Commando Quarter Mile Times (2014)

8) :mrgreen:

:shock: :twisted: :mrgreen:

The 12.2 came with the ' optional ' 17 T sprocket ,on the ' Standard ' Dunstall .

Theres a string of 12.7 Second early 750 tests . Before Villiers got in on the act .



Hows YOUR Hole Shot ? :mrgreen:

:shock: :?

Cycle Guide 1972

Its the launch that makes or breaks sprint times on same/similar cycles, especially if engine as weak as a Commando as things happen so slow after shift out of 1st it don't take much skill the rest the way just stay tucked and snick up fast as possible though a kill button/WOT shifts is faster than throttle and clutch shifting. Best launch on Norton power and flywheel effect gotten dropping clutch about 6000 rpm for a wheelie about 45' with some tire spin below 10% best traction leaving the line. It not going fast enough on 2nd shift it can cause hesitation in acceleration d/t tire spin so a bit of moderation off WOT if your Norton is powerful enough to worry about this. This can cause a road racer to flinch to conservative side of power dump as quite possible to wheelie vertical & beyond or just make black marks going no where fast. Drag launches scare me more than trying to toppie a Commando or any bike. Btw had little Harley bad boy type tour with a fella in Eureka Springs with him leading the way up/dn the narrow steeps with him blipping to jerk forward and make more noise so I did too on factory Combat Trixie > to soon be taming down as after a couple-three revs up shut downs in a row it would start to wheelie too dam easy. I have not learned the balance point of a Commando but did eventually on the P!! but would take such hi rev low throttle clutch release skill to over come the 2" built low front I had to be going over 40 mph or just spun rear and already knee it was powerful enough to pull a vertical wheelie down a steep to leave me like a flag off handle bars and feet jerked off pegs with seat flipped up into my face hard from breaking through its fiber glass weakness. But the P!! was purpose built so not fair comparison to the over weight road going Commandos. Peel was abnormal too able to out pull moderns to 90 as they were wheelie limited but Peel was like 2 sec slower 1/4 miler than the P!! I don't know who was more surprised my this, me or the sportsshots, as we both aimed into a tight turn I'd see them rear up then fall back so didn't take too long to realize I really could get away with pissing em off before a contesting type joy ride with - Can I tag along... till bored. Of course once past 90 in the opens they could catch me after about 130 down the straights though from standing starts the liter bikes would snick 3rd and pass me but being a corner cripple we'd all pile up at next turn but no room to pass in public. So go out and enjoy excessive power play though I always ask myself is this a good day to die doing it.

I can't remember the names of the two local riders....but I do recall that I recognised both of their names as national/international racers.....names I have seen before.....

Yes, it has to be said that Norman White is not a large man....but the article is more generous and makes no references to garden ornaments, pointing out that works testers have a different skillset to the rest of us, including those local riders....

Wish I could find the article, maybe else someone can, but I also recall that the Norton literature gives a figure in the 12.9s and the dealer had not been able to get anyone to do that, struggling with 13s, along comes Norman and does 12.26 and lo and behold the local riders did then get into the 12.6s....

I think it is more about technique, and maybe if the dealer had recruited drag racers they would have performed better that circuit racers....

" by beng » Sun Apr 24, 2011 7:36 pm

In 1964 the Norton 500cc Daytona twins that were put together by Dunstall for Berliner Motors to race that year made over 50 crank horsepower with a stock 88ss engine. The only modification was lightened rockers and cylinders were skimmed .033" to raise compression to 10.4:1, Amal Gp's were added and an open megaphone exhaust. Engines had all standard street internal parts. On another actual dyno sheet I have from the Norton works, it shows 54bhp @7600rpm. I have the dyno charts, sheets and spec. sheets for the engines and bikes telling all modifications signed by Dunstall..... "



therefore 76 2 750s not off . :lol:

Matt Spencer said:

