Petzl Zoom as bicycle headlight.
Francis Cooke
I have used a Petzl Zoom mounted on the handlebars as my primary front light for several years now.
I wouldn't want to dissuade anyone from investing in one of the modern purpose-designed front light systems such as CatEye or Vista, but the Petzl offers a viable alternative with one or two virtues of its own.
The Petzl is sold as a light for helmet mounting, primarily for use by pot-holers, and comes in various guises. The standard model comes fitted with a 4.5V filament bulb and a flat 4.5V battery (weight 150g) in a separate pack, and this is the best buy for cycling purposes - the bulb and power pack can easily be uprated if required, the bulb is screw-fit, ie compatible with those used in Vista VL4xx series lights. There is a super model which has a halogen bulb and a 3x D cell pack but is otherwise the same, a mini-version which is 3V running off 2 AA cells and I have seen a new super-duper verion which is a twin light, low and high beams in one oval-shaped housing.
The main virtues of the Petzl are the excellent beam pattern and the very weatherproof switch.
The beam, which is focussable over a wide range, is the best and smoothest of any light I have ever used. This is especially true of the filament bulb for which the lamp was obviously originally designed. With a halogen bulb there are some circular patterns, very similar in fact to the VistLite VL4xx series, but the large focussing collar makes it easy to minimise these. The light puts all the beam where it is needed, on the road. It does not light the hedgerows and trees.
The down-side to this is that there is no sideways spill, which means that, not only does it not comply with the British Standard for front cycle lighting (neither does the CatEye or Vista or any other decent front light) but it does not even comply with the spirit of that Standard, that there should be some sideways illumination.
The switching arrangement is quite cunning, being operated by an initial turn of the focussing collar. The actual switch contacts are buried right in the heart of the lamp and very well waterproofed indeed, as befits a light designed for potholers. Of course this arrangement means that the focus cannot be preset to a preferred setting, as on the Vista VL4xx, but the collar is easy to operate even with mittens on so this is not a serious problem.
The lamp is best mounted in a central position on the handlebars, by removing the helmet straps provided so that the remaining plastic bracket fits snugly over the front of the handlebar stem, and tightened into place using nylon cable ties. It is important to mount the lamp upside down, as it has a 90 degree pivot designed to allow the light in normal use to swing downwards for close inspection work. This pivot is fairly slack so the lamp will droop due to road vibration if it is mounted the right way up. Mounted upside down the lamp can be easily flipped up for checking roadsigns, etc, which is an added bonus. There is no provision for side-to-side movement. Depending on other extraneous handlebar clutter (computer, bell, cuddly toy) it should be possible to mount two lamps side-by-side, although I have never tried this.
Many riders use the Petzl, strangely enough, as a head-mounted light. I can't recommend this. I find the movement of the beam on the road very distracting, but worse still in humid conditions the eyeline straight down the beam becomes blocked with mist, an effect familiar to drivers who try to use full beam headlights in foggy conditions. Riding in company, headmounted lights are rather anti-social - turning to talk to your companion you blind them in the process.
Other versions - the mini-Petzl is not really viable as a serious cycling light but it is perfect as a head-mounted light for occasional or get-you-home use - as the only light for a light tourist for instance. The lens is rather bulbous and so needs protection (I wrap it in a thin glove) when packed away in the luggage.
The super Petzl offers nothing that the standard version can't provide, bearing in mind that the bulb and battery are likely to be uprated anyway.
The super-duper Petzl should, I suggest, be avoided, on the grounds that it no longer has the advantage of the ultra-weatherproof switch - the oval casing requires that more orthodox switching arrangements (almost certainly less waterproof) are used.
Using low-technology geometry for lens (a simple plane of plastic) and reflector, the Petzl is perhaps 'yesterday's lamp'. It is not in the same league as the latest VistaLite VL4xx models in terms of the excellent mounting arrangements or the overall build quality, but for reliability and effective beam pattern it is difficult to fault.