Bottle Dynamos

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iandusud
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Joined: 26 Mar 2018, 1:35pm

Bottle Dynamos

Post by iandusud »

We have just acquired a second tandem with a view to using it as our everyday bike and saving the "good one" for weekend rides and touring. Part of the thinking behind this is that our "good one" owes us getting on for £5k and as we don't have a car and cycle everywhere we often need to leave our tandem locked up outside and would rather have £600 worth of bike stolen should that happen. I love the dynamo lights our best tandem (we regularly ride on unlit paths where good lights are essential), and the new one has a bracket for a bottle dynamo. I don't want to go to the expense of replacing a very good wheel (Phil Wood hub) with a dynohub. So how about a bottle dynamo. What are peoples experiences of current offerings? Your thoughts greatly appreciated.
rogerzilla
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Joined: 9 Jun 2008, 8:06pm

Re: Bottle Dynamos

Post by rogerzilla »

They're horrid. Even if set up properly, they are prone to slipping in the wet. A wire brush roller solves that, but eats your tyre very quickly. There is a reason they have almost died out.
bgnukem
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Joined: 20 Dec 2010, 5:21pm

Re: Bottle Dynamos

Post by bgnukem »

Very draggy, bit noisy, rubber wheels can slip in the wet without a tyre with a sidewall track for such a wheel. OK for shortish utility trips I guess but a basic Shimano dynohub neednt cost much and easily outperforms a bottle.

Think I used an AXA bottle for a few years of commuting before I saw the light (groan!) and started using a series of hubs. Only thing I'd say is adjust the hub bearings properly before use - the Shimano hubs are always set too tight.
rjb
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Joined: 11 Jan 2007, 10:25am
Location: Somerset (originally 60/70's Plymouth)

Re: Bottle Dynamos

Post by rjb »

I put a bottle on my dawes kingpin folding shopper. It never slips but i dont go far on it, just local trips generally in the dry. I dont notice the drag apart from the noise. It was a super cheap 99p bargain from SJSC. Just looked and all gone now. I use home made led lighting which is fine for my purposes. I would give some thought to removable rechargeable led lighting from the likes of Aldi and Lidl. They generally get excellent reviews and come in couple of times a year, so when autumn approaches keep an eye out.
At the last count:- Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X3, Raleigh 20 stowaway, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840 :D
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Paulatic
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Re: Bottle Dynamos

Post by Paulatic »

I’ve had a few :) Bring back memories of overnight Audax rides. The noise I enjoyed going downhill but hated it going up as it told you how slow you were going. Problems I recall blowing bulbs going too fast but slipping I always mastered with precision fitting and sometimes a bit of rubber hose over the wheel.
I’ve still a Litespin in the shed, now that was a lot less drag.
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Carlton green
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Joined: 22 Jun 2019, 12:27pm

Re: Bottle Dynamos

Post by Carlton green »

I’m a fan of Bottle Dynamos and think them unfairly dammed, but it all depends what the OP wants to do.

If you want anytime drag free electric generation then you’ll have to cough up for a hub dynamo. If in reality more perceived than real a bottle dynamo does suffer a little drag; a bit of light oil might help with that (I believe it does) and so might an extra cap / cover on the dynamo drive wheel (not tried that yet but have some covers ready). I’ve covered loads of night time riding miles with just old style Union Dynamos and never had any bother with them, they just kept working for me as I steadily rode along in all weathers. With the LED lights and bottle dynamos on my bikes I can literally walk pushing the bike and have plenty of light - I find that amazing.

The best advice I can give is to pick a moderately powerful set of lights and then try them out with a second-hand Bottle Dynamo, it’ll be at least a stop gap arrangement and if you really can’t get on with the bottle then it’s no big financial loss.
Don’t fret, it’s OK to: ride a simple old bike; ride slowly, walk, rest and admire the view; ride off-road; ride in your raincoat; ride by yourself; ride in the dark; and ride one hundred yards or one hundred miles. Your bike and your choices to suit you.
Nearholmer
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Joined: 26 Mar 2022, 7:13am

Re: Bottle Dynamos

Post by Nearholmer »

Why are they traditionally run on the tyre sidewall?

Couldn’t they be run from the “road face” of the tyre at/near the top, thereby using the bit that is designed to take hard wear?
rjb
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Joined: 11 Jan 2007, 10:25am
Location: Somerset (originally 60/70's Plymouth)

Re: Bottle Dynamos

Post by rjb »

Nearholmer wrote: 30 Jun 2022, 4:43pm Why are they traditionally run on the tyre sidewall?

Couldn’t they be run from the “road face” of the tyre at/near the top, thereby using the bit that is designed to take hard wear?
"Mudguards" is the reason. No mudguards then you could make a bracket to run on the thread. :wink:
At the last count:- Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X3, Raleigh 20 stowaway, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840 :D
rogerzilla
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Joined: 9 Jun 2008, 8:06pm

Re: Bottle Dynamos

Post by rogerzilla »

Nearholmer wrote: 30 Jun 2022, 4:43pm Why are they traditionally run on the tyre sidewall?

