Battery versus Dynamo

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mjr
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Re: Battery versus Dynamo

Post by mjr »

pete75 wrote:BTW if this report is anything to go by the N30 offers reasonable value for money particularly for a not too high mileage rider.
http://www.bikequarterly.com/VBQgenerator.pdf

Thanks for that. I don't often bother downloading pdf files so I probably wouldn't have read it otherwise. I wonder what "not too high mileage" is? The trial bike does at least 300 miles most months and sometimes more, but not much of that in the dark (more in winter).

I suspect it gets ridden less often but about as far in the dark in summer, as the local Cycle Nation group goes on after-work sunset rides to country pubs then, so I think it would be an all-year thing.
MJR, mostly pedalling 3-speed roadsters. KL+West Norfolk BUG incl social easy rides http://www.klwnbug.co.uk
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Brucey
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Re: Battery versus Dynamo

Post by Brucey »

re the 3N30 and similar; the hub is slightly more heavy/draggy than a more expensive hub but it isn't that bad; 1/4 of a bidon in extra weight and about the same extra drag as losing 5psi in one tyre. No big deal at all.

The bearings are usual shimano quality on their mid-range stuff with fairly reasonable seals. This means they respond very well to small amounts of TLC and last a very long time if they get it. The windings are copper. You can unscrew the left cone and then slide the internal assy to the right a few mm. Usually there is then enough of an opening to allow you to introduce more grease into the RH bearing without stripping the hub down. Do this once a year and the thing will probably last for ten years or more; without relubing however three winters will be enough to see the bearings off if what I have seen is anything to go by.

As usual, getting the correct bearing adjustment is less easy than with a non-generator hub, because you can't feel small amounts or play or small amounts of overtightening very easily. You can buy new cones and seals very cheaply. The RH side takes the same cone as the LH side IIRC but you need to be careful of the wire when stripping the RH side bearing down.

cheers
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kwackers
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Re: Battery versus Dynamo

Post by kwackers »

mig wrote:on the subject of mileage on generator hubs i take it that most users use a different front wheel for the 'summer' months?

I don't. Too much hassle to swap and I suspect if the quoted mileage is even remotely correct the bike will be long gone before I need to worry about it. Don't bother turning the lights off either - although I do get the occasional "Oy! Your lights are on mate" from concerned citizens.
Edwards
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Re: Battery versus Dynamo

Post by Edwards »

kwackers wrote:
mig wrote:on the subject of mileage on generator hubs i take it that most users use a different front wheel for the 'summer' months?

I don't. Too much hassle to swap and I suspect if the quoted mileage is even remotely correct the bike will be long gone before I need to worry about it. Don't bother turning the lights off either - although I do get the occasional "Oy! Your lights are on mate" from concerned citizens.


I did not know you now used a dynamo I thought you worked from home. How long have you had that?
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mjr
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Re: Battery versus Dynamo

Post by mjr »

I was looking at the bike after today's ride. Any tips on how/where to fix the wires that go to the back light?

I think I could zip-tie them to the cable covers most places (taking care not to crush it and hinder the braking or shifting) but the cables run without covers along most of both the front-back tubes, which I think is commonplace. Once it reaches the pannier rack, I'll tie it to the rack.
MJR, mostly pedalling 3-speed roadsters. KL+West Norfolk BUG incl social easy rides http://www.klwnbug.co.uk
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kwackers
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Re: Battery versus Dynamo

Post by kwackers »

Edwards wrote:I did not know you now used a dynamo I thought you worked from home. How long have you had that?

I do contract work - so I work from home if I can otherwise I have to go into an office like everyone else... :cry:
I've had the dynamo a year now, probably done around 2 or 3 thousand miles on it.

Currently I'm working in Liverpool and using the train but I'm psyching myself up to start commuting again (a little over 40 miles a day). I've given the route a go and can do it in about 75 mins, whilst door to door by train (bike to station, train, one mile walk) takes 70 mins so in theory it's a no brainer...
(In practice I'm not quite fit enough and so the journey back is a bit of a killer... )
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interestedcp
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Re: Battery versus Dynamo

Post by interestedcp »

mjr wrote:
pete75 wrote:I don't think it's brand prejudice. For two examples, I found mainly nice words about the Axa bits I was considering, whereas I saw the Shimano DH-3N20 and 3N30 often criticised by people who also praise the 3N80.


I have often recommended Shimano "Sport" dynamo hubs like the 3N80 instead their entry line hubs like the 3N30, but only because the discussion was about high mileage riders. For shortish commutes and utility bikes, it offers outstanding value for money.

The 3N30 is probably the currently most sold hub dynamo in the world, and I must admit I have never seen a 3N30 owner saying it was a bad hub, in fact, I usually hear owners say it has worked flawlessly for many years etc.

Sure, its bearings and sealing isn't as good as the modern Sport hub dynamos like 3N72 or 3N80, but that doesn't mean they are bad, just not as superb. Eg. I have just serviced my 3N80 hub, after estimated 6000 km there are almost no wear marks on the cones, and none on the bearing races.

The 3N30 is being succeeded by the new 3N31. Same low price (around 30 Euro), but without any inbuilt over-voltage protection (not needed with modern LED lights). Otherwise they seem very identical, including sharing many parts.

