Best lights for Brompton

Page may contain affiliate links. Please see terms for details.

berlinonaut

Veteran
Location
Berlin Germany
just as lumens can be misused and give a good numerical value for a light spreading its output all around, so can lux give a high value for a rather unusable keyhole pattern.

its nice if the light has a good and wide gradient concentrating the light further away.

the gvolt80 gives a such a light pattern, with reach and intensity comparable to your b+m. both are better with some fill-in in midrange. also for safety reasons i like the redundance of two separate front lights.

have taken away the dynamo lights (with led) on two of our brommies.

Regarding redundancy: I've never had a hub dynamo light failing on me. It is an upfront investment but fire and forget after that initial investment. Totally reliable. I've had battery lights failing on me countless times: Flat batteries, lights forgotten at home, lights falling of, lights deadjusting when hitting a pothole, lights becoming defect.

So in terms of reliability and comfort hub dynamo lights are literally lightyears ahead of battery lights, judging from my experience. In terms of weight battery lights tend to be slighly better but this obviously depends from the products involved - when using higher quality dynamo lights and battery lights that deliver a comparable output the weight difference is pretty neglectible. You may end up as low as a 50g advantage for battery lights (with a worse beam) that even turns into a disadvantage when carrying spare batteries with you.

Regarding the additional power necessary for the dynamo this ist totally neglectable with modern hub dynamos and unnoticable as well (the former Brompton-Shimano being an exception here as it is a very low-end model) - totally different from the bottle dynamos of the olden days.

I ride quite a lot in the dark, therefor most of my bikes that I use a lot have hub dynamos. However - suffering from the n+1 syndrome I can understand your issue with more bikes than would like to equip with hub dynamos for cost reasons. For a bike that get's ridden at night only occasionally I can live with battery lights personally. For a bike that get's ridden at night regularly (let alone almost daily) I'd always go for a hub dynamo.

Lumens are totally useless to compare lights as they only refer to the theoretical light output of the LED (which has nothing at all to do with the real world output let alone usable light or how well you will be able to see with this light). Lux is a bit better as it refers to the amount of light within a certain area in front of the bike - but it does not take the beam pattern into account. Thus lights with better/wider near view (desireable) may end up having lower Lux than those without.
 

Kell

Veteran
With all the comments and updates, I'd certainly like to try a newer Brompton with a better dynamo - just to see.

There are arguments for and against with regard to dynamos in general, but as I said earlier my main gripe is the lower placement of the light. I just think it's dangerous in town.

And with SMIDSY such a prevalent excuse anyway, I'd rather not take the risk.
 

freiston

Veteran
Location
Coventry
With all the comments and updates, I'd certainly like to try a newer Brompton with a better dynamo - just to see.

There are arguments for and against with regard to dynamos in general, but as I said earlier my main gripe is the lower placement of the light. I just think it's dangerous in town.

And with SMIDSY such a prevalent excuse anyway, I'd rather not take the risk.
Is it any lower than most car headlamps? How low down are you thinking of mounting it? If it's fork-crown height, then I don't follow how this will make it difficult to be seen or dangerous unless it is shrouded/cowled beyond practicality. As far as the law goes, there is an upper height limit but not a lower height limit .
 

kais01

Regular
Location
Sweden
there are different sides to the story. plus and minus. some dynamo systems today are really good. but so are also battery systems.

to me the unnecessary weight penalty 90 percent of the time with dynamo lights is a decisive factor. people pay a lot to rid them of a comparable weight.

but when from data on cyclingabout i concluded that the almost unnoticeable drag of dynamo lights nevertheless means about a half more hour on a pbp, i understood they are not for me. that is a pretty stiff handicap.

of course true randonneurs argue that you should be self-sufficient also with lights:smile:)

the number of different bikes i use nighttime is another factor.

when it comes to the specific question in the thread about lights on brompton, the factory fitted cables and connectors on brompton dynamo lights have been a fiddly and a must-be unstable affair. that alone a good reason to remove the system, let alone buy it in the first place. might have become better on later models.

the nowadays almost always german-approved dynamo lights do not spread much light outside their keyhole light pattern, and really need help to be noticed in traffic. so a second (battery?) light is a good idea also for them. thus not only for redundancy reasons.
 

freiston

Veteran
Location
Coventry
the nowadays almost always german-approved dynamo lights do not spread much light outside their keyhole light pattern, and really need help to be noticed in traffic. so a second (battery?) light is a good idea also for them. thus not only for redundancy reasons.
I do not understand how you are coming to this opinion - it really is not the case. I have seen other cyclists both with dynamo and battery/rechargeable lights, and also seen my own bike in the dark being ridden by someone else, the visibility to other people of my light is comparable to a moped/small motorbike and as it is a shaped beam, does not dazzle - it is very bright and very noticeable but not detracting/blinding other people. The shaped beam gives better visibility for me to see by - it gives a wider more even throw across the road without the effect that I found with torch style lighting of either (when angled low) floodlighting a limited point of the road (with a brilliance that makes everything else look black) or (when angled high) illuminating all the trees in front of me and dazzling on-comers without giving much illumination of the road in front (in my experience, any angle of the light gave problems). I'm not saying all battery/rechargeable lights are as bad as the torch-style that I have experience of but I am saying that your account of "german-approved dynamo lights" and their comparison to battery/rechargeable lights couldn't be further from everything I have seen and experienced.
 

berlinonaut

Veteran
Location
Berlin Germany
to me the unnecessary weight penalty 90 percent of the time with dynamo lights is a decisive factor. people pay a lot to rid them of a comparable weight.

