Dynamo system choices

For discussions about bikes and equipment.
SA_SA_SA
Posts: 1709
Joined: 31 Oct 2009, 1:46pm

Re: Dynamo system choices

Postby SA_SA_SA » 15 Jan 2018, 8:15pm

Brucey wrote:....dip beam patterns on cars are skewed leftwards* but thus far such shaped beams have not appeared in bicycle lights....

Isn't the absence in cycle lamps due to German and Dutch Cycle paths often having one direction of the path cycling against the adjacent traffic lane direction (now also occurs on some two way separates paths in UK) so the upturn would be in drivers eyes?.


*I don't think they have to be, I have seen website mentioning some modern ECE dipped lamps not needing conversion stickers for travel to Europe because they don;t have the upturn on offside. I suspect projector headlamps are like this.
------------You may not use this post in Cycle or other magazine ------ 8)

Giles Pargiter
Posts: 65
Joined: 15 Sep 2012, 11:34pm
Location: N & Mid Wales.

Re: Dynamo system choices

Postby Giles Pargiter » 12 Feb 2018, 12:20pm

brynpoeth wrote:
Giles Pargiter wrote:I know it is deeply unfavoured and unfashionable in the UK but I use modern B&M bottle dynamos on my bikes, upon which I do a considerable amount of night riding.
These are the lightest type of dynamos available and due to the fact that they revolve much faster suffer from no flicker at all even when wheeling the bike. When turned off they are completely off.

..
.


Unfashionable is good I think
Like to see some pictures, front or back? Diolch
I was always a bit afraid a bottle dynamo might go into the spokes


Sorry about the inordinately long time for to reply, I live off grid and my internet access and power is sometimes a bit "random" and not always available.
People seem to imagine all sorts of problems about these dynamos, that just don't happen. They can very occasionally have trouble in very sticky mud or snow, but this is rare. For example traversing one of the hills yesterday afternoon, traction between my tyre and the road in the snow almost meant I had to walk up it - the dynamo was absolutely fine.
Here are a couple of pictures of them mounted. In the usual Brit way I prefer them behind the rear stay. They are better protected there, the spray in wet weather does not make your legs wet, you can hardly here the magnetic whine. A little awkward to turn on when panniers are in use.
Well I would include pictures but I'am informed the "file size to large" it is a 635kb Jpg so I am at a loss on that. I am definitely not buggering about putting them online somewhere.

Brucey
Posts: 33924
Joined: 4 Jan 2012, 6:25pm

Re: Dynamo system choices

Postby Brucey » 12 Feb 2018, 12:35pm

SA_SA_SA wrote:
Brucey wrote:....dip beam patterns on cars are skewed leftwards* but thus far such shaped beams have not appeared in bicycle lights....

Isn't the absence in cycle lamps due to German and Dutch Cycle paths often having one direction of the path cycling against the adjacent traffic lane direction (now also occurs on some two way separates paths in UK) so the upturn would be in drivers eyes?.


*I don't think they have to be, I have seen website mentioning some modern ECE dipped lamps not needing conversion stickers for travel to Europe because they don;t have the upturn on offside. I suspect projector headlamps are like this.


well don't get me started on modern car headlight designs.... a lot of them are b. awful IMHO.

But regarding cycle lamps, it occurs to me that the IQ-X can be rotated slightly in its collar mount to give the beam pattern a longer throw up the LH gutter if you want that. Anyone tried it?

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

mercalia
Posts: 10366
Joined: 22 Sep 2013, 10:03pm
Location: london South

Re: Dynamo system choices

Postby mercalia » 12 Feb 2018, 3:57pm

Giles Pargiter wrote:
brynpoeth wrote:
Giles Pargiter wrote:I know it is deeply unfavoured and unfashionable in the UK but I use modern B&M bottle dynamos on my bikes, upon which I do a considerable amount of night riding.
These are the lightest type of dynamos available and due to the fact that they revolve much faster suffer from no flicker at all even when wheeling the bike. When turned off they are completely off.

..
.


