Commando motor in solid frame

The effect on the way your bike slows down from high speed when you back-off is interesting after you have fitted a fairing to it. Even your hands being outside the fairing must have an effect on your top speed. Of course a lot depends on how much torque your motor has got - often when you turn a two stroke into a head-wind, they feel as though they have stopped.

Dances with Shrapnel said:

The example cites a car, not a motorcycle,

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The 10 hp at 50/60 mph was where all the interest is.

Finally, we get some content/sense out of you, rather than abuse.
Do you know, we'd swear when things don't go your way, you turn into Mr Trump...

So, how does Jim measure how much hp his engine in a solid frame is putting out for that 100 mph at half throttle. ? Or any engine when motoring down the road, in fact...

Hey Shrapnel,
Is it possible that you can reserve the ad hominem attacks against rohan and others for PM's and simply state your views. I'm a relatively new member here but it seems to me that this type of banter belongs somewhere else.

Ed

Stick around for a while Ed and you will see the pattern is one of being so full of himself with snarky remarks only to be pointed out that he's spewing bogus information - remember Baghdad Bob? This thread is a good example where he makes a statement which is utterly incorrect, the correct information is stated and he goes on and on with confusion, and twisting in the wind to deflect. This will fade away and then come back like a Whack-O-Mole for another public mounting.

I've invited him in the past to PM or start a separate thread but apparently that is not what it is about. I have a low tolerance for Grand BS'ers.

I thought I was being rather civilized. Now I have been associated with Trump; my feelings are really hurt. :lol:

If you'd confine yourself to a useful technical discussion, we could cut the wordage here by 90%. (?)
And your technical input was mostly to suggest the hp/mph figures I quoted were wrong !

And, would we say that that wiki page is well explained and perfectly clear to read ?
Needs a good editor, who can explain in plain english what should be quite an easy subject....

This started out to be a good thread on hard mounted Commando's into Featherbed frames or any other frame for that matter, but as usaual things change pretty quickly and then turns into a shit fight who cares about the sicence of how things go all I know is I have had a love affair with Commando set up in Featherbed frames for most of my life well since I was 17 anyway, I built mine up with limit knowlege at the time, built up with a limit budget and making things with my own 2 hands with limited machines to do the job and over the 35 years of building my Commando/Featherbed it has gone through a lot of changes in that time but the handling and lightness of this bike has not changed, its still my faviorite bike to ride and to push it to its limits excites me everytime I ride it, the harder I push it through the corners the better it handles and with moden tyres makes it even more fun, so get back on topic, if you want to argue go else where before this topic gets locked, we all have our own opinions but no need to get nasty in trying to to push your own opinions and take offence when someone disagress with your opinion, well I have had my say now let get back on the subject, where all meant to be friends here.

Ashley

I remember seeing one in a magazine years ago and it was fantastic-looking. Profile and cosmetics of a Manx, but with the tilted Commando engine. Low clip-ons, exposed fork springs and a headlight mounted so high it could double as a flyscreen.

What about the Featherlastics? Do the rubber mounts detract from the handling?

Rohan said:

If you'd confine yourself to a useful technical discussion, we could cut the wordage here by 90%. (?)
And your technical input was mostly to suggest the hp/mph figures I quoted were wrong !

And, would we say that that wiki page is well explained and perfectly clear to read ?
Needs a good editor, who can explain in plain english what should be quite an easy subject....

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Useful technical discussion? You were corrected and then provided with a technical reference that backs up the correction, a reference which is consistent with other well know and well-respected references (ex. Phil Irving) and then you throw out assertions of commonly quoted numbers which just don't add up when you do the math and then confuse power requirements of a car with a motorcycle. Now you are throwing darts at the English in Wiki links. I suggest you forget the "wordage" and just stare at the pictures and try to muddle through the equations because therein lies the truth.

The next time when you do not understand, pm me and I will take the time.

What about the Featherlastics? Do the rubber mounts detract from the handling?[/quote]

You don't hear to much about them these days, my own opinion about them is once you try to make a Islastic Featherbed you be changing the whole purpose of the Featherbed frame they were designed to be hard mounted with solid mounts engine gearbox become part of the frame and of course part of the handling, by rubber mounting the engine in one will change the whole bike handling, but who knows as I have never rode one to compare to the way mine handles its so good I wouldn't even think about putting islastics mounts on it as I don't have any problems with vibrations at all.

Ashley

The twin-loop cradle of the Featherbed was copied and modified by every manufacturer for years until aluminum frames became the norm. Even the Commando frame mimics it with the large backbone substituting for the twin top tubes and the slant of the rear of the twin lower tubes eliminating the large radius. I don't know the exact specs of a Featherbed (tube size, wall thickness etc.) but I know the integrity of a motorcycle's handling depends upon the rigidity of the frame as it pertains to tying the swingarm pivot and the steering head together. The Commando frame appears less stout than a Featherbed at a glance. So how, with a larger, harder vibrating engine floating in rubber mounts, does it have any handling integrity at all compared to the 'bed? And how (other than with the lightened internals) can one of those larger engines be made to vibrate little enough to solid mount, when the whole purpose of the rubber mounts was to compensate for the shaking of the ever-larger displacement vertical twin?

