LED Lighting On Newly Acquired 1973 TR7RV

ManInTheJar

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Tiger 800XRXand Street Triple R
I am in the final stages of negotiating a deal for a really nice 1973 Tiger 750 which is not only very clean but has some nice touches such as twin disks, belt primary, electronic ignition and a modern regulator. I plan to use this regularly (alongside my Tiger 800 XRX) rather than let it be a garage queen and would like to tweak it to give a classic riding experience but with some modern convenience.

My first thought is to do something about the lighting to let me reliably run with the lights on all the time. My first thoughts are to fit LEDs with their lower power consumption, either by converting to negative earth or using bulbs which are designed to have a positive earth. I have seen suppliers selling positive earth LED bulbs for the classic market but wondered if anyone has experience of these in terms of reliability (vibration resistance) and light output.

Plan B could be a higher output alternator to get more power for a high wattage halogen headlight but this would rob some power from the engine and seems a less elegant solution.
1973-triumph-tr7-62c7e72c81c81 (1).jpg
 
Late classic Triumphs are very nice with dual discs. That one's a beaut!
 
I can't help you, but that's a beautiful bike TUP TUP
 
lighting to let me reliably run with the lights on all the time.
Two questions need answering before it is possible to offer detailed advice:-

. When you intend to use the bike - just in daylight or at night as well?

. Detach the headlamp from the shell and look at the base of the bulb installed now. Standard originally was British Pre Focus:-
96c2d0272634beb199c0104cd819ad59.jpg

... if the bulb you find is not BPF, please post a photo.
 
Two questions need answering before it is possible to offer detailed advice:-

. When you intend to use the bike - just in daylight or at night as well?

. Detach the headlamp from the shell and look at the base of the bulb installed now. Standard originally was British Pre Focus:-
96c2d0272634beb199c0104cd819ad59.jpg

... if the bulb you find is not BPF, please post a photo.
The bike is currently sitting about 460 miles away from me so I am not sure what the existing headlight arrangement is. I want to change all the lights including tail and flashers and am not too bothered if this involves fitting a replacement 7" reflector unit to achieve a compatible bulb fitting.

The main point is do +ve earth LEDs such as those shown below work reliably in this kind of application?

Screenshot_20220820-195703_Chrome.jpg
 
higher output alternator to get more power for a high wattage halogen headlight but this would rob some power from the engine and seems a less elegant solution.
I plan to use this regularly (alongside my Tiger 800 XRX) rather than let it be a garage queen
A single horsepower is 735 Watts. The most powerful alternator capable of being fitted to these bikes without major modification produces 240 Watts (if its maker is to be believed, no technical data has ever been made available).

Without an upgraded alternator, your prospective bike's standard one produces 120W at 5,000 rpm, 75% at 2,400 rpm.

I bought a brand new electric start Triumph made only two years after the Tiger, with the same alternator. It was inadequate then. During 1978, the original Lucas company began offering 3-phase alternators that fitted in place of the previous single-phase; when I upgraded my Triumph, I chose the higher output one (180 Watts at 5,000 rpm, 85% at 2,400 rpm), I still have the bike, I have never had reason to regret the inelegant solution.

As you want to use the 73 Tiger regularly in place of your modern Tiger, even with LED lighting, it must generate at least 60 Watts reliably any time it is running. Maybe look around and see which other modern bikes have a 120W alternator ...? Ime, LED lights are a useful modern development. But they are still not an alternative or substitute for adequate generated power.

The bike is currently sitting about 460 miles away from me so I am not sure what the existing headlight arrangement is. I want to change all the lights including tail and flashers and am not too bothered if this involves fitting a replacement 7" reflector unit to achieve a compatible bulb fitting.
Headlight in particular, little wisdom in the ambition without knowing what is fitted to the bike now.

Standard fitting on most 1973 British bikes was a bulb base and lens/reflector made by the original Lucas company (as opposed to the current Wassell "Lucas") known as British Pre Focus; the 120 mph Triumph I bought brand new was fitted with that headlight. In those days, in the UK, headlights were generally just used for lighting the road in front of the vehicle at night, the Lucas BPF combination was absolutely appalling, as much use as the proverbial chocolate teapot, even at only the 60 mph national speed limit.

