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Is a Trident always going to be a fuel guzzler ? #751527 10/04/18 6:34 pm
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I've got a T150V (1974) sitting on the back burner as it were.
In a thousand pieces at the moment.
I keep getting asked why I don't press ahead with the Trident instead of wasting my time with my A65T, or my T140V.
Well my answer is that at the moment, all out performance isn't a top priority (if it was I'd be riding some modern plastic thing) and that I'd rather build something that I can go touring on, with reasonable performance coupled with good fuel economy.
A large capacity single carb twin would seem to fit the bill.
So I'm just wondering if the Trident deserves its poor reputation as a fuel guzzler (I bought mine as a basket case, I've never actually riden it yet)
I've heard claims of milage as low as 20mpg when used hard.
I know that the accent was on performance at the time they were made.
BSA/Triumph needed to be seen to be keeping up in the superbike race and all that.
But I've had '70's bikes with a similar performance, (Japanese I admit) and fuel consumption was in the mid 40's.
Is there any particular reason that the triples have such a heavy thirst, and can anything be done about it ?

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Re: Is a Trident always going to be a fuel guzzler ? [Re: ferretjuggler] #751538 10/04/18 8:19 pm
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I'd agree that a single carb large (relatively by today's standard) twin, such as a TR7 or late A65T would be a good choice for long distance touring. I also have a T150 in 1000 pieces (and a T160 almost ready to go). I like the idea of touring France on one of the Tridents, but the fuel consumption issue also bothers me.

I had a T160 many years ago, which I built from a 1000 pieces basket case. It performed very well, and I don;t think the fuel consumption was anything like as bad as I'd feared, from the stories I'd heard. I can't honestly remember what it managed, but I reckon t wasn't less than 40mpg, or it would have annoyed me and I'd probably have remembered it! It certainly wasn't anything near 20mpg or even 30.

Last edited by Tigernuts; 10/04/18 8:20 pm.

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Re: Is a Trident always going to be a fuel guzzler ? [Re: ferretjuggler] #751540 10/04/18 9:03 pm
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It's odd that when I ride with friends, I get superb fuel economy. When I ride by myself, it sucks royally.

I'm not sure what that means. It's possible that my friends are just old coots. I am too, but I'm still twisting the throttle too much?

The difference is 32mpg vs. 55mpg. That's on my Honda. The Commando is similar. The Triumph just doesn't care what I do with the throttle. It gets a zillion miles to the gallon......

It just doesn't make much power is all so I ride it in a much more conservative way.

Cheers,
Bill



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Re: Is a Trident always going to be a fuel guzzler ? [Re: ferretjuggler] #751546 10/04/18 9:52 pm
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Step #1 would be to renew the needle jets. They wear out...

Re: Is a Trident always going to be a fuel guzzler ? [Re: ferretjuggler] #751554 10/04/18 10:32 pm
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Tridents don't have the low-end torque of twins, but get their power at higher RPM,
And higher RPM usually means higher gas consumption.

Re: Is a Trident always going to be a fuel guzzler ? [Re: ferretjuggler] #751560 10/04/18 11:23 pm
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Obviously if you twist its neck at every opportunity you are going to get gas consumption in the high 20s/30s (US gallons).
But ridden more soberly on a tour you should get in the 40s in terms of gas consumption.
But from your profile you live in England --so--using petrol you should get in the low 50s per Imperial gallon.
All this assumes that the bike is in good fettle.
Carb floats set right, new needle jets and needles, all three carbs asynchronized together etc etc and that the bike is otherwise in fine fettle---ignition timing, tappets, brakes etc all adjusted OK.
HTH

Re: Is a Trident always going to be a fuel guzzler ? [Re: ferretjuggler] #751569 10/05/18 1:59 am
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I ride my Brit bikes for the enjoyment. Care less about mileage cus I don’t mormaly ride them that far. For touring I have a Aprilia future. Gets the job done. To scare myself a 72 h2 or a 04 Aprilia rsv factory r . If I go that far. It’s in the car. Too old to beat myself up on long distance touring.

