# Best lights for Brompton



## Steppers (9 Sep 2018)

I have been riding my Brompton through London on a commute for three years. I have a standard set of handle bars, the slightly extended seat post and the more robust luggage rack in the back. Otherwise it is standard. During that time I have gone through a number of lights (I did not order the Brompton lights when I bought it) and have still to find a set that works well with the fold (particularly the front light). 

Grateful for any advice on a reasonably priced front light that will not need moving or removing when I fold the bike down. 

Many thanks. 

Steppers


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## Kell (10 Sep 2018)

There are two things you can do to help yourself massively with regard to front lights. 

The first is mount it to the left of the stem. Less likely to hit anything when folded.

The other is to buy an extension for the nipple on the front stem. This pushes the bars ever so slightly further out when the bike's folded and makes it even less likely that anything will catch when folded.

I've just looked on the site where I thought I got mine, but either they don't sell them anymore, or I didn't buy it from where I thought I did. 

Maybe someone else will be along to tell you where to pick one up.


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## steveindenmark (10 Sep 2018)

Failing that. If you want to go along the USB route. The Exposure Joystick is a small, well made light and it is very effective.


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## mitchibob (10 Sep 2018)

The Cateye that is made for Brompton at the front works really well, and I get really decent battery life out of it. On the rear, if your saddle is a 2016 model or later, the tiny cateye for the rear, that screws directly into the saddle is a great little light. Super bright and long battery life too, plus small and cheap enough to have a spare in the saddlebag.


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## doginabag (10 Sep 2018)

I can't find where I have stored my lifhts ovet summer so just been down to Evans. I did intend to pick uo some lezney lights that were recommended a few posts up but they had none in stock. So being the impatient type and not wanting to go to another store i picked up these. Will report back with a verdict. 







I do have a cheap Chinese triple cree led light that is stupidly bright in the shed. I may make up a bracket to replace the front reflector if I decide I want more'see where I'm going' light.


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## Mrklaw (10 Sep 2018)

I bought the Cateye mini rear light but was disappointed to find it didn’t come with the fitting for the seat. Maybe you have to buy a special Brompton version? Luckily I have the extended seat post (not by choice but was all they had in stock), and that leaves enough space so I can leave the light mounted to the seat post

Front i’ve bought a Cateye 400 but not tried it yet. Have an M handlebar so I expect it may be a challenge to find a home for it.


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## Kell (11 Sep 2018)

To buy that Cateye Brompton specific one, you can get it direct from Brompton:

https://www.brompton.com/brompton-g...rapid-mini-rear-battery-lamp/c-24/c-75/p-1738

But if you want to see a little clearer how it works, then check out this link:

https://brilliantbikes.co.uk/brompt...rompton-cateye-saddle-mounted-rear-light.html

As stated though, it only fits certain Brompton saddles with the square cut out underneath. I bought a new saddle last year, but it's clearly the older style so check before you buy as it doesn't look like you can buy the different fittings without buying another light.


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## Mrklaw (11 Sep 2018)

can you buy just the mount? I already have the light. Happy enough with it on the seat post, but if I can make it neater by mounting under the seat that'd be good


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## ianrauk (11 Sep 2018)

Hope Vision 1's work well with the fold. I have 2 on my Brompton.


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## Kell (11 Sep 2018)

Mrklaw said:


> can you buy just the mount? I already have the light. Happy enough with it on the seat post, but if I can make it neater by mounting under the seat that'd be good



According to the stuff I've read online, no you can't. But then the little booklet I also got said that they did sell accessories and listed the bracket and the charging wire as those, so who knows... It would be daft if you couldn't. But then most lights you can't seem to buy the brackets separately - so even if you damage them you end up having to buy a whole new light.


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## srw (11 Sep 2018)

Shimano hub dynamo, or SON if you're feeling flush. Fit and forget.


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## bikegang (11 Sep 2018)

srw said:


> Shimano hub dynamo, or SON if you're feeling flush. Fit and forget.


New Dynamo will be introduced in new Brompton. Sutter Precision SP-8
Here is the description from brompton build page
Select lighting
SP Hub Dynamo, SS, E-Vers 
Weight: 0.24 kg , Price: £ 120.00
The new single Shutter Precision SP-8 offers a superior performance, improved reliability, efficiency and a 271g weight saving over the previous Shimano dynamo. It has comparable efficiency to the previous SON dynamo, 91 g lighter and is less than half the cost. (Available on both Silver and Black componentry bikes).