The original Lucas BPF bulbs and lens/reflectors had two problems - the dismal light output for the power consumed, the poor lens/reflector design that did not focus the light that was produced. The original Lucas company produced BPF bulbs and lens/reflectors of at least two different designs, but any combination is just different degrees of abysmal. :(

The BPF LED does produce more light than any original Lucas or modern pattern incandescent BPF bulb, but it does not solve the poor lens/reflector design, neither of the originals nor of the current Wassell Lucas production.

That is why I asked:-
When you intend to use the bike - just in daylight or at night as well?
... just in daylight, BPF LED in matching lens/reflector appears to be 'good' for daylight riding, in that the poor-design lens/reflectors scatter the light over a wide arc; however, at night, you want the light focussed in front of the bike, which none of the BPF lens/reflectors can or could ever do. :(

The "H4" LED replacement shown on the CDRC webpage is the current automotive standard P43t bulb base ("H4" is just the three spade terminals electrical connection). However, £50, doubtless plus p&p and VAT, is a vast expense for fairly ordinary light output compared to the best quartz halogen bulbs, which cost a fraction of that, can be had post free from the likes of Amazon. If the bike does not have a P43t lens/reflector already, that is another expense.

Whether or not your intention is a P43t LED bulb and matching lens/reflector, be aware the better the lens/reflector is at focussing the bulb's light in front of the bike, the worse it will be for daylight riding, when you want other road users to see the bike before they are almost directly in front of it ... Also note that a well focussed dip beam is brilliant (pun not intended) at shining in car drivers' rear view mirrors, not only is a dazzled driver an annoyed driver, he or she cannot judge the bike's distance accurately.

Many British motorcycle riders now in their sixties and seventies will have been city dispatch riders in their teens, twenties and possibly thirties. Based on first hand experience, the previous two paragraphs and not just on my old Triumphs (I do not own any modern bike), I use quartz halogen headlamp bulbs just for nightime riding in the dark, quartz halogen or 15W Eagle Eye LED pilot bulbs for nighttime riding under streetlights, daytime visibility to other road users. Powerful pilot bulb spreads light in a wide arc in front of the bike, good visibility to other road users without dazzling them, uses very little power, useful if low rpm (low alternator output) riding is required for any length of time.

The bike is currently sitting about 460 miles away
I want to change all the lights including tail and flashers
Afaik, CDRC does not sell a specific tail/brake LED replacement bulb that will work in the standard Lucas 73 onwards rear lamp. When you actually have the bike and can remove the rear lens, you will see the primary problem is the bulb holder holds the bulb vertically, not a problem with an incandescent but, because LED replacements are a mixture of red and white LED and individual LED are directional, one of Pete's LED replacements will emit fairly feeble light rearwards (because the white LED are intended to light the numberplate) while the numberplate will be lit brightly ... in red ...

LED replacement bulb that will work correctly in your bike's rear light.

If the bike is to be ridden lights on in daylight irrespective of ambient light, the primary purpose of replacing the rear incandescent with LED should be greater contrast between tail (always on) and brake, to reduce the chances of being rear ended, especially in bright sunlight - a CRDC "light board" that replaces bulb holder and reflector might be better than just a bulb replacement?

Similarly, replacing incandescent speedo and tacho bulbs with LED should be to improve the visibility of the faces at night (you will not know their standard lighting is poor). However, due to the design of the speedo and tacho, white might end up dazzling you by the time the single LED lights each face well, consider red LED which will less affect your ability to see in the dark. :(

Ime, converting indicators to LED is more trouble than it is worth. The visibility is not improved, the power saving is negligible, the cost is ridiculous, especially as a new relay is also required, the warning bulb in the headlamp shell must be rewired. (n)
 
As has already been said. The only way to do it properly is to replace the headlight unit completely. I have a LED unit in my 2001 Ducati. Daytime it looks great with a crisp white light. At night, because of the incompatibility between the reflector designed for a halogen bulb and the now installed LED unit, it’s hopeless, not only is the beam not focussed but I found very little difference between dipped and main beam.
 