I guess I would just have to ride one to believe the Featherbed/Commando combo is smooth enough to tolerate. My Commando shakes less than any other British vertical twin (360-degree) I've ridden, including 500cc Triumphs. I currently have the adjustable isos set a bit tight to help the stiffness, but I don't feel like I'd lose a lot of handling prowess by loosening them up for a bit more comfort. For me, the weak point has always been the too-flexible front fork.

Dances with Shrapnel said:

then you throw out assertions of commonly quoted numbers

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i PROVIDED commonly quoted numbers for motorcycles.
And questioned how they related to those quoted car numbers.
And YOU initially suggested the motorcycle numbers I contributed were wrong (!!).
Talk about confusion. Look in the mirror, Mr Trump.

By anyones standards, that Wiki page is not as well written nor clear as it could be.
I've helped clarify some other wiki pages - but its disheartening seeing idiots press the revert button...

So here is my version of a Commando motor solidly mounted in a frame. The chassis is a BSA A 10 frame. The adapter plates run the full length of the engine bay and fix the motor and trans into the frame. It was a shoehorn fit but this is lovely combination with terrific handling and that wonderful Norton torque. This engine is a 270 degree and yes the vibration is an issue at low RPM, the engine is happier as the revs increase. The level of vibration is not objectionable.

Thats gorgeous.

Must be the Norvil yellow color...

Danno said:

The twin-loop cradle of the Featherbed was copied and modified by every manufacturer for years?

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The frame guy that repaired a wideline here commented that every featherbed he's ever straightened had the 2 loops displaced to each other - there simply aren't enough (frametube) connection points between the 2 sides.

BTW, he builds frames to order, and in his Vincent engined beastie the engine simply slots in.
Try that with your factory featherbed....
Looking at it, you can't even see where its different, apart from the extra crossbrace tubes.

Rohan said:

Dances with Shrapnel said:

then you throw out assertions of commonly quoted numbers

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i PROVIDED commonly quoted numbers for motorcycles.
And questioned how they related to those quoted car numbers.
And YOU initially suggested the motorcycle numbers I contributed were wrong (!!).
Talk about confusion. Look in the mirror, Mr Trump.

By anyones standards, that Wiki page is not as well written nor clear as it could be.
I've helped clarify some other wiki pages - but its disheartening seeing idiots press the revert button...

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You clarifying wiki pages? - god help us

Your commonly quoted motorcycle numbers continue to not add up as they defy the laws of fluid dynamics. Plug in the numbers and you will see or are you disputing the laws of fluid dynamics?.

You were comparing (apparently) trying to reconcile motorcycle values to car values - totally crossed wires by comparing apples to Orangutans. Yes, talk about confused.

Dances with Shrapnel said:

You were comparing (apparently) trying to reconcile motorcycle values to car values - totally crossed wires by comparing apples to Orangutans. Yes, talk about confused.

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Since those 10 hp values were quoted, that was a perfectly valid question to ask.
And you 'clarified' it for the readership here by suggesting the oft quoted motorcycle numbers were 'wrong'. (!!).
Mmmm, helpful, very helpful.
Should have lead to a meaningful discussion about aero effects, and measuring applied hp on the road.
Your bull-in-the-china-shop-approach doesn't seem to recognise when the discussion is being steered in a particular direction....

Much of my wiki clarifications are still up, so folks in the know might disagree with your Mr Trump style hot air.
The discussions behind the text are often more revealing than the text itself.

BTW, when I first saw this title, thought it was going to be something more along these lines.

Apologies for the skewed pic, and not quite C'do content.
http://i.ebayimg.com/images/g/bOUAAOSwT ... -l1600.jpg

jseng1 said:

This is my personal favorite style of Norton. A super efficient Commando motor with the vibration reduced by 1/3, mounted in a solid frame and set up cafe style.

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Its Fairly TIDY , but HOW does it STOP . :evil: :?

Rohan said:

And you 'clarified' it for the readership here by suggesting the oft quoted motorcycle numbers were 'wrong'. (!!).
Mmmm, helpful, very helpful.

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For the benefit of the readers, I am not suggesting, I am stating they are wrong. Do the math. But this is not about understanding and enlightenment for you, right?

Rohan said:

Your bull-in-the-china-shop-approach doesn't seem to recognise when the discussion is being steered in a particular direction....

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No, not changing direction but another subterfuge of yours; when sh*t goes sideways for you, change the topic.

Rohan said:

Much of my wiki clarifications are still up, so folks in the know might disagree with your Mr Trump style hot air.

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yet

Rohan said:

but its disheartening seeing idiots press the revert button...

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Uh huh. I know a BS'er when I see one.

Whilst talking about getting the motor weight as far forward as possible, have a look at a good photograph on the side of a Manx Norton. Figure out where the crank centre line is, relative to any fixed points, wheel spindles, swinging arm spindle etc. Then have a look at a Triton with a unit motor and see where the crank centre line is, relative to the same fixed points.
The Manx crank is about as far forward and as low as possible, the triton maybe not...
cheers
wakeup