Drainpipe Commando

[video]http://www.youtube.com/watch?v=QreNam7_wmY&feature=related[/video]

Gday hobot,
thank you for that, watched it a few times as its an interesting bike. No doubt about them Noo Zellanders, definately some top machinery over there.
Foxy

Every day I work 20' away from one of the 4 original Dunstall Drainpipe bikes. It is quite a sight. I will take some photos soon.

Hi

I love topics like this. I read about the Drainpipe racers down under a few years ago in Clasic Racer.
I contacted Tim asking for info on his German Drainpipe, as I thought it would make a facinating road bike.

The reason for this facination is I took a Drainpipe owned by my friend to Stafford in 2004. A cracking bike, just like my Seeley MK3 but so much narrower in the thigh area. Ray Pickrel signed the tank at Mallory but was crocked & could not parade it but always said "thats mine that is" his 69 season was unbelieviable plus the Monza records.
Rob sold the bike to the National Motorcycle Museum. It was a parts bike ie no proof of any part being used by anyone. It was purchased from "the factory"
He also has a frame & enough spares to build a second bike. This frame has brackets for road use? Paul Dunstall stated that he never intended building a road bike Drainpipe. As to other bikes. At Stafford I met a CRMCC rider who raced his Drainpipe for a couple of seasons with the club. Before my time unfortunately as I would have loved to see it. I will post a couple of photos.
Anyone else got any info?
all the best Chris

I took a few shots of the Jamie Waters Drainpipe Norton at Grattan a couple of years ago-- here they are



douglasmacrae.com

Doug, was floored by the photo's region and subjects you displayed. Intrigued.

Do ya know how much oil was contained and if over heating or under heating of oil was an issue?

Back to Commando adaptations to get around better, like this drain pipe extreme
or Sealy solid frames - can you give me some feedback on what solid mounts feel like at limits that make ya back off in turns? I remember reading how well the mono-coupe frame handled to allow short cutting corner drifts rather than upsetting chassis oscillations into tire contacts. Do these 'Cdo's' act like any other solid mount?
Slight to scary fork slap coming out of sharper apexes, wobble on CoG in long held sweepers, tire slip causes lean angle to change and therefor the line of aimed travel away from pilot intentions-expectations?
Do they benefit by steering dampers?
Do they leave ya tingling by vibration rather than pure smooth adrenalin?

hobot

Ludwig, on the site you added a link to, there is a Norton 905 section. I can't read the writing, is the crank a machined down standard crank? is the piston a blank? What is the rod made from?
Thanks,

graeme.

Every day I work 20' away from one of the 4 original Dunstall Drainpipe bikes. It is quite a sight. I will take some photos soon.

Click to expand...

Wow, only 4 originals?? Really?? A fellow that was in our local club about 10 years ago had one but I had no idea it was that rare (and no idea if it was original frame). It had an incorrect Dunstall double disc front, but the rest seemed to be original and in good shape. He was always looking for a front brake like the one on the Pickrell bike. He had it for years but never raced it. Might have had a Quaife 5-speed. I know he had a couple.

We thought he was crazy because he tried to sell it to us for $10K. Maybe he was not so crazy after all. I'll have to try to look him up again.

GRM450: from what I understand, there are 2 types of crankshaft on the site:

1: under Products:
the centre is a machined disc from 16MnCr5 steel (high ductile strength).
Balance weights are screwed onto this to suit either a 650, 750 or 850 motor.
Standard journals.
All bolts are 9mm.
Costs: 390 euro + VAT.

2: under Norton 905:
the centre again is a disc, probably form the same material as above.
Journals modified to take balance weights on the inside (closer to the bearings so less crankshaft flex?).

Rod: own production, high tensile steel, 100 grams lighter than the alloy original.
Piston, incl. rings, clips: 250 grams
Lifter: hardened steel, 35% lighter

The motor was scheduled to run by beginning of 2010.
However, the site has not seen changes over the last couple of months.

Regarding the oil Capacity , Long Range tanks or a gallon , Run with 3 pints total.
level around 2 1/2 as 1/2 outside of tank whilst llubricating.

Long Distance , 12 - 24 Hr racers the generally steadier pace alowed 3/4 Gallon without excess
losses in Breather, catch tank level idicateing usage at pit stops.

Personally Id be scared to run a Commando with less if given the choice.Bar lower for short distances in winter.

The Origan ' Fastback ' Oil tank FORMED the left side panel.

