modding a NiteRider Trail Rat to LED's?

Hi,
This *may* be my first light mod, depending on the answers I get... I just bought a used NiteRider Trail Rat on craigslist for very cheap, which I believe uses a MR11 type bulb. This particular one comes with a 15W halogen. I've been poking around online trying to see if its even worthwhile to try to upgrade it to LED's... I read somewhere that I might not be able to get an LED MR11 replacement that's brighter than the 15W halogen... is this true?

Even if there IS something out there that can outperform the 15W halogen, can the plastic housing take the heat generated by the high-power LED's? I've heard of putting fins on, but I'm not sure that's worth the trouble...

How many lumens is a 15W halogen MR11? I'm trying to make it as bright as possible keeping-in-mind the plastic housing for heat dissipation, and also a decent beam angle for biking use. Any suggestions?

Thanks!

I would suggest a Googling of this section 'Mod+LED+halogen' or similar as there have been several similar threads to yours of late.

Ditto here. If not a member there and don't wish to join, you will need to scroll the first three or four pages and look for them.

There are MR11 LED bulbs on the market, most are floody or low power BUT that seems to change rapidly so Google 'MR11 LED spot'. They tend to be in heat sinked modules probably not overly water proof, some holes to let air by the fins and out the back might work.

Keep in mind that you can buy a light that outshines what you have for $80 -a bit over $100 (new version) Magicshine, if in the US go to Geomangear.com as they back them fully.

If the housings aren't aluminum, forget going a custom LED build route. If there are no MR11 LED bulbs suitable, use it as it is.

There are old threads here and the other link that have tables of the lumen output of X watt halogens at Y volts. The lumens go up very rapidly with overvoltage and the life span drops about as precipitously. Between 10-15 lumens/watt as a crude estimate for less insanely overvolted lights. They burn faster and more furiously, but not not nearly as long. Overvolting has a long and effective use with Halogens.

Thanks BrianMc,

I just ran across this MCE MR11 kit at Cutter. I know you said that if the housing is not aluminum, I'm probably out of luck... but just to prod a little further...

Will it fit into the Trail Rat housing? It looks like the "kit" is missing the bi-pin connector that is typical of the MR11 bulbs. Also it looks like the driver board is separate and needs a place to live?

Since the light already has a 15W halogen, I suspect the housing could take the heat... but I guess it's the LED we're concerned about here.

ok, another option

A friend of mine suggested using this LED module:
http://ledsupply.com/creexpg-w417.php

with this lens:
http://ledsupply.com/10510.php

and this driver:
http://ledsupply.com/03021-d-e-1000.php

Driving these 3 LED's at 1A should give 1042 lumens (according to the data sheet for XP-G LED)... right?

The form factor for this LED module is smaller than the MR11, so theoretically it would fit with some thermally conductive epoxy. Maybe I would leave the stock lens cover out to get more airflow, but is something like this actually possible? Keep in mind...plastic housing.

Something seems wrong with this setup.

I will take you questions comments in order (not their order of importance).

Cutter also sells a light engine with the driver intergrated. I'll let you look that up.

In this case, 'MR11' means the diameter to fit an MR11 halogen lamp head, NOT a direct plug and play. The driver or buckpuck needs a waterproof situation, but it can be external. If you are using some boost drivers under some applications, they need a heat sink too.

Heat: A primer
Heat is the enemy for electronics of an LED light. A Halogen sheds most of its heat as IR wavelegth light our the front, so the case only had to deal with radiative heat off the backside of the lamp. Improved reflection on the back surface of the reflector helped send more out the front.

This sadly, is not the case for a white power LED. The output is mostly in the visible spectrum with little infrared. They are efficient BUT 60-80% of the energy going into them is converted into heat in the process that generates the light. This must be wicked away quickly and effectively, light output drops then the LED fries. In a lab, you can just mount the MCPCB (Metal Core Printed Circuit Board) on a big ol' chunk of aluminum and be good to play. I used a largish Athlon square heat sink to test with. The fins move the heat on to the air. That is what the heat sink in a bike light must do, it doesn't store heat but efficiently passes it to the air. Usually this is the outside shell of the light body. The problem with a plastic shell is it has no radiative surface since plastic is an insulator. Some DIY'es have modded Planet Bike lights with old Pentium CPU coolers in the case and venting/scoops to pull air over them. I don't think you can do that to cool an MC-E enough, a single XP-G? Maybe. (Cutter also has single XP-G light engines, FYI, circa 300 lumens out the front, about the same as a 20 Watt halogen and the Regina reflector would be a great optic for a halogen-like spot.) BUT cooling is everything.

Another idea within the handy person's scope is to use copper pipe fittings to mount the LED MCPCB on and then have parts of it it exposed with fins outside of the head unit somehow. Water tightness needs to be solved in this approach, but at least one someone has done that to good effect with a plastic light body, too. Lastly, you might consider $10 Marwi aluminim housings instead. Google the threads here to see if that is a solution for you. Oh and have a gander at the sticky link at the top of this section and old light builds/mods. Some of the approaches are still valid though we have better drivers and LEDs now.

Hope this helps.

BrianMc, you've been most helpful. I'm very interested in these $10 Marwi aluminum housings you speak of. Found one here.:thumbsup: Actually that site has a TON of cool stuff!

EL34 is a really good guy to deal with. I wanted you to discover his stuff yourself. It's part of the fun. FWIW I have four of the Bullet housings, two as twin 1 watt tail lights, and two as headlamps one helmet one about fork crown height. They are in the Another Marwi or Performance COnversion on the first page and in the Lets design a rear commuter light thread (or something like that 2nd last page of that thread) one to three pages back. FYI.

This hobby is addictive. I also ride a bit less, but mental exercise keeps the brain healthy as riding does for body and soul (stress). So it can be part of a holistic health program, at least that's what I tell my spouse.

Glad to help. Oh and a sign:

:welcome: