Anyone used Dynamo hubs

ren531

Senior Member
Location
Lancaster uk
I plan to do a full service on my winter bike over the summer a Islabike Beinn 29 ,I am thinking of getting a hub dynamo for it ,does anyone have any thoughts or experience with modern hub dynos ,what sort of drag effect do they have when in use or when off, is the weight penalty noticeable ,there seems to be a big difference in prices between the cheaper Shimano ones and the higher end ones ,do the more expensive ones perhaps have less drag ? your help would be much appreciated .
 

the snail

Veteran
Location
Chippenham
Yes the more expensive ones have better bearings and are lighter.I have DN3N80 (?) and I don't notice any drag, or the weight. There must be some drag, but Ican't tell if the light is on or off in daylight, similarly it's heavier than a normal hub, but the weight is in the hub where it has least affect, and the difference in weight vs, a normal hub + lights/battery isn't huge. At the end of the day dyno setups aren't designed for weight weenies though.
 
I have a shimano dynohub on one bike and can't notice it on or off. The benefit of having lighting that never runs out of batteries and can't be (easily) stolen is priceless. The output of the front light is the only real decision in my opinion.
 
OP
ren531

ren531

Senior Member
Location
Lancaster uk
Sorry mods ,I should have thought to put it here . I am defenatly not a weight weeine ,the thought of permanent fix lights is certainly appealing ,having to strip al the lights off just to pop in to a shop is a pain ,as is charging them up every week ,sounds like there isn't much in the way of drag .
 

yello

Legendary Member
I've had a Shimano dynohub for years, it's actually my 2nd. The Schmidt is reportedly more reliable, and serviceable, but is also more expensive. You pays your money etc but I've not regretted opting for Shimano.
 

alicat

Legendary Member
Location
Staffs
I've got a Shimano dynohub on my sit-up-and-beg bike and an SP dynamo hub on my Brompton. I can't say I notice any drag or extra weight. My SUAB bike weighs a ton anyway and I can't notice any extra weight on the Brompton. I find it so handy to have permanent lights that just work with no hassle.
 

Ian H

I am an ancient randonneur, & I stop often for tea
Location
East Devon
I have four SONs. The oldest (one of the first, black-barrelled ones, about 15yrs old) recently failed and I returned it for service. For £63 it was returned almost as new, and with a mod (breather hole) which was adopted on later models. Should go the same distance again.
Drag is not noticeable. Lights are reliable.
 

DRHysted

Veteran
Location
New Forest
I’ve got 1 shimano and 2 SP Dyno hubs. I cannot tell if there is any drag, but absolutely love the convenience of not worrying about lights. Added to that the light beam from the b&m front lights is better for controlled beam pattern and output than any of my battery lights.
Saying that for my early morning commutes I still have a battery front and rear fitted just in case something goes wrong, but then pre-dynamo I always had 2 battery lights front and rear in case 1 stopped working.
 

Fab Foodie

hanging-on in quiet desperation ...
I have SON hubs on my Brompton and my Audaxy bike. Love ‘em!
No faff with batteries or charging, just grab bike and go!
If out on all-nighter I’ll have a headtorch and a battery back-up rear anyhow.
Drag is said to equal a gradient of 1 foot/mile. I just leave mine on all the time.
Unlike @Dogtrousers I like the beam and output of the B&M lamps.
 

YukonBoy

The Monch
Location
Inside my skull
I've used them for 9 years. I have them on my road bike and recumbent. I'm a year round all weather commuter and audaxer with a love of night riding. If I was an occasional night rider or fair weather rider then I'd probably have stuck with battery lights. But for the sort of stuff I do, Dynamo lighting is far less faff and just works. Plus it doesn't even get a glance. Never been worried about someone nicking my lights ever...
 

Vantage

Carbon fibre... LMAO!!!
I've been using a dynamo setup for the last 3 or 4 years. One of the best decisions I've ever made.
My first hub was a Shimano dh3n72 and I'm now using a Shimano dht780.
Nothing wrong with the 3n72 but it was laced to a 700c rim when I needed new 26" wheels building for a new frameset.
The 3n72 puts out 6v 3w and the t780 puts out 6v 1.5w.
This is where you'll need your thinking cap. If you intend on only running a lamp or 2 then a 1.5w hub will suffice. You'll get a lighter hub with less rolling resistance.
On the other hand, if you find you want to be charging things on the move then you'll need something more powerful. The majority of hubs are 3w.
Regarding rolling resistance/drag, I do find it noticeable when switching the lights on and off. It's negligible.
You'll barely notice the increase in weight tbh
And if you do alot of night cycling it might be worth keeping a small torch/headtorch in the saddlebag etc as dynamo lights are literally bolted to the bike and don't work if the bike isn't moving. I'm thinking of punctures/repairs etc.
Upsides.
I've used battery lights in the past. Lots of them. Very few were cheap. Save for 1 that still runs perfectly, they've all died. Water ingress, wonky circuit boards, failed switches, leaky batteries and in the case of 2 of them, leaping off the handlebars and plummeting to their death. Then there's the cost of endless batteries or recharging. Plus the risk of them being nicked by scumbag Sammy.
The initial cost of my setup was over a hundred quid. Quite a bit really. But, its paid for itself many times over and it never ever fails. I've not worried about run time since fitting them either.
Even at 2.5mph, I get a steady constant usable beam of light.
I wouldn't go back to battery lights if a gun was held to my head.
 
I've had a SON dynamo hub sitting on a shelf for three years which I finally got built up and fitted to my touring bike two days ago. It'll have a system which can swap between front light and charging gadget batteries.
 

mjr

Comfy armchair to one person & a plank to the next
I didn't notice drag.

Most dynamo users are very happy with them to the point of being enthusiasts. I'm the exception.

I tried one but never got along with it. The light was feeble and flickery at very low speeds - crawling uphill. I broke the cable connector by removing the front wheel without disconnecting it - entirely my own fault but it was dark, cold and I had a puncture so I wasn't in a good mood and crawling round looking for bits of connector didn't improve it. The front light developed a fault. I got a replacement but by the time it arrived I'd removed the wheel and I've not refitted it since. I reverted to rechargeable batteries.

But most other people are happy with them, and I'm an idiot so its generally best to ignore me.
Broke a Lego brick connector? How had you attached the wires? I've snapped the wires twice but not damaged the brick.

I forget to recharge lights - or simply overestimate their remaining runtime - or forget to remove them when parked far more often than I forget to disconnect the hub (as removing the wheel is rare - I mostly patch punctures in place). I like the dynamo hub and I'd always like one on a bike, but I'm in no rush to fit my other bikes. I'll just take the dyno bike if I know I'll be out at night. I've not noticed drag and the weight penalty is mainly noticeable if you have to lift the bike.
 

glasgowcyclist

Charming but somewhat feckless
Location
Scotland
I plan to do a full service on my winter bike over the summer a Islabike Beinn 29 ,I am thinking of getting a hub dynamo for it ,does anyone have any thoughts or experience with modern hub dynos ,what sort of drag effect do they have when in use or when off, is the weight penalty noticeable ,there seems to be a big difference in prices between the cheaper Shimano ones and the higher end ones ,do the more expensive ones perhaps have less drag ? your help would be much appreciated .

Take a look at Peter White's site for everything you need to know about dynamos.

It's been the best investment in lighting I've ever made.
 

yello

Legendary Member
So it's best to charge a power pack and then use the power pack to charge the gadget.
That's what I do. Mainly because I might use the power pack to (potentially) charge my phone as well as the Garmin, and might do so when I'm not on the bike (coffee stop etc) Maybe I read about the Garmin being fussy, not sure, but if I did then I'd forgotten about it being my reason for charging a power pack! FWIW, I use a Dahon charger (but there are now loads of other options to choose from these days) and a Veho Pebble power pack... all a bit old now but still functions.
 
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