Electrical upgrade

[gmlaverda]

I have recently acquired a 1969 350 Scrambler partial basket case. A fair amount is missing and I am planning to build a custom street bike. I have recently completed 2 British bike restorations and am excited to build this Ducati without having to be "correct". At this point I am planning out the electrical system and would like to know what the experienced Ducati owners here would consider an ideal electrical system for this bike. If you you were starting essentially from scratch what would you choose? 12 volt or 6, battery or none, electronic ignition? Brand recommendations? I currently have the original alternator, a headlight shell and not much more. The bike will be used for short distances during daylight hours but will be required to have all of lighting and horn functioning anyway. I have read a fair number of posts here regarding electrical systems and this may have been covered before. Thanks

[Dave450]

12 volt is good. Electronic ignition is also good, but you can also make do with a good set of points, condenser and 12 volt bottle coil. Electronic systems are usually 'fit and forget'. I have an Electrex 12 v alternator and solid state rectifier/regulator to replace the old 6 volt alternator on my late model Desmo. You can get ignition and charging systems from from Nigel Lacey: http://www.laceyducati.com/ducati-parts ... 1_255.html

Make your own wiring loom and keep it as simple, logical and bullet-proof as possible. I used Vehicle Wiring Products: http://www.vehicle-wiring-products.eu

Hunt around in your local bike breakers for a suitable modern 12 v headlamp unit to fit the original shell. Or make your own custom with a modern H4 or LED. Lots of options here but not cheap. Bear in mind that even the modern replacement alternators don't put out that much current, so maybe LED lights would help here.

You can also fit electronic clocks. Again not cheap, so you could keep the originals if they still work.

A modern left hand handlebar switch is all you need for lights on/off and dip/main beam and horn. Why bother with the truly dreadful original switches when you can use / adapt modern ones!

If you are not a strict originality freak, there is a lot you can accomplish without changing the outward appearance of the machine too much. Subtle changes while keeping as many of the stock parts such as tank, seat, panels, mudguards, etc, can work very well.

However, the most important part of your build will be mechanical integrity. The electrics will come after all this. There is a mine of information on this site on how to build Ducati engines and assemble cycle parts. Dip into the database and ask questions. Workshop manuals will only get you so far, and the knowledge base has increased considerably since these were written.

I am sure other members will chime in with their electrical creations.

Good luck and keep us posted.

Dave

[JimF]

You are going to get a lot if different opinions...

12-volt power (power being the ability to supply many amps at 12 volts of potential) to my thinking is expensive to implement. And 12-volt electronic ignition systems add even more cost.

I converted a 450 desmo to 12-volts with a 12-volt alternator and a RITA ignition so I have done it.

My daily driver is a AC powered 250 (the stock so-called 6-volt 40-watt system though both those numbers are quite arbitrary.) I left the ignition system bone stock AC with points and coil on one winding of the alternator.

I took the second winding and converted it to 12-volt DC with an under $100 Podtronics unit. That being said there is not enough power (watts) resulting from the 12-volt potential and the amperage it can supply to run a normal headlight. I use the 12-volt DC to run a LED taillight and white LED headlight. The headlight does not work well at night. Day and night it appears to cars as a regular headlight but it fails to illuminate the road to any reasonable degree.

Jim

[Dave450]

The Electrex 12 v alternator is rated at 120 watt output, while the original had 60 watt.

[Nick]

http://www.electrexworld.co.uk/

The above has all you need. I put one of their AC systems (including electronic rectifier/regulator) on my 250 Diana MkIII. It bolted right on, works perfectly (12V of course) and I no longer think/worry about crazy Ducati electrics. I'm still using points and have never had any problems, but if you're starting from scratch, may as well go electronic ign also.

I made my own super-simple wiring loom using two toggle switches: one for Ignition one for lights. Mounted rectifier/toggles on an aluminum plate attached between the frame rails under the seat. Worked out very sano.

[gmlaverda]

First of all thank you all for the responses. Regarding the recommendations for Electrex products, I notice that Classic Ducati of England shows them listed in their Electrics/Lighting section with the following comment: "we can no longer supply or recommend this product from Electrex World Limited, due to problems beyond our control. In the mean time we will endeavor to find a suitable replacement". Anyone have any idea what that means?

[Dave450]

First of all thank you all for the responses. Regarding the recommendations for Electrex products, I notice that Classic Ducati of England shows them listed in their Electrics/Lighting section with the following comment: "we can no longer supply or recommend this product from Electrex World Limited, due to problems beyond our control. In the mean time we will endeavor to find a suitable replacement". Anyone have any idea what that means?

I wasn't aware of that. I suggest calling Nigel Lacey and asking him if he has encountered problems with Electrex and what their warranty is like. I doubt Nigel would stand over a product that has questionable quality. I have had no problems so far with the Electrex alternator supplied by Nigel. I had a problem with the Electrex rectifier/regulator that came with the alternator, about 4 years ago, which I replaced with a Podtronics unit. I read of a few others experiencing malfunctioning units some years ago and I understand that Electrex now sell a better rec/reg.

