A completely normal amount of things to do (...again)

I turned my attention to the Fastback in the spring of 2026. After a very long absence from the road, I was finally able to get this riot of a bike back where it belongs.

Let me take a moment to appreciate the unbelievable lines of this machine: truly timeless and, to me at least, this motorcycle still looks futuristic today (actually the adjective that best describes it is the Italian "avveniristico", but English being a no-nonsense language, doesn't quite reach the same heights). The Fastback in particular also has something so lean about it that reminds me of an English Greyhound: it's long, slim, agile, fast...

Above: what you see isn't lens flare, that's just pure speed oozing from the machine, it can't be helped.

There were several things I needed to take care of, only a couple of which were a bit of a pain, the rest was part routine, part unnecessary... but looked good once it was all done.

Surrounded by an olive grove, with little outside interference, the shed sits in an idyllic setting that's conducive to making a maintenance day more than just repair of a machine, but also of the soul.
At a farm off in the distance, but close enough to be heard and unmistakable, is a donkey. And somehow it seemed to know whenever I was doing something questionable or foolish with my tools, and would bray loudly to mock me and underline that I was being an idiot. "Hee-haw!!! That's not how you use a soldering iron!"
"Hee-haw!! That's a good way to strip a thread or round a fastener!!"
More than once, I had to concede that the donkey had a point...

Handlebar and control levers:
I started by taking off the clutch and front brake levers at the handlebar, cleaning out old grease and putting it all back together, properly lubricated and with an added shim on the clutch lever to eliminate an annoying rattle. I also replaced a missing 'E' clip that holds the clutch lever pivot pin in place. These small jobs are always oddly satisfying, and do make a difference. I also replaced the brake lever with one that matches the clutch: they weren't exactly the same before, something that had been bothering me for a while. 

The lever I took off is now part of the spares kit and can be used for either the clutch or the brake (ah, the beauty of simple, mechanical controls) in an emergency. I'll talk about the "spares & tools" separately.

And then I thought I could do better than this, and got some nice new "Biltwell Recoil" grips and a stock handlebar as fitted to the very first Commandos: it's lower and narrower than the previous one I had, giving a nicely tucked in riding position. Coupled with the new grips, this feels absolutely spot on.

As is typical, unnerving and inexcusable for these things, the throttle didn't fit over the new handlebar. Vernier calipers confirmed a small but not insignificant difference between the two parts, probably indicative of very thick chrome plating. In itself, that's not a bad thing and the handlebar is a very nice piece with excellent finish, but it must have mushroomed towards the bar end during plating. That said, after a couple of in-house attempts at resolving this, I actually had to resort to a professional machine shop in Garbatella where they were able to achieve a lovely slip fit.

Years ago, when I upgraded the clutch on this bike, I had remarked that "this doesn't just feel like a better clutch, it feels like a better motorcycle." and here again it's evident how a few small details (handlebar, grips and rev counter as we'll see later) make this look and feel like an altogether different motorcycle. The only possible explanation to this is that the Norton Commando - much like all other refined, high end machines - exists at such a rarefied level of performance and design, that even the smallest change has a noticeable impact on the overall experience.

Now, I don't want to spoil the look by fitting a mirror, but I need a mirror, so I went rummaging in our box of rear-views (anything from an old Stadium, to some Japanese items, cheap Italian moped ones) and found this:

I paused because I realized just how much time has passed since I originally bought it. Decades... 

Back then, I didn't even have my Norton yet. I was riding the Morini and wanted something a bit sharp for it, so I went to a famous shop on via Marmorata and paid a pretty penny for this thing. When the Morini was eventually restored, this mirror ended up in the box with the others, so I am actually glad to get it out again and bring it along the country roads we love so much. It polished up well, tricking me into thinking that "decades" isn't really that big a deal; then I selected a couple of washers of the right thickness and installed it. I know it probably doesn't suit the bike all that much, but the aforementioned decades have transformed it into a nice "neo-vintage" accessory with some personal history, so I'm happy to keep it at least for now.

Why not refit the previous bar-end mirror, you may ask; firstly, I didn't want to cut into the brand new grips and secondly I wanted to emphasize the narrower front end by also removing the bar-end mirror.

