P11 basket case

Junglebiker · Mar 30, 2019

Also not pictured here are the various front suspension parts, hubs, spokes, (no rims yet--I'm looking for 18" flanged Akronts or similar--preferably good used ones, anybody have any?), front and rear brakes, an Atlas donor engine, transmission, oil tank, primary cases, handlebars and magneto.

I still need a seat, a set of high pipes, fenders/mudguards (I think I know where I will get these), electrical system (I might make my own harness/loom), hand and foot controls, footpegs (might fabricate these, too), tires, lighting (I think I know what I am going to do for lights), rear shocks, primary drive chain, final drive chain, drive sprockets, and oh, a hundred other little things.

Fun, fun, fun!

mdt-son · Mar 30, 2019

A genuine P11 gearbox is for sale on Fleebay at the moment.

Junglebiker · Mar 30, 2019

Thanks, I have a P11 transmission case and access to Commando internals, I was thinking about seeing what I could do with those, but I'll have a look at the fleabay one.

Ron L · Mar 30, 2019

Junglebiker said:
Thanks, I have a P11 transmission case and access to Commando internals, I was thinking about seeing what I could do with those, but I'll have a look at the fleabay one.

Can't use the Commando mainshaft or outer cover, but gears, layshaft, quadrant, kickstart shaft will work. Atlas, N15 mainshaft will work.

Junglebiker · May 29, 2019

Alright, finally made some decisions.

--bought a new Joe Hunt mag
--bought a new seat
--bought a new complete exhaust system
--splashed out and bought an NEB clutch. Thanks to MDT-SON Knut, I am aware of the lack of dampener in the NEB, however I will be running a rear wheel with a very good dampener in it. Not a Matchless or Norton wheel, prices are outta site for that stuff.

Junglebiker · May 29, 2019

Aside from the kickstart spring, what's the difference between a pre-1962 and a post-1962 Atlas transmission?

(I do know that an Atlas transmission will not work in a P11, at least not in it's original Norton case.)

jagracer · Jul 23, 2019

Standard norton gearbox internals fit inside an AMC/norton shell. Use a standard Atlas mainshaft and roller bearings. I have an earlier complete matchless box, seems similar, but weaker bearings. Late Atlas clutch is fine. I had probably the last N15CS sold in the UK in December 1969, which had the points housing and coil and Capacitor ignition with double points and never any trouble. I have a 1967 N15CS in bits, and looking at fitting a Yamaha XS750 custom set of forks with twin discs. A late Triumph T140 twin disc set-up will fit as well. I have Norton Forks, but decent drum brake linings are difficult to source (as no asbestos in modern ones). I bought a front wheel for £20 off of ebay, so watch for bids finishing Monday morning early. Early Gearboxes are usually worn out, tolerances are iffy. Use all later parts if possible. Kickstart area is weak.

BillT · Jul 29, 2019

Hey, Haven't been on the site for a while. Every large Norton, AJS and Matchless from mid 1955 on used the same gearbox. The case, however, is different between AMC (Matchlees/AJS) and Norton. Norton case has the mounting lugs at 12 o'clock and 6 o/clock. AMC boxes have those lugs at 12 and 4. The internals will work throughout the 20+ year run, as long as you match the gears from the same era. In other words, you could place the gearset from a 1974 Commando in the case of a Dominator. I believe Mike Patrick used Roadholders and a magneto on his P11 because that was what he was used to. Before he ran the P11 that is on display at Barber, he ran the earlier G15/N15 hybrid in the District 37 races. That model had the K2F and Roadholders. The P11, as raced by Patrick, used the same motor/primary/transmission in a package that was over 40 lbs lighter. By using the Roadholders and K2F, he could use the larger Norton front hub and run without a battery (I understand that there was some doubt about the reliability of the new Lucas distributor, which was standard on the P11)

Paul W · Jul 29, 2019

BillT said:
Hey, Haven't been on the site for a while. Every large Norton, AJS and Matchless from mid 1955 on used the same gearbox. The case, however, is different between AMC (Matchlees/AJS) and Norton. Norton case has the mounting lugs at 12 o'clock and 6 o/clock. AMC boxes have those lugs at 12 and 4. The internals will work throughout the 20+ year run, as long as you match the gears from the same era. In other words, you could place the gearset from a 1974 Commando in the case of a Dominator. I believe Mike Patrick used Roadholders and a magneto on his P11 because that was what he was used to. Before he ran the P11 that is on display at Barber, he ran the earlier G15/N15 hybrid in the District 37 races. That model had the K2F and Roadholders. The P11, as raced by Patrick, used the same motor/primary/transmission in a package that was over 40 lbs lighter. By using the Roadholders and K2F, he could use the larger Norton front hub and run without a battery (I understand that there was some doubt about the reliability of the new Lucas distributor, which was standard on the P11)

Good to have your input again Bill. Missed your wise words of knowledge.

p400 · Jul 30, 2019

I would encourage poster to include meaningful, clear photography when posting to keep the interest up in this P11 model.

