Commando Top Speed? (2010)

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I had a '70 Bonneville many years ago and it ran very well. One day on a high speed test I saw 130 mph on the speedo. Doubting what I saw I took the speedo head into the local Smiths shop ( we had an actual Smiths repair shop in Don Mills at the north end of Toronto ) and asked to have it tested at 70 and 130 mph. It came back about 5 mins later and I was told it read 70 at 70 and 131 at 130 so was accurate. Took it out for another high speed run and crouched over on the tank I again saw 130 on the speedo. I whipped the clutch in and chopped the throttle and it instantly dropped to 114 and then rapidly slowed due to wind resistance. So Triumphs vibrate!!
Who knew? Of course Nortons don't vibrate due to their superior patented Isolastic system.
 
Wesley took me to my 1st 2004 INOA rally 1000 miles away in Ohio, delayed by both our various Commando issues, to hesitate at entrance, that we made it and to scan the gathering, for him to say - "Its all only about the Commando."
 
as far as facts & #s go today
https://www.accessnorton.com/Norton...do-land-speed-racer-update.23695/#post-349189
149.2mph
dyno'd at 90 rear wheel hp
Norton Commando, 920cc; Mikuni VM40 carbs, bored to 44mm; extensive headwork to accomodate 44mm intake valves & 38mm exhaust valves; JS Motorsports rods and pistons; .480" lift cam; running on VP Racing Fuels C12 Gasoline. Stock Norton 4sp gearbox. 1.5 mile @ 149.2MPH.

https://www.accessnorton.com/Norton...d-speed-racer-update.23695/page-2#post-349202
I think it's likely that Andy's run is the fastest officially recorded time at a landspeed event for an unstreamlined, un-blown, conventional framed Norton on gas.

https://www.accessnorton.com/Norton...g-saga-of-my-commando-land-speed-racer.22694/
 
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Yes 84K
149+mph with 240 lb rider Andy and no streamlining, officially timed. Herb built the motor.

dyno'd at 90 rear wheel hp
Norton Commando, 920cc; Mikuni VM40 carbs, bored to 44mm; extensive headwork to accomodate 44mm intake valves & 38mm exhaust valves; JS Motorsports rods and pistons; .480" lift cam; running on VP Racing Fuels C12 Gasoline. Stock Norton 4sp gearbox. 1.5 mile @ 149.2MPH.

Commando Top Speed? (2010)
 
So long as we remember that there is no universal thruth
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ah but I beg to differ sir, for we live in a world of science proven truths, verified and peer reviewed
and laws of physics and mechanics are known, and stock Combats do NOT do 135mph
and particularly they do not with a single Mikuni
and no amount of long and rambling deflections will ever cover up for insistent lies
1970s era Commandos do not give handling lessons to modern "corner cripples"
Les rightfully allows that kind of talk on this forum, I get that, but I have every right to speak out
in a respectful and non personal attacking manner
 
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If anyone truly believes a stock Commando can do 135 mph, then I suggest they have all sharp instruments removed from their home. Definitely no power tools.
 
I have every right to speak out
in a respectful and non personal attaching manner

Indeed you do sir! I genuinely couldn’t agree more.

And we should all exercise that right. That is in fact my main argument in recent threads.

Provided, as you say, it is done in a respectful and non personal manner.
 
Also, it is correct and proper to call BS when one see BS. Nothing disrespectful or personal about it. BS is BS.
 
The top speed of my 750 commando is around 110 maybe 115 if you waited long enough
This is sitting upright
My 850 would do just over 100
I had a combat interstate that was running on R this would nudge 120 but this was almost prone with Vincent straights fitted
 
this part jumps out

https://www.accessnorton.com/Norton...-commando-land-speed-racer.22694/#post-337486
Commando Top Speed? (2010)


& sez what stock cases can take with this combo, in this application
Commando Top Speed? (2010)
Yes but there is a reinforcing plate on those stock cases to help prevent them from cracking - probably heat shrunk into place. And the crank would need a radius as below.

Commando Top Speed? (2010)


And it would never stay together without the reduced vibration/stress from the lightweight pistons shown above and modified by Herb Becker.
 
I value the clearly stated factual information that is posted here and many of the funny comments too. I've owned my norton for 40 years. It's an overwhelming task to learn every quirk of a commando by yourself. Prior to the internet, learning it by yourself was the norm. The technical knowlege in this community has helped me greatly in the short time I've been here. I appreciate the tone of the site which is set by the combination of the many people who contribute here.