K&N:
After that, I moved to the air filter... oh dear. It's a K&N reusable filter that looks cool and works very well, but it was long overdue for a proper cleaning. The color of the sludge that came out of it was concerning to say the least; I'm expecting a noticeable surge in power after this! You're supposed to wash these from the inside out using a mild degreaser or soap and warm water at low pressure, taking plenty of time to get all the crap out until it's clean again. After drying, the filter has to be oiled to preserve the cotton medium. Some people use ATF, but there is a proprietary blend as well, which is what I'm using here. Ridge by ridge until the whole element takes on the distinctive K&N reddish/purple hue.

The last tour I did with the Commando was by any measure a superb trip that put the machine to the test and took a toll on it. That's the reason for this current round of maintenance and small repairs.

Roadholder forks:

Next, it's time to replace the fork oil, nothing extravagant, although there is something worth noting here: the workshop manual specifies 150cc of oil per leg, however the correct quantity for the Commando is actually 180cc. I believe the lower figure comes from previous models that had the "short" Roadholder fork (specifically the damper tube) and that might have been carried over in print for the Commando. There are a few of these typos in the manual ready to catch you out, most notably the torque value for the clutch center nut, which is dangerously too high. Research the topic and de-rate accordingly...

The top bolts were a little bit looser than I'd have liked to find, I'm going to keep an eye on these. There is no specified oil weight as far as I'm aware, I believe this is a matter of personal preference. I'm using 10w30 here, and replacing the two small fiber washers for the drain bolts.

I also took the opportunity to fit these special top bolts from Andover Norton:

As you can see, they are shorter than the stock ones and are meant for the Production Racer or other specials without the instrument pods, such as is the case with my Fastback. When the bike was originally rebuilt and we removed the speedo, Peppe fabricated the two spacers you can see in the previous photos to make up for the thickness of the now-missing instrument pods, but this is a neater solution and gives me a little bit more room, now that I have the lower and narrower handlebar.

They are made of a light alloy, which means automatic bragging rights:

Considering I also removed the two spacers, which weigh around 7g each, this means I have shaved off a not insignificant 250g from the steering and around the headstock axis.

Since these are aluminum, it also means it's probably a good idea to use an ever-so-impalpable veil of copper paste on the threads so I don't end up cursing and weeping next time I do an oil change.

Gearbox inspection cover threads repair:

the first thing to do here is to drain the oil. The drain plug is located at the back of the gearbox shell, and as the bolt head is somewhat domed and shallow, you have to be very careful that your socket is a nice positive fit to avoid rounding off the fastener. I actually used my trusty ¼″ Whitworth ring spanner since the angle between the ring and the handle is perfect to clear the center stand of the bike, as well as the gearbox shell itself. A little bit of heat and a few gentle taps always help with this sort of thing. The oil itself was predictably dark but contained almost no bronze bush dust, so nothing concerning. A new copper crush washer goes on, and the drain plug is back in place.

Over to the inspection cover, I removed the zip ties and aluminum tape I had used as a get-me-home repair during the first Gran Giro delle Montagne. That patch job was needed because one of the threads had stripped completely, so now I was able to re-tap both to M5 and fit a couple of nice parkerized allen heads. Apologies to the purists.

While I was at it, I also cleaned the tiny breather hole you can see in the photo above, it was clogged, as is commonly the case with these. This was also a good chance to check everything on the inner cover: the clutch actuating mechanism, all the retaining nuts, the knuckle roller, the gearchange bush as well as all the components behind the outer cover (the ratchet plate, pawl, and the infamous spring, the kickstart seal, etc.). I found nothing out of place apart from one stud whose corresponding thread in the gearbox shell is probably not in great shape: it's not stripped and I'm not about to dismantle the whole thing for a repair that's not needed, so I'm leaving it well enough alone for the time being.
I do have one upgrade I'd like to try out, which is the knuckle roller from the later Mk3 Commando; it can be retrofitted to earlier gearboxes and supposedly makes shifting action even smoother than it already is. The original roller is a barrel shape, whereas the later one is somewhat spherical: this should help to radially align it with the ratchet pin as it travels in its upwards/downwards arc when gears are selected. Is it needed? Does it really work? I'm not about to find out anytime soon, as fitting it requires dismantling half the gearbox.