Thanks Rudie and Bloodknot, plenty of good advice there. My primary aim is improved visibility in daylight but I can't rule out the occasional need for riding after dark on longer trips especially during the colder months when the days are shorter.

A primary reason for considering LEDs is to get decent lighting with the meagre output of the standard alternator. I am no stranger to alternator upgrades, for example I fitted an RD350 alternator to my XS650 using an adaptor plate and built a new custom wiring harness for the entire bike using correct Japanese bullets and multi-pin plugs and what a difference this made. With this bike I thought I would explore if advances in LED technology could be the solution so the issues you have highlighted are very useful.

Another factor I need to consider is reliability of LEDs especially when subjected to vibration, I have had several LED pilots fail in the past although LED indicators haven't been a problem. But some halogen H4 headlight bulbs have also been less than robust. Osram Nightbreakers have been the best I have tried in this respect.
 
Thanks Rudie and Bloodknot, plenty of good advice there. My primary aim is improved visibility in daylight but I can't rule out the occasional need for riding after dark on longer trips especially during the colder months when the days are shorter.

A primary reason for considering LEDs is to get decent lighting with the meagre output of the standard alternator. I am no stranger to alternator upgrades, for example I fitted an RD350 alternator to my XS650 using an adaptor plate and built a new custom wiring harness for the entire bike using correct Japanese bullets and multi-pin plugs and what a difference this made. With this bike I thought I would explore if advances in LED technology could be the solution so the issues you have highlighted are very useful.

Another factor I need to consider is reliability of LEDs especially when subjected to vibration, I have had several LED pilots fail in the past although LED indicators haven't been a problem. But some halogen H4 headlight bulbs have also been less than robust. Osram Nightbreakers have been the best I have tried in this respect.

My youngest son fitted a LED light to his 865 Thruxton and it works a treat. I believe he kept the shell and just replaced the innards.
 
I am in the final stages of negotiating a deal for a really nice 1973 Tiger 750 which is not only very clean but has some nice touches such as twin disks, belt primary, electronic ignition and a modern regulator. I plan to use this regularly (alongside my Tiger 800 XRX) rather than let it be a garage queen and would like to tweak it to give a classic riding experience but with some modern convenience.

My first thought is to do something about the lighting to let me reliably run with the lights on all the time. My first thoughts are to fit LEDs with their lower power consumption, either by converting to negative earth or using bulbs which are designed to have a positive earth. I have seen suppliers selling positive earth LED bulbs for the classic market but wondered if anyone has experience of these in terms of reliability (vibration resistance) and light output.

Plan B could be a higher output alternator to get more power for a high wattage halogen headlight but this would rob some power from the engine and seems a less elegant solution.
View attachment 52871
Doesn't adding another disc also add about thirty pounds to the bike? That's s'posed to be funny, hear?
That aside, my '78 bonneville is all stock factory electrics with the exception of a halogen headlight bulb that I stuck in there, which is plenty bright and the alternator has NO problem running it and anything else the bike requires. I don't understand why I hear so much talk about needing mo-powuh than that which the alternator can produce. Is it the bulb I used, or is it just that MY Bonneville is so special, er whut?

By the way, who doesn't want one of these:
 

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  • Triumph-Quadrant-1.jpg
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Doesn't adding another disc also add about thirty pounds to the bike? That's s'posed to be funny, hear?
That aside, my '78 bonneville is all stock factory electrics with the exception of a halogen headlight bulb that I stuck in there, which is plenty bright and the alternator has NO problem running it and anything else the bike requires. I don't understand why I hear so much talk about needing mo-powuh than that which the alternator can produce. Is it the bulb I used, or is it just that MY Bonneville is so special, er whut?

By the way, who doesn't want one of these:

Yep, why do you need more power when you’ve got enough already? My 61 pre-unit Tbird has a Lucas RM14 alternator which, depending how the pairs of coils are connected on the stator, will only give a max of 10 amps at 5,000 rpm.

