Since a while I am considering adding some light to the front of my Transalp. I ride around as an express-courier in heavy day traffic so I wouldn't mind being noticed faster. On top I also noticed at night it ain't always that easy to really see what kind of mess you are riding around on (mud from road works, snow, gravel,...). That's why I would really like some extra light on the front.
(The back is already taken care of with a fog-light. Gives a safer feeling in fog, heavy rain,...)

My questions:
* The Transalp alternator only has an output of 310 watts. Seems not too much to me. How can I figure out how much I have left over to use for my frontlight? The back foglight is 21 watts extra.
* All the possible lights I come around are 50 watts or more. This seems a bit on the high side to me. How can I get around this? Just put in a lighter bulb? Or does anyone knows about a good model that doesn't drink that much?

50w is about the minimum for a headlight. 45/55 is the lowest I've seen.

You shouldn't have a problem with anything up to about 100 or so watts on high. I run an 80/100 which my BM (280w total) handles adequately, even with an electric vest on. With two vests on, it's overloaded. I also run 4 extra running lights with a total of about 50-60 watts.

Try PanEuropeans suggestion of the Philips Vision bulbs.

------------------
Grant Johnson

Share the Dream!
at: www.HorizonsUnlimited.com

__________________
Grant Johnson
Seek, and ye shall find.
------------------------
Inspiring, Informing and Connecting travellers since 1997!
www.HorizonsUnlimited.com

Huan:

Some additional thoughts for you, in support of your quest for more light:

You might want to consider re-plating the reflector on your existing lamp assembly, and carefully examining the clear lens assembly for any contamination on the inside (if it is glass) or any degradation that would cause increased opacity (if it is polycarbonate). I don't know if the headlight assembly on your bike will disassemble into the component parts of reflector and lens. If it does, try cleaning the reflector with dish detergent and a very soft cloth (either lens cleaning tissue or facial tissue wadded up into a ball). Ditto for the inside surface of the front lens. If the lamp assembly does not disassemble, try cleaning it by filling it up with warm water, detergent, and a handful of rice (don't laugh, I am serious, this will provide gentle abrasion) and agitating it. Then rinse it out thoroughly with clear water and let it dry for a day. Finally, rinse it out once again with isopropal alcohol, and let it dry for several days in a well ventilated location before putting it back into service.

If your front lens is not made of glass, but of polycarbonate, consider replacing it. At work, we replace polycarbonate lenses on aircraft landing lights every 5 years because of the natural increase in opacity that takes place with exposure to the sun. With aircraft that are used in the desert and subject to sand erosion, we replace lenses every 6 months to a year. The constant abrasion of sand on the outside surface of the lens causes light diffusion, the net result of which is much less light delivered where we want it.

You could have the reflector replated fairly easily by either a conventional chrome plater (if it is metal) or a custom bike plating shop (if it is plastic). I think you mentioned your bike is a 1988 model, I would not be surprised if the reflector has degraded quite a bit.

It might just be cheaper and easier to purchase a new lamp assembly from Honda. FYI, I just purchased a complete replacement headlamp assembly for a ST1100 last week in Switzerland, the cost of this, with all bulbs, all accessories, wires, etc. was € 210. This was for a complex, dual lamp assembly, I am sure the cost for your bike would be less.

I'm stil not convinced that pure wattage alone is the answer to your current shortage of light. Consider that on my ST1100, I have two (premium quality) 55/55 H4 bulbs, and this gives me all the light I need to cruise at 140 km/h in the dead of night in Northern Canada, where moose, deer, etc. are a constant hazard.

Lastly, have you had the bike's electrical system checked to ensure that it is putting out the correct voltage? Normally vehicles that have 12 volt batteries have a nominal operating voltage of 14.2 volts with the generator or alternator running. An automotive electrical shop should be able to test both the voltage output, and also the ability of the generator/alternator on your bike to deliver full rated output.

If your bike's electrical system is not putting out full rated output (amperage under load, as well as voltage), this could account for why you are unhappy with light output. Under these conditions, uprating your bulb would only put a 'patch' on the problem.

Fireboomer:

In response to your post above inquiring about electrical reserve capacity on your Transalp, below is a letter I recieved from a very knowledgable friend in response to the same question I asked apropos my ST1100. I think you might find some useful information in it.

According to my calculations, a stock ST1100's electrical demand is ~292-293 watts broken down as follows:

lighting - 144 watts - 10.7 ampere [Ed. note: A ST1100 has two 45/55 watt headlamp bulbs, which are both on whenever the headlight is on]
ignition - 124 watts - 9.2 ampere
battery - 13.5 watts - 1.0 ampere
wiring losses - 10.8 watts - .8 ampere

The theoretical max output of the generator is .54 Kw or about 40 amps at 13.5VDC. So the reserve electrical capacity is about 18.3 ampere. The above breakdown assumes no brake or turn signal lamps operating, no cooling fan operating, and a nearly charged battery. Immediately after engine startup, the battery will obviously require more than 1.0 ampere for recharge for a brief period of time. One should never load the electrical system to max capacity as it will shorten the life of the generator stator and reduce overall reliability. In extremely warm weather (ambient temps above 100 deg F), I would say the max load on the generator should be about 75% of rated, or about 30 ampere continuous. At ambient temps below 50 deg F, where a rider would start to use electric clothing, the generator could be loaded to 90% of capacity as long as system voltage is monitored and not allowed to fall below 13.5VDC measured at the battery. If voltage drops below the regulated value of 13.5, generator life is going to suffer.

I'm a mechanical engineeer, with my specialty being internal combustion engine design, so this is only an opinion. But the calculations are fairly simple, and could be verified with the use of an ammeter on each circuit, or if you have a large enough capacity meter, by measuring the draw at the main fuse. The ST's main fuse is a 30 ampere fuse, and it's normal to load a fuse at about 75% of it's capacity (normal load), so I think my figures are very close.

It's also obvious that the pre -'96 model ST's with the oil cooled 28 amp generator are not capable of running very much more than about 5 ampere of accessory equipment (the accessory fuse happens to be 5 ampere).

Note: I refer the the "alternator" as a generator here. It's actually an excited field, three phase AC generator that uses solid state rectifiers to convert AC current to DC, so I refer to it as a generator.

Hope this helps.
--
Chris Olson - Barron, WI



[This message has been edited by PanEuropean (edited 15 February 2002).]

According to Bajadesigns the NX650 Dominator
has a 3 phase AC generator that can't be rewound to produce 2x 125W like the XR600
They claim that 180w should be plenty however there is probably not much call for heated vests...etc in Southern California.
Thanks for all the info.
BTW XR600R owners can have their generators rewired by Baja designs to give the 125wx2 if they feel it is necessary.

Huan


[This message has been edited by Huan (edited 15 February 2002).]