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Norton Commando Land Speed racer update

Classic Norton Commando Motorcycles.

Re: Norton Commando Land Speed racer update

Postby lcrken » Fri Sep 08, 2017 9:55 am

Fred's best recorded speed was 155.722 mph. Some more info and a great picture on page 6 of this thread

commando-top-speed-t8277-75.html?hilit=commonwealth%20norton

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Re: Norton Commando Land Speed racer update

Postby lcrken » Fri Sep 08, 2017 10:07 am

And one last link. More pictures on page 2 of this thread

john-caffrey-vendetta-seeley-mk4-t2307-15.html?hilit=commonwealth%20norton

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Re: Norton Commando Land Speed racer update

Postby jseng1 » Fri Sep 08, 2017 12:23 pm

I think Fred tied (or nearly so) the record back then at 155 mph on Nitrous.
My question - is Andy's 149mph run the fastest recorded unstreamlined Norton on gasoline?
Both Andy and Fred's high speed bikes hold a lot of interest for me because both used JS pistons & rods (Fred also used a JS2 cam).
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Re: Norton Commando Land Speed racer update

Postby acotrel » Fri Sep 08, 2017 3:49 pm

How do you know if your motor is capable of pulling a higher gear and taking the bike to a higher speed, if you don't raise the overall gearing ? If the strip is long enough, you probably don't need a close ratio box to get you up through the gears quickly, but the heavy Commando crank determines how fast the motor will spin up to peak revs in response to the throttle.
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Re: Norton Commando Land Speed racer update

Postby lcrken » Fri Sep 08, 2017 4:05 pm

acotrel wrote:How do you know if your motor is capable of pulling a higher gear and taking the bike to a higher speed, if you don't raise the overall gearing ?


Not sure what you're getting at here, Alan. That's exactly what they did. Started with 40T rear, switched to 39T for a run, and down again to a 38T for their best run.

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Re: Norton Commando Land Speed racer update

Postby lcrken » Fri Sep 08, 2017 4:50 pm

jseng1 wrote:I think Fred tied (or nearly so) the record back then at 155 mph on Nitrous.
My question - is Andy's 149mph run the fastest recorded unstreamlined Norton on gasoline?
Both Andy and Fred's high speed bikes hold a lot of interest for me because both used JS pistons & rods (Fred also used a JS2 cam).


Fred's 155.722 mph was an exact tie to the existing record, so he didn't get credit for a new one, but it was still a pretty good run for a Norton. When Fred first ran the bike at Bonneville in 2008 he was running on gas, with no nitrous, and his speeds were in the 130s, as I recall. More engine mods and adding the nitrous eventually got him into the 150s. The fastest time recorded at a landspeed meet for an unstreamlined, conventional framed Norton that I know of is the 161.093 mph record set by Jack Smith at El Mirage in 1999 in the 1000 A-PBG class. He was running an 850 Commando (unstreamlined) on gas, but with a turbocharger. That doesn't mean there haven't been higher speeds at other landspeed courses around the world, just that I don't know about them.

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.

Of course we still have the anecdotal stories of 160+ mph Commandos on race tracks, and some of them might even be true. But that's not the same as showing a time slip from a real speed event.

FWIW, the current records at Bonneville in the 1000 M-PG (1000 cc modified production bike, pushrod engine, naturally aspirated, on gas) class are 163.303 mph with AMA and 157.980 mph with SCTA. The first is held by a Triumph triple and the second by a Guzzi.

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Re: Norton Commando Land Speed racer update

Postby acotrel » Sat Sep 09, 2017 1:31 pm

'Not sure what you're getting at here, Alan. That's exactly what they did. Started with 40T rear, switched to 39T for a run, and down again to a 38T for their best run.'

I realise that is what they did, but when you are riding the bike and the motor is revving near peak, it always looks as though it is going as fast as it can. When you use the combination of close ratios and increase the overall gearing you get to a higher speed quicker. It is very deceptive. In a land speed record attempt, getting there quicker probably does not matter so much as long as the strip goes far enough towards the horizon. What always puzzles me is the difference between torque and horsepower and the effect they have on gearing. With a Commando, you usually have relatively more midrange power then top end - which one counts more in a land speed record attempt ? In other words would it be better to use 6 speeds, very close ratio with very high overall gearing, so that by the time you reach the speed trap, you have just stopped accelerating ? Or is it the fact that wind resistance means the determining factor for top speed is simply top end horsepower ?
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Re: Norton Commando Land Speed racer update

Postby lcrken » Sat Sep 09, 2017 4:20 pm

acotrel wrote:'Not sure what you're getting at here, Alan. That's exactly what they did. Started with 40T rear, switched to 39T for a run, and down again to a 38T for their best run.'

