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A BSATechniques: Light Up Your Life!

Richard M is dim. No, hang on, that's not right. Richard M's lights were dim. But now they're not. It's all to do with his spending habits, apparently...

Now I'm not going to get technical on this since I'll only confuse myself, but I have noted various comments both in the RealClassic magazine and on the website about battery problems. And I myself recently came to an involuntary halt during a recent weekend ride out, A Triumph when I ran out of sparks. So I've started taking the issue altogether more personally.

The electrical specialists tell me that my problem is very common, but often misdiagnosed. So this may apply to you.

As explained to me by that doyenne of the classic bike electrical world, Paul Dunn, my battery is simply my deposit account. My alternator or my dynamo makes payments in and my ignition and lighting draws out. My bike stopped because I kept drawing out without paying enough in.

A Moto GuzziSo while the battery stores enough to cope with the high demands made by the system from time to time, in my case I continued to draw out more than I was putting in. Hence I ran out of sparks.

Time was when magnetos supplied both lights and sparks and motorcycles coped quite well for the most part. Then we got clever. Bigger 60W headlamps, nice bright tail lamps, electronic ignition… all jolly good but they have a price. And often it seems as if that price is more than the poor dynamo or alternator can pay. Another Moto Guzzi

I have a good dynamo but it doesn't really get its act together until I'm doing a sustained 2000-2500rpm plus. Fine for something nice and revvy like a 500 twin but not so dreamy for a lovely slow revving thumper, or even a big twin that's pulling over 70mph before the rev counter shows 2500 in top.

So what's the cure? Ride around in second gear? Hardly. Buy some high output dynamo? It was explained to me that it's not an output A Motobiproblem... is it? Once the generator is up to operating speed output is not a worry. Splash out on a super alternator? Well, I always thought that an alternator generated at much lower revs than a dynamo. Wrong! An alternator will beat most dynamos for output but apparently they both wake up at about the same revs.

But don't despair. Modern technology gave us the problem and now modern technology has solved it. In a word, halogen!

A Ducati

RC Club Member Paul Goff (01494 868218 www.norbsa02.freeuk.com) explained to me that a low wattage halogen bulb will produce more light yet draw less of your precious amps. And thinking about it, a typical four AH battery will run my Lucas electronic ignition for an hour when fully charged, even without a dynamo. Switch on a 60W headlamp taking another four Amps and we're down to half an hour's running. Throw in a bright rear lamp and…well, you get the picture. A tall order for a poor old dynamo.

But 'Goffy' now has all kinds of direct fit quartz halogen lamps which draw And a Gilera. Why all the Italian bike headlights? If you'd owned one, you'd know... tiny amounts of power yet melt the tar on lamp posts. Sort of. He also has some other clever ideas such as a quartz halogen pilot bulb that's as bright as a headlamp (so ideal for daytime and dusk visibility) yet uses a fraction of the power. I have fitted both of these upgrades and I'm well pleased. Now I've asked Paul for one of his bright but low-current stop and tail lamps.

I now feel safe, my battery feels as if it's on holiday, and my dynamo is my friend again. Plus I don't need to pack a pound of spare sparks in a rubber bag each time I go out anymore. Good old Goffy!

Anyone know much about using LEDs?


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