Rob North Framed Commando

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Once again Al
Both feet.
Well read, reserched?
Just plain wrong!
It's documented (Jack Shermans) that they never had a crankshaft break!
The North is a road based engine.
The MV is designed as a gp race bike.
It weighed 260lbs made 78bhp
The Daytona Percy rode weighed 292lbs !

Keep walking through everything!

Ps just for your information. Percys bike was a 4 speed!
 
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Roger Middlebrook said:
My bike is Period 4 pre Dec 72 approved by Motorcycling Australia. The compliance took into consideration the bike from top to bottom albeit am sure behind closed doors there was two discussions on approving similar to the thread above, the only question they came back with was around a rear disc break. Once I commented that nearly every other Rob North racing in Australia P4 had a disc break, the questions stopped and approval was granted. appears there will always be two sides of an argument for a bike like the RNN for historic pre 72 eligibility, Fast Eddys cut paste from BHR is very closely aligned to MAU historic P4 pre 72 rules.
Rob North frames first recognized as raced in 1969 and available to general public in 1970, Norton engines, AMC gear boxes, triumph wheels,11" rotors, Marchozzi forks all available pre dec 72 so any combination of these could have been assembled and raced in the period. Fact that no one recalls seeing a Norton in a RN frame kit does not mean it was not done. If my bike was a chopper triple and not a hand crafted special would that make it any more eligible ?? I have to wonder.
Fact is I love my bike for what it is, it has been a part of my life for 20 years the dream or racing it in a high profile period 4 historic event in Australia will soon be a reality and one that I most excitedly am looking forward to. :) Apologizes in advance attachment two formats upside down no matter how it s saved outside of this forum.
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Roger, your North Commando is the best looking example I’ve seen, I don’t mean pretty and polished, I mean it just looks sooo ‘right’.

Some of the others we’ve seen have strange tanks or seats or finishing touches, etc.

Yours looks the bollox mate. Well done.
 
Yes Roger
Cudo's as Nige said really nice bike & I am glad you are going to race it. The big engine is a joy.
The first time I rode my North at Donington down Cramer Curves I thought, Ohh it's very neutral. The Seeley just went where I looked. I gave it a bit more " input" & it went exactly where I wanted it, the more I pushed the better it got. Probably one of the finest packages I have ever ridden. Not to mention the noise. Now under the Claiming rule its ridden by my son! Lol
Our eligibility rules have the onus of proof on you proving the bike raced in period.
It's a bit of a dream to cherry pick the best bits of kit from the period & build the ultimate bike. We are not allowed.
The rules get bent! People push them, parts get updated & I love the attitude of "it doesn't make a difference to the performance". The best thing is the more successful classic bikes the more they get used the more original parts get made BUT the rule never gets changed back to you must refit the original part. More & more people drop out as the bikes move more & more away from standard & the grids drop. Up to 85 now 93? Mixed classes sometimes 3 classes in a race & again numbers drop. I like racing with the CRMC club but a lot of my mates have moved fully to BHR. I've reached the stage where I choose where I go because of the circuit.
As I said before get the bike done, get out there & enjoy yourself.
Ps I would still love to ask Rob if he ever did a Commando.
 
Fast Eddie said:
Al, Trident cranks are as strong as they come! In fact, my layman’s understanding is that the forged and twisted method is stronger than billet as the grains of the metal remain in line as they would in a normal forging.

at a recent auction, where a works experimental Trident with single OHC was sold, someone else into Tridents said that it didn’t make much difference to max. power, and the limitation was the cylinder head / downdraught angles etc, which they didn’t alter subsequently.
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A very impressive bike, Martin. I wish my German was a bit better:).

Ken
 
Chris said:
Ps I would still love to ask Rob if he ever did a Commando.
Click to expand...

