Billet Crankshaft

SteveA · Jan 23, 2023

B+Bogus said:
I recently saw a photo of a late factory racer that actually had a Triumph gearbox fitted.

No, I don't think you did....

I have seen a photo of a bike that was a 'replica' of a late factory racer!

It had a Triumph gearbox fitted, but it wasn't a factory or even period built bike.

The resolution to the factory problem was spinning the gearbox faster, a lighter clutch, and an outrigger bearing.

The resolution in my 75/76 850 build was being guided to a 4 speed box with Manx ratios, a Manx style layshaft bearing in place of the bush in the kickstart and a 33 tooth engine sprocket.

Box didn't break in the four seasons I raced it. Not having 5 speeds wasn't much of a problem since we push started, me in first, those with 5 speeds in 2nd, same ratio!

Fast Eddie · Jan 23, 2023

SteveA said:
Bruno Perlinski builds some of the most competitive 750 long stroke Nortons in France, probably Europe.

We were talking about revving my short stroke to 8000, which I have done on occasion, but don't do regularly.

He told me he NEVER revs his motors above 7000rpm.

Wrong goal for an 850 for sure. Do remember that Maney built 1007 motors with 3 piece cranks.

I am with FE, a Molnar crank would not let you down....and if you have faith in the other parts....you talk about exploding flywheels......he can supply a flywheel only!

That’s a good call Steve, Andy does indeed offer the flywheel only. That’s a very economic solution. Weight looks somewhere mid way between Maney and stock.

There you go Al… nothing stopping you now mate…

Norton Twins Steel Flywheel

Norton Twins Steel Flywheel Commando Atlas Dominator Dommi Racer Dommiracer Domi Domiracer 650 750 850 920 cc 650cc 750cc 850cc 920cc 89 mm 89mm stroke Featherbed Feather Bed

www.tga.co.uk

worntorn · Jan 23, 2023

marshg246 said:
Coula, Woulda, Shoulda! The Commando was already touted as "The First Production Superbike". Strange since Triumphs kept beating them at the Production 750 TT.

IMHO, since Norton actually designed and assembled motorcycles rather that built them, they were hamstrung. There's always extra cost when you sub things out.

Norton's actual problem was marketing and sales, not so much the product. Still today, if you design and want to sell a product, if you don't get the marketing and sales right you'll either fail due to buying too much product and not selling or buying enough but at such a high cost that the product costs too much to sell.

Norton, the bad/good: Cost more than others/Somewhat eliminated vibration.

Of course, this tread is not really talking about Norton Commandos - just some parts taken from Norton Commandos or possible aftermarket parts for Norton Commando engines.

Iirc Norton was profitable when money losing Triumph et al were forced onto it by the UK Government.
That's what took it down, not the Commando which was a rip roaring success for small Norton.
Overall sales were around 50,000. That was a very big number for the times.
The Combat fiasco did hurt them but they recovered nicely with the 850s.
I'll add that the Commando did very well at the most important Production race, the Thruxton 500 miles.
Thruxton 750 Production Race winners below.
Meatloaf figured 2 out of 3 wasn't bad.
3 out of 4 is better!

Glen

B+Bogus · Jan 23, 2023

SteveA said:
No, I don't think you did....

I have seen a photo of a bike that was a 'replica' of a late factory racer!

Looks like I've been fooled yet again!
In my defence most of my FB surfing is rather late in the evening and wine-fuelled

The outrigger bearing (or a TTI box) does appear to be the answer

marshg246 · Jan 23, 2023

worntorn said:
Iirc Norton was profitable when money losing Triumph et al were forced onto it by the UK Government.
That's what took it down, not the Commando which was a rip roaring success for small Norton.
Overall sales were around 50,000. That was a very big number for the times.
The Combat fiasco did hurt them but they recovered nicely with the 850s.
I'll add that the Commando did very well at the most important Production race, the Thruxton 500 miles.
Thruxton 750 Production Race winners below.
Meatloaf figured 2 out of 3 wasn't bad.
3 out of 4 is better!

View attachment 103044

Glen

Cool thing about opinions! Not meant to be history, just an opinion like worntorn stated: So, BSA made a mess of Triumph and of itself. They pissed the Triumph workers off which was almost the final nail. Norton was receiving government subsidies as I understand it so "profitable" is a funny way of looking at it. To attempt to save the industry, the govt put up money but insisted on there being one company. BSA was quickly gone once NVT was formed which basically left Norton, I guess Villers, and multiple Triumphs (some workers and some NVT). In the end, the non-rotary NVT was gone and only the Triumph workers remained. and only Triumphs were being built and sold.

