Dynamos - Hub or Bottle?

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gregoryoftours
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Re: Dynamos - Hub or Bottle?

Postby gregoryoftours » 26 Jan 2019, 9:33pm

Ontherivet77 wrote:Looks like I need to get down to Decathlon.
Thanks for all the in depth replies.

I'd pay a bit more for a significantly better quality wheel from Taylor's wheels as others have recommended. Stainless spokes and double walled eyeletted rim. Even the cheapest Shimano Dyno hubs are well sealed, much, much better than their own low end regular hubs.
I've also been running one of Taylor's for a couple of years with no issues.

Carlton green
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Re: Dynamos - Hub or Bottle?

Postby Carlton green » 25 Jun 2019, 10:33am

Ontherivet77 wrote:After a couple of front light failures while commuting I'm considering the dynamo option.
I've been looking at this :
https://www.sjscycles.co.uk/dynamos/axa ... namo-left/

and these:
https://www.sjscycles.co.uk/wheelswheel ... ub-silver/

Although, I accept/presume that hub dynamos are much better than bottles are they worth 10 times the difference.
Also, what is your experience with drag and weight with both these options?
Many thanks in advance.


I would refer you, and future readers, to Mercalia’s post on this thread dated 24/01/19; to my mind it’s a rather good answer to your (the original) question.

As others have pointed out the typical relative cost of hub and bottle dynamos is much less than 10:1.
Edit. Looking through the Holland Bike website (https://hollandbikeshop.com/en-gb/bicyc ... mo/?page=1) at bottle dynamos I think the relative costs are more like 5:1 - bottle dynamos can be very reasonably priced.

About 3 decades ago my sole transport was a bike. I commuted to and from work on one, all year around and in all weathers, and did long runs with my local CTC that sometimes returned in the dark. Some of that riding was on un-lite country lanes and cycle paths. My longest night time runs were around two hours and my longest commute was 45 minutes. Lighting was supplied by a halogen bulb headlight and a Union Dynamo, slipping was never an issue and I never had tyre wall damage. My point is that a bottle dynamo can be perfectly adequate for all year round commuting - at one point the bulk of riders were happy enough to use them.

In addition to the points made in Mercalia’s post I would add that good bottle Dynamo’s are relatively inexpensive, relatively easy to install and that should they fail then they are easy to replace - but that’s fairly obvious.

Rather than say bottles are better than hubs, or the opposite, I’d say that it all depends on individual circumstances. I have a decades old bottle Dynamo on one of my bikes and it's there as a good back-up light source that can be put into use if needed. These days I rarely choose to ride in the dark. The enthusiast will very probably go for a hub because it’s the best possible technical solution for all eventualities. I’m a pragmatist who requires functionality rather than perfection - the existing arrangement works well enough and I could cycle right through to dawn using it - and hence am happy enough to use a bottle Dynamo for my current and anticipated needs. However, I would look at hubs and wonder about investing in one if I started to commute with night time rides of over say 40 minutes.
Last edited by Carlton green on 25 Jun 2019, 10:33pm, edited 5 times in total.

Greystoke
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Re: Dynamos - Hub or Bottle?

Postby Greystoke » 25 Jun 2019, 11:39am

I commute year round on unlit country roads. I've recently changed to a hub dynamo, it makes a bit more power and is always on.
Bottle dynamos are fine, just use a Tyre with a dynamo tread on the sidewall.

De Sisti
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Re: Dynamos - Hub or Bottle?

Postby De Sisti » 25 Jun 2019, 11:50am

robc02 wrote:B&M do an all weather wire roller for their bottle dynamos:
https://www.sjscycles.co.uk/dynamos/busch-muller-dymotec-all-weather-roller-cap-wire-brush-type/

If you use this roller make sure your tyre has the dynamo track on it, otherwise it'll chew into your tyre
(DAMHIKT). After it happened I converted to a hub dynamo (over 17 years ago).

bgnukem
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Re: Dynamos - Hub or Bottle?

