Commando motor in solid frame

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jseng1 said:
The bike below as Ken Canaga set it up when it got on the BOTT podium with Rob T riding.
Commando motor in solid frame
Rob Tuluie was one hell of a rider and builder. He exhibited some extraordinary building and riding at Daytona with the short stroke Rob built. If anyone is interested, read up on the Tularis. Rob has a Ph.D. in Engineering (Mechanical I think) and moved on to Formula 1 (Renault I recall).

As for your bike Jim, it is a neat build. One comment is that it looks like the motor is set fairly far back from the front wheel; it could be the angle of the photo. Do you recall the dry front/rear weight bias?
 
Dances with Shrapnel said:
Rob Tuluie was one hell of a rider and builder. He exhibited some extraordinary building and riding at Daytona with the short stroke Rob built. If anyone is interested, read up on the Tularis. Rob has a Ph.D. in Engineering (Mechanical I think) and moved on to Formula 1 (Renault I recall).

As for your bike Jim, it is a neat build. One comment is that it looks like the motor is set fairly far back from the front wheel; it could be the angle of the photo. Do you recall the dry front/rear weight bias?

Rob got his Ph.D. in Physics (Astrophysics, to be exact). He taught briefly at an east coast university (I don't recall which one), and then decided he really didn't want to do that for the rest of his life. He moved on to a development position at Polaris, mostly doing chassis development and testing for the new (at that time) Victory motorcycle. From there, he moved on to a company (MTS) building 4-post simulators for cars, where he was tasked with developing one for motorcycles, which he did. He eventually left to become the head of R&D for the Renault F1 team, moving to their base in Oxfordshire. After several successful years there, he again moved on to a position with Mercedes, but I've kind of lost touch with him since then, and don't recall exactly what he is doing there. He's quite an interesting guy. Last I heard, he was racing his 1929 Riley in vintage car races in his spare time.

Regarding Jim's monoshock bike, there is a full side view in the picture below that shows the relationship better

Commando motor in solid frame


Ken
 
Dances with Shrapnel said:
jseng1 said:
The bike below as Ken Canaga set it up when it got on the BOTT podium with Rob T riding.
Commando motor in solid frame
Rob Tuluie was one hell of a rider and builder. He exhibited some extraordinary building and riding at Daytona with the short stroke Rob built. If anyone is interested, read up on the Tularis. Rob has a Ph.D. in Engineering (Mechanical I think) and moved on to Formula 1 (Renault I recall).

As for your bike Jim, it is a neat build. One comment is that it looks like the motor is set fairly far back from the front wheel; it could be the angle of the photo. Do you recall the dry front/rear weight bias?

I don't remember the exact bias but I do remember checking it and I spent a lot of time on those details - pushing the tire close to the motor with forks bottomed etc. It handled great as Rob can tell you. I remember being able to take turn 8 at Willow springs wide open with the tires just starting to skitter. You could push it into a drift in the turns and hold it there - passing other riders. I remember measuring the pavement grind marks with a protractor on the earlier low pipes at more than 55 degrees (past 45 deg) with springs removed and suspension bottomed. This in the mid/late 80s with tubed tires/spoke wheels before I sold it to Ken. I have detailed plans - maybe you should have them. I only know of one other person building it but don't know if they finished.

The bare frame in Ken's possession below
Commando motor in solid frame


Another track shot against jap multis below. We never even considered dragging our elbows back then and I was taught to keep my head parallel with the track.

Commando motor in solid frame


Swing arm in progress (the 2nd frame).
Commando motor in solid frame


Frame in progress (2nd bike). These photos are a few years old and I don't know if its finished or not.

Commando motor in solid frame


Commando motor in solid frame


You can see the swingarm pivot plates and 1/2 tube on the table in the photo above matching the plans below.

Commando motor in solid frame


I've talked to Framecrafters about a rolling chassis and got a quote but went no further. I'm sure they could make a tank with smoother curves.
 
There is a problem with using frames such as the featherbed - the exhausts have to go out and around the front frame tubes if you want a two into one with collector under the motor. That means that when you try to reduce the offset on the fork yokes to change the handling, the front wheel can be close to fouling the exhaust pipes. If you use a two into one pipe which comes off the side of the bike, you need a big loop in one of the header pipes to get the lengths near equal. The MK3 Seeley and the Egli don't have these problems. The Egli frame only has short front down-tubes, so the pipes can be in closer at the bottom-front of the motor.
 