They have even lighter one SV-9 also brompton compatible


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## Kell (12 Sep 2018)

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.


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## stoatsngroats (12 Sep 2018)

I have Lezyne Femto front and rear, both mounted high up, in additional n to the dynamo lights, which should solve your concern?
I haven’t ridden during the dark yet, other than a very quick blast up the lane!


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## chriscross1966 (13 Sep 2018)

Kell said:


> 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.


I run dynamo lights on my commuter Brompton and i cant say i notice the drag from the hubs, plus the B+M Luxos headlight i have is perfectly capable of floodlighting the road even from its position under a T bag.


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## TheDoctor (13 Sep 2018)

I think Kell is concerned about being seen, rather than seeing.


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## srw (14 Sep 2018)

TheDoctor said:


> I think Kell is concerned about being seen, rather than seeing.


In London, which is the OP's use case, street lighting does that for you. In practice it's not a problem anyway given light leakage.


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## ukoldschool (14 Sep 2018)

I've just fitted the Brompton specific cataye rear mini which attaches to the underneath of the seat. Its tiny, but very very bright... only £20 posted from brilliant bikes, came the next day too...

https://brilliantbikes.co.uk/brompt...rompton-cateye-saddle-mounted-rear-light.html

Am still searching for a reasonably priced front solution, I think the brompton branded front cateye 400 is well overpriced at £50, and I am inspired to try and find a DIY solution using this blog as a guide, it uses the bracket that the standard reflector comes on:

https://handsonbike.blogspot.com/2017/10/brompton-m6r-cateye-volt-400-front.html

The only problem seems to be the volt 400 isnt very common, UK shops seem to stock the 400XC, which has a handlebar mount rather than the clip type on the standard 400...


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## Kell (14 Sep 2018)

It's not the lighting of the road I have a problem with, it's the being seen by your lights by other road users (cars, pedestrians, other cyclists). 

Being so low down on the bike means they're hidden from direct view by pedestrians crossing between cars, or by the driver of a car you're following if you're closer than.. well, I don't know the answer to this - but I suspect it's a long way back.

And while you say you didn't notice the drag, I definitely did. It was noticeable from when they were switched off to when they were switched on on the hire bike I had for a month.


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## berlinonaut (22 Sep 2018)

Kell said:


> And while you say you didn't notice the drag, I definitely did. It was noticeable from when they were switched off to when they were switched on on the hire bike I had for a month.



Which dynamo did this bike have? Being a hire bike I'd assume it was the (now discontiued Shimano). With this drag ist noticable, at least to sensitive persons. And then psychology comes into play: If you assume you'll notice somthing chances are that you will... However: With the SON you won't notice any drag, but it is no factory option any more and was heavily overpriced when buying it from Brompton. The new SP8 should be far better than the Shimano and worse than the SON regarding drag. I own both, a SON and a Shimano, on my Bromptons and clearly would avoid the Shimano and always buy the SON again (still available via the Schmitt dealer network far cheaper then what Brompton charged). I've a SP9 on an 20" bike - it is according to tests lighter and better than the SP8 but the SP8 should be a fair compromise: Much cheaper than the SON, possibly not as long-lasting and a bit worse in terms of drag.

Judging from the experience with one single dynamo model that you would always feel the drag is the same as judging from the experience with an el-cheapo folder that all folding bikes would be crap...


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## Kell (24 Sep 2018)

Maybe I'm just very sensitive then...

All I can say is that I hired the bike for a month to check which things I thought would and wouldn't be useful. This was around three years ago and it was one of the bikes from the Brompton Docks. No idea what was fitted, other than it was enough to put me off paying the money to get one fitted on my factory bike.

Nowhere near as bad as the last dynamo I tried which would have been way back in the 70's...but still, IMHOOC, overpriced for something which I also didn't think would end up being that useful.


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## chriscross1966 (24 Sep 2018)

Modern decent dynamo lights are brilliant, the only reason I replaced the Shimano +B+M Cyo iQ on Henrietta when I did all the upgrades is because I could afford to have the SON custom built and colour-matched and the Luxos was a bit brighter....