Postby bgnukem » 25 Jun 2019, 12:10pm

Have been using hub dynamos for years now after having a bottle previously. The basic Shimano hubs are not expensive and I found the bottle dynamo to be a pain in terms of noticeable drag, noise and the fact that it tended to slip in wet, icy conditions. Also the need to buy tyres with dynamo tracks to withstand the wear/obtain better grip.

The hub drag is almost unnoticeable I find and I tend to leave the front light on all the time through the winter months, though I do switch to a lighter non-dyno wheel in summer.

Would however point out that the dynohub bearings are usually excessively tight from the factory (like all other Shimano cup-cone bearing hubs) and I'd strongly recommend adjusting them via the non-contact-wire-side cone/locknut before using the hub.

Re-greasing the bearings is also a pain as it involves disturbing the fragile contact wire on one side and I found it impossible to get the hub assembly re-centered in the hub shell when both cones had been loosened off. In future I'd just run the hub to death on its original grease.

Carlton green
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Re: Dynamos - Hub or Bottle?

Postby Carlton green » 25 Jun 2019, 12:19pm

De Sisti wrote:
robc02 wrote:B&M do an all weather wire roller for their bottle dynamos:
https://www.sjscycles.co.uk/dynamos/busch-muller-dymotec-all-weather-roller-cap-wire-brush-type/

If you use this roller make sure your tyre has the dynamo track on it, otherwise it'll chew into your tyre
(DAMHIKT). After it happened I converted to a hub dynamo (over 17 years ago).


I’ve always used a standard roller and whilst I’m sure that the brush type work they also do so in a way that I’d be concerned about. To my mind they’re more of an emergency solution to extreme weather conditions than a sustainable arrangement. Did I mention that having some battery lights available as an alternative light source is a good idea? I have some Smart Brand ones on my other bike; they didn’t cost much, have been reliable, don’t eat batteries, are compact and do a job around town. If I ride slowly (jogging/running pace) in un-lite places then they give me just enough light to get me home on a ‘pitch black’ night.

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Mick F
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Re: Dynamos - Hub or Bottle?

Postby Mick F » 25 Jun 2019, 1:38pm

bgnukem wrote: ................... In future I'd just run the hub to death on its original grease.
I bought an SP dyno hub from Spa.
£69 at the moment. Bargain!

At that price, it's not worth worrying about it at all. Maybe buy two, and they'll outlast you and your bike!
https://www.spacycles.co.uk/m2b0s133p30 ... YNAMO-PV-8
Mick F. Cornwall

mercalia
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Re: Dynamos - Hub or Bottle?

Postby mercalia » 25 Jun 2019, 1:59pm

Carlton green wrote:
De Sisti wrote:
robc02 wrote:B&M do an all weather wire roller for their bottle dynamos:
https://www.sjscycles.co.uk/dynamos/busch-muller-dymotec-all-weather-roller-cap-wire-brush-type/

If you use this roller make sure your tyre has the dynamo track on it, otherwise it'll chew into your tyre
(DAMHIKT). After it happened I converted to a hub dynamo (over 17 years ago).


I’ve always used a standard roller and whilst I’m sure that the brush type work they also do so in a way that I’d be concerned about. To my mind they’re more of an emergency solution to extreme weather conditions than a sustainable arrangement. Did I mention that having some battery lights available as an alternative light source is a good idea? I have some Smart Brand ones on my other bike; they didn’t cost much, have been reliable, don’t eat batteries, are compact and do a job around town. If I ride slowly (jogging/running pace) in un-lite places then they give me just enough light to get me home on a ‘pitch black’ night.


I have the wire roller for the B&M bottle, though never used it much as if the weather is that bad I dont go cycling. BUT when I did I didnt notice any harm to the Marathon tyre walls - the dyno track on the tyre wasnt damaged in any way.