Taking the requirements regarding visibility, brightness, light-pattern etc. that you claim for dynamo-lights onto battery lights you'll probably not end up lighter with battery lights. Definitively not if you take a spare light with you for redundancy reasons (as you said) and even worse if you take spare batteries with you. You only end up lighter if you leave your lights at home - but then you obviously do not have lights. As linked earlier: The weight penalty on a Brompton if you use a SON, Edelux2 and a BUMM Rear-light is 50g vs. ok-ish but not brilliant Battery lights (w/o spare Batteries) - and w/o any lights you are saving ~320g agains a hub dynamo solutiion if you are using the ultralight front wheel from Brompton or 240g if you are using the standard Brompton front wheel. This small weight difference is not worth the hassle for me.

but when from data on cyclingabout i concluded that the almost unnoticeable drag of dynamo lights nevertheless means about a half more hour on a pbp, i understood they are not for me. that is a pretty stiff handicap.

The SON uses about 1Watt in turned off mode at 25 km/h in a 700cc wheel and about 5,5 Watts if you generate 3 Watts power output. In both cases you have to additionally substract the loss that you would alternatively have with a dynamo-less wheel. Data read from the graphic some postings earlier. I know the guy who did that test personally and am totally sure that it was done as scientific and exact as possible. I highly doubt that you are able to notice the difference in power, especially given the fact that for 25 km/h on a Brompton you have to put in roughly 185 Watts (w/o) lights already.

when it comes to the specific question in the thread about lights on brompton, the factory fitted cables and connectors on brompton dynamo lights have been a fiddly and a must-be unstable affair. that alone a good reason to remove the system, let alone buy it in the first place. might have become better on later models.

Seems you are talking about the old bottle dynamos. The SON option for the Brompton has been available since 2005 - 15 years now - and the Shimano hub dynamo option has been invented in 2010 (10 years ago). Since then the bottle dynamo (which was indeed a non-brilliant solution) has been eliminated and so have your points of criticism. So if you give advice today it may be a good idea to know today's world and refer to it instead of riding 20 year old prejudices that have no foundation already since ages.

the nowadays almost always german-approved dynamo lights do not spread much light outside their keyhole light pattern, and really need help to be noticed in traffic. so a second (battery?) light is a good idea also for them. thus not only for redundancy reasons.

Fully agree with @freiston here - can absolutely not agree to your point but to the exact opposite.
 

chriscross1966

Über Member
Location
Swindon
Nothing to stop you mounting the light on the handlebar, just trace the cable layout from the front brake.

With all the comments and updates, I'd certainly like to try a newer Brompton with a better dynamo - just to see.

There are arguments for and against with regard to dynamos in general, but as I said earlier my main gripe is the lower placement of the light. I just think it's dangerous in town.

And with SMIDSY such a prevalent excuse anyway, I'd rather not take the risk.
 

kais01

Regular
Location
Sweden
well good luck with your dynamo lights:smile:

and they of course have their definite positive sides. mainly the no-fuss. but on my bromptons; no thank you.
 

Ming the Merciless

There is no mercy
Location
Inside my skull
My problem with the dynamo lights is twofold.

The first is that they do sap your power to make them work - IIRC 4% when they're running and 1% when they're off. It doesn't sound like much, but it is noticeable.

However, the biggest problem I have with them is the height of the lights. To me, it's way too far down to make you visible. It might be a great place to be for a light that lights up the road, but if you're following a car, I'd like to see how far back you have to be for them to be able to see your light.

A standard hub has some drag as a dynamo turned off. Unless your power output is extremely low it is nothing like 4% when turned on. You can get bigger differences in drag from tyres and wrong inflation pressures.
 

Kell

Veteran
A standard hub has some drag as a dynamo turned off. Unless your power output is extremely low it is nothing like 4% when turned on. You can get bigger differences in drag from tyres and wrong inflation pressures.

I was quoting the official figures for the dynamo fitted to the bike I used.

I googled them after I'd used them a few times as, despite what everyone else says, I definitely could tell the difference.
 

Kell

Veteran
Is it any lower than most car headlamps? How low down are you thinking of mounting it? If it's fork-crown height, then I don't follow how this will make it difficult to be seen or dangerous unless it is shrouded/cowled beyond practicality. As far as the law goes, there is an upper height limit but not a lower height limit .