I realise that is what they did, but when you are riding the bike and the motor is revving near peak, it always looks as though it is going as fast as it can. When you use the combination of close ratios and increase the overall gearing you get to a higher speed quicker. It is very deceptive. In a land speed record attempt, getting there quicker probably does not matter so much as long as the strip goes far enough towards the horizon. What always puzzles me is the difference between torque and horsepower and the effect they have on gearing. With a Commando, you usually have relatively more midrange power then top end - which one counts more in a land speed record attempt ? In other words would it be better to use 6 speeds, very close ratio with very high overall gearing, so that by the time you reach the speed trap, you have just stopped accelerating ? Or is it the fact that wind resistance means the determining factor for top speed is simply top end horsepower ?


Kind of both. The determining factor for top speed is always top end horsepower, as long as the course is long enough, but you also have to have gear spreads small enough to stay in the power band (which can be pretty narrow) when you shift, or you will fall far enough off the power curve that you can't pull the taller gear. I've had that happen when I geared too tall, and had to drop back to 4th gear because I couldn't pull enough rpm in 5th to get into the power band. I run a close ratio 5-speed in my Norton, and don't normally have that problem. I think it would work as well with a close ratio 4-speed, as long as it had the same ratio for the top two gears as the 5-speed, but I already had the 5-speed in the bike when I first went to Bonneville, and haven't had any reason to change it. I'm a little nervous about the period Quaife's durability with the larger motors on nitrous, but Bonneville doesn't require harsh downshifts, which is what I think causes most Norton gearbox failures, and it's working ok so far.

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Re: Norton Commando Land Speed racer update

Postby Eldo » Sat Sep 09, 2017 5:50 pm

acotrel wrote:How do you know if your motor is capable of pulling a higher gear and taking the bike to a higher speed, if you don't raise the overall gearing ? If the strip is long enough, you probably don't need a close ratio box to get you up through the gears quickly, but the heavy Commando crank determines how fast the motor will spin up to peak revs in response to the throttle.


We started our weekend with a 40T rear sprocket (40:70 primary, 18:40 drive = 3.88 final). We dropped to a 39T in the rear, and still pulled just over 7000rpm (peak hp is at 7500rpm on the dyno). As we were still accelerating between the 1 mile and the 1.5 mile, we decided to try dropping another gear, down to a 38. We pulled the gear right up to ~7200rpm no problem, and again found we where accelerating between the 1 and the 1.5.

We did 6 runs over the weekend, and we consistently accelerated 2.5mph between the 1 and the 1.5. On my last run, I missed the 2-3 shift, and it took 3 tries to get the bike into 3rd. I'm thinking we lost ~2-3 seconds of power, so I actually (and for the first time) took my feet off the pegs and pointed my toes back, hugging my ankles on the rear shock springs. This run we picked up 5mph between the 1 and the 1.5, but rpm stayed pegged at ~7200rpm.

This leads me to think that we have gains to be made in aerodynamics. I am 6' 3", and 240lbs. I can definitely loose 20 lbs, but I doubt I could shed much more than that, as my BMI (Body Mass Index) isn't terrible. So far I have not given "aero" too much thought, instead focussing on getting to the track, being prepared, making consistent runs, keeping the motor together, etc. Now I will begin to look at ways to improve my aero. Moving my front brake M/C, cleaning up my cable routing, handlebar position, etc. The more I look, the more I see areas for aero improvement.

That being said, I also think we could pull another gear. We pulled that 38T very strongly all the way through, so I am really interested in seeing where it will drop off.

The point is, I guess, I don't "know" the motor is capable of pulling a higher gear, but I think it might, as we are still accelerating though the 1.5 mile. I feel when my speed is the same from the 1 to the 1.5, I will then be "topped out". We'll have to see. One of the nice things about Loring is the lack of wait times. You can get so many runs in that it's not so bad giving a couple up for experimenting. At Bonneville (Speedweek, anyway) You can go a day and only get 1 run in. Even later in the week, 5 runs in a day is a lot of work, so you're really trying to make each run a record run.
Last edited by Eldo on Sat Sep 09, 2017 6:12 pm, edited 2 times in total.
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Re: Norton Commando Land Speed racer update

Postby Eldo » Sat Sep 09, 2017 6:08 pm

One thing I found curious was that we dyno'd with 7500rpm being peak hp, and we wound up not being able to pull 7500, but pulling just below that very consistently. To me, this shows that the torque curve is playing a more important part than I thought. I, too, wonder what a close ratio 'box would do for us.

