ALERT - Bicyclists - Phantom Mode Changes

LED Flashlights – General Info
1

The first two flashlights we purchased as inexpensive bicycle handlebar lights have one thing in common.

A few weeks ago I spotted a bright flashing light coming my way and it was so far away I could not tell at first it was a flashlight on a bicycle handlebar. This was in broad daylight! I said to myself, "Self, we need to mount an inexpensive led flashlight with a strobe mode to these bicycles so cars can clearly see us in the daytime."

Two different flashlights were purchased. One was an Ultrafire E17 and the other was a Miaojia Super T6

The quantity of light is adequate (at night) BUT neither of these stay in the mode chosen (strobe for daytime). So...now there is an additional consideration to be checked and that is how well the switch stays where it is put. It seems that the bumps in the road are what causes the mode to change. All riding was done on the street so since the tires are at about 100psi every little bump gives these lights a good shake.

The problem is cheap switches it seems.

This is just an ALERT for those who are contemplating purchasing inexpensive LED flashlights for the bicycle. Ascertain ahead of time how well they stand to mild shock. It is probably not going to happen if one is contemplating buying a flashlight from China without some kind of feedback from one of our esteemed members about this first.

Best wishes!

UPDATE: Please see post #20 for the resolution.

2

It sounds like the battery breaking contact either end causing the mode changes. If it is, springs either end if there is room should fix the problem.

3

I agree.
The battery is moving too much.
Improve the springs or wrap the battery to keep it from bouncing in the tube.

4

Hmmm that sounds like an interesting and plausible solution. The tests used a 3AAA holder but I will try the 18650's. I believe they both can take a 26650 but I have none right now. I do have the 18650 sleeve I will use with them. I have many laptop pulls (of 18650's) but do not wish to use any of them until they are evaluated and I was hoping not to have to buy an Opus. I have been waiting for the SkyRC MC3000 to come out and the latest word is that it will not be anytime soon.

How else can I test an 18650 laptop pull to see if it is good to recharge? Maybe the only negative I would encounter is that it will not take a full charge? I only have a DMM at the moment and do not even have any charger. I had a XTAR VP2 but it was stolen. While waiting for the MC3000 I was thinking about getting a very cheap one-bay 18650 charger.

Any thoughts on the matter? Thank you for the above possible solution!

5

single mode solution I had a similur unintentional mode changing whie riding I went with single mode drivers and the problem is solved.

6

Well that would not work so well for me since the strobe is a VERY good daytime bicycle identifier and safety tool and then at night regular mid or high is needed.

Thank you for the suggestion anyway.

7

I had a WF-501B that would change modes. I damaged the driver so swapped out one of these: https://www.fasttech.com/products/1612/10001683/1186300-6-amc7135-2-group-35-modes-led-flashlight-driver-n

This has resulted in a light I couldn’t be happier with. The 105 doesn’t seem to change mode if there is a single momentary loss of contact (multiple, hard bumps will sometimes make it change) and the strobe mode can be hidden at night. If you don’t want to mess with modding, many of the Convoy models come stock with this driver.

8

Check battery length. Use protected 18650 if the contacts are loose. That is where compatibility comes in.

9

labrat - that looks like a good interim idea.

When I have the ability to experiment I will post back.

Thanks for ideas.

10

Using flashlight strobes in the day light is still tolerable, but using it at night is really annoying,( how do you see the road with strobe anyway? :slight_smile: it’s better to ride with just high or mid mode, they can still see you from far away, even from 1/4 mile away.
Better leave the strobe mode for the tail ( use red color please )

11

I use a nice red strobe for the rear day and night and use strobe for the front in the day and solid for the night. I make sure the night light is not in driver's eyes and am working on a slide-on hood for this issue and for many lights. It will be a kind of universal bike keep-the-light-out-of-driver's-eyes kind of shade.