Unfashionable is good I think
Like to see some pictures, front or back? Diolch
I was always a bit afraid a bottle dynamo might go into the spokes


Sorry about the inordinately long time for to reply, I live off grid and my internet access and power is sometimes a bit "random" and not always available.
People seem to imagine all sorts of problems about these dynamos, that just don't happen. They can very occasionally have trouble in very sticky mud or snow, but this is rare. For example traversing one of the hills yesterday afternoon, traction between my tyre and the road in the snow almost meant I had to walk up it - the dynamo was absolutely fine.
Here are a couple of pictures of them mounted. In the usual Brit way I prefer them behind the rear stay. They are better protected there, the spray in wet weather does not make your legs wet, you can hardly here the magnetic whine. A little awkward to turn on when panniers are in use.
Well I would include pictures but I'am informed the "file size to large" it is a 635kb Jpg so I am at a loss on that. I am definitely not buggering about putting them online somewhere.


pictures you need to use a free picture editor like xnview to reduce the size both in kb and dimensions? I too have a b&M bottle on the front wheel, though these days i tend to use a lidl battery lamp ( for urban riding) - if you use the wire roller then almost nothing will stop them working and it doesnt seemt to damage the tyre wall much if at all. The only thing re the B&M bottle is they are a bit small with a small mounting arm so attaching them can be a bit heath robinson - usually need some kind of adapter to attach to the brake boss?

Giles Pargiter
Posts: 65
Joined: 15 Sep 2012, 11:34pm
Location: N & Mid Wales.

Re: Dynamo system choices

Postby Giles Pargiter » 12 Feb 2018, 5:26pm

Thanks for that info Mercalia, had a look at xnview.

The way I have them fitted they run on to the wheel, which is no doubt one reason why I have no trouble with them slipping. The B+M is of course adjustable in this respect. I have one mounted on a bracket that is fastened with the cantilever brake bolt. The other which is on a frame with caliper brakes I have made my own simple mounting which is much neater than those one can buy. It is very similar to the braze on that I think Thorn(?) offer for such. In my case it is bolted of course. (Shame the forum won't accept my pictures.)
On one of my bikes the dynamo is running on a Marathon tyre which has so far clocked 3400 miles with extensive night riding - it has just about made the shwalbe label illegible.

Brucey
Posts: 33924
Joined: 4 Jan 2012, 6:25pm

Re: Dynamo system choices

Postby Brucey » 12 Feb 2018, 7:02pm

FWIW I use a program called 'FastStone photo resizer' on my PC.

It allows batch conversion and seems to work in a fairly pain-free fashion.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

brynpoeth
Posts: 9851
Joined: 30 Nov 2013, 11:26am

Re: Dynamo system choices

Postby brynpoeth » 12 Feb 2018, 7:10pm

I would always be a little bit afraid of a bottle dynamo going into the spokes
Entertainer, juvenile, curmudgeon
Cycling-of course, but it is far better on a Gillott

De Sisti
Posts: 684
Joined: 17 Jun 2007, 6:03pm

Re: Dynamo system choices

Postby De Sisti » 13 Feb 2018, 8:25am

mercalia wrote: - if you use the wire roller then almost nothing will stop them working and it doesnt seemt to damage the tyre wall much if at all.

Providing the tyre has a roller track. :wink: The last time I used a bottle dynamo with a wire roller was on a Schwalbe tyre
without a 'roller track' in 2001. After the the tyre was eventually ripped to shreds I decided that I'd use a hub dynamo in future.

mercalia
Posts: 10366
Joined: 22 Sep 2013, 10:03pm
Location: london South

Re: Dynamo system choices

Postby mercalia » 14 Feb 2018, 12:23pm

Giles Pargiter wrote:
brynpoeth wrote:
Giles Pargiter wrote:I know it is deeply unfavoured and unfashionable in the UK but I use modern B&M bottle dynamos on my bikes, upon which I do a considerable amount of night riding.
These are the lightest type of dynamos available and due to the fact that they revolve much faster suffer from no flicker at all even when wheeling the bike. When turned off they are completely off.