I miss my P11.............but not the kick start.
I'm claiming "old guy"

Junglebiker · Dec 26, 2019

Believe me, I would love to post pics, but I am currently on the other side of the earth from my P11. I am in Papua New Guinea and the bike is in North Carolina. Next time I am in the US (2021) I plan to start putting it together, and will take lots of pics then. Right now I am in the process of collecting all the parts I'll need.

Junglebiker · Dec 26, 2019

BillT said:
Hey, Haven't been on the site for a while. Every large Norton, AJS and Matchless from mid 1955 on used the same gearbox. The case, however, is different between AMC (Matchlees/AJS) and Norton. Norton case has the mounting lugs at 12 o'clock and 6 o/clock. AMC boxes have those lugs at 12 and 4. The internals will work throughout the 20+ year run, as long as you match the gears from the same era. In other words, you could place the gearset from a 1974 Commando in the case of a Dominator. I believe Mike Patrick used Roadholders and a magneto on his P11 because that was what he was used to. Before he ran the P11 that is on display at Barber, he ran the earlier G15/N15 hybrid in the District 37 races. That model had the K2F and Roadholders. The P11, as raced by Patrick, used the same motor/primary/transmission in a package that was over 40 lbs lighter. By using the Roadholders and K2F, he could use the larger Norton front hub and run without a battery (I understand that there was some doubt about the reliability of the new Lucas distributor, which was standard on the P11)

BillT, thanks for the info, that will come in handy. I'm going with a magneto on mine because I like the idea of a self-contained ignition that doesn't depend on a battery. I'm thinking that I probably am going to do my own wiring and run without a battery, because I am pretty sure I have the know-how to do that. I'm planning to start with a 3 phase alternator, use a Japanese solid state regulator-rectifier, put in a capacitor where the battery would normally be and then run all DC lighting, which will mak eit easy to use LED's if I want to. Thanks for reminding me that I need to buy an alternaotr...

Junglebiker · Jan 2, 2020

Just ordered most of the JS Motorsport catalog... Pricey? Yes. But so far I still have less in the bike than what basket cases seem to be going for these days.

Anyway, that's how I sleep at night.

Schwany · Mar 12, 2022

Junglebiker said:
Just ordered most of the JS Motorsport catalog... Pricey? Yes. But so far I still have less in the bike than what basket cases seem to be going for these days.

Anyway, that's how I sleep at night.

Did you ever finish this build? The JS parts are only 2/3rds of the total cost and that is doing the work in your own garage.

I'm starting to think I should have left the ole P11 alone... yet again.

Does this look familiar?

mdt-son · Mar 12, 2022

BillT said:
By using the Roadholders and K2F, he could use the larger Norton front hub and run without a battery (I understand that there was some doubt about the reliability of the new Lucas distributor, which was standard on the P11)

Patrick's use of the Roadholder fork was a surprising move, as it would add quite a bit of weight. Maybe he was in doubt if the 1-1/4" stanchions or sliders were up to the task?
The points housing and internals were well proven by the time the P11 was launched. AMC had fitted the same to the standard model G12/M31 since 1964. The use of a K2F was likely motivated by the desire to get rid of the battery and the alternator.

- Knut

Junglebiker · Mar 21, 2022

Back again! The pandemic put my travel plans back by a year, so instead of getting started in 2021, I'm getting started in 2022. I've got my wheels built, Akront replica flanged rims Buchanan stainless spokes. I won't reveal what hubs I used just yet.

I was given access to a big stash of transmission parts and the instruction that I was allowed enough parts to build one good transmission. In that stash was a good sized box labelled "P11 transmission". It contained 1 very nice P11 transmission case and a bunch of Atlas parts. Going through the box, I found good shafts and gears and figured out 3 or 4 ways NOT to put together a Norton transmission, but all in all, as this is the first time I've attempted to assemble a non-Japanese transmission, I feel like things are going well. There were pre-1962 and post 1962 parts in the collection, I had at first incorrectly identified the earlier stuff as "P11" and the later parts as "Commando", but I eventually figured out my error.