Pretty sure not, Chris, at least not in the style we are discussing. Quite a few years back I took the frame from my Manx restoration project to him for some major restoration work that was a little too touchy for me to do myself (and he did a marvelous job on it). That was at his shop, Rob North Fabrication, down in National City, near San Diego. Last I heard, he was still in business there. I had the Hemmings kit at the time, and I discussed it with Rob. I don't recall his exact response, except that he was not involved in it. But he did mention that he never did one of the triple style frames for a Norton. I wouldn't be surprised if he had worked on some other sort of Commando. He was doing all sorts of one-off interesting work in his shop. A very talented and interesting guy.

Ken
 
Chris said:
Yes Roger
Cudo's as Nige said really nice bike & I am glad you are going to race it. The big engine is a joy.
The first time I rode my North at Donington down Cramer Curves I thought, Ohh it's very neutral. The Seeley just went where I looked. I gave it a bit more " input" & it went exactly where I wanted it, the more I pushed the better it got. Probably one of the finest packages I have ever ridden. Not to mention the noise. Now under the Claiming rule its ridden by my son! Lol
Our eligibility rules have the onus of proof on you proving the bike raced in period.
It's a bit of a dream to cherry pick the best bits of kit from the period & build the ultimate bike. We are not allowed.
The rules get bent! People push them, parts get updated & I love the attitude of "it doesn't make a difference to the performance". The best thing is the more successful classic bikes the more they get used the more original parts get made BUT the rule never gets changed back to you must refit the original part. More & more people drop out as the bikes move more & more away from standard & the grids drop. Up to 85 now 93? Mixed classes sometimes 3 classes in a race & again numbers drop. I like racing with the CRMC club but a lot of my mates have moved fully to BHR. I've reached the stage where I choose where I go because of the circuit.
As I said before get the bike done, get out there & enjoy yourself.
Ps I would still love to ask Rob if he ever did a Commando.
Click to expand...

Chris, Give me bit of time and I'll let you know if Rob North did a Commando.
 
lcrken said:
Pretty sure not, Chris, at least not in the style we are discussing. Quite a few years back I took the frame from my Manx restoration project to him for some major restoration work that was a little too touchy for me to do myself (and he did a marvelous job on it). That was at his shop, Rob North Fabrication, down in National City, near San Diego. Last I heard, he was still in business there. I had the Hemmings kit at the time, and I discussed it with Rob. I don't recall his exact response, except that he was not involved in it. But he did mention that he never did one of the triple style frames for a Norton. I wouldn't be surprised if he had worked on some other sort of Commando. He was doing all sorts of one-off interesting work in his shop. A very talented and interesting guy.

Ken
Click to expand...

Sorry Ken, I hadn't read your post when I replied to Chris ref Rob North Commando frame, I've asked my mate who is in contact with Rob to ask him if he ever did one either "back in the day" or recently.
 
Roger Middlebrook said:
My bike is Period 4 pre Dec 72 approved by Motorcycling Australia. The compliance took into consideration the bike from top to bottom albeit am sure behind closed doors there was two discussions on approving similar to the thread above, the only question they came back with was around a rear disc break. Once I commented that nearly every other Rob North racing in Australia P4 had a disc break, the questions stopped and approval was granted. appears there will always be two sides of an argument for a bike like the RNN for historic pre 72 eligibility, Fast Eddys cut paste from BHR is very closely aligned to MAU historic P4 pre 72 rules.
Rob North frames first recognized as raced in 1969 and available to general public in 1970, Norton engines, AMC gear boxes, triumph wheels,11" rotors, Marchozzi forks all available pre dec 72 so any combination of these could have been assembled and raced in the period. Fact that no one recalls seeing a Norton in a RN frame kit does not mean it was not done. If my bike was a chopper triple and not a hand crafted special would that make it any more eligible ?? I have to wonder.
Fact is I love my bike for what it is, it has been a part of my life for 20 years the dream or racing it in a high profile period 4 historic event in Australia will soon be a reality and one that I most excitedly am looking forward to. :) Apologizes in advance attachment two formats upside down no matter how it s saved outside of this forum.
Click to expand...