For ' Summer ' climates such as Australia , a typical british moderfication and Future ' Omission '
was the ORIGINAL Oil Capacity . Scalded legs from the Long Exposed part of the oil tank ,
Your Std. Tank , Plus the Side exposed surface and interior. Suitable for ' winter " Conditions .
Basically the 110 Deg. Temp , Thrashed in summer , scalded the riders Calf . An Oil Cooler in
that System would obiviate any concerns there , and would be the largest capacity ' Standard "
manufacturers Eqipment , ON a Commando .

The First 'Side Covers ' series one Interstes ? were this panel , without the Oil compartment.

Drifting , Iso Equipped on the Monocoque , were the Dunlop " TRIGONIC " tyres (as seen on
the Japanese Speedway 40 cu. in. triumphs on Tarmac in 'On Any Suday Two ' the sequel ! ) .
The Characteristics of the Design and Compound , The ' HARD Carcass ' tyre was designed
for Optimum Top Speed , in that the ' Center of Contact " was High Aspect ratio , Long and
Thin , Stable UPRIGHT , the narrowness made it possible to take advantage of all of the
Horsepower .As the Upright frictional losses were minimised , adequate traction being
available ,Particularly for BRAKEING .Upright .
The Transition was another Area .
Feathered , to a Degree Brakes and throttle were essential .

Fully Banked , the Area of Adhesion was appoximately Two inches Across on the Front Tyre .
This is the area where a Std. commando will 2 wheel Drift , and Ordinarily doesnt lend
Toward ' sliding the Rear.' trumps slideing progressively Front to back into drift, throttle steered.

Commando Throttle tends to Increase the Angle of Bank , to enable full use to be made of side area
on Trigonic dunlops. THE coeffecent of Friction increased proportionately for a time WITH Drift .

So , he Commanddo LED by Rayborns IRON XR in the SNOW , Blitzed there rivals in the last two races
of the First ? "Trans Atlantic F-750 Challenge ,

Early Jap. 750 racers Suffered these Tyres , Jeff perrys Daytona Suzuki T-500 and T-750 WHOS
frame tubes were Comando diameter ( One Inch ) . Does your Kawasaki weave at Speed ! (Not Q. )

Dunstall Considered that Chassis an improvement over the Previous Endevours . But he wasnt the
' Pilot ' .

Have a picture of Mick grant 'on his beam ends ' I.O.M. on a Seely Commando .lucky not to hit wall.
Grant road ' Factory Norton's ' and Vellocettes prior to his Orientalisation.AND rode ; The Triumph
PR 750 triple , on its last I.O.M. win . Debared from futher participation thereafter as a decade ' Old ' .

Triumphs ran the Same Trigonic KR 76 Tyre Fwd. as Commando , and same Rear K-81 Trigonoc ,
fitted standard fore and aft on all Disc brake Dunlop fitted Norton Villiers triumph 19 in. wheels .

The KR 76 had three Compound choises . acording to Race Track Temperature.
The Harder not finding temperature easily riden of of a race Track,or the middle.
327 compound had tyre life dictated by Brake use . A B-31 without a modern front brake
I saw with tread under but Bald sides.Quite as Excetion to normal race use wear even .

'No sound here'. Id thought the kiwi was Muttering about an Isolastic when his hand was up under
Aft the gearbox mount there. A Commando at pukekohe , ' on the hill ' had Iso There ,
Handling Characteristics were as per triumph , with the Low Triangulation Plane
of the Three ( Two std and One Under ) Isolastic mounts,as in that it would steer through
walking the Aft on the Throttle ,balanced use of which at Speed on track OR on Gravle roads
led to acceptable ' bloody marvelous ' Steering .

So the tyres or the Era defined The Rideing styles of drifting under Power , combined with
High F-750 top speeds , 158 HD , 158 - 160 Commando , Triumph Triples 160 in 1970.

Being in a rift and Leaned over , also on Breaking had enormous side area in Contact,
Drift Controlling Breaking, Perry on the TR 750 presumably loseing 40 MPH from 130
by Drift , before switching lean from Right to Left and continueing progess to 60 MPH
for the Double Right onto the Pukekohe Main straight. A one Kilometer Drag Stip,to
the Brakeing Markers for 'The Hairpin ' . A demanding Horse Power Track ,

Start of the water Cooled Aera. 74 , and the 'Kids bikes' Yam 350s ,
a over ten stone rider would find advantage on the Norton .