There are a lot of things I like about the transmission, primarily how slick it seems to be in spite of its somewhat bulky internals, especially in the shifting mechanism. There are a few things that are not super impressive to me, as well, but hey, it's a 65 year old design that still works well, so I'm not complaining. And of course it's possible to beef it up a bit nowadays with roller bearings and so on.

Got an N.E.B. clutch to go with it.

Junglebiker · Mar 24, 2022

In the continuing saga of my transmission, I got it all together and then found that it won't shift into 1st and also that it will only turn a couple of times in 3rd or 4th before it locks up. Not sure what's wrong, but I did notice that the problem seems to have started once I torqued on the nut on the right end of the mainshaft. Anybody got any hints?

Schwany · Mar 25, 2022

Are you trying to make it shift on the bench by hand, or is the gearbox back in a running bike?

This is my experience. I do not disassemble and reassemble gearboxes daily, so take it for what it is worth.

Theory: The P11 gearbox I have doesn't shift worth a darn into first without the motor spinning the gears and shafts so that the dogs can line up while moving the shift forks.

That said my P11 gearbox did shift by hand (motor not running) easier before I rebuilt it. It is hard to get it into first without a stiff pull by hand while spinning the shafts manually on the bench. I should have just replaced the lip seals and o-rings and left it alone because absolutely nothing was wrong with the internals. Almost looked new in there except for some frightening looking sludge that had collected over the years. The sludge stays down on the floor of the gearbox apparently. It never came out during oil changes. Maybe because of the angle of the drain, and the gearbox never got that hot.

Like you I don't know exactly why mine is not shifting as easily on the bench after the rebuild other than all the seals and bearings are new and everything has been tightened up to spec. Shafts all move freely enough without bind. Also I did not take a lot of time to be absolutely sure that the fork selector spindle was perfectly straight when I had it out. It did roll on a flat surface like it was straight, but I did not go anal on it. Plus it could just be there is not as much gear oil everywhere as there will be once the gearbox starts spinning at a normal RPM.

Junglebiker · Mar 25, 2022

Schwany said:
Are you trying to make it shift on the bench by hand, or is the gearbox back in a running bike?

This is my experience. I do not disassemble and reassemble gearboxes daily, so take it for what it is worth.

Theory: The P11 gearbox I have doesn't shift worth a darn into first without the motor spinning the gears and shafts so that the dogs can line up while moving the shift forks.

That said my P11 gearbox did shift by hand (motor not running) easier before I rebuilt it. It is hard to get it into first without a stiff pull by hand while spinning the shafts manually on the bench. I should have just replaced the lip seals and o-rings and left it alone because absolutely nothing was wrong with the internals. Almost looked new in there except for some frightening looking sludge that had collected over the years. The sludge stays down on the floor of the gearbox apparently. It never came out during oil changes. Maybe because of the angle of the drain, and the gearbox never got that hot.

Like you I don't know exactly why mine is not shifting as easily on the bench after the rebuild other than all the seals and bearings are new and everything has been tightened up to spec. Shafts all move freely enough without bind. Also I did not take a lot of time to be absolutely sure that the fork selector spindle was perfectly straight when I had it out. It did roll on a flat surface like it was straight, but I did not go anal on it. Plus it could just be there is not as much gear oil everywhere as there will be once the gearbox starts spinning at a normal RPM.

Yeah, I've been trying to shift it mounted in a vice by hand--if I try doing the same with a complete Atlas transmission (there's one of those on hand) it shifts nicely, though of course you do have to spin the shafts to do it--having to spin the shafts to get a transmission to shift is a concept I am very familiar with.

On Japanese motorcycle transmissions, I put them together and if I can't get them to shift through all the gears on the bench, I usually don't sweat it and when the engine is assembled and oil added the transmission just works. In this case, because I had already examined that complete Atlas trans, I had an idea of what I should expect from the P11 and it didn't feel the same.

This afternoon I may get a chance to do some more investigating. If not this afternoon, then probably tomorrow.

Schwany · Mar 25, 2022

Junglebiker said:
Yeah, I've been trying to shift it mounted in a vice by hand--if I try doing the same with a complete Atlas transmission (there's one of those on hand) it shifts nicely, though of course you do have to spin the shafts to do it--having to spin the shafts to get a transmission to shift is a concept I am very familiar with.

On Japanese motorcycle transmissions, I put them together and if I can't get them to shift through all the gears on the bench, I usually don't sweat it and when the engine is assembled and oil added the transmission just works. In this case, because I had already examined that complete Atlas trans, I had an idea of what I should expect from the P11 and it didn't feel the same.

This afternoon I may get a chance to do some more investigating. If not this afternoon, then probably tomorrow.

If you figure it out report back.

P11 basket case

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