H100 sg 6v to 12v?

[ocatoro]

does anyone know how i would go about changing my 6v electrics to 12v?

i've found that at low speed, on the brakes, my headlight is all but extinguished. not good in rural wales with lots of slow, downhill roads.

seems to be a lot of ideas out there, mainly on other bikes like cb100, or just other makes all together. even some that just say change the battery and the bulbs, and the rest will be fine.

can't be that easy can it?


could this drop in power which almost cuts the lamp off also cut the engine?

[ocatoro]

anyone got any ideas?

[cb1rocket]

can be done, make sure you haven't got a 12v headlight bulb in there to start with!

New battery helps.

H100 owner

[Teflon-Mike]

I take it this is carrying on from your other post deeming licghts 'crap' and going dim when engine revs low, or stop lamp on.

OK... lets start at the top.

First of all 6v lighting need not be SO dire. Others mentioned that they lived hapily with 6v lights, though the CD200 benley mentioned runs a fully regulated battery damped 6v system, not as I believe a 6v AC 'direct-lighting' from magneto system as the H100.

BEFORE looking for MORE than a standard.... make sure you have what you should have AS standard.

Old rule of racing.... no point trying to find more power from fancy carbs if your bikes not making the power it should from fucked rings....... same applies here.

Quirk of AC-Direct lighting; the reason that lights are dim, is the power to supply them is limited to the output of the oine coil in the magneto, and there is no 'reserve' to keep them lit from a battery.

People get two problems... crap light output, and frequently blowing bulbs.

To remidy the low light output, they apply a little very basic logic and fit a higher wattage bulb.... more power = more light, right?

Well, yes, but only if the generator delivers enough electric to light it up.....

Blown bulbs? Higher wattage bulbs often stop them blowing.... but tackling a symptom rather than the cause... bulbs blow from over-voltage or vibration.

Some systems use a simple zenner diode to 'regulate' voltage, and these can eventually burn out.... if the lighting is regulated, then this can cause bulb-blowing.

SO: first step is to investigate the book; see what you SHOULD have, then go over the bike and see what you DO have.

6v bulbs aren't all that common these days; good chance that when bulbs have blown they have been replaced with 12v bulbs and quite possible not the correct wattages, which for many devices were probably lower or more uncommon ratings.

Doing that, and spending time cleaning contacts and earths, not just in bulb holders, but earths, bullet connectors and in the switches, COULD completely change your view (pun) of the bikes lighting..... contact corrosion has twice the effect on a 6v system that doesn't have the electrical pressure to get through copper oxide so easily!

THEN... you can decide if it needs more seriouse mods!

My DT had 6v Direct lighting; but I discovered a 'cheap & easy' 12v conversion method for it. Whether it would work on the H100 depends on the Magneto, but on the DT the old 6v Mag banged out enough volts at a little above tick-over to charge a 12v battery.....

12v generators I think commonly can make up to 16v, especially flywheel magneto generators where the voltage increases with rotor speed... a regulator rectifier, which is a bit more sophisticated than a zenner diode, then provides 'full-wave' rectification of that out-put gathering possibly twice the power from some coils, before delivering it to the battery to supply equipment.

IF, and it is an IF.... you spike the out-put wires from your magneto, and get helpful looking voltages around 12.5v or so at a high idle.... then you MIGHT be able to do a full 12v conversion with minimum mods, as I did on the DT.

You redirect the feeds from both the AC direct lighting coil in the mag, and the 'charging' coil in the mag to a 12v 'pit-bike' regulator/rectifier... about £10 on e-bay.....

This then gives a single out-put 12v stabilised current to charge a battery..... so find a 12v battery that you can locate conveniently on the bike.

You then have a disconnected direct lighting circuit, and the original accessory circuit... so to make lights work, all you need to do is take the snipped feed that used to come from the magneto, and tap it into an ignition switched live from the battery.

Wiring and switches will take the current OK.... P = I x V so double the volts you halve the Amps.... wiring & switches is rated by amps, so good-good.

