Dr. Blair on Dyno Hill- Place your bets!

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My old Ducati Darmah (the touring version of the 900ss) would do 115 MPH up the cut (the highway that goes up hill from the Ironworkers bridge into North Vancouver) It would do that in fourth gear or fifth gear. I have never had the opportunity to go faster on any of my other bikes because now days there is always to much traffic. A lot of the modern bikes go so fast I am never going to find out how fast they can go. I don't think my Norton 850 will get over 100 MPH on that hill. I am pretty sure it is faster than my buddies 750 that has PW3 cams Dunstall 2 -1-2 exhaust and long Dunstalls. Sometimes I trick my friends though by leaving my bike in 3rd for a lot longer than they do.
 
Fast Eddie said:
Interesting to read the John Hudson notes posted in another thread recently. He seems to agree with you Glen that balanced pipes and peashooters will decrease performance, note he’s also negative about the black airbox. Not scientifically conclusive perhaps, but interesting nonetheless:

“As previously mentioned the black cap annular discharge silencers do not significantly reduce power, but they must be kept with the balanced exhaust pipes. If you want to fit earlier separate pipes then you must fit the earlier reverse cone silencers. The reverse cones can be fitted onto the balanced pipes but with a slight loss in power What did restrict performance was the black plastic air box, remove this for a 750 type one to gain performance”.
Click to expand...
When the weather warms I'll try removing the rubber hoses between the airbox and the carbs. It should be fine to run a few miles on clean roads without an aircleaner.
This will require the usual mainjet size trials.

Glen
 
worntorn said:
When the weather warms I'll try removing the rubber hoses between the airbox and the carbs. It should be fine to run a few miles on clean roads without an aircleaner.
This will require the usual mainjet size trials.

Glen
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That will be interesting Glen, my money is on it not making a great deal of difference.
 
“I am pretty sure it is faster than my buddies 750”

let
the
horses

RUUUN!!!
 
A friend has lent me some SS headers for Dyno Hill testing.
He also gave me a full set of early non-balanced Interstate pipes and open mufflers.
In addition I have a new set of big bore pipes to try.
These will all be tried on the 850 Mk3.
Just for fun, I ran it up the hill twice today with its regular exhaust fitted. The result was the same as ever, 100 kmh at bottom and 110 kmh at top.
Will try the SS pipes in a week or two.

Glen
 
I wonder how many quarter mile runs it takes to destroy a Commando's gearbox?

Over the last 3 years I lost 65 pounds, and saved money doing it. I wonder how many 2-1-2 exhaust systems that is good for? It was hard to begin, but thinking of food as fuel rather than an intoxicant helped.

If you operate a Commando understanding what it was designed to do and keep up with the maintenance it will out live you. If you think you can keep up with a modern sport bike, on its' turf stay home crack another frosty and dream on. Bring the spot bike into Norton turf, and for the most part all the sport bike pilot will see is your tail light. There are some very good sport bike pilots, those will always get to the road house before you, but they will respect your challenge. The majority of this fearless genre are waiting/hoping to find a spouse/partner that will insist they stop riding they are the ones who are destined to see your tail light.

So go ahead and pack on as much HP/torque as you can afford. Do you feel lucky?

Best
 
I agree with much of the post with the exception of..."Bring the spot bike into Norton turf, and for the most part all the sport bike pilot will see is your tail light."

If the comparison is about a good rider on a Commando vs a cautious rider on the sport bike, I totally agree. But as much as I'd like to say otherwise, I can't think of anything a Norton Commando (or any other moto of its era) can do better than a modern sport bike of any displacement as far as performance on the road. OTOH, the Commando will certainly generate more interest/lookers when parked out in front of the local bar/pub!! :)
 
Road Scholar wrote " Over the last 3 years I lost 65 pounds, and saved money doing it. I wonder how many 2-1-2 exhaust systems that is good for? "

An infinite number I guess.
The Dunstall 2-1-2 slowed the bike down vs separate pipes.
So does the balance pipe.
Testing is not going as folklore says it should!

Glen
 
RoadScholar said:
If you operate a Commando understanding what it was designed to do and keep up with the maintenance it will out live you. If you think you can keep up with a modern sport bike, on its' turf stay home crack another frosty and dream on.
Click to expand...

Many moons ago when my Commando was my only bike and served as a tourer, sport bike and daily commuter I thought that I had everything I needed. Reality came when I was following a CB1000 through some twisties. I was flogging the Norton quite hard and got right up on his tail. Then I saw him glance in his mirror, saw me and he was gone in a flash.........
 
MexicoMike said:
I agree with much of the post with the exception of..."Bring the spot bike into Norton turf, and for the most part all the sport bike pilot will see is your tail light."

If the comparison is about a good rider on a Commando vs a cautious rider on the sport bike, I totally agree. But as much as I'd like to say otherwise, I can't think of anything a Norton Commando (or any other moto of its era) can do better than a modern sport bike of any displacement as far as performance on the road. ..! :)
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Depends on the type of road and rider.
On really twisty roads ( not twisty by US standards..) it is 10 % bike, 90 % rider.
In the Alps, no matter how much HP you have, or how fast you THINK you are,
the locals will piss on you ..
 
ludwig said:
Depends on the type of road and rider.
On really twisty roads ( not twisty by US standards..) it is 10 % bike, 90 % rider.
In the Alps, no matter how much HP you have, or how fast you THINK you are,
the locals will piss on you ..
Click to expand...
That just gets back to the ability/knowledge of the rider and we all agree on that. But with two equal riders, both with knowledge of the road in question, a Commando is not going through any set of twisties faster than a modern sport bike.
 
MexicoMike said:
..with two equal riders, both with knowledge of the road in question, a Commando is not going through any set of twisties faster than a modern sport bike.
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But not ( much ) slower either.
I know. I have done 1000 's of km in the Alps in company of modern bikes.


Dr. Blair on Dyno Hill- Place your bets!
 
worntorn said:
Road Scholar wrote " Over the last 3 years I lost 65 pounds, and saved money doing it. I wonder how many 2-1-2 exhaust systems that is good for? "

An infinite number I guess.
The Dunstall 2-1-2 slowed the bike down vs separate pipes.
So does the balance pipe.
Testing is not going as folklore says it should!

Glen
Click to expand...
I'd hazard a guess that your test procedure is maybe not quite consistent? :eek:.... Not to start a fight or a war, but i do believe that DR. Blair in an engineering lab setting should have reproducable result . however an open mind says anything is possible , after all Dr. Blairs work is at least 40 yrs old....
 
850commando said:
I'd hazard a guess that your test procedure is maybe not quite consistent? :eek:.... Not to start a fight or a war, but i do believe that DR. Blair in an engineering lab setting should have reproducable result . however an open mind says anything is possible , after all Dr. Blairs work is at least 40 yrs old....
Click to expand...
I get very consistent results after many, many runs (100+ runs) on several motorcycles.
 
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850commando said:
I'd hazard a guess that your test procedure is maybe not quite consistent? :eek:.... Not to start a fight or a war, but i do believe that DR. Blair in an engineering lab setting should have reproducable result . however an open mind says anything is possible , after all Dr. Blairs work is at least 40 yrs old....
Click to expand...
Did Glen ever say he disagreed with Blair?

AFAIK Blair worked on 750s, different CC, CR and head to late 850s.
 
I suspect that the HP increase with the 2-1-2 exhaust as detailed back in the day was accompanied by other changes - main jets, adding velocity stacks, change of muffler, etc - stuff like that. I don't believe a HP increase occurred simply by bolting on the 2-1-2 exhaust with everything else left as OEM.
 
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