Re: Is a Trident always going to be a fuel guzzler ? [Re: ferretjuggler] #751571 10/05/18 2:24 am
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It's amazing what people will ride around for a state of tune and think its' normal. Especially considering a bike might be 50 years old, there can be a lot of accumulated problems added by multiple previous owners. Step by step, get the basics right.

Re: Is a Trident always going to be a fuel guzzler ? [Re: ferretjuggler] #751572 10/05/18 2:26 am
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As long as it uses more gas than oil you got a good one.

Last edited by htown; 10/05/18 2:35 am.

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1971 Norton Commando
1972 Norton Commando
1973 Norton Commando
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Re: Is a Trident always going to be a fuel guzzler ? [Re: ferretjuggler] #751585 10/05/18 6:53 am
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I get up to 60/50 mpg (imp/us) on my 72 Trident riding with my wife, and down to 47/39 solo outside of the motorways. Not bad at all for any biggish bike. In fact it used less than my wife's 2009 Hinckley Bonnie. Her 2016 Street Twin returns something like 76/63 though. Nice.
My 900 Daytona gives around 47/39 mpg average and is thirstier than the old Trident. New needle jets in the Mikunis every now and then is imperative, just as with Amals.

Side note; my 71 Bonnie ran almost as cheap as the Street Twin and my old T110 used even less, where's the progress?

Re: Is a Trident always going to be a fuel guzzler ? [Re: Irish Swede] #751597 10/05/18 9:02 am
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Originally Posted by Irish Swede
Tridents don't have the low-end torque of twins, but get their power at higher RPM,
And higher RPM usually means higher gas consumption.


That's true, but they've still got a fair amount more low-end torque than Japanese bikes from the era, and they can be ridden at low-ish engine speeds quite happily.


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Re: Is a Trident always going to be a fuel guzzler ? [Re: ferretjuggler] #751628 10/05/18 3:44 pm
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Which I do most of the time.
You can ride reasonably fast on secondary roads keeping it with traffic on fifth gear around 100 kph and 3500-4000 rpm. with my gearing ( 20 / 53 ).
Engine just hums happily and effortlessly with this speed and I'm in low 50 mpg with fuel consumption during those times.
I also don't feel any problems with lack of low end torque with 5 speed gearbox and pretty open 3 in 1 Jardine exhaust system.
4 speed, high geared home market Tridents from 69 - 71 gave this feeling.
However it is difficult not to "ring it's neck" from time to time, getting revs to 7000-8000 on lower gears and feel the "flying sensation" from it, you can be sure your fuel consumption
goes to heel as soon as you hear it howl smile
All together much worse than my little flying brick which is fuel injected and water cooled, I believe around 1.5 more for every 100 km.
I still think is worth it.

Last edited by Adam M.; 10/05/18 3:46 pm.
Re: Is a Trident always going to be a fuel guzzler ? [Re: ferretjuggler] #751633 10/05/18 4:28 pm
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My buddy Don likes Tridents, owns 4 of them. I have ridden three of his.
It's pretty hard to NOT "twist the throttle" too much as quick and smooth as they run!

But he has traveled all over the eastern USA on them, and has never complained about gas mileage with any of them.

But remember: too low on the RPM risks "lugging" the engine, and that destroys lower end bearings.

Re: Is a Trident always going to be a fuel guzzler ? [Re: ferretjuggler] #751663 10/05/18 7:29 pm
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Hi Ferretjuggler, Interesting subject of mileage. We kick this around all the time. I'm currently observing MPG closely tuning my new carb. I've made a good baseline so I can see changes in mileage with carb mixture changes.

Does mileage matter? If you ride long distances with few fuel stations it's huge.


I ride with a few BSA triples, Tiger 650, & 650& 750 Bonnies, a few 500 twins duel & single carbs. Interestingly riding in safe & sane manner they get pretty much similar mileage. About 40-45 mpg. Speeds above 65mph, hills & especially headwind can push that down to 30-35 in a hurry. This is with California fuel which is less efficient that many US states fuel is. My car will reliably get 2-3 more mpg in Arizona. Very interesting.... My riding partner has '69 Bonnie. We compare mileage often. Very close indeed even over 200 mile ride.