At this time, I'm not too interested in exploring forced induction (turbos or supercharges). I am interested in investigating the "Partially Streamlined" class, as I feel it would level the playing field a bit, in regards to my size. While I don't feel that my weight is too detrimental, I think my shoulders are pretty wide, and I'd love to see what we could do if I was tucked in behind a fairing.
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Re: Norton Commando Land Speed racer update

Postby jseng1 » Sun Sep 10, 2017 10:21 am

Can you lower the ass end with shorter shocks? Can you cut down the gas tank - or is your face already in the triple clamps?
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Re: Norton Commando Land Speed racer update

Postby Fast Eddie » Sun Sep 10, 2017 10:33 am

Aerodynamics makes an exponentially bigger difference the faster you go.

Altering small things on the bike to allow you to tuck in better, and, as daft as it sounds, practicing tucking in as tight as you can, could well yield several MPH.

Unless you're experienced at racing or similar, most of us aren't nearly as tucked in as we think we are, so it's definitely something to practice, and get someone to take side on and frontal photos so you can see where you might be able to reduce that frontal mass a little here and there.

When's your next outing? Your results are awesome and I can't wait for the next round!
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Re: Norton Commando Land Speed racer update

Postby Eldo » Sun Sep 10, 2017 6:27 pm

jseng1 wrote:Can you lower the ass end with shorter shocks? Can you cut down the gas tank - or is your face already in the triple clamps?


I made the rear shock mounts with 2 holes; the first set for stock ride height, and the second set for a 2" drop. Also, I'm running Honda CB650 forks, and I made several different lowering spaces to install under the compression rod, above the top out springs. I made sets to lower 1", 2" and 3", and I am currently running the 1" lowering spacers, to bring the forks to the factory "Norton" ride height. I could install the 3" lowering spacers in the forks, and move the rear shocks to the 2nd hole and have the whole bike sitting level, at a 2" lower ride height.

We made the gas tank out of fiberglass from Dunstall molds, and it is made in 2 parts, the top and the floor. I "sectioned" the top 2" before we glued the floor in, so the tank is actually 2" shorter already. , and the seat is extended 5" so I could get my butt way back and lay down with my head right down on the tank.
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Re: Norton Commando Land Speed racer update

Postby Eldo » Sun Sep 10, 2017 6:37 pm

Fast Eddie wrote:Aerodynamics makes an exponentially bigger difference the faster you go.

Altering small things on the bike to allow you to tuck in better, and, as daft as it sounds, practicing tucking in as tight as you can, could well yield several MPH.

Unless you're experienced at racing or similar, most of us aren't nearly as tucked in as we think we are, so it's definitely something to practice, and get someone to take side on and frontal photos so you can see where you might be able to reduce that frontal mass a little here and there.

When's your next outing? Your results are awesome and I can't wait for the next round!


Yeah, we live in Waterloo, Ontario, and the University of Waterloo has a great engineering and physics faculty. Also, we are becoming a real "high tech" hub, and there are lots of "start-ups" being fostered, many in conjunction with the University of Waterloo. One such "start-up" company is working with the U of W Fluid Dynamics laboratory, and is developing a computer generated "Virtual" wind tunnel, so I have been in touch and we'll try to get some aerodynamic positioning info over the next few months. I'm looking forward to seeing where I can make some gains.
I also contacted the real, actual U of W wind tunnel facility, but they suggested I have a budget of $10,000 to START the session, so that is just not financially realistic for me.
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Re: Norton Commando Land Speed racer update

Postby Fast Eddie » Sun Sep 10, 2017 11:21 pm

Eldo wrote:
Fast Eddie wrote:Aerodynamics makes an exponentially bigger difference the faster you go.

Altering small things on the bike to allow you to tuck in better, and, as daft as it sounds, practicing tucking in as tight as you can, could well yield several MPH.

Unless you're experienced at racing or similar, most of us aren't nearly as tucked in as we think we are, so it's definitely something to practice, and get someone to take side on and frontal photos so you can see where you might be able to reduce that frontal mass a little here and there.

When's your next outing? Your results are awesome and I can't wait for the next round!


Yeah, we live in Waterloo, Ontario, and the University of Waterloo has a great engineering and physics faculty. Also, we are becoming a real "high tech" hub, and there are lots of "start-ups" being fostered, many in conjunction with the University of Waterloo. One such "start-up" company is working with the U of W Fluid Dynamics laboratory, and is developing a "Virtual" wind tunnel, so I have been in touch and we'll try to get some aerodynamic positioning info over the next few months. I'm looking forward to seeing where I can make some gains. I also contacted the U of W wind tunnel facility, but they suggested I have a budget of $10,000 to START the session, so that is just not financially realistic for me.


I think a wind tunnel would be good if designing a fairing from scratch, but to find ways to tuck in as much as possible, I'd say that practicing tucking in, and taking pictures of you in that position, and making some tweaks to clip ons, foot rests, fuel tank, etc will get you a long way. Without having to spend $10k to 'start' the process!
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