The Commando Weave

It's not about hobot its abuot UN-tammed vs Tammed Commandos vs rest of the world - that even a screw up like me can get away with stuff - no one else is willing or able to discuss but by name calling to protect the innocent. So the protective riders here say they have no issue with weave, so nothing to worry about- to cover their scope of isolastic phenomena. Relax get on w/o me I admit and accept judgments I don't know any better d/t narcissism and yummy intimate animal fetishes.

Whoa...

I didn't want to open a can of worms or start a witch hunt..

I do not intend to block or ignore you Hobot because you occasionally have good advice to share...

Just that I lose interest after the first sentance or two!

Sorry Chap!

Mike

To all that are annoyed by Steve's ramblings incoherence, just skip over his posts and keep your comments to yourselves.
I for one at first found his muses a bit confused, trite and verbose. But as I have got to "know" him I have been able to decipher his thoughts and have made sense of
what he is saying and think if I met him I too could be friends.
So all you all who don't like what someone has to say or the way they say it, grow up and stop acting like a 12 year old.

Just fill it all up with concrete , thatll do it .

No HELMETS Steve , and the front ones growing horns , and gotta funny kind of jacket on . Probly no licence eather . Maybe its India & Holy Cows dont need motorcycle licences .

Lay off Hobot. He knows more than most on here.

Just a gental ribbing on the picture. Nothing personal.Im sure he has a sense of humour .


But , Well , its cause the Frames to damn light .

Anyone want and we'll tool up for some 3 in top tube , 1 1/4 cradle , lowered seat suckers , to the std. datums . to secure things a little .

Also ' the works ' went to double discs , as the Norvil type twisted the front end , under brakeing .( friction coefficent -
modern tyres would be equal to the old race tyres )

Haveing cut the teeth on a 61 Bonniville , with 4:10 19 TT100s . Which LIKE ALL TRIUMPHS before 67 odd ), had a torsion bar ( the seat tube ) for the Swing Arm Mount .
On a smooth twisty road , two up , over and holding it on the throttle , there was the ODD corner you could get the sideways movement , discernably . ( with a good steady pillion )
and being a Hill Billy myself ,on the Commando IF YOU KNEW THE ROAD , you didnt get the snake snap weave , EXCEPT in the runs through the unavoidable bumps if you didnt use your discretion , WITH low bars .

The old up forward & on the inside for the intrepid pilot if he wasnt going to back of provided a better counterweight with better attachment.
But seeing , on Tarmac , we took the classic approach .Feet on the pegs if your moveing , and moveing about ( much ), putting ' the nose under '
as in getting the front leant in excess of normal sees that end through .

The sensible thing was to ride at YOUR limit . :shock: factor .

Swt up with Tallish bars with a straightish back are a better set up for intrepid pilot multi surface rideing . Primarily as he is etter located .And big boots for dropping a foot .3.60 & 410 roadrunners , and agian , it would do most of the work for you .

The moden Tyres on anything ( on a older car , the door locks ' click ' with torsion twisting through fast bends , even smooth ones . Chassis Twist .
So , PZ2s & Pirrli Phantoms were ' the new ' high grip tyres mid/ late 70s , but most people didnt use the road a a grand prix track or the Ilse of Man ( in the rush hour , anyway )

But , BEHOLD , the old ' Iso under the Gearbox ' trick TOTALLY ALTERS the dynamics of the STRESSES in the Stock Frame .
Though still dont try it in the rush hour .

With respect , a blankety great tube welded in , is at a lower loading per in stess than the rose joint link.And not dynamically
being identical load / stress wise .

Further Rant .

As the ISOLASTICS were a inovateive & ground breaking inovation , and a inherant part of the COMMANDOs Character ,
Developing the system beyond the FIRST GENERATION / introduction level ( in 20 yr old new speak ) seems obvious .
Much in the manner that Williams used them to blitz the opposition in the I.o.M. in 73 ( no , it wasnt the rush hour )

THEREFORE , as the SEELY is said to be seable sans top mount , we visualize the load path there .
Putting two iso's aft , either side of the swing arm load path ( on paper ) above & below , wve halved the lateral loading
and severely increased the longitudeinal torsional location. Two rear isos .
ALL those forces are therefore fed into the most trianglated frame area .
AND if we believe the SEELY MYTH , this just leaves the front ISO along for the ride , pretty much .
RATHER than haveing the THREE POINT ( maximm dimensional displacement , a understandable method ) with he top
accepting the lngitudenal tosion , way out in the middle off nowhere far tween other load points ,
weve taken out the orces at the source ( almost ) . a more pure evolution of anaylis .

