Recent P11 article in the Feb., 2018 issue of the The Classic Motor Cycle

jerrykap

jerrykap

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My good friend and former P11 owner sent me this PDF scan of the UK based magazine article. I've tried unsuccessfully to get a back issue from the US distributor so the best I can do is a link to his PDF scan. I hope it works for you.

What I told my friend about the article; "I must say that this particular P11 mash up has so many little issues wrong with it that I have a hard time liking it. The article is OK, typically English verbosity but the bike itself is meh." I also enjoyed that they mentioned my UK buddy Anthony and included a photo of the Patrick racer now residing at the Barber Museum.

C-ya, Jerhttps://1drv.ms/b/s!Aq-dhqkiO93RyXv2Dc4C2D4ksyFk

Hopefully this will open as a PDF document for you?
 
Interesting rear brake rod routing! I agree there are enough oddball inconsistencies to make one wonder why they could not have found a closer to original example for a magazine article.
 
I think it was put together by people who didn't particularly care if it was the correct part or assembled correctly so long as it worked and looked ok they were satisfied. In this case the bones of the bike are good (engine, tranny & frame) but the details are poor. IMHO.
 
A P11 Norton story and a Vincent story in same Classic Motorcycle mag, Wow!
Not a show perfect P11, but nice article.
We need more P11 Norton stories. The articles keep the P11 model alive and well.


Recent P11 article in the Feb., 2018 issue of the The Classic Motor Cycle
 
pierodn said:
Hi.
I really didnt know that there was P11 brand as Matchless.
Piero
Click to expand...
It was known as badge engineering...dealers were free to sell P11's as Norton's or Matchless'. Whatever the customer wanted. Even the various US titles could say Norton or Matchless. When I bought mine in May of 1968 I didn't know this until a few months later my good friend bought his Ranger 750 from the same Illinois dealer and it was badged and titled as a Matchless. Sometimes to confuse people, I would run both badges on different tank sides. However you badge it it's still a P11.
 
I cannot explain why!
Even if i have some beautifull Commando (S and SS too), N15 and G15, my eies go first on my P11.
Piero
 
As I said in my post on the other thread, I just couldn't handle the level of vibration on the P11. I've never ridden an Atlas, so all my experience of the 750 has been with the Commando prototypes with their experimental Isolastics, and that brief encounter (about 600 miles total) with what became the P11.
 
frankdamp said:
As I said in my post on the other thread, I just couldn't handle the level of vibration on the P11.
Click to expand...

Low weight of the frame means that engine vibrations are easily amplified beyond the level of the Featherbed and G15 frames (the latter are better at coping with vibes apparantly, being smaller and stiffer). Elasticity in supporting the engine means mass reactions (X-Y-Z) of the engine lump itself also transmits into the frame.

My P11A is still in bits awaiting a frame repair, but I tried a restored sample some 10 years ago and was horrified at the level of vibrations.

There are ways to reduce the vibes, primarily by fitting lightweight reciprocation parts (pistons, conrods), by sticking to low CR pistons (7.6:1), and having static and dynamic balancing of the crankshaft performed. Fitting a solid crankshaft and using a shorter stroke (80.4mm or less) should also help significantly.

These options were not available at the time the P11 was assembled though. Maybe some of the serious competitors made changes along these lines?
I guess the pressure having the P11 bikes delivered prevented N-V from developing the engine further. Anyhow, from 1964 on the Atlas engine was considered a stop-gap only by AMC as well as N-V. All hopes were put on the P10 engine, and as such any development work of the stretched Hopwood design was kept to a bare minimum, which is comprehensible.

-Knut
 
mdt-son said:
Low weight of the frame means that engine vibrations are easily amplified beyond the level of the Featherbed and G15 frames (the latter are better at coping with vibes apparantly, being smaller and stiffer). Elasticity in supporting the engine means mass reactions (X-Y-Z) of the engine lump itself also transmits into the frame.

My P11A is still in bits awaiting a frame repair, but I tried a restored sample some 10 years ago and was horrified at the level of vibrations.

There are ways to reduce the vibes, primarily by fitting lightweight reciprocation parts (pistons, conrods), by sticking to low CR pistons (7.6:1), and having static and dynamic balancing of the crankshaft performed. Fitting a solid crankshaft and using a shorter stroke (80.4mm or less) should also help significantly.

These options were not available at the time the P11 was assembled though. Maybe some of the serious competitors made changes along these lines?
I guess the pressure having the P11 bikes delivered prevented N-V from developing the engine further. Anyhow, from 1964 on the Atlas engine was considered a stop-gap only by AMC as well as N-V. All hopes were put on the P10 engine, and as such any development work of the stretched Hopwood design was kept to a bare minimum, which is comprehensible.

-Knut
Click to expand...

Hi Knut,
my P11 s have the sotck crankshafts (not rebalanced), stock conrods, flat commando pistons, etc.
I dont feel more vibrations than with Commando, Atlas, N15, G15.
Sure the vibration of my BSA Lightning are much more.
And i love these vibrations.
Piero
 
pierodn said:
<..>
I dont feel more vibrations than with Commando, Atlas, N15, G15.
Sure the vibration of my BSA Lightning are much more.
And i love these vibrations.
Click to expand...

If you can't distinguish vibrations between your Commando and your P11, you must be insensitive to vibrations! :) Maybe you are talking of idling revs?

Otherwise, you have quite unusual samples of these bikes. The Commando should be rather quiet above 2500 rpm whereis the P11 vibes will increase with revs.
Do you own your P11 since new? If not, do you know for sure the crankshaft hasn't been statically and dynamically balanced by a previous owner?

Anyway, I am happy for you that you feel P11 vibes to be tolerable! :)

-Knut
 
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mdt-son said:
If you can't distinguish vibrations between your Commando and your P11, you must be insensitive to vibrations! :) Maybe you are talking of idling revs?

Otherwise, you have quite unusual samples of these bikes. The Commando should be rather quiet above 2500 rpm whereis the P11 vibes will increase with revs.
Do you own your P11 since new? If not, do you know for sure the crankshaft hasn't been statically and dynamically balanced be a previous owner?

Anyway, I am happy for you that you feel P11 vibes to be tolerable! :)

-Knut
Click to expand...

Hi Knut.
When i ride i am so happy that i cannot able to distinguish vibrations between my bikes.
If they built this bikes to have vibrations, is right that they continue to be.
Own a P11 is fun, with vibs it is more.
In any case, please, i have post a new thread in "other norton" because my N15 doesnt start: a your suggests and help will be very apreciate.
Thanks.
Piero
 
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