Thursday, November 19, 2020
Sunday, November 8, 2020
Isolastic once again.
As you may remember, I overhauled the Isolastic on my Commando many moons ago. It was a very satisfying winter project that - as usual - took way too long even though I could have had it done in under a week if I'd had some free time.
The result was unquestionably a better motorcycle, an improvement measured in megaparsecs, simply put, a proper Commando.
Then Alessio decided to carry out the same upgrade on his Commando, going from the original shim type units, to the vernier adjustable that can be retrofitted to all Commandos.
Seeing as I had already done this on mine, we decided to try this together on his Fastback, which also has a belt drive primary and is therefore an almost identical set-up to mine.
Removing the primary was surprisingly quick and aided by the fact that almost everything that had to come off was barely finger-tight. Good grief!
We found an unacceptable amount of rust in the front mount, and although the rubber itself was showing some wear, I have seen much worse. The front mount itself came off the bike with no resistance, probably because Alessio's crankcases are the original ones and in all likelihood a hair narrower than mine (which are a contemporary reproduction).
A hydraulic press sure comes in handy for this (but isn't strictly necessary):
This particular bike is gradually returning to a "close to stock" look, and in that effort Alessio will be refitting the rear chain guard; to do that, he needs to go back to a 520 chain, and while we had the gearbox sprocket within reach, we replaced it with a new one (still 20 tooth). Again, the mainshaft nut came off with very little effort (i.e. worryingly it was barely more than finger tight).
Everything there is now back on, tight and properly secured.
Moving onto the rear mount, this is where things get trickier, and with one substantial difference from my Commando: Alessio's bike is a 1970 model, which means the center stand is mounted to the main frame, as opposed to the gearbox cradle as it is on mine.
Aside from the fact that he has actually removed the center stand altogether (you rebel, you!), we still need to consider a different way to support the engine-gearbox-swingarm-wheel as we separate that sub-assembly from the mainframe.
The exhausts being tied to both, we unbolted the Z-plates to let them move without the risk of damaging anything (or making things harder for ourselves).
The head-steady on this bike is the original type, made up of the same rubber mountings used for the silencers, as opposed to the actual Isolastic upgrade that's fitted on my Fastback. This too was unbolted to allow extra room to move, as were the ignition coils, rear mudguard, oil tank (actually removed), air filter, battery tray and rear shock absorbers. Yes, that is a lot of stuff, but the alternative would have been to remove the engine altogether and there was no way we were going to do that.
Because of the different position of the bracing tube on the 1970 frame, the operation to get at the rear Isolastic mounting was significantly trickier and harder than on my (1971) machine. This is something I was not expecting, although with some effort (see long list above) we managed to get it done.
Above: finally able to get at the rear mounting (only just), Alessio scrubs it clean of old rubber particles that were stuck on. The rubber mountings themselves were showing signs of compression (the metal tube being way off-center) and were probably not able to provide much in the way of cushioning anymore.
Below: the new unit in place (minus the dust cover).
Meanwhile, these two keep guard on the shed:
Ferocious.
The grey one is (kind of) a Manx cat. He lost his tail in an accident but he has a good life nonetheless:
We can now begin to realign the mainframe and sub-assembly, bolting the front unit back on, the Z-plates with spacers, nuts, bolts and washers all accounted for, and finally the long mounting bolt/stud that links the whole motorcycle together.
Everything else that has had to come off or moved out of place goes back to its rightful place aboard the machine, ready to ride again at top speed. Fun fact: Norton Commandos are known to set off nearby seismometers due to the huge amounts of torque they unleash on the ground; however, thanks to the Isolastic system, the rider is unaware of the tectonic shift going on underneath the bike, and can concentrate on chasing the vanishing point to the next bend.
This was a good opportunity to give the clutch plates and basket a good clean; outside and in the winter sun:
Most of the plates were stuck together, the basket was predictably dirty (gearbox oil) and Alessio appears to be missing one friction plate, we'll look into that later on.
Below - Happiness is: wrenching on a motorcycle!