When my carb was too lean I was getting 60-70 mpg, plugs were white & blistered. Ping was so bad as to be un rideable. But back in 70s was fine running no ping... Plugs did not show lean or blistered back in 70s. I still have every plug I've used in bike from new.


You are not wasting time on the twins. Spending time is more correct.... Wasting is my wife's thoughts, ours is spending! Maybe spending time on triple is something that is soon coming?


Triples I ride with seem to be able to pull steep hills & maintain speed better in strong head winds. They prove trouble free on the group rides which are 100-600 miles long. Start & run well, but the owners are good mechanics & keep them well maintained. I've always wanted one. I've only sat on one at idle & rev'ed motor at a standstill. I don't know owners well enough to swap bikes... So my experience is only observation & speaking with owners.
Don


1973 Tiger 750
Re: Is a Trident always going to be a fuel guzzler ? [Re: ferretjuggler] #751668 10/05/18 8:10 pm
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Hi,

Originally Posted by ferretjuggler
I've got a T150V (1974)
I keep getting asked why I don't press ahead with the Trident instead of wasting my time with my A65T, or my T140V.
at the moment, all out performance isn't a top priority (if it was I'd be riding some modern plastic thing) and that I'd rather build something that I can go touring on, with reasonable performance coupled with good fuel economy.
A large capacity single carb twin would seem to fit the bill.

Seems to depend on your definition of "touring"?

I've owned at least one triple for over forty years, I've toured GB and Europe several times on 'em two-up. Having ridden 650 and 750 Triumph twins, and ridden in both GB and Europe with people riding them, there is no way on God's green earth I'd want to do my type of 'touring' on one. Cue howls of protest from 650 and 750 twin owners but, ime, at speeds a triple can keep up for days and hundreds of miles on end, 650 and 750 twins start to fall apart; speeds one of those twins can keep up for days and hundreds of miles on end without falling apart are simply not my definition of "reasonable performance".

Originally Posted by ferretjuggler
So I'm just wondering if the Trident deserves its poor reputation as a fuel guzzler (I bought mine as a basket case, I've never actually riden it yet)
I've heard claims of milage as low as 20mpg when used hard.
I've had '70's bikes with a similar performance, (Japanese I admit) and fuel consumption was in the mid 40's.
Is there any particular reason that the triples have such a heavy thirst,

First thing to do is stop reading and listening to reports on triples by Hans Christian Andersen and the Brothers Grimm. Nothing in this thread or Forum suggests you've posted in the right place. As you're in GB, the person you should talk with is Richard Darby at 3D Motorcycles in Wolverhampton - he is "darbs" on Triples On Line or he/3D has a Faceache page. Last time I saw his T150 (some years ago), it'd covered over a quarter of a million miles; he and a small group of other high-mileage triple owners would think their triples' main jets had dropped out if they only got 40 mpg.

Hth.

Regards,

Re: Is a Trident always going to be a fuel guzzler ? [Re: ferretjuggler] #751674 10/05/18 9:08 pm
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My triple has a bit over 100,00 miles on it. It has been rebuilt a couple of times. For most of that time it has had big bore kits. First an old Routts 867 kit over bored to 880, and then a Hyde big bore kit. The worst mileage was with the stock displacement, however I was young and dumb and inexperienced then. Screaming the bike could result in mileage in the high 20's. Mileage significantly improved with the Routts kit. As I progressed from an ignorant truly awful mechanic to just a bad one, and maintenance on the bike and its condition improved, mileage with a heavy throttle rose to mid to high thirties. A moderate throttle hand would return mid to low fifties (U.S. gallons). When the Routts kit finally pulled the studs out of the barrels, I went to the Hyde 830 kit. With a moderate throttle hand mileage has dropped to high forties. The bike is in good shape. I ascribe the differences to the following:
1) I think the stock cam and carb were suited for the big bore Triumph was planning on coming out with;
2) The Routts kit had flattop pistons, didn't change the jetting at all; and
3) The Hyde kit uses Bonneville pistons with a large bump on the top that blocks flow. Had to rejet it quite a bit higher to get it to run right;
4) Ed V ported my head, now I am running 200 main jets.
Last thought-with a big bore kit, the Trident torques up like a twin on steroids, I will never get rid of mine.