If your original alternator checks out and if you only need day time lights for short trips, it guess it would do, but it is 45 years old, so even if the coils are still good, how much magnetism does the flywheel have left? We all know that most breakdowns on old bikes are caused by old and dodgy electrical components. If it was me, I would have new everything electrical to begin with.

[DewCatTea-Bob]

____ So sorry that I just happen to have failed to bother looking for any recent posts (such as yours here) for the past few days, that might've been of specific interest to myself !
Your thread-topic matter actually happens to be concerning my favorite subject (concerning DUCATIs) ! _ And-so I hope to offer you top-notch (and multi-optional *) guidance through your electrical-system project.
(* When constructing a non-stock electrical-system from near scratch, ya then encounter a number of forks-in-the-road which ya get to pick&choose between.)



[quote= gmlaverda ...
" I am planning out the electrical system and would like to know what the experienced Ducati owners here would consider an ideal electrical system for this bike. "

____ With that,, I-myself happen to not-only likely be the one member here with the greatest 'experience' in that field, but also seem to have the highest understanding of most everything related. _ However your specific inclusion of the word "ideal", may possibly take you down an optional-road where my-own guidance could be fairly limited, as I'm only a top-expert concerning stock Ducati electrical-systems.



" If you you were starting essentially from scratch what would you choose? "

____ Short of a complete stator-rewinding endeavor, I-myself would prefer to retain the stock alternator.
A 12v.system is more efficient (but doesn't make much difference if an equivalent 6v.system happens to have low wattage loads).
A system which includes a battery, enjoys certain advantages !
(This paragraph has already encountered three forks-in-the-road which I've now offered suggested optional steering through, so next you only need accept or prefer your-own choices.)



" I currently have the original alternator, "

____ The stock 6-pole alternator was insinuatedly claimed by Ducati to be RATED* for '70-watts', apparently for adequately-handling that amount of system-load wattage-demand,, (* 'rated', rather than simply a proven constant source of an even 70-watts). _ However that particular rating was certainly not the maximum-wattage which can possibly be attained, (as most everyone seems to assume). _ And due-to Ducati's very-own methods for (rather conservatively) 'rating' their alternator-wattage,, it's really not fair to directly compare their publicized wattage-ratings with those of other alternator-manufacturers who most-likely choose to employ otherwise concocted rating-methods for determining their-own wattage-rating for their-own alternators, (and-so, are quite likely biased to prefer rating-methods which bolster their output-superiority by rather claiming maximum-output as opposed to some more realistic means of determining a wattage-rating that's rather more in-line with actual real-world motorcycling [as apparently Ducati-themselves preferred trying to reside with] ).
To fairly compare the wattage-outputs of various alternator-units, they'd both have-to be tested for maximum-output or otherwise rated by the very-same applicable rating-method that's chosen as a real-world averaged-wattage capability for general motorcycling conditions, (as power-wattage capability varies along-with motor-RPM, etc. !).
__ Besides concerns of power-wattage created by alternators, there's also the somewhat common over-concern pertaining to amounts of voltage-levels available from them...
Whenever anyone states "6-volt alternator" or "12-volt alternator",, whether they realize it or not, they're actually just referring-to it's 'voltage-rating', which actually indicates very-little because running alternators by themselves alone really don't produce any actual 'voltage' at-all (until after becoming connected to a circuit). _ (The common-belief that alternators can be any particular 'voltage', is pretty-much the same concept as trying to conceive that a running air-pump can somehow possess a preset amount of air-poundage without being connected-up to an air-line/tank.)
Alternators actually only produce just raw-power, which becomes divided into amperage & voltage only after being connected-up to a circuit (which is what really determines the resulting voltage-amount !).
If alternators could possess any such bias compliance to any particular voltage, then there wouldn't be any use for voltage-regulators !
So the stock alternator is pretty-much as good as any for use with either 6v or 12v.systems.



" The bike will be used for short distances during daylight hours "

____ Then in such case,, the stock alternator is way-more than adequate, (since you won't need a high-power headlight to well see unlit roads at night) !
__ So-then why go-with any expensive aftermarket charging-system of which it's only real advantage is to fully power-up rather high-power headlights (only needed for night-time road-riding) during overly extensive low-RPM riding-periods !?



" I have read a fair number of posts here regarding electrical systems "

____ I-myself usually tend to be considerately consciously-aware of not getting too-far side-tracked away with other irrelevant system-types which have little commonality with your particular non-AC.powered wide-case type system. _ So within this posted-thread of yours,, I'll try to refrain from having you needlessly read-through any posting-info that's not directly associated with your presented project, (at-least whenever directly responding to your submitted posts).
__ I look forward to assisting you with your picks of route-fork choices,, but at this early point, I of-course really don't prepossess the drive-incentive or gumption to draw-out a complete map of all possible routes which you may possibly prefer. _ As your final-route is rather more-so up to yourself (and perhaps anymore further steering submitted by others).