The standard mounting point for factory fitted dynamo lights is just above the mudguard - way lower than any car lights.

Consider ...

You're following a car with your factory-fitted dynamo light switched on. A pedestrian is waiting to cross. They see the car, but they haven't seen you because your light is blocked by the body-work of the car and because lots of people don't look out for cyclists at the best of times.

The car passes them, and because they think the road is clear, they step out into your path.

Happened to me on the hire Brompton. I narrowly avoided them, because I had that spider-sense feeling they hadn't seen me. Despite me wearing a night vision jacket, they basically said the classic SMIDSY and shouted after me if I had lights on.

Of course according to other threads, that's anecdotal and doesn't constitute evidence. It's just that after over 20 years of commuting in London, my considered opinion is that doing as much as possible to make yourself seen and riding as if no one has seen you are both very sensible things to do. That includes having a light mounted high up on the bars so that it will/could/has a fighting chance of being seen by the driver of the car as well as other road users.

YMMV.
 

freiston

Veteran
Location
Coventry
Consider ...

You're following a car with your factory-fitted dynamo light switched on. A pedestrian is waiting to cross. They see the car, but they haven't seen you because your light is blocked by the body-work of the car and because lots of people don't look out for cyclists at the best of times.
Are you saying that you expect/want your front light to be seen by the pedestrian shining through the rear and front windscreens or above the roof of the car? :blink:
 

berlinonaut

Veteran
Location
Berlin Germany
The standard mounting point for factory fitted dynamo lights is just above the mudguard - way lower than any car lights..

The Brompton lights on the fork crown are ~47cm above the ground (just measured it). According to German law car headlights have to be mounted at minimum 50cm above the ground and maximum 120cm above the ground. As today cars legal in one European country are legal in all other European countries, too I'd assume this "50cm min." probably is true for all other countries within Europe as well. And I assume that there are cars out there that use that 50cm min.. I would not consider these 3cm difference "way lower".

Consider ...

Yup, consider....

You're following a car with your factory-fitted dynamo light switched on. A pedestrian is waiting to cross. They see the car, but they haven't seen you because your light is blocked by the body-work of the car and because lots of people don't look out for cyclists at the best of times.

The car passes them, and because they think the road is clear, they step out into your path.

Happened to me on the hire Brompton. I narrowly avoided them, because I had that spider-sense feeling they hadn't seen me. Despite me wearing a night vision jacket, they basically said the classic SMIDSY and shouted after me if I had lights on.

Of course according to other threads, that's anecdotal and doesn't constitute evidence. It's just that after over 20 years of commuting in London, my considered opinion is that doing as much as possible to make yourself seen and riding as if no one has seen you are both very sensible things to do. That includes having a light mounted high up on the bars so that it will/could/has a fighting chance of being seen by the driver of the car as well as other road users.

YMMV.

There is nothing that stops you from mounting your lights on the bars. The factory front light fitted by Brompton is pretty crappy anyway in my opinion - it is a lowest end cheap BUMM Lyt with something like 20 Lux (were the currently best front lights like the Edelux 2 or the IQ X deliver 90-100 Lux and average ones 50 Lux or more). So it is worth exchanging the front light straight away anyway. You can mount a dynamo light on the bars w/o any issues. If you i.e. go for a Schmitt Edelux there is a hanging version as well as a bar-clamp (similar solutions exist for other dynamo lights as well):

Halter-Schmidt-delux-lang_schwarz_web.jpg


EdeluxII_haengend_mitSchalter_poliert_web.jpg


On the Brompton it looks like that (not my bike):

32322264hh.jpg


According to German law a bike front light has to be fitted in between 40cm and 120cm of hight, so both positions, the factory one as well as on the bars, are equally legal over here. I have mine btw. fitted to the fork crown at the factory position and never had an issue like the one you are mentioning. However: There are fools out there that step onto the street w/o looking. They get hit by cars, busses - and bicycles. Not so much you can do to stop them being idiots. Darwinism will rule it out for you over time.
 

berlinonaut

Veteran
Location
Berlin Germany
I was quoting the official figures for the dynamo fitted to the bike I used.

I googled them after I'd used them a few times as, despite what everyone else says, I definitely could tell the difference.

As until now you did not mention which dynamo you used (and did not seem to know it): Which dynamo was it? And could you link those official figures please? I never saw official figures from Shimano regarding drag and efficiency and - until now - we were assuming that you were using the Shimano hub dynamo on your Brompton.
 

kais01

Regular
Location
Sweden
very nice mount of the edelux there berlinaut: and its a very good looking light.

there are however laws of physics limiting output here. there is unfortunately only so much light output you can get from 2.4 watts. an optimistic figure would be 10 lumen per watt.

if two lamps both give a good 80 lux (that is what you actually perceive from the the surface of the road) but one is say 250, the other 800 lumen, the latter will be able to give an identically bright light pattern at least three times as wide as the former.

which is rather in accordance with what i find when i use my gvolt80 and pass people with such dynamo lights.
 
Top Bottom