I'm glad we were able to get this done together, in a relatively short time and with no major mishaps.
Alessio now has to find the right setting/adjustment of the new Isolastic to suit his Norton and his riding style (hint: it's called a Fastback), and while adjusting the vernier units is certainly fiddly, it is far, far easier than dealing with shims.
The result was unquestionably a better motorcycle, an improvement measured in megaparsecs, simply put, a proper Commando.
Then Alessio decided to carry out the same upgrade on his Commando, going from the original shim type units, to the vernier adjustable that can be retrofitted to all Commandos.
Seeing as I had already done this on mine, we decided to try this together on his Fastback, which also has a belt drive primary and is therefore an almost identical set-up to mine.
Removing the primary was surprisingly quick and aided by the fact that almost everything that had to come off was barely finger-tight. Good grief!
We found an unacceptable amount of rust in the front mount, and although the rubber itself was showing some wear, I have seen much worse. The front mount itself came off the bike with no resistance, probably because Alessio's crankcases are the original ones and in all likelihood a hair narrower than mine (which are a contemporary reproduction).
Moving onto the rear mount, this is where things get trickier, and with one substantial difference from my Commando: Alessio's bike is a 1970 model, which means the center stand is mounted to the main frame, as opposed to the gearbox cradle as it is on mine.
Aside from the fact that he has actually removed the center stand altogether (you rebel, you!), we still need to consider a different way to support the engine-gearbox-swingarm-wheel as we separate that sub-assembly from the mainframe.
The exhausts being tied to both, we unbolted the Z-plates to let them move without the risk of damaging anything (or making things harder for ourselves).
The head-steady on this bike is the original type, made up of the same rubber mountings used for the silencers, as opposed to the actual Isolastic upgrade that's fitted on my Fastback. This too was unbolted to allow extra room to move, as were the ignition coils, rear mudguard, oil tank (actually removed), air filter, battery tray and rear shock absorbers. Yes, that is a lot of stuff, but the alternative would have been to remove the engine altogether and there was no way we were going to do that.
Below: the new unit in place (minus the dust cover).
The front Isolastic gets replaced on the bench and is obviously a much easier thing to do.
The grey one is (kind of) a Manx cat. He lost his tail in an accident but he has a good life nonetheless:
Everything else that has had to come off or moved out of place goes back to its rightful place aboard the machine, ready to ride again at top speed. Fun fact: Norton Commandos are known to set off nearby seismometers due to the huge amounts of torque they unleash on the ground; however, thanks to the Isolastic system, the rider is unaware of the tectonic shift going on underneath the bike, and can concentrate on chasing the vanishing point to the next bend.
This was a good opportunity to give the clutch plates and basket a good clean; outside and in the winter sun:
Below - Happiness is: wrenching on a motorcycle!
Alessio now has to find the right setting/adjustment of the new Isolastic to suit his Norton and his riding style (hint: it's called a Fastback), and while adjusting the vernier units is certainly fiddly, it is far, far easier than dealing with shims.
Wednesday, November 4, 2020
Drinking the Kool-Aid.
Those who've known me long enough will tell you that I'm not very open minded when it comes to motorcycles. I'm set in my ways and I'm very, very picky (though luckily I don't have very expensive tastes) about what I like.
Anything with too much electronic gadgetry like fuel injection and ABS is out. And generally speaking, anything that's too popular is also out, as a matter of principle.
And yet, there is a motorcycle in our stables that by all accounts should not be there, has no business being there! I'm talking about, of course, our 1988 BMW R100GS.
BMW have done something remarkable with the GS line in general. Starting with the G/S in 1980 that invented a new genre of motorcycles (yet using what they already had! More on this concept below), in and of itself no easy feat, they evolved them over 40 years (and counting) and it has always been an extremely popular machine. And to that I say "bah, humbug." in no small part because so many of these behemoths that are actually capable of touring around the planet spend most of their time going from home to the office and back, all within the safe confines of a city, with tow-trucks and filling stations aplenty. What's the point?!