3 of 4 is good, 3 of 5 less so and that a Triumph 650 posted better than two of those three...

1969	Percy Tait, Malcolm Uphill	650 Triumph	84.30 mph
1970	Peter Williams, Charley Sanby	745 Norton	74.80 mph
1971	Percy Tait, Dave Croxford	744 Triumph	84.64 mph
1972	Dave Croxford, Mick Grant	745 Norton	85.00 mph
1973	Rex Butcher, Norman White	745 Norton	82.57 mph

worntorn · Jan 23, 2023

"Coula, Woulda, Shoulda! The Commando was already touted as "The First Production Superbike". Strange since Triumphs kept beating them at the Production 750 TT."

Norton winning 3 times out of five doesn't seem to fit with "Triumphs kept beating them at the Production TT"?

Glen

marshg246 · Jan 23, 2023

worntorn said:
***"Coula, Woulda, Shoulda! The Commando was already touted as "The First Production Superbike". Strange since Triumphs kept beating them at the Production 750 TT."

Norton winning 3 times out of five doesn't seem to fit with "Triumphs kept beating them at the Production TT"?

Glen

ISLE of Mann Production 750 TT verses Thruxton 500 miles

acotrel · Jan 23, 2023

Fast Eddie said:
That’s a good call Steve, Andy does indeed offer the flywheel only. That’s a very economic solution. Weight looks somewhere mid way between Maney and stock.

There you go Al… nothing stopping you now mate…

Norton Twins Steel Flywheel

Norton Twins Steel Flywheel Commando Atlas Dominator Dommi Racer Dommiracer Domi Domiracer 650 750 850 920 cc 650cc 750cc 850cc 920cc 89 mm 89mm stroke Featherbed Feather Bed

www.tga.co.uk

Thanks for that. I don't think lighter is better, but it IS an answer. I wish I had known this when I built the bike. Screwing and gluing a steel plug into the hole in the counterweight works, but I really do not like it. If I crash, I would rather do it to myself than have it come from nowhere. 650 pounds UK is about $1300 dollars Australian - it is almost achievable. Now that I know it, I can work towards it.

acotrel · Jan 23, 2023

worntorn said:
"Coula, Woulda, Shoulda! The Commando was already touted as "The First Production Superbike". Strange since Triumphs kept beating them at the Production 750 TT."

Norton winning 3 times out of five doesn't seem to fit with "Triumphs kept beating them at the Production TT"?

Glen

Triumphs are also good, but Nortons are better. I have had both. The only thing wrong with a Commando is the crank with the wrong balance factor. Most Triumphs can be revved higher without doing damage.
One of my friends has the 750 Triumph with the Nourish crank anf the Puma cases. It is a Triton. He has won several historic championships. He said ' I cannot beat the Nortons.'
I never believed in my 850 motor until I started developing it. Norton must have known something when they created it. You don't get so many things correct by accident.

Fast Eddie · Jan 23, 2023

acotrel said:
Thanks for that. I don't think lighter is better, but it IS an answer. I wish I had known this when I built the bike. Screwing and gluing a steel plug into the hole in the counterweight works, but I really do not like it. If I crash, I would rather do it to myself than have it come from nowhere. 650 pounds UK is about $1300 dollars Australian - it is almost achievable. Now that I know it, I can work towards it.

Do it Al.

Seriously, you only live once. How painful is it gonna be looking back and wishing you had?

Do it Al. And post the video. You need to.

marshg246 · Jan 23, 2023

acotrel said:
Triumphs are also good, but Nortons are better. I have had both. The only thing wrong with a Commando is the crank with the wrong balance factor. Most Triumphs can be revved higher without doing damage.
One of my friends has the 750 Triumph with the Nourish crank anf the Puma cases. It is a Triton. He has won several historic championships. He said ' I cannot beat the Nortons.'
I never believed in my 850 motor until I started developing it. Norton must have known something when they created it. You don't get so many things correct by accident.

Opinions! My statements were about Production Races, specifically the Isle of Mann TT. You're not comparing Triumph to Norton. These statements: "
One of my friends has the 750 Triumph with the Nourish crank and the Puma cases. It is a Triton. He has won several historic championships. He said ' I cannot beat the Nortons.'" Make no sense. You start off calling it a Triumph, then says it's a Triton that has won championships, but he can't beat Nortons".

As long as we're talking opinions, the 67 and later Triumph 500 out handles other Triumphs and Commandos as long as you're not too big for it - I'm sure that's why it was able to win the Daytona 200 a couple of times with its weak engine. I feel way more confident riding a Trident fast on the street than riding a Commando fast on the street, especially in turns. A non-OIF 650 feels much lighter to me than a Commando and is closer to the ground which is good for my short legs. I really like riding Commandos but they are not, IMHO, better than Triumphs, just different.