Back in the 60s I converted it to 12 volt and ran a 55W halogen bulb quite happily and did a lot of night riding. Also, using the 2MC capacitor ignition system enabled me to run the bike without a battery. I also completely rewired the machine to negative earth which is surprisingly easy to do.

By converting to LED light sources you are significantly reducing power demanded by the lighting system, so why even consider increasing output?

As for the Quadrant very nice. If you haven’t already come across him search for Allen Millyard on YouTube who specialises in extending engines such as 4 into 6 or 1 into V twin. All done in a single car size workshop. The man is a genius.
 
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Doesn't adding another disc also add about thirty pounds to the bike?
If the steel calipers are used. If the aluminium alloy calipers are used, no. Plus even the standard discs can be lightened. Ime, even if a second steel caliper is fitted, the suspension is not sophisticated enough most riders would notice.

my '78 bonneville is all stock factory electrics with the exception of a halogen headlight bulb that I stuck in there, which is plenty bright and the alternator has NO problem running it and anything else the bike requires. I don't understand why I hear so much talk about needing mo-powuh
A 78 Bonneville with "all stock factory electrics" should have a headlight lens/reflector that takes a P45t bulb base. This was then the international automotive standard, the Lucas version is excellent, in stark contrast to the awful BPF.

The P45t had been the international standard since 1969, Triumph and BSA fitted them to European continental versions from some time in 1972; quite why Triumph and Lucas continued to inflict the appalling BPF on the rest of the world until about mid-1977 is a mystery. :mad: That is why I have suggested the OP waits until he has the bike before deciding anything about lighting - a 1973 originally had a BPF headlight as standard but the bike could have a replacement headlight with P45t or P43t bulb base. P45t base LED bulbs are another can of worms ...

The RM21 alternator - standard on Triumphs between 69 and 78 - balances output to requirements (ignition, lights including original 40W dip and some for battery charging) at about 3,000 rpm; if the bike can be ridden at that rpm or above most of the time, great.

However, I have been riding long enough to have needed to ride across London in the Friday evening rush hour before the M25 was built. Enforced low rpm riding for a long time, a RM21 could not supply ignition and lights including the headlight, luckily I discovered 20W quartz halogen pilot bulbs about the same time I started needing to ride across London in the Friday evening rush hour.

Also, if the alternators that particularly Triumph and BSA fitted as standard had been adequate under all conditions, why would Lucas have made more powerful ones - single-phase RM20 alongside the RM19, single-phase RM23 alongside the RM21, 3-phase from 1978, low and high output versions of the latter? If the RM21's output was really adequate under all conditions, why would contemporary motorcycle makers from other countries have been fitting more powerful alternators?

Forty-odd years ago, I had triples, I found any single headlamp with even a 60/55 quartz halogen bulb to be inadequate at the speeds a triple and youthful bravado were capable of maintaining. The contemporary motorcycles from other countries could run more powerful lights without problems, a British triple fitted with the high output Lucas RM24 3 phase can too.

By converting to LED light sources you are significantly reducing power demanded by the lighting system, so why even consider increasing output?
See previous paragraph. Also:-
I have a LED unit in my 2001 Ducati.
At night, because of the incompatibility between the reflector designed for a halogen bulb and the now installed LED unit, it’s hopeless, not only is the beam not focussed but I found very little difference between dipped and main beam.
... as I posted earlier, same with the BPF LED bulb.

Bike like the OP's Tiger, the LED only 'solution' - if it can be called that - is to fit a complete modern LED headlight in the original shell. Potential problems to be overcome:-

. There are no positive earth complete LED headlights; it is not necessary to change complete positive earth electrics to negative earth but the selected LED headlight must not earth through its mounting and the fitter must be comfortable with both the principle of the necessary wiring changes and be able to accomplish them practically (and neatly?) on Lucas electrics.

. The selected LED headlight must be able to fit with the lighting switch, warning lights and standard wiring already in a 78 Lucas/Triumph headlight shell.

. The bike's owner must not mind the front of the bike looking like something from the final scenes of Terminator films ...