Matt, maybe you got dumped on head like me, its hard to convey thoughts into text.
Anywho, enough got from it to connect with me. Talking to old 125 riders and other feed back from vintage races on those triangle profile tires, basically meant that they had two bike positions, straight up and full lean that tire dictated.

You are one of the few who mentions 2 tire drifts and the advantage in bleeding speed by trading one vector of momentum for another in maxed out traction states. There are 2 types of 2 wheel drifts.
One: more upright and crossed up in counter steer dolly wheel front with tires leaving two separated traces. This relieves loads and prevents much if any forward acceleration till over. I only do this to save a turn on loose stuff, NOT to go faster, JUST not add more loads to drift too far over a edge berm to ditch.
Two: remaining in same lean angle, same counter steer [or better straight steer] with both tires presenting their edges to direction of travel drag. This is the supreme chassis and adhesion testing states in powered cornering. It causes both my factory Combats, SV650 and Ninja to go berserk into hi side antics.
If I lean em more they low side, if I don't lean enough they hi side, sucks and limits them to ordinary corner loads I'm bored with. Give em much power in these states just upsets em more or slows em down till the trill is removed.

I'm very surprised but even more pleased to read that the mono coupe Commando retained its isolastic mounts. Wonder how it'd do with a hot Maney 920. Think hard about counter steer pointing front to outside of turn when its the other way you want the front to point to help aim thrusting rear tire.
There comes a time in tight leaned high power turns front will pull bike down.
Only way to use straight steering in times like this is to let or make fall over enough front does not have to help rear tire/bike to lean. It takes going in fast enough to have to crash if doing corners the normal way, wheewoooie.

My wonder is how rigid is too rigid vs how flexy is too unstable. Is there a compromise and what and where should it be made?
My by gosh and by golly testing implies that chassis should be rigid at the ends in wheels and forks and swing arm, suspension but articulate in the middle.
My sense is that even drain pipe has same limitations I've run into on modern rigids. Only bike I've not been able to upset no matter what I've tired is an isolastic Commando with its rear iso pivot stabilized.

hobot said:

Matt, maybe you got dumped on head like me, its hard to convey thoughts into text.

Click to expand...

Maybe you two can understand each other, but I sure have a hard time with both of you :mrgreen:

Don't be insulted, english is a second language to me :wink:

Jean

Its hard to describe handling and bike performance issues no matter the language.
But the whole world is ever trying to make them go faster and handle better yet not over tax pilot. Why else such ugly contraptions as drainpipe or mono-coupes?
In my case, I'm so spoiled now by linked smoothie Commando I want nothing to do with any fast motorcycle that takes the skill and risks real racers do on such scary dangerous handling machines, un uh I'm all done with all that nonsense.

Unless you've regularly and routinely run a bike beyond its predictable controllable states you really can't relate to the weird reports from those that have or still try to. Going by how I see riders position themselves on bikes and the sound of their power use, tells me they are still scared as I am to ride similar bikes in turns.
Just don't know how rigid Norton racers on narrow tires compare but if they are not laughing at the fat tired sports bikes up to 100 mph or so, may be same limitations I've run into on rigids with best hot scrubbed race rubber.

All's I can tell you for sure is that get going good enough on Gravel or Tarmac and the front tire becomes a real danger to depend on as it lifts out of usable traction or is pulling front away from way ya need to go. How do ya handle that?

Alledgedly the Dunlop K-70s and Perrili wots it's (liquerish) were 'The' Dirt Track tyres,
A warehouse in Auckland N.Z. had these weird 4.00 19 Perrilis , I d read were the hot
' Soft track ' tyres.On the Commando ,at any lean ,moveing the trottle meant under
or oversteer generated at the rear wheel.LOW budget at that time, leathal in wet .
so was replaced with 4.00 dunlop K-70.This wasnt Quite as bad, and only 'spun up '
in the wet if you were injuditious with the clutch or throttle. Intentional arrogance
would light it up in 2nd in rain , on the 23 tooth G'box sprocket .Almost became
part of a lampost on old continentals , old style roadrunners , 'through the bays ' ,
( it really did resemble the I.O.M. ? ) if you tried to pull it in more , would drift .
Pilot felt somewhat a passenger , waiting to see if traction regained , observing
concrete curbing approaching . So 'wernt for me '. The KR 76 F & K-81 rear , the
progression in dry from / into drift and corner exit (dont get me wrong, just
approaching ordinarily) were progressive and feedback was excellent.

