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Discussion Starter #1
Hi Gang,



Sorry. I'm a real rookie when it comes to electrical systems. I just bought an '87 "T-Dub" and I would like to start upgrading some things right away. First I'd like to mount a round (H4)? headlight. Second, I'd like to mount a better (louder) horn.

I've read that the '87 has a weak re-charging system. Are these upgrades possible? and if so, how?



I'm sorry if these sound like dumb questions. Like I said New...



I have the skills necessary to build a headlight mount and bracket, etc. I just don't know if the electrical on the '87 can handle it.



Thanks in advance for any advice.
 

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You really should consider babying your '87's electical system.



The '87 lighting coil was designed to power one 35w bulb at full rpm.



Depending on the "look" you're trying to acheive you can go with a larger round or square headlight with a bigger reflector. This will give you a broader, further reaching light pattern for the same 35w. In effect it "feels" like a brighter bulb. If you're gunna go with the smaller 5" Bates type headlight you'll probably get even less usable light than the stocker.



TThe horn doesn't present quite the same issues as it runs off the battery/charging system. There are several threads concerning upping the horn output and installing horn relays, etc.
 

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Discussion Starter #6
Thanks. You guys are fast responders. More light and sound is what I'm after. Seems like a horn upgrade with a relay will be pretty easy. what would you guys recommend for a headlight assy. to continue using the 35w lamp?



Also.. Stator coil rewinding? I'm kinduva dummy. Please explain.
 

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Electricity is produced on a motorcycle by a rotating mass that has magnets on it (rotor) spinning around a stationary coil (or set of coils) of wire (stator). The alternating poles of the magnet spinning around the coil creates a magnetic field which causes electrons to flow in the wire that makes up the coil... or something like that, anyway.



The number of turns of wire on the coil, as well as the size of the wire, have a large effect on how much electricity is generated. Many people will unwind the old coil, and rewind with a different size wire so that their bike will generate more amperage. amps * volts = watts



In the early TW setup, there is a coil for the lighting/charging circuit, and a coil for the ignition. both of these coils generate A/C power as a result of the alternating magnetic field around the wires as described before.



The way I understand it currently is that A/C power is used directly to power the headlight, and that there is then a seperate circuit from the same coil that goes through a rectifier to produce ~12v DC for charging the battery, running the horn, etc.
 

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As the light, here's some food for thought. Reflector size is a bit more difficult to calculate, so here's a comparison of the area of the lenses (the glass part) of three. Size matters when you're resticted to 35w. Suffice it to say that reflector size goes up exponentially with lense area:



Stock rectangular headlight: 24 sq. inches



7" round headlight: 38.5 Sq. inches



6" round housing: 28 sq. inches



5" round headlight: 19.5 sq. inches



Older bikes are a good source for 7" and 8" headlights. I found 8" lights a bit too bulky and vulnerable, so mine wears a '78 Goldwing 7 incher.



The 5" Bates types obviously give a lighter and airier look to the bike, but in practical terms they won't even reflect reflect the light of the stocker.



Sometime back in the late '70's studies were done which supposedly indicated that rectangular headlights were somehow safer and more focused in highway driving conditions. I disagree. I think the world was bored with round headlights and the headlight dudes got together and justified rectangular ones so they could sell 'em for a higher profit.



Round lights hit more of the road directly in front of you and peripherally illuminate more into the treetops. Call it an old guy preference, but as far as I'm concerned they're better, particularly off road.
 

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Discussion Starter #9
Thanks again. Lzrd.. I'll be shopping ebay and craigslist for a round light right away.



Sounds like stator re-winding is something to contract out. And If I can run accessories i.e. horn, off the charging side, then maybe it'll work. I do wish I could up the wattage of the headlamp. Anybody ever try an LED headlight? Lower wattage, brighter light....?
 

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Stator rewinding is indeed something that is best farmed out in most cases. TTR guys do it all the time so they can run big lights and stuff. There are several companies that offer this service for that particular model, but not for the TW as the market is likely nil.



These other guys know way more about headlights than I do and will defer to them for that type of advice
 

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These other guys know way more about headlights than I do and will defer to them for that type of advice


OK, so maybe I need a life. lol.
 

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Add a rectifier to the AC headlight circuit and a small battery and you can run an HID headlight. $$$$$
 

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