Combat Vs 73 Commando

Any engine is better suited to flat crown pistons d/t better flame spread for less detonation d/t Comp Ratio.
Schimdt has the best solutions so far in low or hi-ish CR and light too.

Yeah sure the '73 is better than a '72, same as bottom line engine is better for wear tear-mileage than racy V8 in a chevy pu.

Ron L said:

PS, '73 750s are the best

Click to expand...

Another has seen the light! ( I have two MkV's)

As to the Hi-comp (domed) pistons, what do our engine building gurus think about domed pistons vs. milling the head to increase compression on Nortons? I was always told that the Norton head design was much better suited to a flat top piston than a dome.

Click to expand...

Hi Ron,

I owned/rode this '73 750 MkV for five years and put on 36,000 miles. They are more dependible than a combat, but don't have the performance. I prefer the 850 of the same year as it adds a bit more low end grunt. Still my choice is my current combat...personal taste.

My Combat still has the 19 tooth sprocket on it. Cripes! I can't crack the throttle wide open without rolling my eyes back in my head! I think the idea was that you were expected to keep the bike at high RPMs and this made it easier to do that. One of these days I will swap it out for a 21, but since most of my riding is on country roads at 55 mph it isn't much of an issue.

Now, the reason I always loved my old 850 and am in the process of rebuilding one is that I always loved the low end torque of that bike. Running the twisties was more like skiing than motorcycling cuz you didnt really have to shift that much. Let's face it, or at least I will, that if you want to ride strictly on big interstates at 80 all day the Commando isn't necessarily your best choice.

Ok to answer a Few questions that seem to be recurring.
First and foremost is i am a garage hobbiest, i can figure most anything out, although it might take me ten times longer to get professional results that is what i aim for in the end.
I chose Norton for a first bike due to the fact its not on every street corner, also im not a huge crotch rocket fan and in my opinion while a grandfather to the genere of bike its not how i view it. Also all the races the Commando won speaks volumes of its engineering at the time.
My main concern is buying a bike that once all upgrades are finished is snappy, reliable, and capable of going on the high way for thousands of kilomoters without constantly having to worry whats going to happen.
Or dare i say is there a different manufacturer that i should go with? Like Triumph as i do like the british bikes.

My Combat still has the 19 tooth sprocket on it. Cripes! I can't crack the throttle wide open without rolling my eyes back in my head! I think the idea was that you were expected to keep the bike at high RPMs and this made it easier to do that. One of these days I will swap it out for a 21, but since most of my riding is on country roads at 55 mph it isn't much of an issue.

Now, the reason I always loved my old 850 and am in the process of rebuilding one is that I always loved the low end torque of that bike. Running the twisties was more like skiing than motorcycling cuz you didnt really have to shift that much. Let's face it, or at least I will, that if you want to ride strictly on big interstates at 80 all day the Commando isn't necessarily your best choice.

Click to expand...

My Dear Rich - we agree to the Nth degree on the flavors of the two engines.
Much as I know Combats can whip on 850's in mostly factory condition, an 850 in 2nd is one scary booger to keep up in Mt twisties when loaded to the gills for interstate travel and I'm on my spiffed up SV650 on non-DOT warmed race tires. 850 fella just skiing the turns this way and that with grunt out of turns my SV had to downshift into about screaming rpms to keep up with.

It not spending must time over 80 mph then 20T on a Combat was most pleasant to me. Did give up much take off grunt and didn't exceed 5000 to keep up on freeways and gave top out speed over 125, and pulled good right up to that too.

Combat flat bearings worked a treat, as long as not lugged and not over rev'd beyond 7000. My pre-Peel Combat had 30+K miles on it when 1st opened to clean the sludge trap and they were still pristine. This was the use it up show it off nail the sale show room bike of vendor I bought it from so not babied & still has reputation of being the hot rod machine of the era for a few counties around. If really wanting to let a Combat's hair out, need steel flywheel, super blend on DS and 11 ball on TS to let the crank whip w/o binding.

If case ya doubt the take off pull potential of the smaller Combat displacement examine real close my avatar, particularly the rear tire. It had not yet reached its power band rpm either, that happened just beyond the X-mass tree, to stand bike on trail flip tire buldge to the side and take out my R knee. Man oh man what a ride them Combat can provide. But also a delight to putt putt along off road through thick and thin too. My favorite forever more.

If clever mechanical challenge is sought to get the most grins for the bux and for as long as any Commando - it was the 750 that took the endurance race wins against rest of the world, not the sluggish bigger one.

If I was to do it again I'd not buy a whole bike but parts already apart
to spiff up and select to suit, as long as ends up mostly a Combat configuration.
Nothing I've mentioned has anything to do with performance mods away from factory items, except brittle cast iron fly wheel.

new_leaf said:

Ok to answer a Few questions that seem to be recurring.
First and foremost is i am a garage hobbiest, i can figure most anything out, although it might take me ten times longer to get professional results that is what i aim for in the end.
I chose Norton for a first bike due to the fact its not on every street corner, also im not a huge crotch rocket fan and in my opinion while a grandfather to the genere of bike its not how i view it. Also all the races the Commando won speaks volumes of its engineering at the time.
My main concern is buying a bike that once all upgrades are finished is snappy, reliable, and capable of going on the high way for thousands of kilomoters without constantly having to worry whats going to happen.
Or dare i say is there a different manufacturer that i should go with? Like Triumph as i do like the british bikes.

Click to expand...

Seems like you'd enjoy owning a Norton.

Yep, another Norton addict in the making.

Quite seriously, while I have no doubt my Combat would do thousands of kilometers I would prefer to do long road trips on the 850 and save the Combat for the shorter, highly spirited rides. It is funny that many Combats came with Interstate tanks, but eventually I will have my Combat in Roadster dress and the 850 in Interstate dress.

Find one you like, buy it, fix it, ride it and then start looking for another. I really believe you should have two. One to ride and one to work on.

Russ