This leaves us ith the frame all nracked & not in pain , so theres a btter chance the tearing head wont try and rench itself off
or f it does , the headstock and adjacent areas ARNT subject to the severe torsional lateral inputs from the stock configureation .

With all the lads down he bottom here , the plot tends o sta better located on terra firma ,
The Axles and powertrain location being about the sme vertcal location .
NOT the stock ' roll ' force location about over he cylinder head ,

as the primary corneing dynamics are primarlly though the seat of the pants and boots,
the gneral improvmnt helps stop the plot buggering things up wobbling about on the bars , too .

So , my 10 cents worth . Chuck a Iso up under the box and improve the ISOLASTIC generation .

This is a nice picture , I will steal it .



Off to find a chassis shot . . .
Opps , done it again . . .


/Norton%20Monoshock%20F750%20JPN/PWandCroxford.jpg
Im looking for the engine cradle shot for this thing .
One can apreciate that the space frame load factor ( load path / stress per sq in metal , etc , wasnt quite the same as the oad bike .
Other ISSUE from a Engineers pont of view . IS THE SWING ARM LOCATION . Mechanically .
Welding a flat piece of say two in wide ( for & aft ) in front of the pivot cross tube .
And useing a RATHER LARGE press to put the pin in at a RATHER TIGHT fit , is required.
or other measures .
ALSO , it was usual to ft press fit cross bolts and reamed pins ( bolts ) in a PRE UNIT Cradle ( or other race thingos )
Steel Sleeves cast into the gear case , with flanged edges , and and high tensile mounting bolts there to , would be
good engineering practise.

And another thing in common with Hobot , I look at the rear axle bolt sideways .

Find one out of a non QD Triumph rear wheel ( 60's ) and contmplate that .

Thats Not an Axle . ! THIS is a Axle . ! as the austrawlians say . Indeed .

Whats a Lotus 40 ?

A Lotus 30 with 10 more mistakes .

Dont go don that road .

Matt Spencer said:

the SEELY MYTH...

Click to expand...

and

Matt Spencer said:

So , my 10 cents worth . Chuck a Iso up under the box and improve the ISOLASTIC generation .

Click to expand...

Well a myth is a myth. Opinions vary on whether to use a solid head mount on the Seeley Mk2 frames. Some use them and some do not.

If I were to choose between an upper head ISO and an ISO down below the gear box I would select the one over the head in a heart beat as would a few knowledgeable race builders. In fact (well more like in my opinion) the factory Commando head steady is really not an ISOlastic but just a lateral support stop.

My opinion is that from a structural stanpoint the head ISO has a leverage arm advantage thus can be made much lighter since the forces (right and left) are much less than if the ISO (or even rod linkage) is beneath the transmission where there are only two small diameter (unbraced) tubes to take up the lateral forces.

Without bracing and proper set up I could see this contributing to WEAVE

Now I went and did it big time.

Coel , variety is the spice of life , a healthy debate is the food of , agh , er . . .

The ' comparison ' as to Seely , is that SOMEBODY ( who shall remain nameless , as I havnt a clue who ) SAYS ,

Hanging the whole powertrain off the rear mounts only , is feasable . :wink: .

HoKay , a lower Iso , derived from a std rear unit , near under the std rear ( vertical line ) , the cantilever of
the secureing pin to frame gussets ( new ) isnt far ( :| ) frome the tip of the triangle lower point .
( where wot the alloy foot rest mounts go )

The Cowboy one I saw , Had a standardish cross tube , fitted under , to the engine plates. Poasitioned so the pin met lugs ( much like the front units frame ones )
OVER the lower cradle tubes ,

SO , Visuaiseing the powertrain load paths , we pretend :?: Its all anchored in down there ( like the seely ) Going further :? the
side members , up above the foot plates , locate the Top Tube , Going forward to the steering head waveing around miles out in front up there . :shock:

Therefore , the cradle tubes are a Extra so can help there , and provide final lateral location to drivetrain lateral missplacement . We Hope . :mrgreen:

A diferant cup of tea , but ALSO , Meant to prattle on about the ' Legal ' :wink: ' CHROME MOLLY ' Honda 750 Daytona winner , & Ducati 750 SS Frames .

