Monday, January 18, 2010

Planet Bike / Smart Superflash rear light mod

When my non-weather-proof Cateye TL-LD270 rear light died from circuit board corrosion (after a one too many rainy rides), I switched to my back up Cateye light.

The Cateye SL-LD100 rear light, though weather-proof, was not very bright; I had cars come up real close before going around me. Definitely not a good choice for Friday and Saturday solo night rides on dark roads (unless you have next-of-kin or significant others waiting to cash in on your life policy).

When I tested out the Planet Bike / Smart 317R Superflash, I was surprised by its brightness and immediately procured one for myself.

Apart from a slight difference in the color of the plastic housing, the Planet Bike and Smart models are identical in function.

The Planet Bike Stealth Superflash is black, with clear transparent plastic; has 3 more syllables to its name (one more than its sibling); and sounds cooler — buy it.

ozphoto did a snappy review of the Superflash versus your standard 5-LED light. There are plenty of reviews of this light, so I won't belabor its brightness; the fact that it uses the cheaper and commonly available AAA cell instead of the N cell or CR 2032 button cell, et cetera.

What I am interested in is addressing 2 design weaknesses in the light.

The light has a belt clip that slides into a receiver bracket (that's attached to the bike). In the above image, the curved part is the belt clip. The straight part has a small tab on it, which prevents the light from sliding up and out. About as secure as the Whitley Road Detention Centre, this arrangement works most of the time, until you hit a bump...

Then, the Superflash sails off, and your bike becomes super light, sans light, stealth-like  :-D

Not a few riders lost weight their lights this way.

On the predecessor of the Superflash — which employs the same mounting system — I used a small cable tie to ensure the light would never sail off like Mas Selamat bin Kastari.

That's one design flaw addressed without a S$2.9 million dollar salary.

On the Candle Power Forums, CDG08 noted:

The clear housing of the components. This half of the light is the the more heavier of the two, rendering it more likely to fall off due to road shock and bumps on the road / trail. . . . The half that is the lightest is also the half securely mounted the the bike. The heavy half that has the components, LEDs, batteries, is all on this other side.

Check out his pictures in the link and it will become clearer.

What this means in plain Ingrish: the light is made of 2 halves: the lighter part, and the heavier part. The lighter part has been secured to the bracket; the heavier part has not. Upon hitting a bump or pothole, the heavier part can still break away from the lighter part... leaving you with a lighter faster bike  :-P

Some riders unwittingly lightened darkened their steeds in this manner as well.

My solution then, was a humble, ever resilient, rubber band.


That served me well, easily lasting through a 14-day tour in the tropics.

However, there's got to be a neater, more reliable, more aesthetically pleasing way to go about this. (Thanks, Karen  :-)  )

The solution? A longer, translucent cable tie!

Loop a 3 mm wide, 200 mm long translucent cable tie around the mid-section of the light and tighten. There's no need to cinch it too tight; the point is to hold the two halves together, not achieve fusion. Cut off the excess with a very sharp utility knife, such that it sits flush. The last detail is to ensure that nothing protrudes to hook or scratch your thighs and/or too tight shorts. The light can still be slid off the bracket at this point, you just need to bend the light out a wee bit further.

Regular alkaline batteries last about 190 hours in flashing mode, so you shouldn't need to remove the cable tie to replace the 2 AAA batteries too often. In any case, the cable ties are very affordable, costing me about S$0.06 (US$0.04) each. For those desiring much, much greater intervals between battery changes — as well as a 33% reduction in battery weight — use a pair of Energizer Lithium AAA batteries.

Here's a shot of the 200 mm (about 8") long translucent cable tie. You might be able to get away with 150 mm (6") but I can't guarantee it.

For the other cable tie, use a shorter length and make a small loop. Use your estimation of your favorite male politician's manhood as a rough guide. You will need a little trial and error in the next step to figure out just how small the loop can be and still remain removable. For aesthetics, you may choose to use a black cable tie as it will blend in with the tab and belt clip.

Tip:  The thin, long cable ties supplied with your speedometers / cyclo-computers are usually 3 mm wide.

Slide the loop over the tab and belt clip until it slips into the hollow formed by the upper curved part of the belt clip. There is just enough space in there for two 3 mm wide cable ties.

What the completed modification looks like.

Rear view.

The light is now ruggedized; short of a crash, nothing is likely to cause your Planet Bike / Smart Superflash to pop off.

You now have no excuse not to be out at night.

Go ride.

No comments: