Monday, September 21, 2015

Our lady of the sacred Fastback

This one speaks for itself I think, Alessio's beautiful Fastback:

Tuesday, September 8, 2015

Handlebar vs. handlebars

After riding the Norton with the new handlebar, I can make a proper comparison with the clip-ons I had before, and I can say this:
pretty though it was, trying to handle the bike with the clip-ons was like trying to write calligraphy while wearing boxing gloves.
With the new handlebar, it's like shooting a rifle with a hair trigger.

Sunday, September 6, 2015

the Campotosto Mystic Trip 2 - "Shamans of the Astral Plane": a report.

Much like last year, we covered A LOT of ground for this trip, our course meandered through so many small towns, hills, valleys, forests and proper mountains, one after the other, until you no longer know where you really are, and the passage of time feels like the memory of a half-remembered song.

As motorcycles and riders started to resonate with each other and everything else around them, that's when we gradually emerged onto the psychic trail and the real trip began. There are no signposts along the way, but plenty of signs, markers and animal spirit guides like the white boar. Far out man...

Once again, only three Shamans rode out to the mountain lake, perhaps such a mystical trip has a component of numerology? Perhaps next year we can make it seven then?

Sandro joined us on his perfectly stock Honda CBR600F, tires down to the canvas and motor oil a little past its prime, but I'm so glad he could come with us.

Witold, still in considerable pain from a broken throttle hand, chose an incredibly futuristic Honda CN250 Spazio, duly thrashed it and was faster than a lot of sports bikes we encountered along the way:
He is the Psychopomp! He manifested himself to guide us across layers and ripples of reality! Make an offering of the sacred herb to him, and all will be well:
Here are some more snapshots from along the way, who knows where we were!
Who's a good boy? YOU'RE A GOOD BOY!!
Here are some more from the side of my head.
Taking in the view at Salto:
Getting things moving:
Grassy lanes? No problem:
It's ok, this doesn't mean what it means in Britain:
Offroading on the Spazio, not for the fainthearted:
Behold, the majesty of this wonderful lake and the Holy Mountains that surround it:
As for the Norton, this outing and the short round trip to the mountain rally last month, made for a good shakedown and real-world test of the newly assembled top end.

I can safely say that this engine has never run so well (and that clutch upgrade is working a real treat, lemme tell ya).

Even Witold had to concede that it sounds spectacular, does not burn oil and feels (even at a distance) purposeful and precise. Hats off to SRM, once again.

Some of you may know what I'm talking about here, you spend the whole day on a motorcycle, especially a British classic with their unrestricted exhausts, and by the time you go to sleep you can't help but notice this peculiar ringing in your ears, part droning sound, part echo, yet very present. You may think it's the effect of all those hours exposed to the loud exhaust but what you've actually tuned into is the eternal cosmic cymbal that's always ringing but only a few can hear, sending out wave after cosmic wave of mystical revelations.

Until next time, safe trips to everyone.

Saturday, September 5, 2015

New gearbox linkage.

One more improvement to the Norton, in this case I've replaced the gearbox linkage that came with the rearsets that were fitted during the initial rebuild.

The link rod that's supplied with the rearsets has a clevis fork at each end, retained with pins and a circlip.

While this is a perfectly fine arrangement - on paper - it does not counteract one of the side effects of the Isolatics when fitting rearsets on a Commando, namely that the gearbox is rubber mounted, while the footrest plate is bolted to the frame. This means that the link rod and the clevis forks in particular end up taking a real beating from all the vibration.

The result is that the attachment points get ovalised, meaning that despite adjustment, they become permanently slack.

To remedy this, I fitted a new link rod with a couple of spherical joints, which make for a much more positive linkage.

Here's "before":

And "after":
Neat huh?

Wednesday, September 2, 2015

Clutch refurbishment.

Alright, it really was high time I got around to doing this, if nothing else because Witold has been bugging me about this for ssssoooooo long! (but you were absolutely right, and thank you for your usual assistance; thanks bro J)

On my Commando, the diaphragm spring, clutch centre and the metal plates are about the only original parts that remain from the standard clutch: a complete belt drive kit from RGM was fitted and I must say I've had absolutely no issues with it whatsoever, and would strongly recommend it to anyone looking for a belt drive conversion. This means the clutch basket is also a non-standard item.

When it came to putting the actual clutch back together, we went for 4 Surflex fibre friction plates with 3 plain plates and the existing pressure plate, which measures 6.something millimeters, and so should be the thicker type (part n.060745):

Unbeknownst to me at the time, this gave a stack height of 26.something mm, which is simply wrong for my set-up: the diaphragm spring is far too inward, making operation unnecessarily heavy.

Add to that about 20.000kms of use without the slightest bit of maintenance... it's clear that it needed a bit of work.

The new clutch plates, with the existing pressure plate, measure 29.5mm. This appears to be just right.

A note about clutch pressure plates: there are two available, 060745 (5.77mm) is the thick one that goes with 4-friction/3-plain plates, and  063768 (2.72mm) is the thin one that goes with 5-friction/4-plain plates. There are endless tech digest articles on the topic, but if in doubt just contact Andover and they'll help you select the right components.

You guys can do your own conversions to miles, yards, furlongs, rods and ells, millionths-of-an-inch and all that, I'll stick to metric this time.

Now, if I were running a standard clutch basket for the triplex chain, all standard parts in general, then there'd be no excuse for not following what the parts list and workshop manual say: adding extra plates, or tweaking parts in any other way is simply not correct.

But, once you start messing around with non-standard parts, then anything goes. You can take all the measurements you want, in the end what works is mix-matching until you can get the diaphragm spring to be as flat as possible so it can disengage with the least amount of effort. The spring "wants to" push against the plates, so maintaining enough pressure on the plates stack shouldn't be a problem, and the clutch shouldn't slip.