While I was down there though, I did look at the swingarm pivot pin (or spindle, whichever you prefer), checked for any signs of unwanted play, but all seems well. A little bit of oil is added by removing the locating bolt on top of the gearbox cradle. Yes, there is a zerk fitting on one of the end caps, which is easier to access and was clearly intended for this purpose, but I don't know how effective this would be. Injecting oil through the top seems like cheap insurance against premature wear of bushes and spindle.

Rear brake ventilation:
I'd had this little kit sitting on my shelf for longer than I really want to say, but I finally got it done now.

These were found on the Production Racers in the 70s and I've always liked the look. You should just about be able to make out one of the two vents on the rear drum in these grainy images:

Witold made the same modification to his Commando years ago, and he did warn me about a couple of things: first, the self-tapping screws provided aren't all that good. Second, it's important to mark the location of the vents on the bike, rather than guess it on the bench, so that's exactly my first step here.

There, that looks about right:

Those who are not familiar with how the Commando's rear wheel is made up may find the following... unsettling. First of all, judging by the looks of the hub, you might assume this is a full width drum brake, but no. The hub is just a hub, larger than it needs to be perhaps, but made this way in order to fit shorter (therefore stiffer) spokes. The brake is a side mounted SLS unit. Then, you might understandably assume that the wheel axle or spindle goes all the way through; that would be normal. But no. The aforementioned drum brake is a casting that also includes the rear wheel sprocket, and the whole assembly is bolted to the swingarm with a dummy spindle. The actual wheel is then bolted to it on early models, or it rides on pretty small cush rubbers on the '71-on machines. The wheel spindle therefore threads into the back of the sprocket/drum assembly's dummy spindle.

Right, adjusters all the way in, wheel removed, chain removed, rear brake cable disconnected, and I can now lift the brake/sprocket assembly off the bike. The brake shoes are in fairly good shape and cleaned up well with some fine sand paper, which, together with correct re-assembly later, yielded a considerable improvement in performance. I had to dismantle everything off the carrier plate in order to drill through it, something that was far more of a pain in the ass than I had anticipated. The plate is 4mm thick and very hard iron, so this really took some effort. While quite a few friends sheepishly joked "why don't you just glue the vent plates on and save yourself the hassle?" I would never fake it.

Is it needed? Is it effective? Probably not, I will admit this is mostly for looks and again for bragging rights, so in that sense it's great.

Kröber

Racer wannabes, vintage accessory fetishists, and bona fide pilots who race classic machines on the track will all be familiar with the name Kröber. I first saw these fitted to high-end single cylinder racers, BSA and Triumph triples and all manner of specials way back at the turn of the millennium. Having one on a road machine was (and still is) a way to show off that you've taken your motorcycle to the next level with a specialist bit of kit reserved for those "in the know". I've always appreciated them even though it was never high on my list of must-haves for my Fastback. Given that decades have passed though, I think I can now afford to fit one, thus doing away with the stock instruments entirely, as well as the gear drives and unsightly mechanical control cables.

Among others, Witold also fitted one of these to his Commando years ago, although his has a white dial and the scale goes up to a scandalizing 10.000 rpm. I opted for something not quite so indecorous...

I took the bike over to uncle Fester as a way to have a nice ride and hang out as he took care of bracketeering it into place.

The ride over was a jolting reminder of just how raucous, loud and brawny this thing is. The Isolastic is set to perfection, so that the higher the revs, the more comfortable the ride actually becomes and the faster you inevitably go, floating over the road on this ultra modern flying carpet of a machine. Because while a BMW delivers linear, surging power, the Norton releases the same kind of sudden shockwave  such as you'd experience when detonating a charge. Time and again this impossible combination of dense, explosive power and panther-like athleticism leaves me stunned.

Some popping on overrun makes me wonder whether I might have an exhaust leak somewhere (perhaps the sealing gaskets are starting to go), or it could very well be the effect of the properly clean air filter, resulting in a leaner mixture. Or maybe it's the timing, or maybe it's an air leak at the inlet manifolds, or somewhere else! By the time I'm done going over a list of possibilities in my head, I actually get to where I'm going and I start looking it over. Yes the exhaust lockrings were a little bit loose, I nipped those up ever so slightly and kept looking around the head and inlet manifolds until I found the obvious culprit: the pilot air adjusting screw from the right hand carburetter was totally missing. No wonder it was popping and protesting with an idle circuit completely out of whack. A replacement goes quickly in place (this is why you carry spares!) and the problem disappears.

This looks so good, but even better than how it looks is how this works: ultra precise, the needle is absolutely steady and very easy to read. I can see how this would be of great use in a true racing application.

One small but important detail is this blanking plate that seals off the location of the previous mechanical drive at the crankcase:

Nice.

Mass reduction

The seemingly small weight saving at the top of the steering head made me think about all the other components on this motorcycle that were either replaced with lighter ones or removed altogether. Unless I'm forgetting something, we are looking at:

• cylinder barrel (the cast iron original was replaced by a Steve Maney aluminum one, known to save at least 5kg);
• belt primary conversion, estimated to save at least 2/2.5kg;
• front fender (a smaller and much lighter item compared to the steel original and its stays)
• rider and passenger footrests replaced with light weight aluminum rearsets and simple passenger aluminum footpegs;
• both wheel rims have been replaced (from original steel to lightweight aluminum);
• the front brake has been replaced (from the original TLS drum to a replica Fontana magnesium 4LS - this may not necessarily result in weight reduction in and of itself);
• the original chainguard, amber light reflectors, speedometer, speedometer gearbox and cable have been altogether removed; The rev counter has been replaced with the Kröber unit, meaning the original mechanical cable is also gone, and the new rev counter is lighter than the original;
• number plate holder and headlamp brackets replaced with lighter weight aluminum items;
• the air filter has been completely replaced by a K&N filter (this also weighs considerably less than the original assembly).
  
• The horn is certainly lighter than original heavy item.

Based on the above, I think I can revisit what I had originally estimated here to a more impressive figure, upwards of 15kg. And it's not just the weight reduction, but from where that weight was shaved off, including a considerable saving in unsprung weight, rotating mass, reduction of inertia and other complicated notions that smarter minds will surely recognize. As far as I'm concerned, all I care about is that the bike looks cooler, feels lighter and handles sharply, which is why I think it has reasonably earned the "Superleggera" moniker.

And since the proof is in the pudding, let's actually put this thing on a scale with oils and a full tank of fuel and see: 183Kg. Not bad.

Oils, filters and torque settings

A bit of a catch-all paragraph to recap on a few things. All oils have been changed; nothing exceptional here, just careful, proper maintenance - gearbox, forks and engine (plus a new cartridge filter while the rear wheel was removed as I worked on the rear brake).

I took this opportunity to remove both sump plugs, dismantle the gauze filter so I could clean it, then reassembled it with a new circlip and new copper crush washers. I then mulled this over and decided to follow Norman White's advice:

I was pleased to find the rear chain in good enough condition that I could reuse it. I gave it an old fashioned kerosene bath (since it's not an o-ring type), brushed off all the grime and old grease and checked every single link and roller. Achieving the correct chain tension is a bit of a process, but it is absolutely critical on the Commando. The sacred texts provide this in the way of guidance:

When you do things by the book, with a torque wrench, you can actually feel when everything is put together properly.

The first ride was just about twenty minutes to bring the engine up to temperature, I then returned to the shed where I had all the tools laid out to retorque the cylinder barrel to the crankcase, and the head to the barrel.

The following day, with the engine fully cold, I set the valve clearance and replaced the gaskets.

I found nothing wildly out of place so I readjusted as per the above procedure. Most of the studs that hold the valve covers in place were a little loose, so I tightened those as well. The gaskets were actually in good shape but as they tore during removal, I replaced them with new ones and used the "Ermetico Vittoria" sealant instead of the usual silicone type for a neater finish. Lastly, I went through all critical fasteners from the front to the back, top to bottom. Everything in the front end, including the wheel axle, the lower yoke pinch bolts, the new fork caps and even the headlamp mounts. Elsewhere in the machine, only a few fasteners were just a little bit loose, most notably all eight bolts that secure the rocker endplates to the head.

All of the engine/gearbox-to-frame bolts, Isolastic mounts and the head steady are accurately tight, as are the shock absorbers and rear wheel axle. We're good to go. Hopefully next time it will just be a simple matter of doing some very basic servicing. What a bike though!