But, you then have to change ALL the rated devices, bulbs, horn, indicator flasher and anything else for appropriate rated 12v items.

Pit bike regulator and small 12v battery... you are looking at maybe £30.....

BUT, change all the bulbs and equipment, you can start pushing fairly big money quite quick.

AND you are likely to be faced with a few dilemahs on the way.

On the DT, I think the indicators were rated at something like 8w 6v, the headlamp, a mere 25w, and the tail lamp a 12 over 4.

Remember you may have 12v, but you have no more WATS coming out that generator! And finding such low powered bulbs in 12v rating AND fitting may be a problem.

On the DT I was lucky the indies were conventional indy bayonets and a 12w 12v bulb fitted straight in... BUT upped power consumption.... sure only intermittent, but still juice out the battery that has to come from SOME-WHERE!

My solution was to use LED bulbs..... dropped power drain on the indies from 8w to 1/4w a bulb, and using an electronic 12v flasher (another £10) probably found a bit more, while keeping flash rate legal. also dropped 12w Also found watts from LED stop lamp bulb, same way.

But we then come to the head-lamp, and finding a replacement 25v tungsten was hard enough for the headlamp fitting, without trying to find non-standard 12v that would go in the same holder.

New headlamp time..... and WOW! Yeah, actually another efficiency loss discovered..... even with a chitty 6v/25w bulb in it (Held in the hold just for comparison!) you could see that the 30+ year old lense and reflector was rather yellowed and dulled and not passing all the light it should have been (so again, on yoru 'before more, make sure standard - check, have a look at that headlamp lense & reflector unit!)......

New Headlamp, alowed not just common 12v bulbs, but also more efficient halogen ones, rather than tungsten..... ony still struggling to find bulbs with low enough power rating...... most Halogens are rated 55/50w or above...... lowest rating, and requiring an adaptor to fit standard H4 bulb-slot was 35w and expensive...... BUT could just about have got away with it.....

By THIS point..... I was in for a penny, in for a pound..... I think this "£10 - Conversion" had totalled up:-

£10 for the regulator rectifier
£20 for the 12v battery
£25 for LED indicator bulbs
£10 for Electronic LED indicator flasher
£10 for LED Tail-Lamp bulb
£25 for H4 Headlamp lense/reflector

And I was in for best part of £100! 10x the notional cost of conversion!

So I splashed the cash and bought an HID headlamp kit, for £40, for a car, which I split with Snowie, putting one bulb in her bike, one in mine.... so only an extra £20 on MY bill.....

But that, more work, to make brackets to locate the balest and control boxes, BUT....35w power draw, only 10w more than stock, found from LED gains in tail & indies.... and the idiot lamps in the dash (Which I made myself for penies from compenents!)

And it worked, and I got BIG-BIKE lighting from the little 4 1/4" headlamp...battery stabilised, worked a treat.

BUT.... its incrimental, and it ent 'cheap'. AND its only viable IF that magneto chucks out enough volts to do it.

If NOT... then you need a higher output magneto....

If you are lucky, you might find that the cases & crank will accept the magneto from another bike, but you may have issues with the ignition, especially if its a CDi ignition system, other wise, you would be down to having to get seriouse with some engineering to machine bits to fit to get the power out of the genny.

OR, going down and dirty..... and running the electrics 'Total-Loss'..... which simply means you ditch the charging circuits, and fit a BIG battery to run your electrics and charge it up on a car-battery charger when you are at home......

SO..... yes, you can convert to 12v..... where there's a will, there's a way.... but if you are LUCKY, you are probably looking at a £100 job. If not? silly money... OR doing it down and dirty, and running something rather 'botched'.

Meanwhile, that rule of racing..... can probably get a LOT more lighting for a LOT less money, doing some remedial maintenence.

Changing bulbs to propper ratings, cleaning contacts, and if not replacing the headlamp lense/reflector, at least cleaning it well.....

