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View Full Version : Were they serious about this frame and swingarm?



Paul Pless
02-28-2013, 08:54 AM
Harleys suck!;)

http://images.motorcycle-usa.com/PhotoGallerys/harley-davidson-xrtt-750-2.jpg

P.I. Stazzer-Newt
02-28-2013, 12:16 PM
Is this some sort of vintage/age-restricted class of race bike?

And is that a period-accurate front brake?

Paul Pless
02-28-2013, 12:25 PM
Its a 1972 XR750TT, of which only ten were built. Outsourced chrome moly frame. Aluminum cylinders and heads ~ 100 HP in race trim, 300 pounds dry.

Here's the current brakes on this bike.

http://images.motorcycle-usa.com/PhotoGallerys/harley-davidson-xrtt-750-3.jpg

Here is how it would have been delivered from HD 41years ago, brakes would have been 4 shoe drum on the front.

http://www.bikeexif.com/wp-content/uploads/2012/10/harley-davidson-xr750tt.jpg

Paul Pless
02-28-2013, 12:36 PM
As it turns out it wasn't the frame and swingarm that was suspect on this bike. It was the last serious racing bike to run drum brakes, and it only had a four speed gearbox. Of course the speedway bike it was on had no brakes and the gearbox didn't really matter. :d

jonboy
02-28-2013, 01:02 PM
there's a lot of gear on that bike that ain't forty one years old........and footrests mounted on the swing arm.....? I know circuits are flt ish but still there's a lot of movement in that rear end , well, an inch or two, but as to the thread start... looks neat to me..... as Aretha said I'm in love i'm in love i'm in love , yes I am

Canoeyawl
02-28-2013, 09:32 PM
In 1974 I built one of those using the Cerrianni forks and Konis, Borranni wheels with a Fontana brake and the XR frame, but used a stroker sportster engine, 1150cc's at about 350lbs. It was a pretty good bike but difficult to start. Not much around here on the coffee racing circuit (which was really cocktail lounges) that could keep up.
I rode it to the drag strip at Fremont airport one night and ran 135mph in 11.5 seconds, but the thing was it handled pretty well too. It had no gauges, and after that timed run, I stopped riding it. Scared the hell out of me.

Sold it, bought a large pile of Mahogany and never looked back

The Bigfella
02-28-2013, 10:42 PM
In 1974, a company by the name of Yamaha buried Harley's racing ambitions

Oysterhouse
02-28-2013, 11:11 PM
QUOTE=Paul Pless;3712710]Harleys suck!;)

[/QUOTE]

Kicking off your campaign for March TOTM?:rolleyes:

PeterSibley
03-01-2013, 12:27 AM
Its a 1972 XR750TT, of which only ten were built. Outsourced chrome moly frame. Aluminum cylinders and heads ~ 100 HP in race trim, 300 pounds dry.

Here's the current brakes on this bike.

http://images.motorcycle-usa.com/PhotoGallerys/harley-davidson-xrtt-750-3.jpg

Here is how it would have been delivered from HD 41years ago, brakes would have been 4 shoe drum on the front.

http://www.bikeexif.com/wp-content/uploads/2012/10/harley-davidson-xr750tt.jpg


A pity they didn't learn from that model instead of build armchairs .

Lew Barrett
03-01-2013, 12:55 AM
As it turns out it wasn't the frame and swingarm that was suspect on this bike. It was the last serious racing bike to run drum brakes, and it only had a four speed gearbox. Of course the speedway bike it was on had no brakes and the gearbox didn't really matter. :d

But in this photo at least it's not running drum brakes. It's got a pair of brakes similar to Girlings (but they are not Girlings). And to me, it looks like it's set up to drag race or climb hills, except it has the wrong tires. But that's where a long swing arm comes into play.

Maybe it's just a matter of perspective. Tires are modern profile, not vintage, and they are siped like road tires.
Sport touring tires at that! My money is on drag bike. Big chicken strips, tires are worn in the center, rear looks like the victim of a lot of burn outs.

I'd call it an Oddster.

Oysterhouse
03-01-2013, 02:03 AM
I'd call it an Oddster.

Apt description.

The Bigfella
03-01-2013, 02:46 AM
Interesting that the swingarm has three lower mounting points for the shock.