I am not saying fitting a more powerful alternator is the only solution to better lighting on a British bike. However, I am saying that is what I have done to all my Triumphs and several others in the past forty-odd years, I have never had cause to regret it nor afaik has anyone else I've done it for. Nor have I had any quartz halogen headlamp bulb fail.

Quadrant very nice. If you haven’t already come across him search for Allen Millyard
The first "Quadrent" - because the engines are made from Trident parts - was made by staff at NVT Engineering (the Meriden Experimental Department before the sit-in) in about 1974, it is in the National Motorcycle Museum.

Although Allen Millyard is excessively talented, the Quadrent in the photo was made by George Pooley around fifteen-twenty years ago.
 
When did Meriden machines change to negative earth?
 
When did Meriden machines change to negative earth?
Essentially 79 although the last batch of US-only 78 T140E had the same electrics and negative earth,

I have been told very early (pre-WW2?) were also negative earth but no experience.
 
If the steel calipers are used. If the aluminium alloy calipers are used, no. Plus even the standard discs can be lightened. Ime, even if a second steel caliper is fitted, the suspension is not sophisticated enough most riders would notice.


A 78 Bonneville with "all stock factory electrics" should have a headlight lens/reflector that takes a P45t bulb base. This was then the international automotive standard, the Lucas version is excellent, in stark contrast to the awful BPF.

The P45t had been the international standard since 1969, Triumph and BSA fitted them to European continental versions from some time in 1972; quite why Triumph and Lucas continued to inflict the appalling BPF on the rest of the world until about mid-1977 is a mystery. :mad: That is why I have suggested the OP waits until he has the bike before deciding anything about lighting - a 1973 originally had a BPF headlight as standard but the bike could have a replacement headlight with P45t or P43t bulb base. P45t base LED bulbs are another can of worms ...

The RM21 alternator - standard on Triumphs between 69 and 78 - balances output to requirements (ignition, lights including original 40W dip and some for battery charging) at about 3,000 rpm; if the bike can be ridden at that rpm or above most of the time, great.

However, I have been riding long enough to have needed to ride across London in the Friday evening rush hour before the M25 was built. Enforced low rpm riding for a long time, a RM21 could not supply ignition and lights including the headlight, luckily I discovered 20W quartz halogen pilot bulbs about the same time I started needing to ride across London in the Friday evening rush hour.

Also, if the alternators that particularly Triumph and BSA fitted as standard had been adequate under all conditions, why would Lucas have made more powerful ones - single-phase RM20 alongside the RM19, single-phase RM23 alongside the RM21, 3-phase from 1978, low and high output versions of the latter? If the RM21's output was really adequate under all conditions, why would contemporary motorcycle makers from other countries have been fitting more powerful alternators?

Forty-odd years ago, I had triples, I found any single headlamp with even a 60/55 quartz halogen bulb to be inadequate at the speeds a triple and youthful bravado were capable of maintaining. The contemporary motorcycles from other countries could run more powerful lights without problems, a British triple fitted with the high output Lucas RM24 3 phase can too.


See previous paragraph. Also:-

... as I posted earlier, same with the BPF LED bulb.

Bike like the OP's Tiger, the LED only 'solution' - if it can be called that - is to fit a complete modern LED headlight in the original shell. Potential problems to be overcome:-

. There are no positive earth complete LED headlights; it is not necessary to change complete positive earth electrics to negative earth but the selected LED headlight must not earth through its mounting and the fitter must be comfortable with both the principle of the necessary wiring changes and be able to accomplish them practically (and neatly?) on Lucas electrics.

. The selected LED headlight must be able to fit with the lighting switch, warning lights and standard wiring already in a 78 Lucas/Triumph headlight shell.

. The bike's owner must not mind the front of the bike looking like something from the final scenes of Terminator films ...

I am not saying fitting a more powerful alternator is the only solution to better lighting on a British bike. However, I am saying that is what I have done to all my Triumphs and several others in the past forty-odd years, I have never had cause to regret it nor afaik has anyone else I've done it for. Nor have I had any quartz halogen headlamp bulb fail.