Ed from NJ

Re: Is a Trident always going to be a fuel guzzler ? [Re: ferretjuggler] #751695 10/06/18 2:40 am
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Stuart,
Can you please quantify YOUR sort of touring, and the mpg resulting? It would be more helpful than generalist comment.

I assume that YOUR sort of touring must be done at continuous high speed. Is that so as to keep face with the other competitors, because the scenery is boring, to avoid the locals, or maybe the last man buys the drinks?

MY sort of touring takes in the country I'm travelling through, stopping as and when something of interest appears, not having pre-arranged hotel rooms but sort it out on the fly. Perhaps as a larger group this isn't so easy, but we always carry a tent etc so we cope. Also, the mere interaction with the locals to find a place often produces great reward.

If you prefer to shoot through a country at breakneck speed, all good, though it seems pointless to me. To avoid motorways and do 40, 50 60 mph is my bag.
My 650 twin will do this effortlessly returning 67 mpg (it was 75 mpg before changing to alloy float needles, but it did run hotter and pink).
At a steady 70 mph for 2 hours it returned 55 mpg.

I'm not sure at which point these twins start to fall apart. What I have observed is that my beautifully oil tight motor had oil sweating from the cylinder gasket after that ride. I fully understand what you are saying, regarding putting up with vibes, and I wouldn't want to use more than 80 mph continuously on mine over a long period. I am sure the engine wouldn't fall apart, it would just be getting more tiring for the occupants.

I reckon a well built twin would stay at max rpm for hours, if the rider was made of the right stuff, this has been shown in racing over the years. They seem to thrive on high rev use, as long as they're set up right.Chuggem and fckem.

It's always noteworthy when a triple does a long distance event, say 4000 miles or whatever. How many miles can one cover between centre main bearing attention?

Re: Is a Trident always going to be a fuel guzzler ? [Re: koan58] #751717 10/06/18 10:02 am
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Oo-er, you're opening up a can of worms here! But I agree with you. I returned last week from the 4th consecutive annual tour of France on my TR7. 2223 miles in total, over half of it on autoroutes, the rest on 80km/h limit D roads and tiny, hairpinny mountain roads. Similar over the previous 3 years but different routes (always starting at Dieppe and most southerly point being the eastern Pyrenees, mileage always 2000+ except the 1st tour). Nothing has ever broken or fallen off. Total faults over 4 years have been a broken clutch cable (last year), a headlight bulb out the year before, and a failure of the Trispark ignition system the year before that (which cut the tour short). Nothing whatsoever to report this time.

I kept every fuel receipt and noted the miles covered between each fill-up this time, so I could calculate fuel consumption. Worst was 51.1mpg, best was 73.8mpg. Average was 62mpg. On Autoroutes I stick at between 80 and 85mph. This can be for 150 miles at a stretch. The engine is at its sweetest between 4200 and 4500 and in top, this is the speed range it equates to. The only issue I complain about is the oil consumption, which has improved slightly, with only 2 litres consumed (I take top-up oil with me rather than risk not finding the right type).

Over the past 4 years all I've done to the bike is change the Trispark ignition system (twice, under guarantee - I'll never buy another). Change the oil & filters; check cylinder base & head fasteners and check & re-set valve clearances, and fit a new primary drive belt (only because of scare stories about them falling apart after a few years - the old one actually seemed fine). Also, a couple of rear chains and a couple of rear tyres. No oil leaks apart from very slight weeping from a rocker spindle (cured by external silicone application!). Vibration is very low - no worse than a typical Japanese four from the same era, except for a patch between 3000 and 3500, during which it is about as bad as a big Guzzi.

A well built twin is capable of almost any kind of touring. Stuart and/or his friends must have been unlucky or just not very good at building them well.

Having said all this, I'd love to do next year's tour de France on the T160, and I might, if it seems up to it once I've got it going and tested it,

Last edited by Tigernuts; 10/06/18 10:06 am.