PeterSibley
03-01-2013, 02:58 AM
But in this photo at least it's not running drum brakes. It's got a pair of brakes similar to Girlings (but they are not Girlings). And to me, it looks like it's set up to drag race or climb hills, except it has the wrong tires. But that's where a long swing arm comes into play.

Maybe it's just a matter of perspective. Tires are modern profile, not vintage, and they are siped like road tires.
Sport touring tires at that! My money is on drag bike. Big chicken strips, tires are worn in the center, rear looks like the victim of a lot of burn outs.

I'd call it an Oddster.

I'd call it a huge improvement on the normal armchair thinking.

Paul Pless
03-01-2013, 05:29 AM
In 1974, a company by the name of Yamaha buried Harley's racing ambitions
A pity they didn't learn from that model instead of build armchairs .The AMF years took their toll. In 1974, the United States was just entering a recession, energy crisis, and manufacturing decline that in many ways was to last eight years. In Britain the same thing was happening, their motorcycle industry was consolidated and socialized and managed to hang on for another ten years before collapsing completely, their auto industry lasted a few more years. In the meantime Japan was on a tear.

The Bigfella
03-01-2013, 06:08 AM
The all time weirdest racing bike.... Kenny Roberts TZ750 flat tracker


http://www.youtube.com/watch?v=qSupEffWQtU

"They don't pay me enough to ride this thing"

PeterSibley
03-01-2013, 06:14 AM
The AMF years took their toll. In 1974, the United States was just entering a recession, energy crisis, and manufacturing decline that in many ways was to last eight years. In Britain the same thing was happening, their motorcycle industry was consolidated and socialized and managed to hang on for another ten years before collapsing completely, their auto industry lasted a few more years. In the meantime Japan was on a tear.

and Ducati had finally learned exactly what a small segment of the market wanted .

Paul Pless
03-01-2013, 06:17 AM
The all time weirdest racing bike.... Kenny Roberts TZ750 flat trackerAs PISN pointed out a few days ago, watch Rossi's reaction!


http://www.youtube.com/watch?feature=player_embedded&v=8k8hJWKIVNs

Paul Pless
03-01-2013, 06:19 AM
and Ducati had finally learned exactly what a small segment of the market wanted .And were very lucky to have survived the Japanese manufacturing onslaught. Guzzi too. And Aprilia. . .

Is BMW the only European motorcycle manufacturer to have come through the Seventies and Eighties relatively unscathed?

The Bigfella
03-01-2013, 06:27 AM
I remember seeing that on a thread, but didn't view it, now you come to mention it. Good to see Kel Carruther's in that video.

The Bigfella
03-01-2013, 06:30 AM
And were very lucky to have survived the Japanese manufacturing onslaught. Guzzi too. And Aprilia. . .

Is BMW the only European motorcycle manufacturer to have come through the Seventies and Eighties relatively unscathed?

KTM was founded in 1934

Triumph... not unscathed

MV Augusta

Moto Guzzi

Aprilia (Piaggio)

Vespa

Husqvarna (motorbikes since 1903)

Ural

I can probably go on.... but I won't

Lew Barrett
03-01-2013, 10:37 AM
And were very lucky to have survived the Japanese manufacturing onslaught. Guzzi too. And Aprilia. . .

Is BMW the only European motorcycle manufacturer to have come through the Seventies and Eighties relatively unscathed?

Aprilia didn't exist at the time. Ivano Baggio's family manufactured bicycles and really wasn't a motorcycle manufacturer apart from component assembly. Ducati is doing better than they ever did back then. Ducati had almost always been an on again-off again affair anyway, having changed hands and gone through periods of state (and church) ownership. Piaggio as a group is healthy at this time as well, and were in the seventies, though they really weren't in the motorcycle business per se at that time; scooters. Now, it's some of the Japanese who are struggling. Suzuki is the most beset, but Kawasaki has issues as well. The worm turns.

The Bigfella
03-01-2013, 07:25 PM
I think you underplay Aprilia a bit, Lew.

They kicked off just after WW2 and were manufacturing bicycles until the late 60's when they moved into small motorbikes. In the late 70's they were winning 125 and 250 Italian motorcross championships and doing well in the world's. Sure, in the 80's they bought in engines for some of their bikes... but, so did BMW (from the same supplier - Rotax). In fact, my F650 Funduro BMW is a repackaged Aprilia Pegaso with a Rotax engine (and a 4 valve head, instead of 5 valves).