The first "Quadrent" - because the engines are made from Trident parts - was made by staff at NVT Engineering (the Meriden Experimental Department before the sit-in) in about 1974, it is in the National Motorcycle Museum.

Although Allen Millyard is excessively talented, the Quadrent in the photo was made by George Pooley around fifteen-twenty years ago.
"A 78 Bonneville with "all stock factory electrics" should have a headlight lens/reflector that takes a P45t bulb base. This was then the international automotive standard, the Lucas version is excellent, in stark contrast to the awful BPF."

Yes. Mine came with that big round P45t lamp, I believe it is a 40/45 watt bulb (which I still have in a box). The lamp I have in there now is a 60/55 . . . plenty o' powuh if I keep my speed below ninety mph at night . . . as I recall . . .
 
i find tbe original BPF headlights completely adequate for pushing my motorcycle around in a darkened garage.
 
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If you gents were to use your motorcycles in the way they were intended to be used this discussion would not be necessary. I refer to the author’s closing comment.

A Treatise on the Importance of Smoke by Joseph Lucas

Positive ground depends on proper circuit functioning, which is the transmission of negative ions by retention of the visible spectral manifestation known as "smoke". Smoke is the thing that makes electrical circuits work. We know this to be true because every time one lets the smoke out of an electrical circuit, it stops working. This can be verified repeatedly through empirical testing. For example, if one places a copper bar across the terminals of a battery, prodigious quantities of smoke are liberated and the battery shortly ceases to function. In addition, if one observes smoke escaping from an electrical component such as a Lucas voltage regulator, it will also be observed that the component no longer functions. The logic is elementary and inescapable!

The function of the wiring harness is to conduct the smoke from one device to another. When the wiring springs a leak and lets all the smoke out of the system, nothing works afterward.

Starter motors were considered unsuitable for British motorcycles for some time largely because they consumed large quantities of
smoke, requiring very unsightly large wires.

It has been reported that Lucas electrical components are possibly more prone to electrical leakage than their Bosch, Japanese or American counterparts. Experts point out that this is because Lucas is British, and all things British leak. British engines leak oil, British shock absorbers, hydraulic forks and disk brake systems leak fluid, British tires leak air and British Intelligence leaks national defence secrets. Therefore, it follows that British electrical systems must leak smoke. Once again, the logic is clear and inescapable.

In conclusion, the basic concept of transmission of electrical energy in the form of smoke provides a logical explanation of the mysteries of electrical components - especially British units manufactured by Joseph Lucas, Ltd.

"A gentleman does not motor about after dark."

Joseph Lucas (1842 - 1903)


1662052885190.jpeg
 
I am in the final stages of negotiating a deal for a really nice 1973 Tiger 750 which is not only very clean but has some nice touches such as twin disks, belt primary, electronic ignition and a modern regulator. I plan to use this regularly (alongside my Tiger 800 XRX) rather than let it be a garage queen and would like to tweak it to give a classic riding experience but with some modern convenience.

My first thought is to do something about the lighting to let me reliably run with the lights on all the time. My first thoughts are to fit LEDs with their lower power consumption, either by converting to negative earth or using bulbs which are designed to have a positive earth. I have seen suppliers selling positive earth LED bulbs for the classic market but wondered if anyone has experience of these in terms of reliability (vibration resistance) and light output.

Plan B could be a higher output alternator to get more power for a high wattage halogen headlight but this would rob some power from the engine and seems a less elegant solution.
View attachment 52871
Hi Cheshire classic bikes do a pos earth LED If I remember correctly it is circa £27.00. Mine seems OK but I only fitted it last month so can't really comment on reliability . BTW that Tiger is a cracker!
 
Hi Cheshire classic bikes do a pos earth LED If I remember correctly it is circa £27.00. Mine seems OK but I only fitted it last month so can't really comment on reliability . BTW that Tiger is a cracker!
Thanks, I'll have a look at that. Paul Goff also has some interesting LED lighting, including an LED board which he says works in the Triumph tail light.
 
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