Who's got a chrome Moly tube , Reynold 531 or wotever " Standard Commando Frame " out there .

=====================================================================================

THEN , ' Torsional Ridgidity ' on Auto Platforms , is measured chaining them down on chocks ( not chooks )
Stuffing a hydraulic bottle jack with a PSI guage plumbed in under a corner , And a Spirit Level .

Degrees per Ft Lb , & the like .

Putting a Mandrel secured through the axle positions fore & aft , secured but moveable ( under Force ) , and start playing games .
A large Square & measureing stick would be ok , the computor / scanner / lights ?? fitted being 2001 space oddessy stuff .

A cider barrel with a stick across the top with a brick on it , slid to touch beeforehand , and a feeler guage ( maybe really thick ones :shock: ) , Would Do . .
God Knows what would happen if the bars through the axles were connected to 3 diminension Shock Testing Machines . Might need a computor there to stop
the fingers getting caught in something , measureing it .
Something like these 100 year old Morgan Thingos , a bit of improviseation . The ends justify the means .

Maybe they shouldve been doing Nortons in Wales . :?

http://www.morgan-motor.co.uk/mmc/resea ... pment.html

Wonder if its the mushrooms there .

Hymph . It Says NORTON .



been looking for a old BSA / Tri load data / anaylisis sheet , Thingo. From M/C Mech.


Morrison Norton . Roberts Yamaha ( so it says )



Er . . . now . Where were we . . UM .

Something like these chaps , . ?


Morgan... the last true (major) sports car manufacturer. Modern cars would be so much better if they were assembled by men with a passion and had interiors stitched by pleasant middle-aged ladies in Malvern. It's this sort of stuff that makes Morgans and older cars great, the way they are assembled by chaps who want to make a car for fun and do away with the techno-rubbish that makes modern cars tedious, bland and uniform.

They will even take back your old Morgan, dismantle it, then re-manufacture it on the same production line! Any model, any age. Remarkable

Addm. Riot . you win . Dancey Boy . Appears to be free . (three as per etc )



Cant find the Aussie Mag Articals with the G box Cradle pic .

Firstly , I look forward to hobot's input .
Back on subject , I have been following this thread with interest .
I am no engineer nor racer , but I would like to improve on my commando's weave . Lumpy roads and high speeds sometimes cause me to fear for my life .
I love my centre stand , so put very simply , would fitting a couple of those rotating eye bolts between the frame and eng cradlle , between the gbox and swing arm , improve things at all ?

Better to put the "rotating eye bolts" over the cylinder head.

Heres trouble , excuse the parabultion , but the logic follows through to a conclusion which forms a comparison . :lol:



Trackmaster chrome molly dirt track race frame /



1971 on type triumph steel production frame . ( any resemblace is entirely co-incidental )



Now , THESE are both PRE UNIT , dual tube cradle . reasonable steering head location , questionable swing arm location .







THESE are QUESTIONABLE in EVERY respect .



No End Locators , swing arm . Transverse loads at rear axle translate into torsional loads at seat post .Then theres the forks . :shock: 61 / 62 H Wt. were stiffer via being shorter ( Long & Short Roadholders too )

However , the unit 500 1959 flexi flyer frame , on a old 3.25 ribbed front , 4.00 old nylon bridgestone rear , ON GRAVLE , was addept at outperforming 70s wizz bangs , on a m/cycle rallye .
( Twin carb ex race motor didnt slow it down any , = to worked TR6P solo or two up , as on the rallye , which tends to stabilise it a bit .YES , the DIMENSIONAL STABILITY relateing to the axles isnt FINITE )


Now , the dreaded pre unit Bonneville , and the dreaded pre unit Commando , display similar tendancies. Caught out in a whoop , cornering .(running OUT of a depression leant over )
Cutting the throttle at the nanosecond it arrives at the edge out of the pothole , and cutting in at the instant of level road , tends to keep the load level less dramatic and gives a straight run ,
if youve braced with your knees and leant the shoulders in a notch or two .You HAVE to ride through it , like a stream of water over the road . Or learn recovery control inputs . :lol:

NOW the comparisons mechanically . The dang welded tube Triumphs tube runs arnt as extreme.The Tube Diameters are larger . The Swingarm has near twice the lateral location at the pin ( pivot )
as in , the max loads and location are at the ends . Norton doesnt have location at the ends ,NOR do any pre 67 Triumphs, Bar Ridgids .