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Re: Is a Trident always going to be a fuel guzzler ? [Re: Stuart] #751722 10/06/18 10:36 am
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Stuart ,
Although you are an electrics cognoscenti, I remember once you telling me ( via email) that you didn't build your engines. S o , who did build the 650 and 750 twins you had your experiences with ? It's a bit unfair to try and cruise something from a different epoch at performance levels that the later "developed and improved " replacement was intended to succeed ! Then decry the older design.
Within their parameters, the twins are , at least, adequate. But, of course, any machine that can compensate for the inadequacies of its rider will be hailed as a paragon !

Re: Is a Trident always going to be a fuel guzzler ? [Re: Tigernuts] #751726 10/06/18 12:01 pm
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Originally Posted by Tigernuts


I kept every fuel receipt and noted the miles covered between each fill-up this time, so I could calculate fuel consumption. Worst was 51.1mpg, best was 73.8mpg. Average was 62mpg. On Autoroutes I stick at between 80 and 85mph. This can be for 150 miles at a stretch. The engine is at its sweetest between 4200 and 4500 and in top, this is the speed range it equates to. The only issue I complain about is the oil consumption, which has improved slightly, with only 2 litres consumed (I take top-up oil with me rather than risk not finding the right type).

Over the past 4 years all I've done to the bike is change the Trispark ignition system (twice, under guarantee - I'll never buy another). Change the oil & filters; check cylinder base & head fasteners and check & re-set valve clearances, and fit a new primary drive belt (only because of scare stories about them falling apart after a few years - the old one actually seemed fine). Also, a couple of rear chains and a couple of rear tyres. No oil leaks apart from very slight weeping from a rocker spindle (cured by external silicone application!). Vibration is very low - no worse than a typical Japanese four from the same era, except for a patch between 3000 and 3500, during which it is about as bad as a big Guzzi.,


My experience riding many Triumph twins and Guzzi's at high speeds is quite different than your story.........On the fuel mileage, I had a T150 and it certainly used more fuel than a T120.. but here in America no one really talks much about bike fuel mileage ...


79 T140D, 96 900M Ducati ....On a bike you can out run the demons..
Re: Is a Trident always going to be a fuel guzzler ? [Re: ferretjuggler] #751732 10/06/18 12:59 pm
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had a new 1974 T150V was a beautiful machine ….it was fast handled well but fuel mileage was bad 30 mpg was average also when warmed up and idling at a stop it would smoke. A friend of mine purchase one form the same dealer about 3 months after me and his had the same issues. Traded in on a new TR7V Tiger in 1977 that was the a very smart move on my part.

Re: Is a Trident always going to be a fuel guzzler ? [Re: Triless] #751739 10/06/18 3:11 pm
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Hi,

Originally Posted by Triless
I remember once you telling me ( via email) that you didn't build your engines.

You're Lobby Lud and I claim my £5! wink

Of my triples, one T160 is as built at Small Heath, the other was rebuilt in the mid-1980's by Martin Russell (aka Rustler Racing - Martin is ex-BSA and, at the time, was recommended by Les Williams), T150 was built by a guy called Austin Pickering.

650 and 750 twins, no idea who built the engines; at most, I've ridden 'em for a couple of hours at a time, doing a swap with the owner. Based on these first-hand experiences, and on the second-hand experiences of riding with those owners, I've (almost) never wanted one (weakened for a short time for a very nice '69 TR6R, I might be persuaded weaken again by an unmolested Les Williams 'Buccaneer').

Originally Posted by Triless
It's a bit unfair to try and cruise something from a different epoch at performance levels that the later "developed and improved " replacement was intended to succeed ! Then decry the older design.

There is a basic misunderstanding of the OP's and my posts. The OP simply posted "touring ... with reasonable performance coupled with good fuel economy", he didn't define or elaborate on either "reasonable" or "good".

You can tour on anything - there has recently been a two-week, 3,000-mile cross-USA tour with bikes at least ninety years old ... 3000 miles in two weeks would be considered good going on a modern Gold Wing?

Aside, depending on what the OP meant by "good fuel economy", he might want to ponder on the difference between "Magnentoman's" mpg on a 90-year-old 500 single and the mpg posted by riders of half-century-younger Triumph 750 twins ...