This frame was available in the 70s and Patrick Godet still uses Egli frames :

Commando motor in solid frame
 
acotrel said:
There is a problem with using frames such as the featherbed - the exhausts have to go out and around the front frame tubes if you want a two into one with collector under the motor. That means that when you try to reduce the offset on the fork yokes to change the handling, the front wheel can be close to fouling the exhaust pipes. If you use a two into one pipe which comes off the side of the bike, you need a big loop in one of the header pipes to get the lengths near equal. The MK3 Seeley and the Egli don't have these problems. The Egli frame only has short front down-tubes, so the pipes can be in closer at the bottom-front of the motor.

what about a 67 bsa frame?
 
acotrel said:
There is a problem with using frames such as the featherbed - the exhausts have to go out and around the front frame tubes if you want a two into one with collector under the motor.

The down tubes in a featherbed aren't much different to what is on a Commando ?

The 2-1 I had on a Commando were out and around the downtubes,
although they merged down low - out of reach of the front wheel !
 
BTW, Just for the record here (since this branched into another thread)
I pointed out very early on here those '60 hp gives 100 mph' numbers.
THEY ARE GRAPHED in the Tuning for Speed book by Phil Irving.
p192 in one edition, much higher page count in later ones.

shrapnels comment turns into "that sand dribbling out his ears" jibe about now....


Dances with Shrapnel said:
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?
<snip>
<snip>
<snip>

Rohan said:
P.S. And before anyone says anything silly, and for those mathematically inclined, it is generally quoted it takes the average moddersickle plus rider just over 30 hp to do 100 mph.

Apologies for reverting to previous cr*p, but jist for the record.
 
Well someone had a Chernobyl meltdown tonight. :lol: Desperate, are we? I would say very desperate if you have to resort to manipulating quotes out of context and out of order. Showing us all what you are about.

Easy to cut and paste out of context. Note in the quote below I state "they are", not "it is", clearly referring more than one number (in fact two sets of numbers or the now famous "Commonly Quoted Numbers"). I have no problem with the 30 hp number at 100mph as it is a number comprised of rolling resistance and aero drag (not aero drag alone as we had initiated this discussion on).


You cut and paste quotes in a lame attempt to dig yourself out of a deep hole. I challenge you to show us all where I said that the 30 hp number was wrong.

Another classic Rohanism.

Rohan said:
BTW, Just for the record here (since this branched into another thread)
I pointed out very early on here those '60 hp gives 100 mph' numbers.
THEY ARE GRAPHED in the Tuning for Speed book by Phil Irving.
p192 in one edition, much higher page count in later ones.

shrapnels comment turns into "that sand dribbling out his ears" jibe about now....

Dances with Shrapnel said:
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?
<snip>
<snip>
<snip>

Rohan said:
P.S. And before anyone says anything silly, and for those mathematically inclined, it is generally quoted it takes the average moddersickle plus rider just over 30 hp to do 100 mph.

Apologies for reverting to previous cr*p, but jist for the record.


You continue to soil yourself. I suggested numerous times throughout for you to challenge the numbers you quoted against the aero drag calculations but you have not for if you did, you would see.
 
Rohan said:
acotrel said:
There is a problem with using frames such as the featherbed - the exhausts have to go out and around the front frame tubes if you want a two into one with collector under the motor.

The down tubes in a featherbed aren't much different to what is on a Commando ?

The 2-1 I had on a Commando were out and around the downtubes,
although they merged down low - out of reach of the front wheel !

Didn't the pipes end up looking too wide and daggy ?

The downtubes on a featherbed frame are much more vertical in order to get the Manx motor further forward and down. That is the reason a Triton never handles as well as a Manx - weight distribution and centre of gravity. Even if the Triumph motor mounts are one inch behind the Featherbed frame mounts, the bike will feel a bit vague and airy in high speed corners - destroys confidence.

The BSA frame I was referring to was the 50s A10 or the B33/B34 frame. Weren't the 60s BSA unit construction ? - probably not enough room when you have separate gearbox. The A10 frame with the standard yokes is dangerous, but excellent when fitted with 60s unit Triumph fork yokes. One problem is the bike becomes a bit shorter and becomes much quicker steering - I loved my Tribsa - I should have raced it instead of buying the Triton.
 
Dances with Shrapnel said:
You cut and paste quotes in a lame attempt to dig yourself out of a deep hole. I challenge you to show us all where I said that the 30 hp number was wrong.

What on earth were you "stating they are wrong" about then, if not that 30 hp for 100 mph quote ??
There was NOTHING else there could be disputed.
Unless we are talking at seriously crossed purposes here, and you didn't actually post what you think you did.

Comes up for me as you posted it -
Post by Dances with Shrapnel » Tue Aug 23, 2016 6:45 pm


Dances with Shrapnel said:
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?
<snip>
<snip>
<snip>

--------------------------------------------------------------------------------------------------------------------------

Dances with Shrapnel said:
I suggested numerous times throughout for you to challenge the numbers you quoted against the aero drag calculations but you have not for if you did, you would see.