Therefore , the best handling improvement is to glue your trousers and boots to the machine , and dress on the bike . Then you cant get spat off . 8) :mrgreen:


One MUST pay attention to what one is up to , UNDEVIDED attention .The old Hailwood and Minter books elaborate on relevant tecnique , as does Frank Gardeners , ( tho 4 wheel )
OLDER chassis and tyres with TWICE the original traction level , can overload a chassis , particullarly on irregular surfaces .Therefore chassis / suspension set up is HIGHLY relevant
to the operation . touring , track , back road , off road , as the traction is lesser on gravle , the suspension is ordinarily softer , and perhaps not as low .Also more rebound damping
than bounce is usual on tarmac . @ 1/3 travel height .
working .
1/2 height for gravle rally type stropping about the countryside .

A comfortable secure rideing position is in any case , the first order . So as control inputs arnt being influanced by wiggles .( the old pillion with the wiggles destabilises the machine and reduces rider confidance )
Rideing the C'do at speed , nonchalantly , with a steady pillion wearing jandles , his nervous reaction approaching bends ( or was that in them ) would set the machine over , all I had to do , was ' catch it , at the right lean , and run the bends. wore the sides of the jandles , dragging . Accelerating onto the straights , at that ballast , would lift the machine . Dum De Dar . . .

http://www.bing.com/videos/search?q=mik ... +500+utube

DEFINITION OF WEAVEING ?

+ 1 Guido, thank god (if you want to buy into one) it's a versitile world. Now the bike related question. Do you guys who have put Comando engines in featherbed frames get wobbles? Are there big differances from a well tuned Atlas or 650ss motor & how do those with iso mounted motors fair compaired to solid mounted power plants? I guess what I'm asking is did wobbles happen on hot featherbed bikes?

Dances with Shrapnel said:

If I were to choose between an upper head ISO and an ISO down below the gear box I would select the one over the head in a heart beat as would a few knowledgeable race builders. In fact (well more like in my opinion) the factory Commando head steady is really not an ISOlastic but just a lateral support stop.

Click to expand...

Luckily, you don't have to choose between the two locations. I have heard though that Kenny Dreer did choose to completely eliminate the headsteady due to ring sealing problems because the aluminium cylinders he was using were distorting from the loads from the headstedy.

Regarding whether the Production Racer headsteady is really an iso, some people have replaced the rubber bushes with a spacer and just used them for the lateral support.

Dances with Shrapnel said:

My opinion is that from a structural stanpoint the head ISO has a leverage arm advantage thus can be made much lighter since the forces (right and left) are much less than if the ISO (or even rod linkage) is beneath the transmission where there are only two small diameter (unbraced) tubes to take up the lateral forces.

Without bracing and proper set up I could see this contributing to WEAVE

Now I went and did it big time.

Click to expand...

You're right that the wide spacing between the two iso's and heasteady makes for lighter loading than it otherwise would be if they were located closer together, but I put a linkage under the swingarm anyway even though it is closer to the rear iso than I would have liked. So there's two iso's and two linkages. I figured that the Commando frame is so weak that spreading the load between four points would be easier on the frame than three. The main reason was because I liked the idea of locking in the cradle from above and below right at the swingarm to locate it in the roll axis. The old engine plates, the fasteners, and the bosses cast into the crankcase were never made to take the twisting forces put on them by the swingarm. The plates flex, the fasteners stretch the holes on the plates and the bosses, and the parts shuffle. And the engine itself flexes. They can't just wake up one morning and decide that the engine is going to be a stressed member like the Vincent and get away with it. The frame where the pickup points are for the lower lingage isn't up for it, like you said. I boxed the area between the rear iso with 1"x3" rectangular tubing and ran a 2" tube from the backbone to it like an OIF Triumph. A couple sets of X or Z bracing would have been better but I am using all of the stock parts in the vicinity and they wouldn't have fit. It tracks pretty well for an old bike on skinny tires. Sorry for the ramble, insomnia is a b**ch. Should probably knock off the coffee after midnight. :shock:

Matt, great frame pic's.