..
.


Unfashionable is good I think
Like to see some pictures, front or back? Diolch
I was always a bit afraid a bottle dynamo might go into the spokes


Sorry about the inordinately long time for to reply, I live off grid and my internet access and power is sometimes a bit "random" and not always available.
People seem to imagine all sorts of problems about these dynamos, that just don't happen. They can very occasionally have trouble in very sticky mud or snow, but this is rare. For example traversing one of the hills yesterday afternoon, traction between my tyre and the road in the snow almost meant I had to walk up it - the dynamo was absolutely fine.
Here are a couple of pictures of them mounted. In the usual Brit way I prefer them behind the rear stay. They are better protected there, the spray in wet weather does not make your legs wet, you can hardly here the magnetic whine. A little awkward to turn on when panniers are in use.
Well I would include pictures but I'am informed the "file size to large" it is a 635kb Jpg so I am at a loss on that. I am definitely not buggering about putting them online somewhere.



these are the pictures he has been trying to upload
click to enlarge

Raleigh M Dynamo close2a 12.2.18.jpg
Raleigh M Dynamo close2a 12.2.18


Carlton Dynamo1a 12.2.18.jpg
Carlton Dynamo1a 12.2.18


wow I am surprised the dyno works under those conditions - maybe the hard mud helps?

Brucey
Posts: 33924
Joined: 4 Jan 2012, 6:25pm

Re: Dynamo system choices

Postby Brucey » 14 Feb 2018, 1:08pm

in fairness those B&M dynamos are some of the better ones; typical bottle dynamos need at least 12W drag to get 3W out, those are perhaps 'only' 9-10W or so, (and have some means of voltage regulation IIRC). Contrast with hub generators which need 5-6W input to get ~3W out.

FWIW I think there is a difference in slippage tendency with bottle dynamos depending on what lamps you have attached to them. Halogen bulbs may be the worst; they have very low resistance when cold, so tend to draw a lot of current even at low speeds. This loads up the generator and makes it more likely to slip. By contrast LEDs don't really draw any current at the lowest speeds so a complete stall (skid) of the bottle generator I would think is less likely.

Maybe if bottle generators had been better BITD, I wouldn't have done what I did, which was to install a heavy (~900g) and low powered SA hub generator in my training bike in the early 1980s. I've done tens of thousands of miles (about a third of them in darkness) using that system. Apart from changing the bulbs when they start to look a bit too black, and the rivets that hold the hub together eventually working loose :shock: , the system gave no trouble at all.

By contrast both battery lights and bottle dynamo lights were just a constant source of trouble and irritation. On the bottle dynamos there were wires that corroded or dropped off, junky brackets that slipped or broke or damaged the frame, problems of slippage, voltage regulation etc, all on top of the drag and the bloomin' noise of the thing. I could hear the dynamo very clearly wherever it was placed. I am sure that things may be better with more modern kit but that all the problems are solved I don't believe for a moment.

Modern hub dynamo systems are half the weight and three or four times brighter (at least) than the system I started with and are something of a no-brainer if you do a lot of night riding.

cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

mercalia
Posts: 10366
Joined: 22 Sep 2013, 10:03pm
Location: london South

Re: Dynamo system choices

Postby mercalia » 14 Feb 2018, 1:50pm

Brucey wrote:in fairness those B&M dynamos are some of the better ones; typical bottle dynamos need at least 12W drag to get 3W out, those are perhaps 'only' 9-10W or so, (and have some means of voltage regulation IIRC). Contrast with hub generators which need 5-6W input to get ~3W out.

FWIW I think there is a difference in slippage tendency with bottle dynamos depending on what lamps you have attached to them. Halogen bulbs may be the worst; they have very low resistance when cold, so tend to draw a lot of current even at low speeds. This loads up the generator and makes it more likely to slip. By contrast LEDs don't really draw any current at the lowest speeds so a complete stall (skid) of the bottle generator I would think is less likely.

