.  This is what you get withadvancing age and quitting caffeine at the same time 🤤

I've had both a shimano DH-3n31 and a SP.

The shimano one i had like above was bombproof, I used it for commuting with a supernova light and didn't look after it at all, Ran summer/winter through all weathers no problem.

The SP i had on my audax bike. again it worked well but was well looked after. I didn't notice any performance difference between the two.

The advantage of the SP is its light and nicer looking.

If i was to buy another i would go for shimano again as it really did do the job well and was pretty much a fit and forget job.

its also £25 at rose bikes.

https://www.rosebikes.co.uk/article/shimano-dh-3n31-hub-dynamo/aid:671388

I saw this a few months ago. It's going back to what we had as kids.

http://bearbonesbikepacking.blogspot.co.uk/2017/11/velogical-dynamo-first-look.html?m=1

It's 75g. Can be installed quickly and easily on any bike. Can be removed quickly if you want to ride your bike on a Sunday run.

Serviceable, robust and red.

I don't know anyone who has one  but it would be what I'd go for.

Edit: just Googled the price. Hmmmmm

my sp8 was a qr one and failed withing a few thousand miles.  I'd get the top of the line shimano simply because IIRC the bearings can be replaced.

Please use a proper german spec road beam light - MTB style ones dazzle like heck and also waste a lot of light because its not in the right place

I’ve a B&M light and it’s fine up to at least 30kmh on unlit roads

Which one? There's quite a selection! 🙂

I have a Shimano XT 3w dynamo hub, bought from Rose bikes. I got it because it was half the price of the rest and only weighed a tiny bit more. The performance has been...completely unnoticeable, which is what I wanted! It's on a commuter, so high mileage and therefore the less maintenance the better and apart from tightening the cup and cone fandangery that's all I've needed to do for tens of thousands of miles.

I got this light which is fine for lit roads but I wouldn't mind a bit more punch if I was regularly using unlit roads:

https://www.rosebikes.co.uk/article/b--m-lumotec-iq-cyo-r-premium-t-senso-plus-front-headlamp/aid:709233

Don't get a 1.5w dynamo! It's some weird German standard and it seems to be all lose and no win. I don't understand it tbh! 🙂

https://www.rosebikes.co.uk/article/shimano-deore-xt-dh-t785-disc-hub-dynamo/aid:515919

OP and shermer75, I suggest you have a look at Peter White's comparison of various dynamo front light beams here

"Peter White’s comparison of various dynamo front light beams here"

I've seen that, it's really useful! 🙂

There's an interesting article available as a pdf if you Google 'Vintage Bicycle Quarterly Testing the Efficiency of Generator Hubs' also

@shermer75 - it's the Lumotec IQ Fly Senso Plus (catchy name eh?), it's one of the ones compared on the Peter White page linked to above.

I have a Shimano XT 3w dynamo hub, bought from Rose bikes. I got it because it was half the price of the rest and only weighed a tiny bit more.

Hi, was that a sale price?  Am considering one of those or an SP for my tourer, it seems they are each around the £80-£100 mark?

I have a Shimano XT 3w dynamo hub, bought from Rose bikes. I got it because it was half the price of the rest and only weighed a tiny bit more.

Malvern Rider, in case you were not already aware, they sell both 3W and 1.5W versions (and 2.4W of other Shimano hubs like Inter). Make sure you get the 3W, unless you are happy to be restricted in your choice of light and its output.

"Hi, was that a sale price?  Am considering one of those or an SP for my tourer, it seems they are each around the £80-£100 mark?"

Sounds like they would be a similar price then. I bought mine about 6-7 years ago, things may have changed.

Thanks for that slowster that's v good info.  It won't be happening until likely next winter so I've added that to the Shortlist/Battle Plan 💡

"@shermer75 – it’s the Lumotec IQ Fly Senso Plus (catchy name eh?), it’s one of the ones compared on the Peter White page linked to above"

Thanks!! 🙂

<span style="color: #444444; font-size: 12px; background-color: #eeeeee;">How long do SP bearings last?</span>

I've got through 2 QR SP hubs in around /a bit over 20,000km of mixed terrain, all-year riding. Not bad going but that's ~15 months each. Shimano or SON next build, just to get longer life from the wheel build. Probably both, SON for a posh wheelset and an XT for winter wheels.

Apparently the SPs don't like over-tight QRs - can add bearing pressure and might be related to some of the shorter life spans. I do my QRs up pretty tight anyway.

I've been running a Shimano XT for 3 years on the commuter in all weathers, and it just gets on with the job without missing a beat. The German online retailers have some really good deals on front Dyno wheels at the moment. I use the IQ Cyo Premium T light, which is great on dark back roads; there's a bewildering range of B&M lights!

I'm wondering about the Hunt Son wheels for slightly lighter, nicer Audax wheels. Does anyone have experience of these? The Son would be a bit of an indulgence, because the Shimano dynos really are good.

I think it was road salt that killed my sp8.  10000 km life for a hub you think is OK?  I don't hence if / when I get another it will be one I can replace the bearings in

I’d agree with TJ

MY Exposure (AKA SP dynamos) have been fine but they’re not user servable. They’re light and neat though. If/when they pack up I’ll be putting Shimano XT in there instead becaus they have normal cup and cone bearings and will last forever on a commuter/tourer.

“I do my QRs up pretty tight anyway.”

Its not a test of your strength how tightly you can do them up! Totally unnecessary.

I think my SON has done around 17,000km, can't remember when I put it on the previous commuter or transferred to the current bike so it might be 1,000km lower. No noticeable play in bearings.

We are currently looking at a dynamo for my wife's bike, unsure whether to go SP or Schmidt.

10000 km life for a hub you think is OK?

Myself, not really no. I've had maybe 3x that of harder use from other front hubs and would expect similar from a dyno hub. Sealed bearings that can't be user-replaced seem daft if the hub won't do 4-5yrs of audaxer-type mileage, so maybe 60-75,000km isn't unreasonable to expect. Not sure what SONs tend to do, as a benchmark?

“I do my QRs up pretty tight anyway.”

Its not a test of your strength how tightly you can do them up! Totally unnecessary.

Thanks for the egg-sucking lesson : ) Pretty tight doesn't mean the result of a strength test. Pretty tight ie secure, resists the disc forces and doesn't shift, but not so tight to be possibly the reason I'm getting 1000km from the hub as others report.

XT hub acquired (£69, bankrupt stock on eBay).

Next stop, lamps.

there’s a bewildering range of B&M lights!there’s a bewildering range of B&M lights!

And Peter White isn't much clearer! Is one objectively the best or is there more to it?

There's more to it. What do you want it for? My recommendations for general/rural riding are above; for urban commuting other options can be better; and if you're taking it off road then things start getting a little more interesting.

Edit: Sorry, you said unlit roads. As above, then: Luxos B or Cyo Premium make good starting points, but they're not the only options.

@jameso - I've seen a figure of 50,000km between services for Schmidt dynamo hubs. Presumably this is for on-road distances.

Re Dynamo big recommend for SON. Costs a lot but I picked one up of ebay for £100. On the bearings side if you ever need to get bearing work done you don't need to unlace the wheel just return the whole thing. SP needs to be out of the wheel as its a split shell so any work requires a rebuild.

Re B&M lights do some research as there was talk of a particular range failing quite quickly. That was a couple of years ago. I had an Edelux 2 again as new off ebay. Great light not over-bright off road but used a Joystick to enhance lighting off road. The Edelux is designed  for road use under TUV in Germany and has a flat top beam. Also has a long stand light when you stop,