Couldn’t they be run from the “road face” of the tyre at/near the top, thereby using the bit that is designed to take hard wear?
Yes, Sanyo bottom bracket dynamo. They get plastered in gritty dirt, though.
Bmblbzzz
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Re: Bottle Dynamos

Post by Bmblbzzz »

If starting from scratch, I'd go for a hub dynamo, but in this case rather than get rid of the decent wheels with Phil Wood hubs or use a bottle dynamo, I'd get decent battery lights. I'd probably go for USB-rechargeable rather than replaceable batteries, but that depends (though most of them are rechargeables now).
Nearholmer
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Joined: 26 Mar 2022, 7:13am

Re: Bottle Dynamos

Post by Nearholmer »

I’m not convinced by the mudguard argument. A tiny bit of ingenuity could solve that problem. I suspect that it was just easier for manufacturers to have them run on the sidewall, and that became the norm.
iandusud
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Joined: 26 Mar 2018, 1:35pm

Re: Bottle Dynamos

Post by iandusud »

Thanks for all the replies. I'm inclined to go along with CarltonGreen assessment. The dynamo lighting is not likely to get a lot of use but it is great to have it when it's needed rather than fitting battery lights that either have to be removed when the bike is parked or risk being stolen. I might even just run a front light off the dynamo and use an LED rear light bolted onto the rear carrier, which is what we use on our other tandem. I do sometimes like to use a flashing rear light in day time. I fitted a Union 35 lux front light on my cargo bike which cost less than £20 and is impressively good, so I would probably opt for one of those.
Bowedw
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Joined: 22 Feb 2011, 10:26pm

Re: Bottle Dynamos

Post by Bowedw »

I used a roller type under the bottom bracket for several winters years ago. Seemed fine as I recall but did slip with frost/snow on the road.
Not sure what is available these days. It had a trigger mounted at the top of the seat tube to let it on and off.
rjb
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Joined: 11 Jan 2007, 10:25am
Location: Somerset (originally 60/70's Plymouth)

Re: Bottle Dynamos

Post by rjb »

Bowedw wrote: 30 Jun 2022, 7:02pm I used a roller type under the bottom bracket for several winters years ago. Seemed fine as I recall but did slip with frost/snow on the road.
Not sure what is available these days. It had a trigger mounted at the top of the seat tube to let it on and off.
With a bit of DIY inginuity you could use a suitably positioned down tube lever and cable to pull your dynamo away from the tyre. I had a soubitez bottom bracket dynamo operated by a gear lever on the down tube. :wink:
At the last count:- Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X3, Raleigh 20 stowaway, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840 :D
a.twiddler
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Joined: 4 Jun 2009, 12:17am

Re: Bottle Dynamos

Post by a.twiddler »

I had a Shimano roller type dynamo many years ago. It was much better than the bottle dynamos of the day but as others have commented was prone to slip in the wet or snow. I tried various ways of powering the lights at a standstill as standlights weren't available -battery packs, etc. As you had to reach down to flick the little lever to engage or disengage it I came up with a wizard wheeze to get it away from the worst of the road spray and make it more accessible by bolting it to the front carrier so that it bore down on the tread of the front wheel ahead of the mudguard. This worked well in the dry though looked a little odd, and its weight ahead of the wheel spindle made the wheel prone to flop when parked or wheeling it about..

In the wet it caused an elegant curl of spray to rise up to face level which wasn't a good thing. I dealt with this by making an alloy spray guard which made the set up even more noticeable but it worked, so it stayed there for a few years. You had to tighten the bolt from time to time as being mounted above the front wheel made it prone to vibrate loose.

Coming back from somewhere towing a home made single wheel trailer in the dark down a long hill in a drizzle kept me occupied as the trailer weighed more than the bike and if the speed wasn't kept down the tail would wag the dog. The lights flickered and went out to add to my enjoyment. I could see that the bolt was loosening causing the dynamo to lose traction on the tyre so to try to get a bit of light as I cautiously came to a stop, and to prevent the dynamo falling off into my spokes I put my hand on it. I can confirm that there was nothing wrong with its generating capacity as its output found its way to earth via my wet arm. I couldn't believe that you could get such a jolt from a bike dynamo. After swerving about a bit (a lot!) I managed to stop without falling off. Despite my initial urge to rip it off and hurl it over the nearest hedge I still had to get home in the dark so I tightened it up and carried on gingerly home.

I persevered with it for several more years as my cycling mileage diminished due to changes in my life. Eventually led lights became cheaply available and the dynamo was relegated to my bits box. Overall, despite its shortcomings, a well made, long lasting product. On reflection, my life had some rather exciting moments back then.
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