Maybe if bottle generators had been better BITD, I wouldn't have done what I did, which was to install a heavy (~900g) and low powered SA hub generator in my training bike in the early 1980s. I've done tens of thousands of miles (about a third of them in darkness) using that system. Apart from changing the bulbs when they start to look a bit too black, and the rivets that hold the hub together eventually working loose :shock: , the system gave no trouble at all.

By contrast both battery lights and bottle dynamo lights were just a constant source of trouble and irritation. On the bottle dynamos there were wires that corroded or dropped off, junky brackets that slipped or broke or damaged the frame, problems of slippage, voltage regulation etc, all on top of the drag and the bloomin' noise of the thing. I could hear the dynamo very clearly wherever it was placed. I am sure that things may be better with more modern kit but that all the problems are solved I don't believe for a moment.

Modern hub dynamo systems are half the weight and three or four times brighter (at least) than the system I started with and are something of a no-brainer if you do a lot of night riding.

cheers


so when lights are off what watts do they still consume when turning the wheel? When I was up Scotland I met a Brompton owner who had a hub dyno and regretted getting it due to the drag when off

JakobW
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Location: The glorious West Midlands

Re: Dynamo system choices

Postby JakobW » 14 Feb 2018, 1:57pm

For most it's less than a watt compared with a non-dyno front hub, isn't it? IIRC the Brompton Shimano hub is a Capreo one for small-wheelers, and isn't great; but even there I can't imagine it's more than a couple of watts (and a Brommie isn't exactly a go-faster machine at the best of times...)

Giles Pargiter
Posts: 65
Joined: 15 Sep 2012, 11:34pm
Location: N & Mid Wales.

Re: Dynamo system choices

Postby Giles Pargiter » 14 Feb 2018, 5:18pm

That second picture of my Carlton of course is straight out of the shed. If I had of wanted the lights that mud would just immediatly fly off as soon as I began to move.
I don't really care what (legal) lights others use, but I say again that those who don't use bottle dynamos imagine all sorts of problems about them that either don't or very rarely occur, if they are well fitted. I have no trouble with slippage and the first picture shows a Marathon tyre which has already done 3400miles - many at night, as it is close to threequarters worn I expect close to the same mileage again (barring accidents) from it. - First half of a tyre wears in about a quarter of the miles till worn out, due to tread "squirm". If you want to check that one I would suggest looking on commercial vehicle tyre web sites. The power figures for the dynamo are available on the B+M web site last time I looked.
They are the lightest you can have and if you do your calculations even though they do drag slightly (a fraction of a W) more than hub dyno's unless you ride over 90% in the dark they are the most efficient energy wise. Their output is identical to a hub dyno at optimum including voltage regulation, but occurs at a lower speed. They don't need inordinately expensive wheel builds either. Here is a link to a type of wheel I use https://www.taylor-wheels.com/bike-wheels/26-inch-bike-wheel/26-inch-rear-wheels/taylor-wheels-26-inch-bike-rear-wheel-ryde-zac2000-5-8-speed-cogset-black Which I usually find has the spokes a little more slack than I would desire, so a quarter turn on them rectifies it. I don't regard spending a penny more as in the slightest bit advantageous, which is of course the same attitude I take concerning my lights - but I will only use legally approved types.
(Afraid there seems no way to give the url a short title.)

mercalia
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Re: Dynamo system choices

Postby mercalia » 14 Feb 2018, 6:01pm

seems like the Busch and muller bottle dyno was discontinued last year 2017. so if you want a spare need to get one now? I suspected this as they are not mentioned on the BM site. I am glad I got a spare some years ago when I bought a batch of stuff from Rose Germany , for just £25 new. So thats another bit of kit become history :(
Last edited by mercalia on 14 Feb 2018, 6:06pm, edited 1 time in total.

Giles Pargiter
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Joined: 15 Sep 2012, 11:34pm
Location: N & Mid Wales.

Re: Dynamo system choices

Postby Giles Pargiter » 14 Feb 2018, 6:05pm

What a shame Mercalia. I have got a spare fortunately.