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## cougie uk (26 Sep 2018)

+1 for the cateye light under the saddle. 
Just make aurs you're not wearing a long coat that goes over it .I've seen that before...

And I wrap a couple of turns of an elastic band around the clamp after mine had slid out. 

For the front you can get very flat but bright lezyne zecto lights. I have to mount mine on the left so it folds ok but it's only a matter of a few inches. The strobe light is very bright and lasts hours before needing a charge.


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## the_mikey (20 Oct 2018)

I've used Knog blinder (the square 4 led) lights successfully on the brompton, although I have added a cateye TL630 (rapid 3) to the seatpost for additional rear illumination, it works for me but then I never really go for long rides, mostly 30 mins each way either between home and the post office or home and work.


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## confusedcyclist (13 Mar 2019)

Modern hub dynamos are fantastic. Efficiency varies between models, but the SP brand is very good in my experience. I haven't had experience with the particular brompton hub, but I run a SP-PD 8 on my main commuter. I wouldn't bother switching off my lights in daylight even with the cheap DH-3N80 hub as below. 6 watts at 30 km/h is next to nothing. I expect if you tried an experiment and asked people to tell the difference between riding with lights off, lights on and without a hub dynamo altogether most riders couldn't perceive a difference. Only when you tell them they are riding with a dynamo would they say it feels like harder work. I think it might make a difference on a 140 mile stage 4 tour and other elite racing, but for a pootle to work with regular stops, slow downs and cruising along with traffic lights, congestion and wayward pedestrians, it's a no brainer. Looking at the brompton builder, there's only £70 difference between with lights and with a dynamo. I'm opting for without either, as I have a garage full of half-used lights. I may build a hub dynamo into my setup down the road.


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## Kell (13 Mar 2019)

Would it make a difference on a 16" wheel?

I could definitely feel the difference when riding a hire Brompton. I normally ride at +/- 18 mph (which converts to 28km/h)


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## confusedcyclist (15 Mar 2019)

Kell said:


> Would it make a difference on a 16" wheel?
> 
> I could definitely feel the difference when riding a hire Brompton. I normally ride at +/- 18 mph (which converts to 28km/h)



I guess it's possible with a DIY build using the wrong hub type. A smaller wheel diameter has a smaller circumference, so for any given speed, it does more revolutions per minute. However this can be countered by using a hub specifically designed for smaller wheels and their faster rotations. You want optimise light output at lower speeds. Drag tapers off significantly after a certain threshold, with the right hub, the drag should be similar, if not identical to a 700c setup.


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## kais01 (21 Apr 2019)

have several bikes and bromptons, and fitting them with dynamo wheels is just not an option. not their added weight either. nor their fiddly connectors and cables. drag? not so bad, but hardly an advantage.

and their light. its really on the spotty and weak side. there is only so much you can do with 3-6 watts. full light and effectively charging your gps or phone, forget about it.

also having the light down by the wheel is an effective means not to be noticed. and hard to reach when you wish to adjust angle or power when on the go.

so usb battery lights and quick mounts up at the handlebars has some advantages. only mounted when needed, and easy to manage.

use for street two cateye lamps, the well focussed but wide gvolt80 set for distance without blinding, and the floody volt800 angled down for nearfield. gives a total max of about 1600 lumen, about the same as a single car headlight. very rarely do i use the combination on full.

when mountanbiking on trails i use two bt40s on the bars and two at the helmet. totals about 5600 lumen.


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## freiston (30 Apr 2019)

kais01 said:


> have several bikes and bromptons, and fitting them with dynamo wheels is just not an option. not their added weight either. nor their fiddly connectors and cables. drag? not so bad, but hardly an advantage.
> 
> and their light. its really on the spotty and weak side. there is only so much you can do with 3-6 watts. full light and effectively charging your gps or phone, forget about it.
> 
> ...