WHAT ??? But now you are saying the numbers I quoted ARE wrong - so 30 hp DOESN'T GIVE 100 mph ?
When they are graphed in Tuning for Speed book.

Now some of us are getting seriously confused here.
The numbers are either wrong or they are not, but you can't have them as both !
And then deny that you said that. !!!
Holy crips batman....
 
acotrel said:
There is a problem with using frames such as the featherbed - the exhausts have to go out and around the front frame tubes if you want a two into one with collector under the motor.
Rohan said:
The down tubes in a featherbed aren't much different to what is on a Commando ?

The 2-1 I had on a Commando were out and around the downtubes,
although they merged down low - out of reach of the front wheel !
acotrel said:
Didn't the pipes end up looking too wide and daggy ?

Not at all - well tucked in and up out of the way.
But note I didn't try them too much at max bank angle.

Commando motor in solid frame


Sorry can't readily find the link to a bigger version.

P.S. We diverge, but note the bump on the end of that seat.
Current remakes don't include that ?
 
Quite slithery there Rohan. Everything that needs to be stated and clarified has been stated and clarified. I am not about to follow you down the Doctor Eliza rabbit hole of crude artificial intelligence. The endless stream of confusion comes from you so please answer my question asked above:

I challenge you to show us all where I said that the 30 hp number was wrong.

Reread my posts for starters....slowly and carefully.

Rohan said:
Dances with Shrapnel said:
You cut and paste quotes in a lame attempt to dig yourself out of a deep hole. I challenge you to show us all where I said that the 30 hp number was wrong.

What on earth were you "stating they are wrong" about then, if not that 30 hp for 100 mph quote ??
There was NOTHING else there could be disputed.
Unless we are talking at seriously crossed purposes here, and you didn't actually post what you think you did.

Comes up for me as you posted it -
Post by Dances with Shrapnel » Tue Aug 23, 2016 6:45 pm


Dances with Shrapnel said:
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?
<snip>
<snip>
<snip>

--------------------------------------------------------------------------------------------------------------------------

Dances with Shrapnel said:
I suggested numerous times throughout for you to challenge the numbers you quoted against the aero drag calculations but you have not for if you did, you would see.

WHAT ??? But now you are saying the numbers I quoted ARE wrong - so 30 hp DOESN'T GIVE 100 mph ?
When they are graphed in Tuning for Speed book.

Now some of us are getting seriously confused here.
The numbers are either wrong or they are not, but you can't have them as both !
And then deny that you said that. !!!
Holy crips batman....
 
You are a slippery character.
Say it, see the proof in the quote, then completely deny it.

Care to explain these words, oh wise one ?

Postby Dances with Shrapnel
<snip>
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?.

Just for the benefit of future readers here, Phil Irving in the Tuning for Speed book states those "commonly quoted motorcycle numbers" categorically - in graphed format - that 30 bhp is good for 100 mph - for "Roadracing machines weighing about 300 lb".
Graph B crosses, very precisely at the 30 bhp and 100 mph mark.

I have no idea what that quote of yours is referring to, if not this.
I stated these numbers 30 bhp for 100 mph VERY EARLY ON in this thread,
and a large part of the subsequent 'discussion' was based around these numbers.

So, shrapnel john, are these numbers good and valid.
Yes or no ?
 
Wasn't this 100 MPH stuff originally about some guy on a Commando sitting up in the breeze ? - It takes a bloody good old British four-stroke road bike to do more than 100 MPH.
 
"Rohan said:
You are a slippery character.
Original thought there Rohan (aka Corium) :lol: Where did I hear that term "slippery" before? Not sure if there's a remedy for plaque on the brain.
Rohan said:
Say it, see the proof in the quote, then completely deny it.

Care to explain these words, oh wise one ?

Dances with Shrapnel said:
<snip>
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?.

Sure, my assertion quoted above is referring to your "commonly quoted" numbers below. And I stand by my assertion as your numbers are wrong in the context of the discussion as I very clearly stated. Did you miss something...again? Go ahead and plug them into the general equation of aerodynamic drag power and try and reconcile. It will be like that Abbot and Costello comedy skit of "who's on first"!
Rohan said:
it is commonly quoted that ~10 hp is needed to do 60 mph,and ~32 hp to do 100 mph.

Oh, and please tell all where we can find the 10 hp number that you allege is so "commonly quoted" in the Phil Irving Tuning for Speed graph that you are now so desperately trying to hang on to. I invite all to check this out as it is off the curve (almost off the chart :D )- sort of like our dear Rohan (aka Corium)

Rohan said:
Care to explain these words, oh wise one ?