Having considered various options, I decided to follow Mario's advice based on his current experience on his lovely Roadster, and go for a Barnett clutch set, with the addition of a "Dyno Dave" clutch rod seal, a really nifty accessory: 5000+ Commando owners can't be wrong!

Time to get into this thing. The spring compressor is essential if you want to avoid maiming yourself; I've seen it happen and it ain't pretty, believe me.

The back of the clutch adjuster shows a good bit of wear.

The dimpled end of the pushrod is fine.

The other end of the pushrod is just about acceptable, but anyway both the pushrod and the adjuster will be replaced; more on that later.

Once into the clutch stack, the biggest problem is readily apparent: oil contamination, and lots of it.

Especially in the photo above you can see it pool at the lowest point of the clutch basket.
It's obvious that this is 80w90 gear oil, there is no mistaking that rancid smell.
Now, just to be clear, the clutch on the Norton Commando is meant to be a dry clutch, always. Even when running the original triplex primary chain in its oil bath, the clutch is still dry. The little bit of oil that's in the primary chaincase is there to lubricate the chain, not the clutch. And provided you keep the level where it should be (below the basket) there shouldn't be any issues.
Gearbox oil, however, travels the length of the mainshaft, along the pushrod, and eventually spills over inside the clutch. To remedy this, a clever little nut with an O-ring is available to effectively seal the mainshaft. Look for "DynoDave clutch rod seal" and you'll find all the info you need.
I forgot to take a photo of the nut in position, but you can imagine how it screws onto the end of the mainshaft, simple and very clever.
But I'm getting ahead of myself.
Upon inspection, the friction plates show a fair amount of wear, though I've seen much worse. The eccentric grooves were all gunked up with gear oil, while the metal plates were entirely coated. I've cleaned everything and put it aside since, as the mantra goes, "you never know".
The clutch center, or hub, is really not in bad shape, sure the splines show a few marks but there are no notches or anything that the plates can get stuck on:
Next, I gave the clutch basket and hub a proper clean, using a strong degreaser/brake cleaner and a clean cloth to get into all the grooves. This is tedious bloody drudgery but it has to be done, or you'll be back to square one before you even get started. I was careful not to spray any of the degreaser onto the belt just in case the material could be affected by the chemicals.
There, much better. Time to fit the new clutch plates, starting with a friction plate:
Normally, this clutch type with the 5 friction and 4 metal plates, plus thin pressure plate, was fitted to the later 850s, and starting with a friction plate, you also end the stack with a friction plate, followed by the thin pressure plate. However, in this case there is just enough room to fit the thick pressure plate and still be able to properly secure the diaphragm spring with the large snap-ring. This seems to make the diaphragm spring sit almost totally flat, but anyway I'll have to test it and see how it actually works.
Above, you can see the complete stack with the thick pressure plate but no diaphragm spring.
From an angle, to show the minimal room available to fit the diaphragm spring between the pressure plate and that groove in the clutch basket, which is for the large retaining snap-ring. This is an optimal arrangement for a very light clutch action with positive and reliable engagement.
Having removed the pushrod for inspection, a common problem occurred, which could leave you stumped if you don't know what has happened: you put everything back together, try the clutch lever... and nothing happens other than a horrible spongy sensation, but the clutch doesn't work. In all likelihood the clutch actuating arm is the culprit, and if you open the small inspection cover on the gearbox, you'll see that it has fallen down from where it should normally sit. This happens when the pushrod is removed, so frequently in fact that it is even detailed in the workshop manual:

There is no sorcery at play here, and you can fix it yourself without having to sacrifice a goat to whatever "specialist" tells you that only they can get your bike to ever work again. Screw the lot of them, sic semper tyrannis.
You can usually use one finger to push the actuator back in place without having to remove the gearbox cover.
In this case, I actually had to remove the cover to fix yet another problem: the entire clutch operating body was loose in the gearbox, and its lockring was coming undone! Who knows how long it had been like that but this is serious. Thankfully I noticed it and I can fix it.
First of all, with the gearbox cover removed (above), you can see the actuator in the wrong position, it has fallen all the way down.
And above, where it's supposed to be. To keep it there you have to maintain some pressure on the pushrod from the clutch side, or you'll have to start all over again. Getting a buddy to help you makes this a lot easier, but it is not impossible to do it on your own.
As for the clutch operating body, checking to be sure that it is aligned with the passage for the clutch cable, I can now tighten the lockring. I should have done this with a proper pipe tool, but I don't have one so hammer and drift it was.
While I was at it, I also inspected the ratchet mechanism and changed the gearbox oil.
With everything properly and firmly back in place, it's time to test the clutch lever: the result is definitely a lighter feel than before, and it seems to disengage by pulling with just two fingers, something that was impossible previously.

Now it's time for a test ride: I'm weary of hyperbole, but in this case I think it is appropriate to say that this doesn't just feel like a better clutch, it feels like a better motorcycle. Being able to operate the clutch so easily and so quickly means that shifting gears is a lot faster and it becomes something that happens "in the background" so you can focus on actually riding the bike. This was the case during our recent trip to Abruzzo, and it made for a much more enjoyable experience.

There is one more thing I will be fitting to the clutch to complete the upgrade, but first I want to use it like this for a little while, to see how the new clutch plates compare with the old ones in terms of smoothness of operation, engagement, etc. Once I'm satisfied with that I'll get back in there and fit a cool bit of kit...
It's not like me to brag, but I will this time: I've done "un ottimo lavoro" with this, it's much better than it was before.