As above it is important to have some battery lights as a back up what ever you do . A little while ago I was coming back from stratford upon Avon, arrived at the railstation in London and the dyno wasnt working - or rather the cabling had broken some where ( after 10+ years). Thats the trouble with all dynos v battery power, hubs included. I always have a couple of those tiny led lights that take a button cell s well as my standard battery lights, in my panniers

skyhawk
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Re: Dynamos - Hub or Bottle?

Postby skyhawk » 25 Jun 2019, 6:45pm

"After a couple of front light failures while commuting I'm considering the dynamo option."

????? why what
Last edited by skyhawk on 26 Jun 2019, 8:25pm, edited 1 time in total.
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bgnukem
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Re: Dynamos - Hub or Bottle?

Postby bgnukem » 26 Jun 2019, 12:52pm

Mick F wrote:
bgnukem wrote: ................... In future I'd just run the hub to death on its original grease.
I bought an SP dyno hub from Spa.
£69 at the moment. Bargain!

At that price, it's not worth worrying about it at all. Maybe buy two, and they'll outlast you and your bike!
https://www.spacycles.co.uk/m2b0s133p30 ... YNAMO-PV-8


I've got one for my commuter already, bought as a wheel from Spa. Dynohubs used to be cheaper from Rose cycles in Germany but the shipping costs and deteriorating exchange rate have kiboshed that!

SP hubs can't be user maintained at all though, but I gather can be sent off for a rebuild by the importer?

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Mick F
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Re: Dynamos - Hub or Bottle?

Postby Mick F » 26 Jun 2019, 1:06pm

bgnukem wrote:SP hubs can't be user maintained at all though, but I gather can be sent off for a rebuild by the importer?
Correct on both counts.

I don't think it's worth sending it back for a refurb. Easier and better, to buy a new one. Easy peazy to rebuild your wheel DIY with it.
Mick F. Cornwall

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andrew_s
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Re: Dynamos - Hub or Bottle?

Postby andrew_s » 26 Jun 2019, 1:58pm

mercalia wrote:As above it is important to have some battery lights as a back up what ever you do .

My experience is that dynamo lights are considerably more reliable than the backup battery lights, so don't forget to check that the backups are still working on a regular basis. If you just put them in the bag (or fit them to the bike) and leave them until they are needed, there's a pretty good chance they won't work.

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Tinnishill
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Re: Dynamos - Hub or Bottle?

Postby Tinnishill » 26 Jun 2019, 4:31pm

There is also the Velological rim dynamo option. Never used one, myself;

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andrew_s
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Re: Dynamos - Hub or Bottle?

Postby andrew_s » 26 Jun 2019, 4:42pm

The Velological has the same problem as previous attempts* at a modern high-tech rim/tyre dynamo - it's too expensive, being comparable in cost with a SON hub.

* Lightspin, B+M S6 or S12

Carlton green
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Re: Dynamos - Hub or Bottle?

Postby Carlton green » 26 Jun 2019, 6:41pm

andrew_s wrote:
mercalia wrote:As above it is important to have some battery lights as a back up what ever you do .

My experience is that dynamo lights are considerably more reliable than the backup battery lights, so don't forget to check that the backups are still working on a regular basis. If you just put them in the bag (or fit them to the bike) and leave them until they are needed, there's a pretty good chance they won't work.


I recall having some Ever Ready battery lamps, indeed they were part of the reason I shifted to Dynamos. These old Battery Lamps seemed to have loads of contacts within them that corroded, and they used to eat D cell batteries too. The Smart LED lights have been great in that they always work and don’t eat batteries. However, word of caution, if used infrequently it’s a good idea to reverse one of the batteries on the front light as otherwise it seems to very slowly self discharge.

It’s always good to have a back-up plan. Some might regard a basic bottle Dynamo as a cheap back-up to powerful and expensive battery lights.