LED bulbs retrofit

So after having had success with a retrofit along the lines of this [You must be registered and logged in to see this link.] on other bikes, I decided it was time to increase light output on the GRiSO. The only thing holding me back is the worry that extra heat off the back of the LED is going to melt my headlight shell due to lack of airflow in the mostly sealed shell, which i'm lead to believe costs a shocking amount for a half-sphere piece of plastic.

So my question is, has anyone had luck with LED bulb retrofits? Any heat issues to watch out for if so?

In general, putting LED retrofit emitters into a reflector assembly designed for a traditional bulb is going to be a mixed blessing. The stock parabolic reflector is designed to handle light coming from a uniform pinpoint source (or nearly so), the filament of a standard or halogen bulb. The multiple diodes of an LED replacement source are all in different locations from that design point, so they won't result in the same cleanly focused output. Their increased brightness (lumens) may make up for this, but the output will still be more diffused. Some LED replacement bulbs make this a bit worse by putting two diodes on one side of their central post for low beam (neither at the focus point) and an additional diode closer to the focus point on the other side of the central post for the high beam.

Since LEDs are more efficient in terms of light output for power input, you'd think they should produce less heat, too - you'd be wrong. Commercial LED products, especially in the automotive world, produce a good deal of heat. There are a couple of brands that use lower than usual profile cooling assemblies, and if you go this route those are the ones to choose. Don't cheap out if it costs a bit more to get what does the best job.

I opted to simply replace the whole assembly with an LED based unit (replaces headlight shell, reflector and bulb). The power draw is lower, the heat issue is avoided, and focus is simply not a problem since each LED is behind its own focused lens.

I tried putting in an LED bulb and there isn't enough depth in the bucket to do so. YOu could cut the back of the bucket so the heat sink could stick out.

Thanks for the heads up fellas. I agree with the different of light argument, I have a fair number of decent LED bulbs that work well in round housings, but the main goal has been to reduce generator load on older bikes. I've been happy with the results in terms of brightness but it's quite difficult to properly measure if I'm truly getting more light output.

But she don't fit. So that puts that to bed

LED's consume significantly less current than an incandescent bulb, so I think it would actually run cooler in the headlight shell if you got it to fit.

Regarding heat, the halogen lamp is cooled through the glass, as the heat is "created" at the fillament.
At the LED lamps, the heat is "created" at the LED controller, witch is at the back of the lamp, so, even if a LED lamp with less wattage than the halogen is installed, its heat would be "trapped" inside the plastick headlight bucket. No radiation at all, contuctivity of plastic about 10 times less than glass.