Considering a '73-'74 Commando

Hi, I'm new hear. This is my 1st post & I thought this would be a good place to gain some knowledge.

I had considerable experience W//BSA/Triumph motorcycles back in the late '60s/early '70s including in depth knowledge of the joys & maintenamce of Lucas electrics. I even have a few Whitworth wrenches left in my tool box.

In 1975 I traded my fast but unreliable hopped up '67 Thunderbolt for a '64 Panhead that gave me years of dependable service. (the problem W/most Harleys is the last guy that wrenched on them)

I haven't ridden much since about 1985 & I sold my stripped down street brawler 86 cu in Panhead in 2006. I'm retired now & live on the Northern edge of the Adirondac Mtns. in New York State near the Canadian border. There are awesome mountain roads near my home that are just the ticket for a snappy handling Limey bike. Short 50-200 mile day trips are my main interest as I am too old for long distance touring.

I can't afford a new bike but I'm confident that I can make any & all reapairs to any British bike if need be so I have been checking out prices on used Nortons. I'm interested in Nortons mainly because of their "Isolastic Susoension" (hated the vibration of the BSA/Triumph twins) but the legendary Commando performance is also a big factor in my choice.

I want front disc brake (drums work fine on the rear for my type of riding from my experience) & I have no interest in an "electric foot" as a well tuned British twin does not need electric start IMO. I would rather go W/the simplicity & lighter OA weight of a kick start only bike. I want an 850 & plan to upgrade the performance a little W/some head work & a modest compression increase.

So, that seems to narrow down my choices to a '73-'74 850 Commando. I will definately want to upgrade to electronic ignition, more modern electrics, & the new generaion of Amal carburators.

Since I don't have any 1st hand knowledge of Norton motorcycles, can anyone clue me in on any pitfalls awaiting me when shopping for a used Norton 850 Commando?

I'm looking for a running, ridable example that needs some minor work if the price is right.

Re: Considering a '73-'74 Comando

The layshaft bearing in the gearbox, the supplier in Portugal made some with a brass cage that would come apart and lock up your tranny, pulling in your clutch doesn't save you on this one, best to figure on replacing the bearing....Previous owner/owners may or may not have replaced it. only way to know is to open the box and look. It can be done while still in the bike, using a heat gun to expand the housing so the race will come out. freeze the new one to help it go in. lots of info here from more experienced guys than me but that is what came to mind at first. Cj

Re: Considering a '73-'74 Comando

cjandme said:

The layshaft bearing in the gearbox, the supplier in Portugal made some with a brass cage that would come apart and lock up your tranny, pulling in your clutch doesn't save you on this one, best to figure on replacing the bearing....Previous owner/owners may or may not have replaced it. only way to know is to open the box and look. It can be done while still in the bike, using a heat gun to expand the housing so the race will come out. freeze the new one to help it go in. lots of info here from more experienced guys than me but that is what came to mind at first. Cj

Click to expand...

Thanks, good info. I'll see if I can find some exploded drawings to get an idea of what's involved.

Isn't the transmission a "semi unit construction" type that can be unbolted from the primary case?

Re: Considering a '73-'74 Comando

BitchinBeezer said:

I'll see if I can find some exploded drawings to get an idea of what's involved.

Click to expand...

Layshaft bearing upgrade "How to": http://www.doov.com/apps/nortoncompanio ... s&Itemid=8

Note that the use of a bearing puller as shown isn't entirely necessary, just pry the old bearing off the shaft using two thin levers inserted between the bearing and the gear.

Re: Considering a '73-'74 Comando

L.A.B. said:

BitchinBeezer said:

I'll see if I can find some exploded drawings to get an idea of what's involved.

Click to expand...

Layshaft bearing upgrade "How to": http://www.doov.com/apps/nortoncompanio ... s&Itemid=8

Note that the use of a bearing puller as shown isn't entirely necessary, just pry the old bearing off the shaft using two thin levers inserted between the bearing and the gear.

Click to expand...

Thanks, I already found that. Googled "Norton Commando layshaft bearing replacment".