If you're the most prolific poster on a site and you're posting hyperbolically in an illiterate manner, you're setting a certain persistant unique tone. IMO, it's not helpful to others seeking factual information, at least I haven't found it to have any value for me.

But as was said, if you don't like what a person writes or the style in which they write it, then don't read their stuff. That's what I do. As a kid, I read the lil' abner comic strip, so I can figure out what he's saying if I read his post 5 times, but I've found the information to be too hyperbolic, so now I don't waste my time. Perhaps I miss out on some unique entertaining gem of a comment occassionally, but his prose is too much work to translate into english sentences for me.

As a rule, If I have something to add to a thread I try to say it in a single post. If someone querys my comment, I'll post again to explain myself further if need be. Unless I'm the thread starter or the thread becomes directed at me, I add my contribution to a thread without making the thread "all about me"...

In all the forums of which I've been involved, there are always people who see the forum as purely entertainment, as well as those who see it as purely a vehicle to fact check and exchange good information. IMO, the site owner has to set the tone as to how much of each ingredient he wants on his site. People posting prolifically should be aware of how much they skew the overall tone of the site. If the site owner isn't annoyed by someone's tone... then there's no problem.

I wish hobot's stuff was easier to read... but it's not so I don't bother reading it.



As far as how fast an average norton can go without blowing up, I know the answer isn't 137mph. I've nipped at 100mph a few times just to see if my commando would blow up there, and it didn't thankfully. I don't have any special parts inside my engine so I wouldn't push it further than 100mph for just a few seconds. I run a 21/42 sprocket combination. I've always wondered what the average safe RPM range a commando can regularly run up to without eventually shooting a rod out of the crank case. I hope my engine lasts a long time as it is. It's been a 40 year long road getting to where I am now. I'm sure I've spent twice as much money on the bike as it's currently worth... so good info is important to me to keep my bike on the road and running well.
 
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Commando Top Speed? (2010)


I have looked for decades for similar Norton build to my P!! dedicated top end only rocket. Woods & Axtel's comes dang close but not as see though minimalist nor front as low - to finally see it shown above in similar gold dusted deep blood red candy tank - to me a bit chopper stance - wheelie limited forks. P!! was cheap d/t Silva Mind Control win with a dash of cocaine dealing d/t Tallahassee's Florida Pagent's Norton dealership pilot crashing on last sprint at ~150 and then Hondas and Kiwi's took over. Thanx for topping hobot out in delight. In Vietnam era, friends/enemies nick named me Kowalski d/t louder sucking open intake than exhaust & embarrassing red necks in Z21 Cameros or crashing Porshes trying to follow on wet frwy clover leafs a Vista Cruiser wagon on Tiger Paws full of stoned witnesses thobbing on Jimmy Hendix 8track. Only thing ever passed Olds wagon was a James Bond Aston Martin DB5 on Hwy 441/Hwy 8/Tamiami Trail, but not in a flash but neat interval of appreciation - inspection. This is how I want to go, not in sleep or squirming in pain like Wes. Sudden Smithereens.

Commando Top Speed? (2010)
 
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not clear on the "heat shrunk" part? i'm seeing what looks like a flat steel plate with 4 allen bolts, is that something new? 1st time i've seen it

what's the "crank radius" about?

Yes but there is a reinforcing plate on those stock cases to help prevent them from cracking - probably heat shrunk into place. And the crank would need a radius as below.

Commando Top Speed? (2010)


And it would never stay together without the reduced vibration/stress from the lightweight pistons shown above and modified by Herb Becker.
Commando Top Speed? (2010)
 
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not clear on the "heat shrunk" part? i'm seeing what looks like a flat steel plate with 4 allen bolts, is that something new? 1st time i've seen it

what's the "crank radius" about?


Commando Top Speed? (2010)

Yes, it’s a plate with 4 screws, but Jim’s point is that it’s probably a shrink fit over the main bearing housing. It needs to be really if it’s going to add max strength.

The radius is referring to the mod to grind a small radius which prevents the primary output shaft having a shape edge where it meets the crank.
 
The "heat shrunk" was a practice back in the day to beef up the drive side bearing boss as it is prone to cracking. The disk is machined with an interference fit, heated, and then placed over the short spigot on the drive side of the case with the hopes of reinforcing the drive side bearing boss. I've seen examples where the plate was also welded in place.

The "crank radius" as shown in JS picture is not very clear. I think the term is "under cutting" where a larger radius is realized by cutting back into the bearing thrust face on the crank cheek. A larger filet radius is a major stress reducer (stress riser reducer). Look carefully at the crank main journal radius where there is normally tiny filet radius is now a much larger radius that is "cut back" into the crank cheek.
 
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