I also refuse to believe that the Telelever front suspension system is something that would work for me, though I'd be happy to be proven wrong.
Add to all that the ever more complex cooling systems, fuel injection, ABS, traction control, riding modes, on-board computer nonsense and you've totally lost me.
I know the G/S and the Paralever GS. I like the G/S's aesthetics if taken within a strict 1980s context, but do not like how it rides, with its annoying torque effect that jacks the bike up and down, and its flimsy top fork yoke that gives a rubbery feeling to the whole thing. I don't really care how our R100GS looks like, I certainly can't say that it's beautiful or even cool for that matter, but by god does it work! Simply put, there is no other motorcycle that I know or own that comes close to delivering the experience you can have with this flat twin. Not in terms of sheer performance (speed, handling, torque), both the Norton and the Sportster will run circles around it all day, and both deliver a visceral, gut-churning punch that the BMW could never do; what the GS does do, is make everything so very, very... easy. And that's why they're so popular.
I think I've said it before: BMW motorcycles aren't really motorcycles. They're 2-wheeled automobiles and they have so many quirks and oddities (that for the most part work, mind you!), to really put them into a class of their own.
Anything with too much electronic gadgetry like fuel injection and ABS is out. And generally speaking, anything that's too popular is also out, as a matter of principle.
And yet, there is a motorcycle in our stables that by all accounts should not be there, has no business being there! I'm talking about, of course, our 1988 BMW R100GS.
BMW have done something remarkable with the GS line in general. Starting with the G/S in 1980 that invented a new genre of motorcycles (yet using what they already had! More on this concept below), in and of itself no easy feat, they evolved them over 40 years (and counting) and it has always been an extremely popular machine. And to that I say "bah, humbug." in no small part because so many of these behemoths that are actually capable of touring around the planet spend most of their time going from home to the office and back, all within the safe confines of a city, with tow-trucks and filling stations aplenty. What's the point?!
I also refuse to believe that the Telelever front suspension system is something that would work for me, though I'd be happy to be proven wrong.
Add to all that the ever more complex cooling systems, fuel injection, ABS, traction control, riding modes, on-board computer nonsense and you've totally lost me.
I know the G/S and the Paralever GS. I like the G/S's aesthetics if taken within a strict 1980s context, but do not like how it rides, with its annoying torque effect that jacks the bike up and down, and its flimsy top fork yoke that gives a rubbery feeling to the whole thing. I don't really care how our R100GS looks like, I certainly can't say that it's beautiful or even cool for that matter, but by god does it work! Simply put, there is no other motorcycle that I know or own that comes close to delivering the experience you can have with this flat twin. Not in terms of sheer performance (speed, handling, torque), both the Norton and the Sportster will run circles around it all day, and both deliver a visceral, gut-churning punch that the BMW could never do; what the GS does do, is make everything so very, very... easy. And that's why they're so popular.
I think I've said it before: BMW motorcycles aren't really motorcycles. They're 2-wheeled automobiles and they have so many quirks and oddities (that for the most part work, mind you!), to really put them into a class of their own.
You could argue, very superficially obviously, that since the /5 series in the late 60s, all the way up to the early 90s, BMW have offered the same frame and the same flat-twin engine; it's always the same bike, always the same stuff.
Except it isn't.
Somehow, by altering the overall recipe ever so slightly, those crazy fun-loving Germans have managed to create vastly different machines; compare if you will an R75/5 (of which I want one, by the way) with Witold's R100GS PD: same mainframe, and both have a boxer twin, yet you couldn't possibly say they're the same bike, or attempt the same type of use or tour with both machines as if they were interchangeable. I think this reveals one thing: the basic design of that same frame & engine is intrinsically brilliant, and has yielded something so versatile as to be able to last a quarter of a century in production and provide machines for a wide variety of applications, with high build quality, better-than-average reliability, and decent performance to boot.
I will never say, or feel, that a BMW could be my favorite motorcycle in the world (that is and always will be the Norton Commando)... but damn, they're looking awful close in that rear-view mirror.
Subscribe to:
Posts (Atom)