Postby Dances with Shrapnel
<snip>
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?.
These have been explained ad nauseam. This is part of your ongoing Rohan (Corium) subterfuge. Questions and doubt, questions and doubt. Sounds like a political part process.
Rohan said:
Already explained above. The analogy is a Dummkopft bringing a cricket bat to a golf game -I really don't think I can be more concise. :lol:

Rohan said:
Just for the benefit of future readers here, Phil Irving in the Tuning for Speed book states those "commonly quoted motorcycle numbers" categorically - in graphed format - that 30 bhp is good for 100 mph - for "Roadracing machines weighing about 300 lb".
Graph B crosses, very precisely at the 30 bhp and 100 mph mark.
Yes! Yes! Rohan is here serving humanity for the betterment of humanity! NOT! From what I can tell, Rohan is here for Rohan. Tell us where the 32 hp @ 100 hp shows up and especially in conjunctions with where the 10 hp shows up on the same curve. :shock: There is some wiggle room there Rohan so let's all wait to see if you take it.
Rohan said:
I have no idea what that quote of yours is referring to, if not this.
I stated these numbers 30 bhp for 100 mph VERY EARLY ON in this thread,
and a large part of the subsequent 'discussion' was based around these numbers.
Yet you manipulated quotes. If you do not know what you are doings, keep your damn hands and fingers off the levers and knobs!

From above: I challenge you to show us all where I said that the 30 hp number was wrong. . I was having fun with this all the while and now realize I have been debating with a fraudster. So you invent things to support your arguments. This puts anything you have contributed on this forum into question, and same for going forward. You fabricate.

You having no idea seems to be the common denominator here dear Rohan. You smugly try to correct someone's statement (Jim Schmidt's) which was accurate with your incorrect information. In a vain attempt to recover you quote some alleged "commonly quoted numbers" and are confused as to why they do not reconcile with the aerodynamic equations I cited. You struggle to understand why your "commonly quoted" motorcycle power numbers do not reconcile with the wiki automotive example (surprise - two wheels versus four; small versus big) I provided as references for you and others. In my naive attempt to enlighten you I steer you to Phill Irving's seminal works hoping you would figure it out, so you stumble upon the answer (sort of) and start quoting a single point (30 hp) (slithery switch) which so conveniently corresponds to one point of Phil Irving's intermediate curve. You then lamely try to bludgeon me by manipulating quotes to make it look like I was arguing about something I would have never argued about. I am sure I missed a few of your slithery steps but that last one is borderline fraud (though fraud requires a criminal element - what colony are you from Rohan?) :lol:
Rohan said:
So, shrapnel john, are these numbers good and valid.
Yes or no ?
With you Rohan, it seems to be which numbers at which point in time. :roll:

I have never had an issue with the qualified number of 30 hp (@ 100 mph) from the Phil Irving graph and I continue to challenge you in front of this forum to prove otherwise!

So tell me more about your commonly quoted 10 hp @ 60 mph and 32 hp @ 100 hp. As I stated earlier, there's some wiggle room, but not much, so we will see if you take it. Oh, and this is all in the context of aerodynamic drag only so the two numbers you state are so commonly quoted must fit the equation for aerodynamic drag. Remember, most anyone can do the math and see your data set does not fit because you were cluelessly throwing these numbers out without an understanding of what they were comprised of.

As I stated earlier, this has been fun but I am disappointed as I have come to the conclusion that someone has desperately stooped so low as to try and manipulate quotes of others to save face..............or maybe he is that confused. Which is it?
 
Oh, and I forgot to ask you, dear Rohan, why you did you jump threads back to this one (to crap it up) during your meltdown? Things too hot in the kitchen in the other thread for you? Trying to be polite here. Was it due to hobot?
 
This is getting a weebit ridiculous. Too bad, because it was a very interesting topic. So, because this thread (as well as the other one) is already sort of polluted, I will add to the discussion, and will have a strong probability of more corium byproducts.

I ride a slimline featherbed with a tilted 850 engine, lightened and prepared in period most likely by Dunstall.
This bike was clocked at 130mph/213kmh on the straight of the Dijon circuit in France. It does, very happily, 100mph on half throttle WHEN FITTED WITH ITS FULL DUNSTALL FAIRING .

Without it will get to about 120mph at full throttle, but just.
By the way, it has a box section swing-arm about 4cm longer than normal Featherbed, Commando forks and Fournales oleo-pneumatic shocks and handle like a dream at all speeds. Its worse limiting factor is...me. By far.

Horsepower? I don't know. It is a good bike and I ride it. It is no armchair...
:mrgreen:

Welcome back, Hobot! We miss you!
 
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