" by beng » Sun Apr 24, 2011 7:36 pm

In 1964 the Norton 500cc Daytona twins that were put together by Dunstall for Berliner Motors to race that year made over 50 crank horsepower with a stock 88ss engine. The only modification was lightened rockers and cylinders were skimmed .033" to raise compression to 10.4:1, Amal Gp's were added and an open megaphone exhaust. Engines had all standard street internal parts. On another actual dyno sheet I have from the Norton works, it shows 54bhp @7600rpm. I have the dyno charts, sheets and spec. sheets for the engines and bikes telling all modifications signed by Dunstall..... "



therefore 76 2 750s not off . :lol:

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As I said in my report on the MkIII Mathew, the machine is more of a cruiser than a dragster. It accelerates quite okay, but not like a combat though both my combats had 19T sprockets, so not a fair comparison. I did later fit a 21T sprocket to my original combat in 73 which tamed it considerably, but that's so long back I could obviously not compare. However, the MkIII just feels more like it wants to cruise and doesn't have that "rev her to 7000 desire" one gets with a combat. The combat is a more free revving engine. Even my 21T version was that, just slower getting there obviously than the 19T.

This discussion started because I queried 1up3down's road test figures putting the MkIII some three seconds behind a normal (no bean can or black box) 850, and his comment about being much heavier. I put the road test in here because it supported 1up3down and was worth reading. I wasn't trying to win anything, just searching for the truth. I think the 3 sec difference sounds wrong, and also weight difference, as does another who posted in here.

But the road test is pretty accurate regarding feel. 2000 to 4000rpm is ridiculous but screwing it up to 7000rpm all the time, not what it wants to do. My MkIII has peashooters and no black filter box, but a Mikuni instead. Big advantage for me is my fastback styling, which adds at least 20mph to the machine, even when parked she looks like she's moving at 20mph. Goes home at that speed from the pub when I haven't even pressed the starter button (it's all down hill)

If you want to go cruising, take a MkIII.
If going to the drag strip, the combat is the machine for you.
Or the 850 1up3down quoted as fastest.

Phil

Matt Spencer said:

Cycle Guide 1972
[i

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Young Mathew
Thanks mate, that's exactly what I was after from the Cycle Guide 7 Super Bike Comparison.
Not that you put it in here for me. But thank you. I print all of these off and they go in my Norton file.

Phil

Phil, I don't think the road test is very accurate in any way.
He cites dual 30 mm carbs, should be 32, and describes the front disc brake as immensely powerful. Must have been on a different machine of some sort!
Some might call the front brake adequate, most call it wooden, I call it hopeless ( for mountain riding at least)

Glen

Front brake actually worked very well when new.

worntorn said:

Phil, I don't think the road test is very accurate in any way.
He cites dual 30 mm carbs, should be 32, and describes the front disc brake as immensely powerful. Must have been on a different machine of some sort!
Some might call the front brake adequate, most call it wooden, I call it hopeless ( for mountain riding at least)

Glen

Click to expand...

Yes, sorry Glen
I should have mentioned I meant accuracy regarding engine feel. Except the power drop off or what ever he mentioned up around 6000rpm. I can't comment on that part as I don't experience it having no black box and sporting peahooters (I have read though the black box was the culprit, not the bean cans).

But yes I saw those issues too. 30mm Amals I thought might be a typo. But description of the front brake? I laughed at that one too. The standard Norton disc brake feels dead and is immensely powerful in resisting doing anything at all. But I guess apples with apples, it was not so bad for 70's technology. Mine now BTW has good feel and is not too bad. All that's been done is a S/S MC sleeve and S/S brake line.

But the MkIII is certainly torquey. Oxleys Hill Rd is a very steep climb heading west out of Bowral township. My MkIII goes up there in top gear at low revs like the hill wasn't even there. More so than a combat would. But same I imagine as would all 850's. Only other bike I experienced similar was my BMW R1150GS, but that wasn't in top (6th) gear. I'm sure a Harley would too. But they are big capacity mothers.

