I think they’re designed for show cars and the like, rather than for practical road use? They aren’t going to be very effective for seeing in the dark, but I dare say will look cool.

The HP LEDs in the links are less than a third of the output in lumens of a 35W HID unit. 25W to get 900 lumens (36 lumens per Watt), as opposed to 35W to get 3000 Lumens (86 lumens per Watt) with HID. A bog standard H7 bulb is about 1650 lumens for its 55W (30 lumens per Watt). A +30% H7 will give 2000 lumens for its 55W (36 lumens per Watt), which is ironically exactly the same as the HP LED bulb (but only costs you �10). The huge advantage of sticking with a halogen H7 is it will be working at close to 100% optical efficiency (unlike an aftermarket LED or HID), because it’s sitting in front of a reflector specifically designed for it.

Lumens output is next to useless as a guide to light intensity, because it is a measure of isotropic radiation (scattered), not focussed light, and in an SMD LED arrangement (as in the ebay units) a well-focussed beam will be totally impossible to achieve, hence why their performance is less than adequate in retro fit applications. They will work at a significantly reduced optical efficiency when installed in a standard reflecting headlight that has been designed (and pre-focussed) for a filament bulb. Nowhere near all 900 lumens (for one bulb) is going to reach the road. Aftermarket HIDs are not ideal in this respect either (check out the annoying glare from your local boy-racer's retro-fit HID headlamp bulbs - which is of course all wasted light), but HIDs are significantly better than LEDs in this respect, mainly because they produce more than three times the light to compensate for the losses.

Besides the mind-blowing cost of HP LEDs, hiding the associated bits and pieces and the lack of focussed light; HP LEDs produce a ridiculous amount of heat. You can see from the images that the whole LED unit (bulb if you like) is one giant heatsink! The headlight shell must be able to dissipate this heat and I’m not entirely convinced the XTZ’s plastic affair would be up to it? The Ducati Panigale and the new BMW GS have LED headlight options, but they are purpose designed and if you take a look inside the fairing of each you'll see what lengths (and expense) Ducati and BMW have gone to in order to keep things from setting on fire!

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