Wiki gives this list of Italian motorcycle manufacturers:



Aprilia (http://en.wikipedia.org/wiki/Aprilia) (motorbikes (http://en.wikipedia.org/wiki/Motorcycle))
Benelli (http://en.wikipedia.org/wiki/Benelli_(motorcycles)) (motorbikes)
Beta (http://en.wikipedia.org/wiki/Beta_(motorcycle_manufacturer)) (motorbikes)
Bimota (http://en.wikipedia.org/wiki/Bimota) (motorbikes)
Cagiva (http://en.wikipedia.org/wiki/Cagiva) (motorbikes)
Ducati (http://en.wikipedia.org/wiki/Ducati) (motorbikes)
Garelli (http://en.wikipedia.org/wiki/Garelli_Motorcycles) (scooters (http://en.wikipedia.org/wiki/Scooter_(motorcycle)))
Gilera (http://en.wikipedia.org/wiki/Gilera) (motorbikes)
Husqvarna (http://en.wikipedia.org/wiki/Husqvarna_Motorcycles) (motorbikes) (Swedish Origin)
Laverda (http://en.wikipedia.org/wiki/Laverda) (motorbikes)
Mondial (http://en.wikipedia.org/wiki/Mondial_(motorcycle_manufacturer)) (motorbikes)
Moto Guzzi (http://en.wikipedia.org/wiki/Moto_Guzzi) (motorbikes)
Moto Morini (http://en.wikipedia.org/wiki/Moto_Morini) (motorbikes)
MV Agusta (http://en.wikipedia.org/wiki/MV_Agusta) (motorbikes)
Piaggio (http://en.wikipedia.org/wiki/Piaggio) (scooters)
Vespa (http://en.wikipedia.org/wiki/Vespa) (scooters)
Vyrus (http://en.wikipedia.org/wiki/Vyrus) (motorcycles)


In the early 50's BSA claimed world's largest status "one in four" being the claim, but were overtaken by NSU in the late 50's. These mobs are so far behind the current leaders in bike production numbers that it isn't funny. The Indonesian motorbike market is 8 million per annum. Honda is building its 4th factory there. Then there's the other Asian countries. China is a whole different ball game.

Lew Barrett
03-01-2013, 09:35 PM
I think you underplay Aprilia a bit, Lew.

They kicked off just after WW2 and were manufacturing bicycles until the late 60's when they moved into small motorbikes. In the late 70's they were winning 125 and 250 Italian motorcross championships and doing well in the world's. Sure, in the 80's they bought in engines for some of their bikes... but, so did BMW (from the same supplier - Rotax). In fact, my F650 Funduro BMW is a repackaged Aprilia Pegaso with a Rotax engine (and a 4 valve head, instead of 5 valves).

Wiki gives this list of Italian motorcycle manufacturers:



From the wiki link, and note motorcycle is in quotes (theirs, not mine!): "Alberto’s son, Ivano Beggio, took over the helm of the company in 1968 and constructed a 50 cc "motorcycle" with a dozen or so[citation needed] collaborators. The first production Aprilia mopeds were named Colibrý, Daniela and Packi. Aprilia later produced a motocross bike in 1970 called the Scarabeo. Produced until the end of the 1970s, the Scarabeo came in 50 and 125 cc versions."

Not to pick too fine a point (or fight), but I called them an "assembler." The article corroborates that. BMW's pick of the Aprilia as the base for the Funduro was a good moment for them, and agreed (as mentioned here before) the Pegaso and Fuduro are essentially the same bike. They were a scooter/moped shop before that with an ambitious racing program to advance them from there. The association with Rotax was a smart move. Since 2008, Aprilia has been building it's own motors. Before that, almost all of them (not sure about the 50cc and 125cc and world beating 250 cc smokers of the late 90s and early part of this century) were outsourced.

I've owned a couple of Aprilias as you know and am quite fond of them. I guess a bit hinges on what you consider a motorcycle manufacturer to be and what their output should resemble. I could have been clearer when I said "didn't exist." I hoped to have it understood as "didn't exist as a manufacturer of full sized motorcycles." I can see how my wording would be easily misunderstood from that point of view.

The Bigfella
03-01-2013, 09:51 PM
Its OK Lew, I'll forgive you....:D

Lew Barrett
03-02-2013, 12:40 PM
I am somewhat encyclopedic, but pretty far from perfect. ;)