I have dynamo lighting on my tourer and how you describe the light is nothing like my experience. On group rides in the dark, others with USB/rechargeable lights have commented on how well my front lamp lights up the road compared to theirs. My front lamp is a B+M Lumotec IQ Cyo Premium T Senso Plus and is measured at 80 lux (not lumens). I have used a 1000 lumen torch mounted on the handlebars and whilst it does flood the hedgerows with light, it isn't as useful as the extremely well-shaped beam of the B+M for road use - whether that be winding single track country lanes downhill at 25mph+ or urban/suburban roads. Because of the well-shaped beam, there is no need to adjust the angle or power (I have only ever needed to do this with torch-style lights whether they be actual torches or sold as bike lights). After faffing about with battery/rechargeable lights, trying to get good illumination and going down the four-figure lumens route (whilst trying not to dazzle anyone else), my dynamo light really was a revelation - you have to experience it to realise how much superior it is to the usual offerings. I also cannot tell the difference between on, off or no dynamo when cycling.


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## kais01 (1 May 2019)

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.


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## berlinonaut (2 May 2019)

kais01 said:


> 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.
> 
> ...



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.


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## Kell (2 May 2019)

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.


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## freiston (2 May 2019)

Kell said:


> 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 .


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## kais01 (2 May 2019)

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)

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.


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## freiston (2 May 2019)

kais01 said:


> 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.


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## berlinonaut (2 May 2019)

kais01 said:


> 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.



kais01 said:


> 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. 



kais01 said:


> 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.



kais01 said:


> 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.


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## chriscross1966 (2 May 2019)

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



Kell said:


> 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.


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## kais01 (2 May 2019)

well good luck with your dynamo lights 

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


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## Ming the Merciless (2 May 2019)

Kell said:


> 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.


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## Kell (3 May 2019)

YukonBoy said:


> 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.


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## Kell (3 May 2019)

freiston said:


> 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.


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## freiston (3 May 2019)

Kell said:


> 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?


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## berlinonaut (3 May 2019)

Kell said:


> 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". 



Kell said:


> Consider ...



Yup, consider....



Kell said:


> 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.
> 
> ...



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):












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






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.


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## berlinonaut (3 May 2019)

Kell said:


> 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.


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## kais01 (3 May 2019)

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.


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## Kell (3 May 2019)

berlinonaut said:


> 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.



The bike I refer to was one of the bikes from a Brompton dock. It was around 4 years ago. Whatever factory fit dynamo was fitted to a Brompton at that time would have been the dynamo in question. 

When I looked on the Brompton site at that time, those were the figures that were quoted for the dynamos. Whether or not that helps you to work out what it was, I don't know.


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## Kell (3 May 2019)

berlinonaut said:


> View attachment 464909



This picture illustrates the point perfectly to me. If the light was mounted on the factory mount under that bag, how visible is it really? Might be brilliantly located for lighting the road, but the bag blocks direct viewing of the light.

As mentioned above, it's all only opinions. Without conducting a test, I have no real evidence to provide you with, but from experience I know that people don't see cyclists at the best of times. Why make it harder?

And if you can find me a modern car with headlights mounted at 50cm, I'll be staggered. The ones on our Q5 are about 80cm. That's a guess based on the heights given below:







Ah, but that's a really tall car, so the lights are higher.

Well even our small car - a Mini, has the lights at about 75cm - again, a guess given on this diagram where the lights appear to be mounted slap bang in the middle of the car's height.






Besides, it's hardly a fair comparison. Car lights are brighter, fitted in pairs and spaced far wider apart.


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## kais01 (3 May 2019)

i would hesitate to trust official figures. they have an agenda.

but tested figures are there for all to see. having a dynamo light on is a drag of 6-8 watts, according to cyclingabout eqivalent to on a flat road and steady speed have 20-30 kg of load on the bike. so no big deal

all giving a light output about a third of a good street legal usb light.

of course these figures are with 622 wheels. how the about 60 percent increased rpm of a brompton wheel influences this we can however only guess.

https://www.cyclingabout.com/dynamo-hub-drag-lab-testing/


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## Kell (3 May 2019)

PS. The irony of the fact that I think I’ve got a really good point, but no one else can see it is not lost on me.


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## Ming the Merciless (3 May 2019)

Kell said:


> 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.



There won't be official figures as a percentage as they have no idea of your power output. Feel feel to provide a link to these official figures you think you have found.


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## Kell (3 May 2019)

YukonBoy said:


> There won't be official figures as a percentage as they have no idea of your power output. Feel feel to provide a link to these official figures you think you have found.



As I keep saying - this was FOUR years ago. And I've invited other experts to work out which factory fit dynamo would have been on a hire Brompton at that time.


