Combat Question

Hi all,
I increasingly realise how little I know about Norton Combats. My Norton is a 1974 Mk 2 850 which to me feels to be in a very soft state of tune and a million miles from the ‘fire breathing‘ Combats that launched their riders down the road as fast as they disintegrated their bottom ends.
So, a couple of question.
# What years were they made?
# Was it a ‘quick fix’ to increase performance to try to match their Japanese opposition?
# Were they available on all Norton models or just the Interstate?
# Could you buy identical looking bikes, one as a Combat and one in standard tune?
# Was there any external badging or distinguishing features to instantly identify a bike as a Combat?
# Were they regarded as a seperate model or just a variant of the basic bike?
# Were they substantially more expensive?
# If retrofitted with better bearings (Superblend?) are they reliable or is the state of tune just too high for reliable long service?
# Sympathetically ridden did some give good long term service?
# surely the engineers must have known the limitations of the Norton engine?
# All things equal, how would a good Combat stand up to a Honda 750/4 and then Kawasaki 900 on the quarter mile? I presume it would be a nose ahead of the Honda and a noticeably slower than the 900, would others agree?

These questions are just to fill out my interest in Nortons Although a happy owner I’m just a little young to remember Combat Nortons when new. I think I became ‘sentient’ regarding bikes in about 1976. As such they weren’t quite on my radar as a kid when we eagerly consumed all reports and road tests.
Interestingly, as an MG owner I see parallels with the wonderful but over tuned (and under developed) MGA Twin Cam. Brilliant in concept but nearly ruined the comany.
regards
Al

I’m a long time owner of my current 750 combat roadster.
Norton factory made combat motors during 1972 only. Toward the end of ‘72 Norton started defining them by installing “standard” cams and lowering the compression. What Makes a combat is the double S cam with .346” exhaust and .391 intake lift compared to .330 both exhaust and intake on the standard cam. The combat head stamped in the middle with “C” had .040” skimmed off to increase compression ration to 10:1 advertised. The carburetors were increased from standard 30mm to 32mm with corresponding intake manifolds. The counter sprocket was lowered to 19 tooth to increase acceleration while taking advantage of the upper rpm power surge the cam provided. These were not far from the production racer tune. After the warranty claims for engine failures Norton Villiers scrambled to detune the subsequent spec.
Keep in mind I’m like others…the older I get the faster I was! My early experience with a new combat roadster was nothing could take me. Honda CB750 was an easy mark. Street racing in Palm Springs I managed to win over a Kawasaki H1. At Ontario Speedway on race what you got night my roadster managed a 1/4 mile in the low 12s at 103mph all stock combat.

Honda 4s didn't come close to me on my 74 Commando, out handled them and out run them as well all my mates bought new Honda 4s but I went with the new Norton they put al lot of sh.t on me about my choice but my Norton has outlived their Honda 4s and do I still let them know lol, when I converted to the Featherbed frame back in the early 80s I built my 850 as close to Combat specs, its been a very reliable motor and is plenty fast for me with the improvements that I have done to it in the 46+ years of ownership and gives plenty of modern bike riders something to think about, it might not be the fastest bike these days but in my hands it does pretty good.

Ashley

Alan L said:

What years were they made?

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Year. 1972 (partly) although production probably began in late 1971 (no known date but supposedly from serial number 200976) and ended sometime around mid-'72 (at serial 211110).

Alan L said:

Were they available on all Norton models or just the Interstate?

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Interstate and Roadster first, then Fastback. Not Hi-Rider.

Alan L said:

Could you buy identical looking bikes, one as a Combat and one in standard tune?

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Apparently not.

Alan L said:

Was there any external badging or distinguishing features to instantly identify a bike as a Combat?

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Black cylinder barrels and hydraulic disc front brake (although the disc brake was also fitted to post-Combat models).

Alan L said:

Were they substantially more expensive?

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Approximately +7.5% (UK prices) over the standard model (Std. Fastback) when introduced.

Alan L said:

surely the engineers must have known the limitations of the Norton engine?

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...Yes but the Norton management didn't or chose to ignore it.

I also have an intact Combat. It did suffer an engine failure back in the mid-70's (I knew the original owner and my uncle Dick rebuilt the motor for him). It had Superblends installed at this time. The motor has not been a part since and is still running great. It did go through a couple of periods of inactivity, and was showing about 25,000 miles when it came to me about 20 years ago. It likely has about 50,000 on it now.

It burns very, very little oil, still has 175 psi compression on both cylinders, and great oil pressure.

And it pulls like a freight train!!

Selling my 750 Combat that I had in 84 is probably my biggest regret with bikes, I then bought an 850 and was absolutely underwhelmed, although these days I do love mine. I'd take anything on with that Combat (young and invincible) I'd be on the bike every day and I ragged it everywhere. It would reach an indicated 117, and Smiths instruments were always known as pretty accurate . Maybe have another one day....... I actually sold it to a lad from the Midlands who'd had his Mk 3 stolen by the local HA, so obviously no chance of getting it back .

They can be reliable if not ridden like a race bike. I rebuilt one for a guy that had 60K on the clock with the original bottom end.