Schwany · Jan 23, 2023

I personally never liked the Commando. (Aim at my head, or it won't kill me.) That front disc was not much better than a drum, handling never appealed to me. It felt tall and sluggish. I can throw my P11 around like a bicycle, which is why I still have it. Well, that and nobody would buy it. lol

I also had a Triumph 500 twin. It was my first, and they say you never forget your first. Great little bike and it was all there. Weirdest thing is I can't remember selling it at all. Too much dirt weed probably.

baz · Jan 23, 2023

Schwany said:
I personally never liked the Commando. (Aim at my head, or it won't kill me.) That front disc was not much better than a drum, handling never appealed to me. It felt tall and sluggish. I can throw my P11 around like a bicycle, which is why I still have it. Well, that and nobody would buy it. lol

I also had a Triumph 500 twin. It was my first, and they say you never forget your first. Great little bike and it was all there. Weirdest thing is I can't remember selling it at all. Too much dirt weed probably.

Don't forget the front disc had to be tamed down with a larger master cylinder for the American market
And the ISOs and swinging arm pivot pin must be in fine fettle to handle really well
I've never ridden a p11 so I can't compare but a commando will sit at 90+ mph for mile after mile dead smooth
That's one of the attractions for me
The effortless miles they can eat up

Schwany · Jan 23, 2023

baz said:
Don't forget the front disc had to be tamed down with a larger master cylinder for the American market
And the ISOs and swinging arm pivot pin must be in fine fettle to handle really well
I've never ridden a p11 so I can't compare but a commando will sit at 90+ mph for mile after mile dead smooth
That's one of the attractions for me
The effortless miles they can eat up

Tamed down. That disc barely worked. lol
It was a $700 used 72 750. All there, but not a super clean example like things I own. I wish I could find a pic of the darn thing. I did a few runs on my commute and was smooth on the HWY, but it was 1986, so not a recent memory. I did not care for it in the mountains. It was a bad fit for me at the time. I bought a '87 VFR right around the same time I bought it and for me the Honda made more sense to hold onto for cruising and the mountains. The Commando was just stuff not a collectable. I'd had the P11 since 74. It wasn't going anywhere. I had plans to modify it and didn't want to put much money or effort into the Commando. Never thought it or the P11 would be worth much. Surprise!!

I would think people happy with a Commando would not like the P11 at all. It would be very hard on them if eating up miles was the goal and they were not staying in good shape. As delivered P11's are lower on HP than a Commando and not particularly that well balanced a motor in that solid little frame. They need to be geared up quite a bit to run at 90 mph all day. I'm getting closer to a cruiser with an additional tooth on the engine sprocket (22T) and an additional tooth (20T) on the gearbox sprocket. I tried the stock gearing again for grins Summer 2022 and it was great in a parking lot, and going around round abouts, but not that great out on the HWY. It should do 75mph without the frantic RPM vibes all day geared like it is. If not a 21 tooth will end up on the gearbox. Kind of the same thing people end up doing with Commandos gearing wise.

If I could find a 72 750 Commando in the same shape that one I had was in for $700, I'd jump on it in a heartbeat. Easy to say knowing it will never happen. Sorry I got a little carried away off topic by a few miles.

baz · Jan 23, 2023

Schwany said:
Tamed down. That disc barely worked. lol
It was a $700 used 72 750. All there, but not a super clean example like things I own. I wish I could find a pic of the darn thing. I did a few runs on my commute and was smooth on the HWY, but it was 1986, so not a recent memory. I did not care for it in the mountains. It was a bad fit for me at the time. I bought a '87 VFR right around the same time I bought it and for me the Honda made more sense to hold onto for cruising and the mountains. The Commando was just stuff not a collectable. I'd had the P11 since 74. It wasn't going anywhere. I had plans to modify it and didn't want to put much money or effort into the Commando. Never thought it or the P11 would be worth much. Surprise!!

I would think people happy with a Commando would not like the P11 at all. It would be very hard on them if eating up miles was the goal and they were not staying in good shape. As delivered P11's are lower on HP than a Commando and not particularly that well balanced a motor in that solid little frame. They need to be geared up quite a bit to run at 90 mph all day. I'm getting closer to a cruiser with an additional tooth on the engine sprocket (22T) and an additional tooth (20T) on the gearbox sprocket. I tried the stock gearing again for grins Summer 2022 and it was great in a parking lot, and going around round abouts, but not that great out on the HWY. It should do 75mph without the frantic RPM vibes all day geared like it is. If not a 21 tooth will end up on the gearbox. Kind of the same thing people end up doing with Commandos gearing wise.