I'm not really surprised that your bike was approved, Roger. It's a gorgeous bike, and as long as the standard is "could have been built at the time", it should certainly qualify. That seems to be the standard with some organizations, while others insist someone actually had to have raced a similar bike back in the day. I tend to favor the more relaxed criteria, because it results in a more interesting field of competitors.

One of the more interesting eligibility questions I was involved in was whether the short stroke 750 Commando engine was legal in AHRMA's 750 Sportsman class. The issue centered on whether the engine was a "production street engine". In the end, AHRMA decided that Norton had not sold the Commando with the short stroke engine as a "production" bike, even if it was listed as such in the factory brochures. Even though I was arguing for it's eligibility, and provided the factory documentation to support that view, I think the officials were probably right in disallowing it. We're now pretty sure that Norton never produced more that a handful, if any at all, of such bikes for sale to the public.

Ken
 
Hi Sam
Thanks for trying to contact Rob. I've seen Triumph frames & I know he was deep in the racing scene & did loads of repairs. Major sidecar racer & constructor.

Ken I never thought he did that style of frame for a Norton but if he did a 650 Triumph for Percy maybe he did a Commando. Love to know.
 
Thanks, Martin. That's clearly a fair amount of work, and I really appreciate it.

Ken
 
Eligibility is ridiculous if the standard is 'it could have existed'. Back in the early 70s CB750 Hondas were bored and CB450 pistons were fitted. The capacity became about 830cc, NOT 1100cc. In those days there were no other large capacity Japanese bikes, so where would you get the pistons to make a CB750 become 1100cc ? - Anything 'could have existed'. We have even had BSA Bantams which have been RS125s.
 
I have never heard of a crank breaking in a triple, but I understand they have a tendency to unwind. Theyare not a motor I would play with
 
I'm surprised that the Percy Tait 500cc was 4-speed. Perhaps the circuits it was successfully raced on were more open and flowing, than others ? At Phillip Island, my short stroke500 was excellent, but on a short tight circuit, I would choose where I wanted to lose a race. Gear it low and it was great coming out of corners, but did not have the legs at the end of the straights. Gear it high and be too slow coming out of corners. It definitely needed more than 4 gears.
 
T
lcrken said:
I'm not really surprised that your bike was approved, Roger. It's a gorgeous bike, and as long as the standard is "could have been built at the time", it should certainly qualify. That seems to be the standard with some organizations, while others insist someone actually had to have raced a similar bike back in the day. I tend to favor the more relaxed criteria, because it results in a more interesting field of competitors.

One of the more interesting eligibility questions I was involved in was whether the short stroke 750 Commando engine was legal in AHRMA's 750 Sportsman class. The issue centered on whether the engine was a "production street engine". In the end, AHRMA decided that Norton had not sold the Commando with the short stroke engine as a "production" bike, even if it was listed as such in the factory brochures. Even though I was arguing for it's eligibility, and provided the factory documentation to support that view, I think the officials were probably right in disallowing it. We're now pretty sure that Norton never produced more that a handful, if any at all, of such bikes for sale to the public.

Ken
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Tks Ken and I totally agree the entire 20+year ownership I was always wondering what would transpire as far as eligilibility was concerned. I now have not only an approved ike for P4 in AU and NZ I can see from the thread it can fit into most historic racing globally with exception of a few categories. That makes it all the more worth while.
 
T
Fast Eddie said:
Roger, your North Commando is the best looking example I’ve seen, I don’t mean pretty and polished, I mean it just looks sooo ‘right’.

Some of the others we’ve seen have strange tanks or seats or finishing touches, etc.

Yours looks the bollox mate. Well done.
Click to expand...
Tks Fast Eddie, the Rob North letter box styling and short track tank is beautiful iconic and never looks wrong in my opinion. I am supprised mine is the only RNN completed in this lay out. I would have done same if it had have been a road bike.
Will get you seated positions and measurements soon.
 
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