Now that you've let the cat out about the MkIII front brake, I guess we'll cop yet another flogging from the boys, not that they have a better one, brace yourself for further abuse.

By now most Commando riders have had one or two good scares from the front brake and are still too shaken to argue it's effectiveness. The rest are busy trying to get stopped :mrgreen:
In fairness, if you have arms like Popeye the stock brake has one good stop in it, after that it is wooden block time.
With the resleeved master cylinder, Popeye arms are not needed, but still just one good stop, then the tiny pads overheat.

Glen

worntorn said:

By now most Commando riders have had one or two good scares from the front brake and are still too shaken to argue it's effectiveness. The rest are busy trying to get stopped :mrgreen:
In fairness, if you have arms like Popeye the stock brake has one good stop in it, after that it is wooden block time.
With the resleeved master cylinder, Popeye arms are not needed, but still just one good stop, then the tiny pads overheat.

Glen

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I only make one good stop, pulling up at the pub from 80mph, I've no idea what it would do after that. I've gotten to where I was going, why should I care?

Phil

worntorn said:

The Rider's manual weights are the same as Haynes.

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Data printed in Haynes manuals of the period is often inaccurate or doesn't apply to all models covered by the manual.

worntorn said:

I don't know why the big white workshop manual gives such a different number.

The weight shown as dry weight in the Rider's manual is about in line with the weight I measured.

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The dry weight in both the the '73 and '74 850 brochures is given as: "418-430 lb. depending on specification".

http://www.classicbike.biz/Norton/Broch ... LineUp.pdf
http://www.classicbike.biz/Norton/Broch ... ochure.pdf

So did the factory get the pre-Mk3 850 dry weight wrong?

Or due to the similarity between the numbers, that the Mk3 dry weight information quoted in the handbook simply hadn't been updated from the previous 850 figure?

I would agree however that the manual figure is perhaps a little on the high side.

L.A.B. said:

worntorn said:

The Rider's manual weights are the same as Haynes.

Click to expand...

Data printed in Haynes manuals of the period is often inaccurate or doesn't apply to all models covered by the manual.

worntorn said:

I don't know why the big white workshop manual gives such a different number.

The weight shown as dry weight in the Rider's manual is about in line with the weight I measured.

Click to expand...

The dry weight in both the the '73 and '74 850 brochures is given as: "418-430 lb. depending on specification".

http://www.classicbike.biz/Norton/Broch ... LineUp.pdf
http://www.classicbike.biz/Norton/Broch ... ochure.pdf

So did the factory get the pre-Mk3 850 dry weight wrong?

Or due to the similarity between the numbers, that the Mk3 dry weight information quoted in the handbook simply hadn't been updated from the previous 850 figure?

I would agree however that the manual figure is perhaps a little on the high side.

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Same same with the Clymer Service-Repair Handbook, gives only one 850 weight yet it covers the MkIII as well.
I think Les, we can only conclude that the MkIII was so much lighter than any other Commando, they had to hide the fact but couldn't remember from one book to the other what lie they had quoted. The rear disc brake shaves 50lbs weight off for starters, and the black filter box saved another 20lbs at least. Standing quarter times were adjusted and mis quoted for the same reason.

That's my story, and I'm sticking too it!

Phil

Phil Yates said:

I think the 3 sec difference sounds wrong, and also weight difference, as does another who posted in here.

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Phil, the difference is TWO seconds, not three, or between 12.5-13.0 the generally accepted pre Mark3 quarter mile time versus the 14.5-15 second Mark3 time

1up3down said:

Phil Yates said:

I think the 3 sec difference sounds wrong, and also weight difference, as does another who posted in here.

Click to expand...

Phil, the difference is TWO seconds, not three, or between 12.5-13.0 the generally accepted pre Mark3 quarter mile time versus the 14.5-15 second Mark3 time

Click to expand...