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## Ming the Merciless (3 May 2019)

Anyway the point is you will really not notice any extra drag from a dynamo. It is not a valid reason for not having one. You may have other reasons but drag isn't one of them.


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## Kell (3 May 2019)

YukonBoy said:


> Anyway the point is you will really not notice any extra drag from a dynamo. It is not a valid reason for not having one. You may have other reasons but drag isn't one of them.



Well - it seems like it's up to a 2.7% reduction in speed - slightly less than the equivalent of carrying a 20-30kg load on a normal bike... 

But the article quoted says that the gyroscopic forces generated by the wheels (assuming 700c or 26" wheels were used) makes the drag less noticeable - how much higher a figure would that 2.7% be for a Brompton wheel which doesn't generate anything like the same forces? For the sake of debate, imagine it doubles it to 5.4% and the article says that would be the equivalent of using Marathon Mondial tyres as opposed Almotion tyres. 

People complain all the time about tyres having a noticeable effect...

As I said, I'm prepared to accept being wrong about the drag produced by more modern dynamos - hence my post about being willing to give a more modern bike a try. 

I will still argue till I'm blue in the face about the factory positioning of them though.


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## Kell (3 May 2019)

YukonBoy said:


> 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.


*
Light Switched ON While Cycling 10-30km/h*
Schmidt SONdelux // 1.80w-6.10w drag
Schmidt SON28 // 2.15w-6.50w drag
Shimano DH-3N80 // 2.30w-7.25w drag



berlinonaut said:


> 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*.



7.25 as a percentage of 185?

3.91891891892

Or if you want to use the power figures that were featured in the article, then they estimate 150 watts. 

So that makes the dynamo drag equivalent of 4.833333333333333%. 

And that was on a bike with normal sized wheels with more rotational mass that generate greater flywheel effect. Would that figure be higher on a bike equipped with 16" wheels?


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## Ming the Merciless (3 May 2019)

Yep tyres cause a bigger difference as do a chain not lubricated.


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## kais01 (3 May 2019)

yes tyres, worn jockey bearings and drivetrain can definitely be in the same league. 

or a baggy jackets or a backpack protruding over your shoulders. 

good reasons to not without thought use schwalbe marathons, marathon plus (ouch), and on your road and mtb bike 10t and 11t sprockets. with more than minimal use these wear themselves and the chain in short time.

taken together these factors can make a considerable difference. and the last watts are the hardest for your lungs and legs


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## Britonabrompton (10 Jul 2019)

Finding something to fit with the fold can be a little bit challenging, personally my issue with the standard lights (battery ones) is that the cateye 400 on the front is a little too bright, and I feel distracting for motorists as most of where I ride is cycle paths, especially on the flashing modes, which I like to use for visibility even in the summer, and the rear, I often forget to turn off, so often have flat batteries.

My solution (P-type bars ) is 2 smaller lights on the vertical part of the bars on the left side (traffic side for me, living in Sweden) as visibility lights. I have a Cateye wearable X (facing behind), and a smallish dual-purpose (does red and white, and flashing) light facing forward, but I guess any of the smaller lights from Knog (or countless others) would also work


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## Kell (12 Jul 2019)

Just bought one of these for the rear.

It's got motion sensors in so it gets brighter when you slow down.

Pretty reasonable at £16.99 but feels really well made. It's all metal rather than plastic. Zip-ties to the seat rails.






https://www.amazon.co.uk/gp/product/B07GYBBXC7/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1


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## Britonabrompton (25 Aug 2019)

just read through the whole thread, and noticed someone asking about the standard cateye light, and replacements for it. The current light is a cateye 400XC but with a different fitting, the same I assume as the old Volt400.

I bought a Volt150XC and an HL-EL135, both are compatible with the standard Bromptom fitting.

I don’t have an issue with the height of the front mudguard mounted light, as I also use a smaller flashing light on the handlebars, as mentioned above, and also a cateye duplex on my helmet


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## PaulRoberts (2 Apr 2021)

Kell said:


> As I keep saying - this was FOUR years ago. And I've invited other experts to work out which factory fit dynamo would have been on a hire Brompton at that time.


My Brompton subscription bike has a Shimano _DH_-_F703_-_SB_ front hub, I'd say they are all Shimano's in the docks.

(and yes I can feel the drag with the front light on)


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