Bob,

You are spot on about this. The question is how best to achieve a stiff torsional link between the swingarm spindle and the steering head spindle.

Referring to the Commando ISO frame pictures by Matt above, with a link below the gear box the swingarm spindle appears to be less cantilevered (spindle is getting close to being "inside" the three point triangle of support but you are relying more on the stiffness of the frame lower tubes at a point nearing furthest from the steering head.

With a cylinder head lateral support you add the stiffness of the engine/trans system as a stressed member, but now the swingarm spindle is cantilevered outside the triangle of support (at least it looks like it is).

It would be intresting to get a commando on it's side (hobot?) on a jig table with the steering head fixed firm, place a bar through the rear axle slots (better yet, through the swingarm spindle hole) and conduct a torsional load deflection test for both the lower link and for the head steady (teflon puck). To me this would be quantitative.

Don't need no stinkin FEA.

As an after thought, I have my stripped down Commando racer at FrameCrafters and I may just have a go at this test.

I have put lever bars though various mounts and stated what I found happened but ignored or spoofed for it. I have investigated the torsion just twisting fork upright too - all the way back to rear patch, 3 things I detect so far counter steering - but also found 3 reversed effects - when suddenly straight steering onsets.

I love=depend on the flex of my tamed isolastic Cod and its for exactly opposite reasons conceived by this list or the space age ringing elites. I make mine crisp and stiff on the outsides yet soft chewy on the inside thank you. Ms Peel has rear frame welded together as well as the flex plates at rear of cradle to take the rump link loads. Bob's transforming invention is worth about 75% of Peel's crazy making ways, 2 other compliant links with hobot fork modes = totally solve any handling upsets I tested for so far. Ms Peel will end up as the stiffest interlinked double framed Cdo but mostly to take crashes, animal-root-leap impacts and side car loads, as not needed to plant higher powered accelerating leans than others. I told i'm so stupid to mount a side car but hey that's me. The extra frame will not hinder the innate twist compliance between front and rear tires nor her energy storage-release slingshot glee.

The whole world to me is divided by transition to straight steering which means must go so harsh on tarmac it becomes loose as off pavement handling, so of course no one can keep up with Peel even in phase 2 - before she lets hair out to power up into next higher phase 3 of energy handling. So what cuts your worldview in half, secure vs crazy? I have learned my lesions that above also means world is divided into Peel Commando vs all the rest. Take it as ego fantasy or try it and see who's missing out the most.

Therefore , the best handling improvement is to glue your trousers and boots to the machine , and dress on the bike . Then you cant get spat off .

Click to expand...

Right on Matt, if pilot has time to shift position between fling sides or can hang on for the side loads while hanging off instead of low down locked in like a drag racer then no worries to treat em like parking lot cones to gynkanna around so easy so securely. I am considering velcro on tank and seat, but mostly to stay on bike braking as all Peel's corner G's get focused straight down spinal column into rear patch so no side loads on me till the tires leave surface and then again on landing sideways.

Hinge always lurking in every other bike there is but one.
think-bike-hates-t13333.html

Dances with Shrapnel said:

Bob,

Referring to the Commando ISO frame pictures by Matt above, with a link below the gear box the swingarm spindle appears to be less cantilevered (spindle is getting close to being "inside" the three point triangle of support but you are relying more on the stiffness of the frame lower tubes at a point nearing furthest from the steering head.

With a cylinder head lateral support you add the stiffness of the engine/trans system as a stressed member, but now the swingarm spindle is cantilevered outside the triangle of support (at least it looks like it is).

Click to expand...