It's all too late 1up3down. I'm very sensitive. Until you admit you bodgey'd the figures, I just can't bring myself to talk to you

But I'll get over it, just give me time.

1up3down said:

Phil Yates said:

I think the 3 sec difference sounds wrong, and also weight difference, as does another who posted in here.

Click to expand...

Phil, the difference is TWO seconds, not three, or between 12.5-13.0 the generally accepted pre Mark3 quarter mile time versus the 14.5-15 second Mark3 time

Click to expand...

But seriously 1up3down,
I had that 12.2 hot 850 time in my head against your stock MkIII time of 15.0.
But I know the two can't be compared.

I guess it's fair to say that now 40 yrs on, the only seriously fast Commando by today's standards is the one piloted by hobot.
The rest of us are just playing with old dinky toys, and loving it.

Phil

My P!! had dual 30 mm Amals so put that in your pipes to smoke a rear on. Sorry to hear about poor front brakes and straining up steeps, as its front tire lack of grip that limits-scares me not lack of brake power and with 19T i tend to habitually try to snick into 5th over drive so not so throttle responsive its invites exceeding speed limits too much. As for low down dirty performance my bench mark is climbing off road slow steeps loaded and giving sudden quite high throttle to keep climbing at a steady pace yet not bog down nor spin right out, wonderful sure control my modern V-twin can't match. If I over do throttle on purpose it spinning up right now as needed yet no more. My V-twin will chug down stall lugging 1st but will snap spin rear in low gears too but tends to over spins rear so delays hook up which is not fun loosing control so gave up on it as last resort to ride and only on real paths.

After my 1st week on 1st Combat of crashes mild to severe past X-mass tree and mostly healed i'd enter hi way steep mid way between two blind turns so incentive to get up to speed - would WOT 1st to 7000ish then slight throttle cut clutch-less snick to 2nd i'd hear grinding/squealing sounds with part a second hesitation i sure didn't want or expect. I thought the clutch was slipping, nope turned out to be catching rubber as they say in the old 4 on the floor days. I tamed down some to accelerate faster. Skinny tires definitely traction limited when up right. The Commando torque to weight is still dang impressive - till down side of torque curve then gets boring waiting on top out in 3rd and 4th.

hobot said:

My P!! had dual 30 mm Amals so put that in your pipes to smoke a rear on. Sorry to hear about poor front brakes and straining up steeps, as its front tire lack of grip that limits-scares me not lack of brake power and with 19T i tend to habitually try to snick into 5th over drive so not so throttle responsive its invites exceeding speed limits too much. As for low down dirty performance my bench mark is climbing off road slow steeps loaded and giving sudden quite high throttle to keep climbing at a steady pace yet not bog down nor spin right out, wonderful sure control my modern V-twin can't match. If I over do throttle on purpose it spinning up right now as needed yet no more. My V-twin will chug down stall lugging 1st but will snap spin rear in low gears too but tends to over spins rear so delays hook up which is not fun loosing control so gave up on it as last resort to ride and only on real paths.

After my 1st week on 1st Combat of crashes mild to severe past X-mass tree and mostly healed i'd enter hi way steep mid way between two blind turns so incentive to get up to speed - would WOT 1st to 7000ish then slight throttle cut clutch-less snick to 2nd i'd hear grinding/squealing sounds with part a second hesitation i sure didn't want or expect. I thought the clutch was slipping, nope turned out to be catching rubber as they say in the old 4 on the floor days. I tamed down some to accelerate faster. Skinny tires definitely traction limited when up right. The Commando torque to weight is still dang impressive - till down side of torque curve then gets boring waiting on top out in 3rd and 4th.

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I'd look into those grinding/squealing sounds hobot, are you sure you didn't hook a rabbit in the rear chain?
Nothing was straining up a hill. All I was alluding to was better low down torque with the MkIII than combat. I'm talking standard combat. And standard front brake, to be polite - shithouse. MkIII also.