A Couple Of Rear LED Questions

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A Couple Of Rear LED Questions

Postby CREPELLO » 4 Sep 2012, 10:20pm

My rear lights don't work. Or won't work :? .

*On one bike I have an old Vistalight Nebula 5LED light. Old, but in good nick. For the second time recently I've switched it on only to find that by my destination it's switched itself off. Has anyone had similar experiences? Are they usually prone to total switch off if the circuit is momentarily interupted?

*This brings me on to my second LED problem. I've bought one of those bright 1/2watt Smart LED rear lights with the intention of hooking it on the LED tab on my saddle and rack bags. I've only hooked it on a Carradice rack bag once. After one mile the thing flew off the bag. Amazingly, this was at a busy junction yet the cars missed crushing the light to bits. But it was supposed to be a backup for when things go wrong with the other rear lights :roll:

So do you guys find the LED tabs on saddle/pannier/rack bags are usually adequate for holding onto a light? Or is there a trick to improving the hook up arrangement?

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Re: A Couple Of Rear LED Questions

Postby David Cox » 4 Sep 2012, 10:30pm

I had a Smart rear light that I was using for emergency back up. At top of Col de Madelaine caugh in fog and rain so on it went. Failed long before I was off the mountain. Then it came back on in the Valley and I couldn't turn it off. Water had got in the rather feeble little switch. Not having mudguards cant have helped but I lost confidence in the light. Bought a much more solid Bontrager Flare clipped it onto a Topeak saddle pack. Reached to put it on in a downpour and it had fallen off!! Then put a Smart on with a cable tie for a while. But have now bought latest Bontrager which now has a very strong metal clip.
Keeping fingers crossed as I await next lot of bad weather.

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Re: A Couple Of Rear LED Questions

Postby meic » 4 Sep 2012, 10:35pm

I have had lights turn themselves off and on due to vibration.
Sometimes you can trace it to slack batteries and pack them tighter with a bit of double sided tape.

Also flat batteries can cause it but you dont know that they are flat! When you turn them on they are OK and when you turn them back on they have recuperated enough to be OK again. If you were to see the light shortly before it went off you would see it was dim.

I havent seen a light in the right position whilst hanging off any strap from saddlebags, clothes or panniers.
I have a small hole drilled through the bottom of the clip on my Smart light and I put a tiny cable tie through it and a hole in the rack it is mounted on to make it stay there. You can do that for the strap too but it will still point the wrong way.

Like the previous post I have had them refuse to obey the switch and remain on and off due to rain and in one case frost damage.
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Re: A Couple Of Rear LED Questions

Postby Brucey » 4 Sep 2012, 10:54pm

All LED lights that I have owned will either default on or off (by design) when you first put the batteries in.

Neither is 100% satisfactory; one runs the batteries down when you don't need it, and the other is dangerous.

If you don't mind a simple steady light, (or you have an 'interrupt = on' light) simple rewiring with a boring old mechanical switch (with series resistors if required) works quite nicely.


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Re: A Couple Of Rear LED Questions

Postby Redvee » 5 Sep 2012, 12:52am

Having had a Blackburn MArs 3.0 commit suicide on a roundabout, I now secure my leds to saddlebag straps etc with an elastic band round the light courtesy or the Royal Mail.

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Re: A Couple Of Rear LED Questions

Postby Ayesha » 5 Sep 2012, 6:58am

The LED rear lamp I am using now is about ten years old. It was £3.99 from Wellesbourne Airfield Market. Its been so good, I bought another about two years ago, which is also faultless. The price had risen to £5.99.

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Re: A Couple Of Rear LED Questions

Postby sbooder » 5 Sep 2012, 7:31am

I overcame the problem of somewhere to put the rear light when loaded up with this. It works really well and has a flashing setting too. It is supposed to last 10,000 hours, though I am not relying on that. I do carry a spare rear light in case of helmet loss or theft.