Re: Considering a '73-'74 Comando

You're planning to buy a 40 year-old motorcycle, likely having multiple previous owners, with an unknown riding and maintenance history. Since the riding season is closing, why not treat the bike as a project and rebuild it over the winter? My own Mk3 rebuild was expensive because I enjoy spending on these wonderful machines, but if you're on a budget, divide the rebuild into two parts:

1. The replacement or refurbishment of parts that, if they fail, will leave you on the side of the road, unhappy but safe. These parts include the loom, lighting, gear box (excluding the layshaft bearing), clutch, nearly all engine components, suspension components front and rear, primary and secondary chains, carburetor, oil tank and lines, fuel tank and lines. Inspect all parts, but replace only those that are clearly worn or broken.

2. The replacement or refurbishment of parts that, if they fail, can kill you. These parts include tires and tubes, wheel bearings, layshaft bearing, all brake components (give special attention to the hydraulic systems if you have disk brakes). Replace these parts with new.

My Mk3 came to me with a stripped hydraulic pipe nut on the front caliper, just waiting for a hard squeeze on the lever to separate; the PO claimed it was a daily driver.

Check out the oldbritts.com website; Fred has many tech articles on rebuilding and repairing Commandos. See what a worn and spalled gear looks like. Commando parts are easily available.

If you enjoy futzing around with mechanical stuff, I highly recommend a rebuild to fill your winter. You'll be on the road in the spring on a Commando you can trust. I'm envious.

Re: Considering a '73-'74 Comando

Commando is a great choice for a vintage British bike that is able to cope with modern roads and traffic and will not vibrate your nuts off. For any bike that you end up acquiring, you will need to make sure that isolastics are in good condition (most likely will need replacing) and adjusted properly to take full advantage of the system. You will also need to upgrade the disc braking system with a master cylinder resleeve and modern pads. As previously mentioned, the layshaft bearing on the 74's MUST be replaced to avoid potentially locking up at speed. You should also consider one of the various swingarm modifcations to reduce play and improve handling. None of these mods are particularly difficult and can be done with basic tools.

Agree strongly with rick in seattle. When you are buying a 40 year old bike you never know what has been (and hasn't been) done to it previously. Better to assume nothing and tear it all down to check for yourself. I have rebuilt several British and Italian bikes, some of which were supposedly "restored" by previous owners who supposedly knew what they were doing. Personally, I would not trust an old bike built or maintained by anyone unless I was absolutely confident in their knowledge and abilities. There are fewer and fewer people around who really understand these bikes. I have seen too much dodgy workmanship that can end up costing you your life. Better to get yourself a nice Commando project, buy the workshop manual and parts manual, learn as much as you can, consult regularly here with your progress and questions (there is a great store of Commando knowledge on this site), and take your time. In the end you will have a great bike that you can have absolute confidence in.

Good luck with your search and welcome aboard! Commandos are awesome motorcycles!!

Hey Ho BitchinBeezer. Maybe went over others heads but I see you have done your home work on the best model year for your applications. I prefer Combat Bombs though. All years need inferior layshaft bearing replaced soon as practical but could ride a good bit prior and low risk compared to just riding. They are out there and there is magic in the air of calling one to you. Beside the online window shopping might get the list of world wide venders in tech/photo intro thread and go down the list asking what they might have or know about. Hint - the ones that show up around major holidays or gift giving events means less competition as many are off on vacation or spent out committed on other stuff. If it ain't being used right up till time of sale offering then likely should go through it soup to nuts to know for sure and know its quirks on unplanned stoppers. 850 will pull like no other Brit Bike you had though not like the hog did, though a lot lot more smooth turbo fan like. Handy easy to steer though not a racer stable so watch it. Brakes rust up brake pistons calipers, fork collect water rust mud in them, hoses swell, cables fray, oil pump get loose to wet sump easy, kick stand wallows out, wheel brearings and stem get stiff, tranny bushes thin and break up and some of em even leak w/o special sealing and breather valve. You do know the Commando Creation Poem don't ya... Everyone about ignores the big twin but youtube "Tunnel of Love" to see what you are in for we just learn to put up with, 'cause they is just so darn cute...



Creationists Evolution Motorcycle poem

Postby hobot » Sat Mar 12, 2011 11:12 am
Surely some newbies don't know this one yet.

http://www.oldbritts.com/evol.html

THE EVOLUTION OF THE MOTORCYCLE

by Geoff Seddon

("The Evolution of the Motorcycle" is reproduced from Ozbike Thunder Down Under, an Australian lifestyle magazine.)

On the first day, God created the Heavens, the Earth, and the Wisemans Ferry Road. But He wasn't too happy, His Kingswood (automobile) would sway on the corners, crawl up the hills, and use heaps of juice.

On the second day, God took a new tack, and created the step through. He enjoyed the wind in His hair (He hadn't created helmets then), it was fun, and used bugger-all petrol, but it still crawled up the hills.

On the third day, God created the Honda Four, and it flew up the hills. With four into ones, it sounded better, it never broke down, but the corners remained a problem. Yet He had tasted power, and craved for more.

Thus, on the fourth day, He added two more cylinders to His Honda, and created adrenaline. His insurance premiums doubled, and it cost a fortune to get the tappets done. He also created fear (His hair turned white), and the cliché "enough is enough".

On the fifth day, God blew a couple of joints, had rap with Willie G., and created the Harley Davidson. He would cruise up and down the hills in top gear, and pick up heaps of babes. He would get off on the note. But the Hog was too heavy, broke down a lot and handled like the Kingswood.

Then, on the sixth day, He made the Bonneville. He would still pick up babes outside Wisemans Pub, and it sounded good. His bike was light, and for the first time, the corners were fun. It handled! God was stoked. But the vibration gave Him a pain in the arse, His kidneys were history, it was a touch gutless and He ran out of juice every 100 miles. He wasn't happy, but shit, He was
So finally, on the seventh day, God produced a motorcycle with the speed of a Honda, the torque of a Harley and the handling of a Triumph. He could afford the petrol, tune it Himself, pick up chicks and still blow off Ducatis through the corners. He called His bike Norton [Commando], and He was happy.

" (the problem W/most Harleys is the last guy that wrenched on them) "

Thats a new one , I hadnt heard of that . might be a chance of that here too . . .

Generally , a well assembled Triumph might have a vibration period , but should be reasonably smooth .
Though any machine of this Era , realizeing H. D.s are twice the displacement so not under similar strain
unless hopped up enough to try a Triumph or Norton at the Drag Strip . :x 8) :lol: REALISEING that
opperating at Raceing Speeds may well require ' race oriented ' meticulous maintanance .

You pays yr money and youse takes yr chances , with a piece of 40 year old machineary , unless youre
prepared to do a cost no object overhaul , or purchase from some who guarantee the serviceability of the machine .

Remembering , like any seventies bike , theyre ' not quite right ' . To compete with the oriental market espionage
ment price cutting , or subsidies like H. D.

Ducatis you got the basics for a good Engineer / Fitter to make a No 1 Machine , Kawaskis you got speed and death wobbles .
Yamaha you didnt quite get either or both , but similar fuel consumption , like Suzukis , which were sturdier , in some cases .
Thus Slower . You met the Nicest People on a Honda . But thyre boreing , and probably have six kids now , like the Brady Bunch .


You wanna bludge a ride on a few / Trade Rides , to see where their efforts at . Or Try a F'bed C'do or Triton , or Both .
or build your own ( Any ) , or go Exotic , Rickman / Seely etc , if your going to aim to embarres the Ducati's & Whizz Bangs .

Low Milage & original parts count , Engine is likely better than one with 18 owners & 100.000 miles . Though a Bonnie at
that milage CAN be essentially sound , and faster than most machines a decade older . It takes bigger balls , on a Commando .

Re: Considering a '73-'74 Comando

tpeever said:

When you are buying a 40 year old bike you never know what has been (and hasn't been) done to it previously. Better to assume nothing and tear it all down to check for yourself.

Click to expand...

Can't agree with that enough,unless the bike was purchased from someone you know or trust or both.
A lot of Brit bikes got parked up with some form of ailment and these days folk pick up bikes to offload on places like eBay or Craigslist for a quick profit.
It can be buyer beware,it might be a gem,it might only look like one.
My advice is look for a bike that hasn't had the cases split and shows no sign of bodgy mechanics,gouges etc from rough wrenching and go over it.
Either way these bikes need some form of ultra service check for peace of mind,I enjoy working on bikes and have both the tools and practical experience so the labour is free (luckily)

Hit them all but the Moto Guzzi.... Certainly can't beat one of those. I'm partial to my 77 Lemans. Just as long of legs as my Norton, just as stable, just as smooth, it actually has great brakes stock, and very very reliable sans the switchgear (easy upgrade). I'd be hard pressed though to choose between my Goose and my Commando for a nice vintage rider. My Hondas will beat them both hands down for shear appliance like utility but as stated are rather boring.

Glad to see you'd stick with the Amals but I never understood everyones aversion to points. I have absolutely no problems with points on any of my bikes, they ALWAYS work even with low batteries. Same can't be said for electronics.

I found a great 73 Commando in a barn, 4800 miles. Needed very little to get it sorted and has been stone reliable for the last 5 years now. I haven't done the layshaft bearing yet (no symptoms but just a preventative measure), on my list for this winter along with a Triumph tranny rebuild.

Just something to think about as you are retired, a Norton is not the easiest bike to kickstart. Cetainly can be fairly effortless once the technique is down, but it's certainly not as easy as a Triumph. Depending on just how good your right leg is, you might consider that Alton e-start. That will be my upgrade once I can't kick my baby over anymore.

rick in seattle said:

You're planning to buy a 40 year-old motorcycle, likely having multiple previous owners, with an unknown riding and maintenance history. Since the riding season is closing, why not treat the bike as a project and rebuild it over the winter? My own Mk3 rebuild was expensive because I enjoy spending on these wonderful machines, but if you're on a budget, divide the rebuild into two parts:

1. The replacement or refurbishment of parts that, if they fail, will leave you on the side of the road, unhappy but safe. These parts include the loom, lighting, gear box (excluding the layshaft bearing), clutch, nearly all engine components, suspension components front and rear, primary and secondary chains, carburetor, oil tank and lines, fuel tank and lines. Inspect all parts, but replace only those that are clearly worn or broken.

2. The replacement or refurbishment of parts that, if they fail, can kill you. These parts include tires and tubes, wheel bearings, layshaft bearing, all brake components (give special attention to the hydraulic systems if you have disk brakes). Replace these parts with new.

My Mk3 came to me with a stripped hydraulic pipe nut on the front caliper, just waiting for a hard squeeze on the lever to separate; the PO claimed it was a daily driver.

Check out the oldbritts.com website; Fred has many tech articles on rebuilding and repairing Commandos. See what a worn and spalled gear looks like. Commando parts are easily available.

If you enjoy futzing around with mechanical stuff, I highly recommend a rebuild to fill your winter. You'll be on the road in the spring on a Commando you can trust. I'm envious.

Click to expand...

While I agree W/most of what you posted above, I would think that the #2 list would be top priority.

1st of all, except for outsourcing the machine shop work, I’m an experience hot-rodder/engine builder & I am capable of doing all of the following myself.

My take would be, in order of priorities after an initial start-up short moderate test ride to hear the engine to assure it’s going to @ least be ride able:

Check tires/tubes, If, needed, replace (Avon of course)
Check rims for rust, clean & paint W/Por 15 if needed
Check the brakes, upgrade if in need of repair
Check the wheel bearings, service & replace if needed
Check the fork/shocks/swingarm, service & replace as needed
Check the state of the lay-shaft bearing (if it’s a roller it will pull right out) upgrade accordingly
Install clutch rod seal
Check primary & rear chain (if needed, replace rear chain & primary W/belt drive)
Check sprockets replace them if needed
Check Amal carburators & upgrade to Premiers if needed
Check points & timing

After a short, vigorous test ride to determine the state of the other mechanicals

Repair any glaring shortcoming in the engine/mixer (transmission)
Service isolastic suspension
Ditch the stock wire loom & do a simplified rewire (I can still do a ‘60s/early ‘70s era BSA/Triumph from memory)
Podronics single phase high output 200W Rectifier/regulator (Is this a good reliability upgrade?)
Tri Spark electronic ignition
LED taillights/turn signals


That should take care of safety/reliability. I could ride the bike W/confidence.

Now, as time/$$$ permits I could do some solid performance upgrades.

Replace steel rims W/allow rims lace, center & true on the chassis
Tear down the engine
Check crank/bearings, cylinders/pistons, replace bearing/rings, pistons if needed.
Install hardened exhaust valve seats, 3mm larger intake valves, beehive valve springs and port accordingly
Raise compression to around 10:1 either by milling the head or replacing pistons if they are needed
Install J&S Stage 1 cam
Install anti-wet sump valve
Go through the mixer
Change mixer sprocket for approximately 17 MPH per 1000 RPM in 4th gear.

I think that would give me a well mannered Limey bike that could mix it up W/the average Rice burner in the twisties & around town. I want something that can make my arse-hole pucker when I twist the wick. A sheep in wolves clothing?

You more experienced Norton hot-rodder please speak up if I have made any omissions or poor choices.

lrutt said:

Just something to think about as you are retired, a Norton is not the easiest bike to kickstart. Cetainly can be fairly effortless once the technique is down, but it's certainly not as easy as a Triumph. Depending on just how good your right leg is, you might consider that Alton e-start. That will be my upgrade once I can't kick my baby over anymore.

Click to expand...

I used to win parking lot bets by starting my 86 Cu In Panhead stroker W/my left hand.

I'm sure I can tune an 850 Commando to start easily enough, especially W/elctronic ignition.

You didn't mention isolastics or swingarm busings. A definite must to do initially. Chances are VERY good that one or both needs attention.

lrutt said:

You didn't mention isolastics or swingarm busings. A definite must to do initially. Chances are VERY good that one or both needs attention.

Click to expand...

You must have missed those. I did mention them.

BitchinBeezer said:

Check the fork/shocks/swingarm, service & replace as needed
Check the state of the lay-shaft bearing (if it’s a roller it will pull right out) upgrade accordingly
Install clutch rod seal
Check primary & rear chain (if needed, replace rear chain & primary W/belt drive)
Check sprockets replace them if needed
Check Amal carburators & upgrade to Premiers if needed
Check points & timing

After a short, vigorous test ride to determine the state of the other mechanicals

Repair any glaring shortcoming in the engine/mixer (transmission)
Service isolastic suspension

Click to expand...

Hehe well some of us have won parking lot bets about which is harder to kick over a big twin twice the Norton size or the Norton. I'd had enough Commando time now to know that they should only need one step on to start cold or hot if tune is correct and if mine didn't I'd step on again just to make sure and if no joy then stop and check key on fuel on or plug lead on to get back to one step on starting, not even a kick at all. But if not tuned to do that they can beat you and your foot and the KS mechanism to a pulp. Only issue with points is the mech adv. unit wear out and no more available but a few over $100. I and a handful of others have video of one arm one shot starts even on Combats. At least the cast iron barrel Brit Bikes will be let in no problemo to Harley Only events and again be center of attention over every thing else.

hobot said:

I'd had enough Commando time now to know that they should only need one step on to start cold or hot if tune is correct and if mine didn't I'd step on again just to make sure and if no joy then stop and check key on fuel on or plug lead on to get back to one step on starting, not even a kick at all. But if not tuned to do that they can beat you and your foot and the KS mechanism to a pulp.

Click to expand...

I always was of the opinion that if a British motorcycle was not easy to kick start, it wasn't tuned properly & shouldn't be ridden in that state anyway.

Technique is also a key. I could start my BSA W/1 stab cold or hot while others would stomp & stomp on the very same kick pedal futiley.

Tickle the Amals till fuel ran out of the tickler, turn on the key, keep the throttle closed & stab @ the pedal.

A Norton will start easily if it is tuned properly but it does take a fair bit of weight on the kick start to turn it over. It is definately not as easy to kick over as my A65. Even with lower compression on the Norton. Not sure why . Long stroke motor. Different kick start ratio maybe.