IMHO, the sweet spot between quality and price for hub dynamos is the 3N72. Cheap, strong, the same superb bearings and electrical output as all the other Sport dynamos. But on a fixed low budget, the 3N30 is a good choice too.
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mjr
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Re: Battery versus Dynamo

Post by mjr »

mjr wrote:Anyway, the order for Axa Pico and Riff lights has gone in - I changed my mind after reading reviews on other websites of the Ray and Riff and deciding I'd prefer a red bar to a blob. Thanks to everyone who's contributed helpful comments to this discussion.

The Pico and Riff are fitted, along with a borrowed B+M Dymotec on the front wheel. There was a bit of trial and error as the Riff doesn't seem to have its polarity marked. I gathered the excess cable under the top tube, which I'm not sure was the best idea but we'll see how it goes. I'm slightly concerned that the cable joints may allow water in and I'm not sure how much that matters.

The first short test ride went OK. Both lights seem bright enough for use on unlit roads. The Pico's standlight seems to last about 5 minutes, while the Riff was on for almost 20... I'm glad I was timing them while I tidied up, rather than waiting with a watch!
MJR, mostly pedalling 3-speed roadsters. KL+West Norfolk BUG incl social easy rides http://www.klwnbug.co.uk
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tatanab
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Re: Battery versus Dynamo

Post by tatanab »

mjr wrote:I was looking at the bike after today's ride. Any tips on how/where to fix the wires that go to the back light?

I think I could zip-tie them to the cable covers most places (taking care not to crush it and hinder the braking or shifting) but the cables run without covers along most of both the front-back tubes, which I think is commonplace. Once it reaches the pannier rack, I'll tie it to the rack.
I run mine underneath the top tube held in place with a continuous run of helicopter tape/freezer bag tape/"magic tape" (as used in a drawing office). Nice thing is that the cable cannot rattle on the tube. If you find it necessary you could use a cable tie at the ends of the tape to stop any flaring.

Years ago I ran the wire along the top tube mounted rear brake cable, even the exposed part. There is only something like half an inch movement in the cable so it is not difficult to allow just enough slack. I found this too scruffy so took to using the tape method.
edocaster
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Re: Battery versus Dynamo

Post by edocaster »

tatanab wrote:
mjr wrote:I was looking at the bike after today's ride. Any tips on how/where to fix the wires that go to the back light?

I think I could zip-tie them to the cable covers most places (taking care not to crush it and hinder the braking or shifting) but the cables run without covers along most of both the front-back tubes, which I think is commonplace. Once it reaches the pannier rack, I'll tie it to the rack.
I run mine underneath the top tube held in place with a continuous run of helicopter tape/freezer bag tape/"magic tape" (as used in a drawing office). Nice thing is that the cable cannot rattle on the tube. If you find it necessary you could use a cable tie at the ends of the tape to stop any flaring.

Years ago I ran the wire along the top tube mounted rear brake cable, even the exposed part. There is only something like half an inch movement in the cable so it is not difficult to allow just enough slack. I found this too scruffy so took to using the tape method.


I coiled the slack into a sort of 'telephone cord' near the head tube by wrapping it around a pen for a moment. Not sure that's the tidiest solution, but it has a nice retro effect.
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breakwellmz
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Re: Battery versus Dynamo

Post by breakwellmz »

Which one should be better do you think?(All things being equal? :wink:
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coast 2 coast
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Re: Battery versus Dynamo

Post by coast 2 coast »

Not having any first hand experience on either of these dynamos, but imagining hypothetically, being forced to make a choice.... I would go for the heaviest of the two. My reasoning and desire being, it would have a chunkier and more robust construction, that would keep it glued to the tyre, providing better traction and hopefully, the unit would also have a longer life span.
Brucey
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Re: Battery versus Dynamo

Post by Brucey »

breakwellmz wrote:Which one should be better do you think?(All things being equal? :wink:


the one with the rubber wheel...erm, that is neither of them, then.... :shock:

cheers
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Urticaria
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Re: Battery versus Dynamo

Post by Urticaria »

interestedcp wrote:The 3N30 is being succeeded by the new 3N31. Same low price (around 30 Euro), but without any inbuilt over-voltage protection (not needed with modern LED lights).


I doubt there is any overvolt protection in any Shimano DH because they sell an additional box for that, the SM-DH10. There must be some other difference?
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mjr
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Re: Battery versus Dynamo

Post by mjr »

The Axa lights and both dynamos seem fine, but I'd like to add some notes from fitting my first two bottle dynamo bikes, including one contrary to what I wrote above:

First, do NOT route the wiring to the rack-mounted rear light along the pannier rack. Tape the cable along the mudguard else it gets yanked as things get attached or removed from the rack, or as the bike gets lifted by the rack sometimes (and not always by me...).

Secondly, a wire with a stripe is usually an earth wire. It seems obvious once you know, but it would have been nice if the Pico's packaging had mentioned this.

Finally, I prefer the simple cantilever brake boss dynamo mount to the dynashoe because it seems less fiddly to set up right, but it seems hard to find anyone in this country with them in stock. reallyusefulbikes.co.uk did this time, but it's still £5 postage and a £5 bracket.
MJR, mostly pedalling 3-speed roadsters. KL+West Norfolk BUG incl social easy rides http://www.klwnbug.co.uk
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