But, at the speeds considered "reasonable" for 90+-year-old bikes, a standard 750 triple engine would be turning over at about 3,000 rpm. Possibly there are triple owners who ride long distances at those sort of speeds and rpm, I just don't know any.

Similarly, it wasn't me trying to cruise 650 and 750 twins with a bunch of triples, it was the 650 and 750 twin owners. Based on my experience, I wouldn't do it, just as I wouldn't automatically expect to cruise one of my triples with a bunch of modern plastic fantastics. So I'm not "decrying" a twin vs. a triple; as you posted, they're different designs from different epochs; as I posted, "ime, at speeds a triple can keep up for days and hundreds of miles on end, 650 and 750 twins start to fall apart; speeds one of those twins can keep up for days and hundreds of miles on end without falling apart are simply not my definition of "reasonable performance"".

To be clear, 20 mpg from a triple always pointed to a lack of understanding of something fundamental. As the OP's in GB, there are a number of acknowledged triple experts who can check and set all the fundamentals of his triple correctly; I've suggested one but some time spent reading the triple-dedicated internet forums would identify the others. Then it'll be the OP's opinion whether he considers the resulting performance "reasonable" and/or the fuel economy "good"? And whatever it is/they are, there will always be others with different criteria and opinions?

Hth.

Regards,

Re: Is a Trident always going to be a fuel guzzler ? [Re: ferretjuggler] #751761 10/06/18 7:08 pm
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HawaiianTiger Offline
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Stuart,
This has been precisely my take on it for decades. However, I once decided that I might just be able to do it. So I built a Triumph 650 specifically to run 70mph all day in comfort and reliability.
I managed it. 1500 miles in three or four days riding. No significant failures. Averaged 69 mpg. I took advantage of slipstreaming big rigs at 70, admittedly.

Comfort? Well that's really subjective. I was never so miserable in all my life. But mostly it was the boredom of droning down California highways, exhaustion from the noise, and of course being cold at certain times or blazing hot at others.

I never did it again on any bike. Not for me.

A great big stable bike like a Harley would actually be less stressful. But, that's all they're good for. Daily driving and twisty roads....forget it.

Cheers,
Bill


Last edited by HawaiianTiger; 10/06/18 7:10 pm.

Bikes
1974 Commando
1985 Honda Nighthawk 650
1957 Thunderbird/T110 "Black Tiger"
Antique Fans: Loads of Emersons (Two six wingers) plus gyros and orbiters.
Re: Is a Trident always going to be a fuel guzzler ? [Re: ferretjuggler] #751767 10/06/18 9:06 pm
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DMadigan Offline
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One reason these bikes get poor fuel mileage is the primitive ignition system. There is no vacuum retard (or advance) so the timing has to be retarded enough at all conditions to prevent knock (pinking). Even the primitive american cars of the era had vacuum retard in the mechanical ignitions to keep knock under control. Retard your ignition 5 degrees and see how much it affects your fuel mileage. The old analog ignitions do not have a "stop" like the mechanical and keep advancing with RPM so the curve has to be slow enough so prevent knock at all RPM.
Another is the ports, they are directly opposite each other. The A65 and T120/T140 twins have the ports angled so when the valve timing overlap has both intake and exhaust valves open the charge does not go straight across the chamber and out the exhaust. Except for the turn at the valve the triples ports are pointing right at each other and with the steep angle of the valves you can see straight through.

Re: Is a Trident always going to be a fuel guzzler ? [Re: ferretjuggler] #751919 10/08/18 10:53 am
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ferretjuggler Offline OP
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Thanks for all the input folks
I'm forming a clearer picture in my mind of the sort of thing to expect.
Not the fuel slurping monster of bar room tales, but rather entirely dependent on the way you ride the thing.
Of course you can always expect a free revving triple with three carbs to use more fuel than a single carb twin would.
But I take on board the fact that if you ride at twin cylinder type cruising speeds, the fuel consumption isn't radically worse .
Obviously if you like to go everywhere at 100mph then you're going to be filling up very frequently.




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