They work OK for me. I also use the velcro ones which work pretty well. You can use them for any torch on your handlebars.

 

http://www.ebay.co.uk/itm/Magic-Tape-Mount-Holder-Clip-Clamp-for-Bicycle-Bike-LED-Light-Lamp-Flashlight-/351096702543?pt=UK_SportGoods_CyclAcces_RL&hash=item51befe864f

I found that the teeth that keep the bracket secured were ground away each time it was opened and closed, until the point where the clamp opens on bumpy ground and the torch simply falls onto the floor. Also I found the swivel functionality unnecessary and play in the joint only added to vibration and that flicker effect while in motion. Maybe the design has improved since though.

Thanks d8veh - read my mind

I've ordered and will report back

 

What switch do you recommend for waterproofness ?

The velcro straps work pretty well as d8veh says. I tried numerous brackets for mounting flashlights before starting to make my own lights and in fact I still use the velcro bracket for mounting a flashlight on my helmet during the winter months.

 

The lumen ratings posted on sites like ebay are complete rubbish. The torch linked to earlier in the thread advertises itself as 2000 lumens although it uses an XM-L T6 LED. The XM-L emitter in T6 binning actually reaches a maximum of between 910 and 975 lumens at 3 amps drive current. Still mighty bright mind you, but the inflated advertised brightness figures cannot be used to make a meaningful comparison.

 

Michael

The velcro straps work pretty well as d8veh says. I tried numerous brackets for mounting flashlights before starting to make my own lights and in fact I still use the velcro bracket for mounting a flashlight on my helmet during the winter months.

 

The lumen ratings posted on sites like ebay are complete rubbish. The torch linked to earlier in the thread advertises itself as 2000 lumens although it uses an XM-L T6 LED. The XM-L emitter in T6 binning actually reaches a maximum of between 910 and 975 lumens at 3 amps drive current. Still mighty bright mind you, but the inflated advertised brightness figures cannot be used to make a meaningful comparison.

 

Michael

Your right of course, but as all the Chinese ones exaggerate in the same way, you can compare between them, i.e. 3000 Chinese lumens is half as many again as 2000 Chinese lumens.

Your right of course, but as all the Chinese ones exaggerate in the same way, you can compare between them, i.e. 3000 Chinese lumens is half as many again as 2000 Chinese lumens.

Unfortunately not - there's no agreed 'exaggeration factor'. The only way of assessing output is to know the emitter(s) and the drive current. An XM-L will do approaching 1,000 lumens - no more is possible and they will all be about the same if driven at the full 3 amps.

The lumen ratings posted on sites like ebay are complete rubbish.

 

I sort of suspected this. I have a torch I bought for work (Lenser Cree LED) which is advertised as 200 lumens, and it is amazingly bright. With the beam focused, it gives enough light to identify an object at 200 metres; closer, it's like someone switched the sun on. These are German lumens, and possibly more reliable than the Chinese variety. 2000 genuine lumens would be setting fire to the hedgerows, I would have thought.

On my cycle home tonight from the pub via a bridleway, I came across someone coming the other way. Not sure who was more surprised, but he did say that I scared the crap out of him.

 

Anyway, he had a set of lights that made my Fenix look like a dim candle. I Googled the make a moment ago, and this was the shock that greeted me! http://www.ayup-lights.com/lighting-kits?product_id=3 Crazy money.

 

 

 

 

.

I have a pair of hope vision 1's clamped to the top of the forks.

http://www.winstanleysbikes.co.uk/product/53959/Hope_Vision_1_LED_2013_Light_HL1L13B?gclid=Cj0KEQjw4uSgBRDZveXz9M-E1aoBEiQA2RMP6irY4scRiGeQxWv_EonNo3jr6GduZjFrGUdNQX-iLg4aAoUI8P8HAQ

Lamp and brackets are substantial and they run off rechargeable AA's and have worked flawlessly for about 4 years. Battery life 3 hours on max power. I have a spare set in a holder ready to pop in.

But consider this.... Having dazzlingly bright lighting is fine until you meet yourself coming the other way.... Especially on the towpath.

you can connect it to your bike's battery with a switch on ]

 

Would you mind recommending a good waterproof switch please .....whilst I wait for the light to arrive !

Would you mind recommending a good waterproof switch please .....whilst I wait for the light to arrive !