L.A.B. said:

Year. 1972 (partly) although production probably began in late 1971 (no known date but supposedly from serial number 200976) and ended sometime around mid-'72 (at serial 211110).




Interstate and Roadster first, then Fastback. Not Hi-Rider.



Apparently not.



Black cylinder barrels and hydraulic disc front brake (although the disc brake was also fitted to post-Combat models).




Approximately +7.5% (UK prices) over the standard model (Std. Fastback) when introduced.




...Yes but the Norton management didn't or chose to ignore it.

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I had a 72 non combat ex Police Interpol at one time

The Kawasaki 900 question:

I skipped the delusional stock Norton's are fast Norton owner stage after the Kawasaki 900 came out. Although my plane old Norton 750 engine at the time could walk away from a 900 in the twisties. The 900 Kawasaki was top heavy and that long transverse crank and 4 cylinders did tend to make the bike stand up in a turn under late braking. Good way to scare the heck out of novice riders, and get dead on the street. I seriously doubt that a stock Combat spec Norton would be faster in a drag race, but not sure. Google puts 1972 Norton 750s about 20 mph under. And if it's on the internet, it has to be true.

Extended Combat (like) BS section:
I built a 2S cammed racier than factory Combat Norton motor in the early 90's. I foolishly built it to see if I could keep up with the Ducati 916's young bucks were riding up at Alice's on Skyline. My little brakes and straights longer than a 150 feet held me back, and I gave up on that fantasy. However, the engine worked pretty good for a 750 and continues to do so.

I have 8743 miles on the Smiths speedo I have, but I put 2K miles on the motor before installing it. I don't study or think about Norton history like a good forum member should, so the only other comment I have is the 2S cam used in those Combat engines does come on hard in the higher rpm range in a well tuned motor, and can cause excessive smiling.

I had a non-Combat Commando motor that was quick enough to out-accelerate Honda 750's every time. I did have a 19 tooth sprocket in it, which might have been one the most important Combat performance item. The cam's high rpm impact coupled with the low gearing may have also been the biggest contributor to all those epic failures.
Back in 1972 one of my friends bought a Combat and threw me the keys. The acceleration was breath-taking to me at the time, but any Commando can get my blood pumping. No doubt somebody on this forum has had the pleasure of riding a Combat back to back with an 850. Could the difference really be that significant?

If Combats were still available I’d swear you guys were on sales commission… You’re certainly making them sound appealing to me !

A good Mk1 850 wouldn't be far behind a Combat.

cash said:

A good Mk1 850 wouldn't be far behind a Combat.

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I'm sure you are correct
But a combat doesn't feel like the linier power of the 850

My good friend George has a stock Combat Interstate, and my 850 MKII leaves him in the dust.

... George has 80 lbs. on me.

maylar said:

My good friend George has a stock Combat Interstate, and my 850 MKII leaves him in the dust.

... George has 80 lbs. on me.

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That's interesting
I can remember when I had a mk2a that was stock apart from bell mouths and a dunstall 2 1 2 exhaust
My mate had an interstate combat and we were playing at racers on a dual carriageway my bike topped out just over 100mph But he pulled away from me very rapidly and he was 2 up
He still owns that bike but it now detuned a little
It has an 850 bottom end , standard cam and I put a 1mm plate under the barrel,longer pushrods
It's still a quick bike but not what it was

Thread 'Commando Quarter Mile Times' https://www.accessnorton.com/NortonCommando/commando-quarter-mile-times.16705/

Atlas Commando said:

No doubt somebody on this forum has had the pleasure of riding a Combat back to back with an 850. Could the difference really be that significant?

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I have a Combat and my Dad has a Mk 2 850 - they have very different engine manners. The 850 has more low end grunt and does not come on a 4000 rpm+ like the Combat does.

That said - Dad's 850 is pretty healthy, and will pull to red line in 4th gear with out much drama.

Both bikes have 20T transmission sprockets. A drag race would likely be a dead heat.

Hard to say which I prefer - the Combat is a bit of a novelty, and has a sharper exhaust note. But the 850 is also a joy to ride.

My opinion.

Another happy Combat owner here. I have upgraded many bits in the 7 years I have owned it, but not touched top or bottom of motor. Still pulls strong when revs hit 3.5k and no (ok - far fewer) worries about reliability since i did a total rewire job.
Couple of follow up questions tho....
Of the 10k or so bikes produced in the serial # sequence LAB cited, how many were Combats?
Did factory install superblend bearings later on during assembly or was that done only for recalls?

tomspro said:

Of the 10k or so bikes produced in the serial # sequence LAB cited, how many were Combats?

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The actual number isn't known or has never been made public. Probably most within the serial number range were
Combats but not Hi-Riders.

tomspro said:

Did factory install superblend bearings later on during assembly or was that done only for recalls?

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According to factory Service Release N.2/9, August 1972, R&M 6/MRJA30 'Superblends' (not the later FAG NJ306E) were "...fitted on production engines from engine number 211891." so after Combat production had ended.

According to the INOA Tech Digest, Superblends were introduced in at S/N 207197. The detuned post-Combat engine came in at S/N 211110.