12

Also helpful: conductive electrical lubricant gel (“nyogel” if you find it, or look for something like “bulb gel” from an auto parts store)

Also, look at the ends of your batteries. Do you see gouges scored into them? If so the ends of your springs are cut off leaving a sharp tooth that both carves up the battery and also makes for a tiny little point of contact that can bounce off easily. Bend those spring ends to where they make a wide long contact arc and add conductive gel.

Plus all of the above — pad the cells for side to side movement; consider soldering on longer or stronger springs.

And yeah, the better drivers from RMM solve a lot of problems.

13

Or order some magnets from Fasttech.

14

After some further investigation it now seems possible that the small nicks in the shrink wrap (from laptop pulls taken out not carefully enough) have exposed some of the battery case and the batteries might be grounding out on the inside of the flashlight body and this may be the cause of the flashlight changing modes when bumps are hit.

This will be checked since now I have placed temporarily some tape over the nicks until I acquire some shrink wrap.

Results will be posted within three days or less.

15

flashlights on bicycles need 2 springs.
One on the driver and one on the switch.
I run flashlights exclusively on my bike and very rarely experience mode switching (I cannot even recall a single incident).

16

I have been reviewing for myself two similar flashlights and they both have a spring on each end. The same battery was used in both flashlights and the same symptoms were seen so it is really looking like the small nick in the shrink wrap is the cause but I will know for sure by this weekend. Stay tuned for our evening report tomorrow.

17

Unless that tear in the shrink wrap is causing the case of the battery to actually short out, then I don’t think that is the problem.

I have come across dual spring lights that are very sensitive to battery length, and a laptop pull with out a button top won’t work reliably…mere hand movements while walking can cause the light to dim and/or change modes randomly.

It acts like the driver is fried, but the lights will work fine with a button top battery or a laptop pull if a solder blob is added to the positive end.

The logical step of stretching the springs doesn’t seem to work.

One could replace the springs or use the right battery, and if you are running a 18650 in a 26650 tube, you’ll need the correct tube insert to stabilize the diameter as well.

I’m not sure if that’s your particular problem, but that’s another idea for you to check out.

18

I taped my K40M to my bike :party: :party: Its overkill in the woods!!

19

A cyclist’s needs are very different than your average person’s. The kind of light that’s best-suited for riding (especially in rough terrain), would, more than likely, be the same kind of light you might actually find mounted on a high power firearm.

The reasoning is simple. People who use dedicated flashlights for their firearms are more inclined to purchase lights that are built for/designed to tolerate heavy recoil; lights that are built for mechanical shock-resistance.

Generally, these lights have really heavy-duty dual springs (one on each end of the battery), to keep the battery firmly in-place, and the light, working, in spite of the tremendous shock that hits that light, every time the weapon is fired. It’s not just to keep the battery in place, but to keep the shock wave from traveling all the way to the head, where all the electronics are - the most vulnerable part of any flashlight.

Most lights can’t tolerate this kind of recoil, without eventually failing, or, best case, working intermittently. They aren’t built for it. You may save a few dollars, here or there; but in the end, you get what you pay for, when it comes to heavy-use, high-shock-capable lights.

I would strongly recommend something like an Olight M series light (I’ve had an M20-X, for about three years, now. It’s pretty much bullet-proof). Use good 18650 batteries in it, for the best run times.


Olight M20-X, pictured with the classic Buck 110 Folder.
Note: the stainless steel bezel is removable.

Here’s an entertaining Youtube video, showing some torture tests done on this light. You’ll find plenty of videos like this. They’re very solid lights.

Some companies make bicycle handlebar mounts for flashlights, so this shouldn’t be much of an issue. If you’re going to be riding for hours at a time, this may not be the best light choice. But there are plenty of nice lights, that should readily suit your needs, without breaking the bank, that you could easily depend upon, to keep your way nicely, consistently lit.

As an added bonus, when you’re not using it on your bicycle, you can use it as a stand alone flashlight :slight_smile:

Good luck!

20

Right, the spring length on both ends must stay connected when one of the springs is fully compressed. Removing the brass button on the tailcap can help by letting the tail end spring flex laterally as the battery moves side to side in the tube. Overall, long throw springs seem to be very accommodating to this requirement.