Two corners , or sweeping redoubts ? I ussually did at 45 , most at 40 , I once
threw into throttle on at 60 in 2nd ,rather than the usual third. Commando
gently kissing interste pipes in a moto cross style crossed up ( slightly )
Drift , no dramas , no fuss , no scares . Figured they were track speeds tho
as one was fairly committed to the exercise.

The 61 Trumph T-120 on 4.10 -19 TT 100s had been the previous motorcycle,
I regard 'units' as nippier steering, but more exciteable.Gritted teeth were
the norm on twisty roads on the Triumph,only ocured on Norton when you
got ahead of youself. The Triumph had taught the definition of
" youre undivided Atention " , & and " Maintaining the Initiative ",
so the Commando was quite relaxing in comparison,tho kept shimmed
between 2 and 4 1/2 thou. , 5 -10 and that 'hinge ' was Triumph like .

The 61 Trumph T-120 on 4.10 -19 TT 100s had been the previous motorcycle,
I regard 'units' as nippier steering, but more exciteable.Gritted teeth were
the norm on twisty roads on the Triumph,only ocured on Norton when you
got ahead of youself. The Triumph had taught the definition of
" youre undivided Atention " , & and " Maintaining the Initiative ",
so the Commando was quite relaxing in comparison,tho kept shimmed
between 2 and 4 1/2 thou. , 5 -10 and that 'hinge ' was Triumph like .

Click to expand...

Food for my soul Mat as I'm newbie that got thrown into poor traction over my head and nil prior experience on motorcycles that could lean much. I can play on Gravel and Tarmac now but still tippy toe when wet. I'd had some wild events on wet roads and muddy off pavement, I saved, so know I've a sense of wet handling, but no confidence I can repeat w/o terror crisis states. What I learned so far is if I cause the skip-drift-slide, on purpose all is well. Its the surprise skips-drifts-slides that's the booga-boo. My solution in desperation on THE G or to get the max out of tarmac ride - is to keep creeping up to crash states, in various ways, [but only one way at a time!], then use the lose of traction you know is going to hit to skew the bike to relieve its loads and shorten the time out of good forward hook up. Best way around for me now, is straight in deepest for the sharpest shortest [to even decreasing radius] turn time, then straight out.

The rigids I've rode, '69 Bonnie to early 2000's Ninja and SV650, ugh and HD's cafe,[ hehe], All get too "excited" to me. I no longer view a crossed up MX or flat tracker slide as a fast or safe way around, unless you have wide clear paths ahead then its a treat, just not best forward hook up. The sharpest corner faceting way is, but that enters the low to high side crash zones.

Consider a slightly banked sweeper, best way around for most, is lean to enter accelerating till steady state they can't exceed or they must widen turn, back off or begin a crossed up slide, not to crash, or if power up some more, lean more or turn forks more, tends tol low or high sides, just exactly like a decreasing radius turn too hot to handle its end.

In above state the CoG and crank inertia, tire profile, road grade etc, determine whether the bike wants to fall right down or hop right up so pilot must compensate-resist, if he don't bike goes its own way. These are the pilot loads that once exceeding traction, vibe bike out of control in a flash or with some terror antics first. I just saw a video of racer getting hi sided off at beginning of a sweeper but bike self corrected out of counter steer into straight steering self leaning and carried on the turn passing other racers! I've looked for example of Ms Peel phase 3 handling for 7 years. Found a stunt rider hands off and above road racer video. I'm still looking for a video that shows a bike handling the transition well, racer got flipped off at transition and the stunter simply never used counter steering to avoid the slow speed flip. Its what makes a flat tire worse to handle right as you are about to put a foot down.

THIS IS KEY PHENOMENON TO OVERCOME!
There are steering phase changes in real cornering, just like going from walking speed to hwy speed in fork and pilot action. If a chassis can handle the steering flip at the transitions and not tend to low or high side then it can thumb is nose at rest of the motorcycledom as poor dangerous corner cripples that can't use a 1/3 of their power, so I've sworn em all off.

The ride I crave requires no athletics, no pilot compensation, no hanging off, no seat motion at all as upsets balance on rear patch, no vibration, no road texture or wind buffet jiggles through chassis, no tendency to change lean angle in slides, with and w/o rear tire spin, just slides wide in same stance and fork setting, as no fight back from a truly Neutral load absorbing-dampened-releasing abnormality.
This of course simply invites one into further cornering states not yet included in human controlled motorcycles physics, only DAPRA Robo Bike. That gives me the hivy jivies, as it knows how to run loose slopes vertical straight steering, YIKES!