Do they exist?

Something like this should be OK. Why do you need waterproof. The worst that's going to happen is that your light comes on!

 

If you really want waterproof, what about using an encapsulated reed switch (needs to be capable of about 300mA) and a magnet.

Do they exist?

Something like this should be OK. Why do you need waterproof. The worst that's going to happen is that your light comes on!

 

If you really want waterproof, what about using an encapsulated reed switch (needs to be capable of about 300mA) and a magnet.

 

I guess that's true! But still - I cycle so much in the rain over the winter it's a slight obsession. All my ebiking woes (or nearly all) seem to be water ingress related

 

Couldn't see a link mind ?

 

Reed switch is a great plan b

Anyway, he had a set of lights that made my Fenix look like a dim candle. I Googled the make a moment ago, and this was the shock that greeted me! http://www.ayup-lights.com/lighting-kits?product_id=3 Crazy money.

I've come across the ayup lights before, and they are likely real lumens rather than inflated figures to sell more. Some people have used the metal chassis to make more powerful lights too.

But consider this.... Having dazzlingly bright lighting is fine until you meet yourself coming the other way.... Especially on the towpath.

All too true. "Power is nothing without control", as someone once said. For singletrack or trails a bright symmetrical beam (torch-style) can be fine and will illuminate stray branches at head height too. But for more heavily-trafficked areas, and especially the road, it is irresponsible and dangerous to blind everyone else.

 

Here is a link to the build thread of the bike lights I made which have a dipped-beam design. I'm running two XM-L emitters but only driving them at 2.5A as the gain in perceived brightness to 3A isn't much. They are therefore putting out a combined total of 1,710 lumens at the emitter in dipped beam. For comparison a standard H4 car headlight bulb is approximately 1,000 lumens dipped beam (1,650 main beam) so a normal car with halogen bulbs is putting out 2,000 emitter lumens on dipped beam.

 

Michael

Sorry about the link:

http://www.ebay.co.uk/itm/Universal-Motorcycle-ON-OFF-Control-Kill-Switch-Button-Handlebar-Mount-Practical-/390862657594?pt=UK_Motorcycle_Parts_13&hash=item5b013ad83a

 

All too true. "Power is nothing without control",

 

Michael

 

Having a 4 year old son I can tell you that "with great power comes great responsibility" is a Spiderman quote !

One frustrating thing with these eBay lights is that hardly any of them specify the burn time on a fresh set of batteries. To be useful to me, any bike light needs to run for a minimum two hours at full power - ideally more like 3 hours in case of any problems en route. I have my doubts that many of them will.

 

Anyone actually bought one and timed how long it stays lit?

Anything with an XM-L will almost certainly be running at 2.8 or 3 amps (the emitter will take 3A but there's a few cheap drivers at 2.8A). On a single, good quality 18650 cell of let's say 2,800 mAh capacity they will run for one hour max, and will be getting pretty dim towards the end. Two cells, two hours etc.

 

The white XP-G LEDs are normally driven at half that current - 1.4A, so one cell gives 2 hours runtime, 2 cells gives 4 hours etc.

 

Michael

Anything with an XM-L will almost certainly be running at 2.8 or 3 amps (the emitter will take 3A but there's a few cheap drivers at 2.8A). On a single, good quality 18650 cell of let's say 2,800 mAh capacity they will run for one hour max, and will be getting pretty dim towards the end. Two cells, two hours etc.

 

The white XP-G LEDs are normally driven at half that current - 1.4A, so one cell gives 2 hours runtime, 2 cells gives 4 hours etc.

 

Michael

I must be the only one who regularly nearly gets driven over, and feel I survive because of some bright Busch and Muller's and a dynohub. seriously, if you fit these (under hundred quid if you settle for (low price shimano hub dynamo), you will never again think about lights or light batteries and it will always be on, day and night for safety/visibility..

Anything with an XM-L will almost certainly be running at 2.8 or 3 amps (the emitter will take 3A but there's a few cheap drivers at 2.8A). On a single, good quality 18650 cell of let's say 2,800 mAh capacity they will run for one hour max, and will be getting pretty dim towards the end. Two cells, two hours etc.

 

The white XP-G LEDs are normally driven at half that current - 1.4A, so one cell gives 2 hours runtime, 2 cells gives 4 hours etc.