____ My-own first pertinent question for you is,
is the alt.stator removed off-from the motor-case, and what's the condition of it's three (1-red & 2 yellow) wire-leads ?


Hopeful-Cheers,
DCT-Bob

[DewCatTea-Bob]

[quote= JimF ...
" You are going to get a lot if different opinions... "

____ And also some actual-FACTs too, as-well !



" 12-volt power
to my thinking is expensive to implement. "

____ Why would that be ? _ As 12v.parts are more available these-days and-thus usually cheaper to obtain than their 6v.counterparts. _ But even if equally priced,, it ought not mater in this case where there are no preexisting 6v.parts to start-out with, so-thus the expenditure ought be at-least pretty-much the same with either implementation.



" I converted a 450 desmo to 12-volts with a 12-volt alternator "

____ I dread to think that even you-yourself have fallen for any such 12v.alternator sales-hype, to have gone-ahead & replaced the stock alternator to (rather expensively) convert to a 12v.system,, when instead you could've rather simply just replaced the stock 6v.regulator with a 12v.version (as employed on any pre-1976 750 bevel-twin).



" My daily driver is a AC powered 250
I left the ignition system bone stock AC with points and coil on one winding of the alternator. "

____ I'd assume that "bone stock" is meant to pretty-much mean 100% factory-stock,, and-so with that latest clue I've been left to uncertainly conclude that you actually have indeed reconnected the ign.coil back together rather with the proper alt.power-coil (originally specifically intended for powering the ign.system-circuit), instead of left connected to the lighting power-coil as you had last bothered to mention having been done. _ So then is that clue and my conclusion based upon it actually correct ?



" I took the second winding and converted it to 12-volt DC
there is not enough power (watts) resulting from the 12-volt potential and the amperage it can supply to run a normal headlight. "

____ By "normal headlight", I assume you mean a std.25-watt incandescent-filament type light-bulb, except rather in a 12v.variety.
If so, then that disappointing circumstance seems somewhat amiss, cuz either power-coil ought-to provide at-least 30-watts and-so there ought-not be any such wattage-issue responsible for not fully powering-up a light-bulb which consumes less power than that amount.
However, when a 12-volt bulb doesn't light-up as brightly as an equivalent 6v.version of the very-same wattage-rating, then the actual blame for that shortfall is no-doubt due-to an 'impedance/resistance-mismatch' ! _ Cuz if the operating-resistance of the light-filament becomes higher than the impedance of the connected power-coil, then the filament's resistance is too great to allow the full-power of the power-coil to become available.
The only way to solve such a (directly connected *) 'mismatch', is to either lower the resistance of the connected light-filament, or increase the impedance of the connected power-coil so that they both then become 'matched' (which then splits-up the produced alt.power rather evenly between the filament and the power-coil's winding).
And that has to do with why the lighting power-coil's winding contains less loop-turns of a thicker gauged wire (than that of the ign.power-coil) !
(* The addition of a battery [seemingly magically] takes that equation out-of-the-picture, so that's another-way to get-around & solve such a shortfall issue.)
__ Matching the alternator-circuit with the intended load-system is at-least part of the main factoring for 'rating' an alternator as either '12-volt' or '6-volt' (depending on the overall resistance-level of the intended load-system & battery-voltage that the associated alternator has originally been meant to be matched-up with).


Dukaddy-DUKEs,
DCT-Bob

[ducwiz]

Hi,

Bob, you wrote:

____ I dread to think that even you-yourself have fallen for any such 12v.alternator sales-hype, to have gone-ahead & replaced the stock alternator to (rather expensively) convert to a 12v.system,, when instead you could've rather simply just replaced the stock 6v.regulator with a 12v.version (as employed on any pre-1976 750 bevel-twin).

Sorry, but I disagree. I had checked this with my 350M3D. I t turned out that using the bevel twin R-R unchanged, the output of electrical power was insufficient, especially at lower revs. I couldn't get the 75 Watt from the alternator, as claimed by DUCATI for the 6 V system with electronic ignition, about 30 -40 Watt was the maximum at 12V.
I made a conversion to the original 6V R-R by adding 2 power diodes from a car's alternator, forming a full bridge with the R-R's SCRs, and connected my special circuit ahead of the "marrone" input terminal (inside the R-R case), taking 7V from the battery's 12-14 V.



In the new system, the red wire from the alternator stayes unused on the double post, only the yellow ones are used. The battery +terminal is now connected to the pos. bridge output, on top of the R-R. Hence, approximately the full power output is available again.
Of course, the voltage reducer can be left off, if a 12V bevel twin R-R is used. But these items are very rare these days, so quiteexpensive.

cheers Hans