AND setting the idle speed properly, to avoid the total black-out of low rev voltage loss....... caused by putting alternator on load, turning lights on, dropping idle speed, set when the bike was stood on its stand, idling lights 'off'!
____________________
My Webby'Tef's-tQ, loads of stuff about my bikes, my Land-Rovers, and the stuff I do with them!
Current Bikes:'Honda VF1000F' ;'CB750F2N' ;'CB125TD ( 6 3 of em!)'; 'Montesa Cota 248'. Learner FAQ's:= 'U want to Ride a Motorbike! Where Do U start?'

[ocatoro]

thanks for that reply. i wasn't being all gaww old crap is crap. the light being "crap", as in, not producing light was a pure observation.

the headlamp unit itself appears to be no more than a few months old. so i will check the bulb and the connections make sure no corrosion and that it isn't too high a power bulb. and check all earthing points.

i shall do some checks on the output of the generator and see what i can come up with there if the above has not come up trumps. very helpful indeed

[Teflon-Mike]

what's 'crap' is a subjective thing....
If you are used to a car with twin 55/50 head-lamps in BIG lenses chucking out 100+w quite efficiently, then coming to a bike, even with a 'good' single 7" 555/50 headlamp, can seem a bit 'dim'.
Get something older or lower tech, that uses tungsten bulbs.... you have another leap into the gloom....... back further to 6v systems, and yeah!
They were 'OK' compared to the Ever-Ready cycle-lamps we had on a push-bike 30 years ago...... but probably not as effective as a modern push-bike lamp, with two 'cat-eye' lenses and a rechargeable lith-ion battery pack!
BUT.. they chuck out light, and we could steer by it twenty years ago; bike cant go any faster now than it could thirty years ago..... hazards in the roads not much different to what they were thirty years ago...
'standard' can still be 'OK' if not particularly inspiring!

Something that's totally tangential, though... IRONICALY... I was watching a poor learner on I think it was a Lexmoto.... chinky CG copy anyway.... has pretty poor AC-Direct lighting, though 12v, and with a wopping 35W tungsten bulb!... negotiate his way accross a dark industrial estate at coming out time a while ago....

LIGHTS EVERY WHERE!

Lads on push-bikes lit up like a christmas tree, with flashing LED's, marker lamps on the sides of lorries, and a Japanese import people mover that looked like a fair-ground ride!

Curiousely, despite his lack of illumination, poor lad actually seemed more 'obviouse' for the lack of it!

He wasn't a 'wall of light'... you didn't see JUST bright points of brightness... you SAW a BIKE...... and the more orange glow from tungsten bulb was less stark and contrasty, and 'different'...

Some-times wonder IF in the battle for conspicuity, we are loosing the plot causing a confusion of bright lights, and NOT actually 'iluminating' the scene......

Maybe a ponder point!
____________________
My Webby'Tef's-tQ, loads of stuff about my bikes, my Land-Rovers, and the stuff I do with them!
Current Bikes:'Honda VF1000F' ;'CB750F2N' ;'CB125TD ( 6 3 of em!)'; 'Montesa Cota 248'. Learner FAQ's:= 'U want to Ride a Motorbike! Where Do U start?'

[symonh2000]

Check the voltage regulator.

On my 6v RXS100 it had failed, which meant the battery became cooked, and the lights were terrible.

You can tell if it has failed by measuring the voltage across the battery teminal with the engine running. On my RXS the battery was getting 14v where as I would have considered about 7-8v to be correct.
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Four strokes is two strokes too many.

[Frost]

40w bulb = dim
100w bulb = bright as fuck.

Both run on mains power and are therefore 240v. So just a simple example that voltage doesn't always have to be the determining factor in brightness.

[symonh2000]

It is all about ohms law.

A 12v electrical system runs half the current as an equivalent power 6v one.

That means the wiring and connectors have to be in much better condition and the battery will have to supply twice as many amps, which gives it a harder life.
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Four strokes is two strokes too many.