Kind regards,

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Re: A Couple Of Rear LED Questions

Postby Brucey » 5 Sep 2012, 8:27am


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Re: A Couple Of Rear LED Questions

Postby reohn2 » 5 Sep 2012, 8:28am

I spray the insideof my lights with GT85,I have four of the Vistalights mentioned for about ten years without problem though one has failed last winter.
The Smart light (one with 3 LED's) does have a bit of a mind of it's and I can switch it one by a bit of static elec near it ie; rustling a nylon jacket near it :?

With regard to them flying off zipties or even those red laccy bands the postman delivers, work wonders :)

Re lights on helmets,I tried one on the back of mine a couple of years ago but found I was get more close passes.I tried with and without it and found adefinate difference,I put it down to appearing to be even narrower with a vertical line of lights(one on my head and one on the rear rack)there was an immediate and noticable difference when I removed the head one.
There was even better/wider overtaking when I clipped a light onto a wide elastic band,on my right arm just above the elbow.A flashing LED on my elbow is something I've been using for years,occasionally during a ride I take it off to reassure myself that it works,it does! :)
Last edited by reohn2 on 5 Sep 2012, 8:44am, edited 1 time in total.
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Re: A Couple Of Rear LED Questions

Postby honesty » 5 Sep 2012, 8:32am

I've just bought a Moon Shield (in a combo pack with a moon xpower 300) which has a click built into the body and comes with one of those quick release rubber attachments for the seat post. So far I've had no problems, and it has the added benefit of being rechargeable from standard usb. Its really bright as well!

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Re: A Couple Of Rear LED Questions

Postby mattsccm » 5 Sep 2012, 9:01am

I have yet to find a seat pack that has the LEd loop in the right place. They look fine but add the light and it all sags a bit and the light shines slightly /partially down wards. Mounting on the seat post is best but that isn't always handy.

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Re: A Couple Of Rear LED Questions

Postby [XAP]Bob » 5 Sep 2012, 9:37am

Bolted onto the rack - that's the best place.

My battery blinky uses a seatpost mount to attach to the top of the seat on the RHS ('bent with a mesh seat). This provides extra lateral width, a blinking light and a secondary light. The only issue I have is battery life - although to be fair that's more a problem with MiniBob, who enjoys pressing the button lots...

I've actually modified it, because the original bracket was pants. I've drilled a hole in the back, and put a bolt through the rear of the light and through the bracket (the head of the bolt is covered in 'leccy tape as it touches the circuit board.
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Re: A Couple Of Rear LED Questions

Postby squeaker » 5 Sep 2012, 10:10am

I've had Smart (?) 0.5W superflashes jump out of their brackets before now. The clip on the bracket (IIRC) may need to be adjusted (hot water) to ensure a good click-in. Otherwise a good rear light, IME, but I'd never (unless in failure mode) clip one onto a bag loop as it wouldn't point in the right direction.

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Re: A Couple Of Rear LED Questions

Postby Vantage » 5 Sep 2012, 10:12am

I've been using one of these since February and it's been super reliable throughout all weather conditions. I wasn't too keen on the fitting's that came with it, so i popped them out and used 2 bottle cage bolts and nuts instead.
http://www.amazon.co.uk/Torch-LA4055-Ca ... 783&sr=8-1

I also have had problems with the not so smart lights switch, partially why I bought the rack light as a backup. I did come up with a solution for where to fit it though as I didn't trust the clip and mounts on the panniers. I drilled a small hole through the rack and just bolted it there using the fittings the light was supplied with. As far as I can tell, there isn't much stress on this part of the rack to worry about and so far it hasn't cracked or failed.
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Rear Light Mount (2).jpg
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Re: A Couple Of Rear LED Questions

Postby tatanab » 5 Sep 2012, 10:41am

Smart light as in the photos above.
There is a slight projection on the rear tag which is supposed to engage with the body of the light. If you simply fit the light to the bracket then these features may not engage. Having put the light in place, then press the rear tab towards the body of the light to make sure they have engaged. That should stop the light jumping out.

I have the Smart as a spare but prefer the Cateye LD1100 which I've been using for about 6 years now with no problems with it switching off or with water ingress.