The thing, as I see it, is that the loads on the frame begin with where the rubber meets the road, the contact patches of the front and rear tires. When you look at the bike from the side you can see horizontal and vertical lever lines. The big vertical lever is the distance from the center of the axle to the contact patch of the rear tire. The main horizontal lever is the distance from the axle center to the first anchor point on the frame, the rear iso, it becomes the fulcrum. With the origin of the forces on the frame being at the rear and front tires, they are always going to be way 'outside' the border of that three or four points that you get when you connect the dots of the iso's/links.

Dances with Shrapnel said:

It would be intresting to get a commando on it's side (hobot?) on a jig table with the steering head fixed firm, place a bar through the rear axle slots (better yet, through the swingarm spindle hole) and conduct a torsional load deflection test for both the lower link and for the head steady (teflon puck). To me this would be quantitative.

As an after thought, I have my stripped down Commando racer at FrameCrafters and I may just have a go at this test.

Click to expand...

When you conduct the torsional load deflection test, the best way to recreate what's happening might be mounting the swingarm and applying a twisting action with the center of rotation being between the axle slots, looking at it front to back. If you could just mount the rear wheel then you could push and pull the wheel up and down at where it would be contacting the ground. This is with the bike laying on it's side. Pushing and pulling up and down on the swingarm spindle or the rear axle don't recreate what's going on.
I had my bike assembled on a frame table, locked down at the headstock, and supported at the rear iso and head on jacks. It's scary how little force it takes to move the front iso mounting points on the frame. The down tubes have no material strength to speak of and there is no triangulation to help. It seems it wasn't until the factories were racing production framed bikes in SuperBike that they got serious about adding gussets, triangulation, and trellises to keep those bikes on the track. Here's a link from Tony Foale on frame stiffening.
http://www.tonyfoale.com/Articles/Frame ... waMods.htm

Good to shorten the down tube sections into stiffer higher frequency springs when that rear patch slaps the mount tabs silly.

[video]http://www.youtube.com/watch?v=FflW3PrzfAI[/video]

rpatton said:

It seems it wasn't until the factories were racing production framed bikes in SuperBike that they got serious about adding gussets, triangulation, and trellises to keep those bikes on the track.

Click to expand...

Was there any effort on the part of Norton factory to stiffen the frame for production racing?

I was chatting with Doug McRae this evening about other stuff and the conversation led to his postings from a few months ago.

http://www.accessnorton.com/race-co...ed-t9553.html?hilit=handling secrets revealed

Good stuff by Herb Becker. I had the opportunity to race one of Herb Becker's Commandos a few years back and it was truely amazing. I never thought a Commando could handle so steady and turn in so quick. All that and the creature comforts of little to no vibration thanks to the Norton Isolastics. It really made me wonder why I started to screw around with Featherbeds and Seeley's

I would still like to test and observe the torsional stiffness of a Commando frame with some or all of the modifications.

Dances with Shrapnel said:

Good stuff by Herb Becker. I had the opportunity to race one of Herb Becker's Commandos a few years back and it was truely amazing. I never thought a Commando could handle so steady and turn in so quick. All that and the creature comforts of little to no vibration thanks to the Norton Isolastics. It really made me wonder why I started to screw around with Featherbeds and Seeley's

Click to expand...

Doug's video of Roebling sure is good at showing what the bike is doing. It's funny but the Mosport video gives the impression that the rider inputs must be very subtle. It looks like the bike is, if not steering itself, not in any need of constant rider input. Maybe that's just what it looks like when somebody knows what they're doing. BTW, The Roebling video looks like the old saying personified, "Passing people like they were standing still."

Dances with Shrapnel said:

I would still like to test and observe the torsional stiffness of a Commando frame with some or all of the modifications.

Click to expand...

It would be nice to be able to check the stiffness of different sections to see if any one of them is really falling down. You could check deflection under a set load with a dial indicator. With the headstock anchored you could see if the front downtubes could use a cross brace or gusset near the headstock for the front iso's. Then you could work your way back, then add the cradle, then swingarm and so forth. I've seen the bracing that Herb Becker uses, but I've never seen those teflon pads before. Nice.

Do you think that the crisp steering is from the rake and offset combination that Herb uses?

Are you using the teflon pad sets?

P.S. FrameCrafters probably has all the dimensions for a Commando but Vern Fueston listed them at the end of this thread.

http://www.nortonownersclub.org/support ... el-offsets