 

Michael

Hi Michael

 

Would you be able to explain to me how the bangood light can take 8v to 85v ? Does it have an internal dc dc convertor ?

 

It says it's 10w , which at 3a means about 3.3v (volts x amps is watts)

 

If you run a high voltage like I will be (48v nominal, 54v hot off charger) what prevents it going pop ?

 

I know it will work and I've ordered a switch to go with it. And am plenty capable of soldering/testing

 

I just don't understand why it works !

 

Thanks

Hi Michael

 

Would you be able to explain to me how the bangood light can take 8v to 85v ? Does it have an internal dc dc convertor ?

That's it exactly. Many LED drivers have voltage conversion in, either up (for driving multiple LEDs from one cell - known as a boost driver) or down as here (known as a buck driver). There are also linear drivers which don't do any voltage conversion.

 

In fact the drivers are actually a constant current source rather than a constant voltage source. With LEDs it is current you are trying to regulate carefully, and a 3A driver connected to a large voltage supply like your battery could drive one, two, or more XM-L LEDs all wired in series.

 

Michael

One frustrating thing with these eBay lights is that hardly any of them specify the burn time on a fresh set of batteries. To be useful to me, any bike light needs to run for a minimum two hours at full power - ideally more like 3 hours in case of any problems en route. I have my doubts that many of them will.

 

Anyone actually bought one and timed how long it stays lit?

 

The single Cree XMLs do an easy 2 hours on maximum with the 4 cell battery pack. They go for longer if you use it on flash or low-beam. You can work back from there. A Torch with a single cell will be 1/2 hour, etc.

 

Or you can calculate. They take about 2.5A at maximum with their supply voltage of about 3v (converted from 7.2v) so that makes 7.5W. If you allow for inefficiency in the driver, say 10w max. A 4 cell pack of 2200mah 18650s has 2.2 x 4 x 3.6 watt-hours = 32.5wh if they're in good nick and you don't mind running them to their minimum.. That works out at a maximum of 3 hours at maximum brightness if you have a 4-cell pack. A single cell will last about 45 minutes, or a 3 emitter light on maximum with four cells will last one hour.

 

The only question is, how good are the cells in the Chinese packs? Most of mine are pretty good. They're 2 years old and still going strong. I've repaired a couple of packs for other people, and they both had wires broken off, so an easy repair. There's a type of BMS (LVC) under the shrink-wrap.

Thanks, folks. The technical knowledge on this forum is great!

 

I must be the only one who regularly nearly gets driven over, and feel I survive because of some bright Busch and Muller's and a dynohub

 

For being seen, I couldn't agree more, derf. I've got a dynohub already and Hermann lights that run all the time, night and day. However, the front lamp just isn't that beefy because it has to share the 1.5w nominal power from the hub with the rear lamp. There's not really enough light for seeing where I'm going on unlit routes, travelling at speed.

 

 

The single Cree XMLs do an easy 2 hours on maximum with the 4 cell battery pack

 

That sounds like what I need then, d8veh. I've found this kit on eBay which looks suitable:

 

http://www.ebay.co.uk/itm/2000-Lumen-CREE-XML-T6-LED-BICYCLE-BIKE-CYCLING-FRONT-HEAD-LIGHT-TORCH-HEADLIGHT-/321484671361?pt=UK_SportGoods_CyclAcces_RL&hash=item4ad9fac981

 

Any thoughts?

That's the one. The price is coming down all the time. I think I paid about £25 for mine from China.

Hi axolotl.I have not timed mine But they will easely last me for my 10 mile comute through lanes to my work and back but that is on low power which belive me with a full power of 5000 lumens low power is plenty good enough and if I put the power up people complain !!!!!! and when I get home its still showing 3 lights of battery left so OK for me and of coarse on flashing it will last even longer and I have forgotten to charge it sometimes and it will still do the job for the 2 days.I don't believe in spending stupid money on a light ( I bought a Cateye front light a while ago for 25 quid and you cant see anything in the dark at all !!)

The most sensible way with lights is to buy one that takes std rechargeables rather than a rechargeable pack. My Hopes take 4 X 2800's which are cheap as chips and 2 spare battery cages for a couple of quid. 3 hours on full power for each set.

The most sensible way with lights is to buy one that takes std rechargeables

 

Or 18650 cells, if you've disassembled a knackered bike battery