If I could find a 72 750 Commando in the same shape that one I had was in for $700, I'd jump on it in a heartbeat. Easy to say knowing it will never happen. Sorry I got a little carried away off topic by a few miles.

Yes the disc brake was tamed down because of the American market
Redesigned at production stage because Norton didn't want riders grabbing a handful of brake and coming off and suing them using American liability laws
This is what we read in the bike press at the time

marshg246 · Jan 23, 2023

baz said:
Yes the disc brake was tamed down because of the American market
Redesigned at production stage because Norton didn't want riders grabbing a handful of brake and coming off and suing them using American liability laws
This is what we read in the bike press at the time

Not saying you're wrong about the reporting or what Norton did, but...

I've also heard that the stupid switch to turn signal on the right was from the American market. More likely a misunderstanding. I can't imagine finding a single US driver that wants to use their left hand for turn signals with every vehicle they drive but wants the Norton on the right!

Norton would have been sued much quicker by producing a more powerful bike (Combat) with a less powerful brake!

The Kawasaki H1 and H2 would do stoppies in 1972 with the single front disk and would flip you (or break the headstock off) if you installed the dual front disk. I don't recall anyone thinking they should stop worse!

When Triumph and Lockheed introduced disk brakes, they weren't dumbed down - they actually work.

APRRSV · Jan 23, 2023

Son of Siredward said:
Ro-Dy built ours, he is one of the best in the business.

Greg Blagus at Ro-Dy just emailed me saying he is retiring and is not accepting new orders. Too bad.

Ed

EstuaryBoy · Jan 24, 2023

Schwany said:
Tamed down. That disc barely worked. lol
It was a $700 used 72 750. All there, but not a super clean example like things I own. I wish I could find a pic of the darn thing. I did a few runs on my commute and was smooth on the HWY, but it was 1986, so not a recent memory. I did not care for it in the mountains. It was a bad fit for me at the time. I bought a '87 VFR right around the same time I bought it and for me the Honda made more sense to hold onto for cruising and the mountains. The Commando was just stuff not a collectable. I'd had the P11 since 74. It wasn't going anywhere. I had plans to modify it and didn't want to put much money or effort into the Commando. Never thought it or the P11 would be worth much. Surprise!!

I would think people happy with a Commando would not like the P11 at all. It would be very hard on them if eating up miles was the goal and they were not staying in good shape. As delivered P11's are lower on HP than a Commando and not particularly that well balanced a motor in that solid little frame. They need to be geared up quite a bit to run at 90 mph all day. I'm getting closer to a cruiser with an additional tooth on the engine sprocket (22T) and an additional tooth (20T) on the gearbox sprocket. I tried the stock gearing again for grins Summer 2022 and it was great in a parking lot, and going around round abouts, but not that great out on the HWY. It should do 75mph without the frantic RPM vibes all day geared like it is. If not a 21 tooth will end up on the gearbox. Kind of the same thing people end up doing with Commandos gearing wise.

If I could find a 72 750 Commando in the same shape that one I had was in for $700, I'd jump on it in a heartbeat. Easy to say knowing it will never happen. Sorry I got a little carried away off topic by a few miles.

Apologies for stating the obvious, but as much as we love the P11 (and you know we do

), let's not overlook the fact that unlike the Commando it wasn't originally designed for the pavement but ended up there by default.

Just sayin'..........

SteveA · Jan 24, 2023

B+Bogus said:
Looks like I've been fooled yet again!
In my defence most of my FB surfing is rather late in the evening and wine-fuelled

The outrigger bearing (or a TTI box) does appear to be the answer

My bike currently has no outrigger, but a TTi, a lighter smaller diameter Norman White clutch and all of that is being spun faster than a Commando standard primary, as are most bikes with a belt drive.

1.857 (35/65) being my current chosen ratio, rather than the 1.727 (33/57) I used back then.

SteveA · Jan 24, 2023

worntorn said:
"Coula, Woulda, Shoulda! The Commando was already touted as "The First Production Superbike". Strange since Triumphs kept beating them at the Production 750 TT."

Norton winning 3 times out of five doesn't seem to fit with "Triumphs kept beating them at the Production TT"?

Glen

When Croxford shared a winning bike with Percy Tait it wasn't by any means his first attempt at the TT, when people asked him, how come you never won before?

He said, it has taken me years to remember my way around!

Billet Crankshaft

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