Organizing a Featherbed project

Hi there,

I am new to Norton's and picked up a featherbed project yesterday and need some help identifying what is what.

I looked up a table with Norton serial codes and was able to identify most of the parts that came with the bike, but I am not sure what the gearbox as well as one of the engine cases are from.

The frame code is 122-51259. The table I read said this should be a 1952 88 Dominator
The first engine code: 20-121920/P......this should be a 1967 Atlas P11, correct?
The second engine code I do not know how to read. I've attached a picture of it and would appreciate some help identifying it. Here is a link to the picture:






The gearbox has the following code: GT101745. Again, I do not know what this is from.

The bike is very very incomplete and was most likely a candidate for a Triton build (also came with a 650cc unit Bonneville engine). I am very familiar with Triumphs, but not Nortons, so any resources would be appreciated. Are most parts interchangeable between models?

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F = 1951, 12= Model 7.

Thanks. Just to clarify, what do the rest of the numbers, the 34678 and T3341, refer to?

The engine builders phone number and his lunch order number for the canteen .
SORRY .

If I were you ! Id Not Let the TRIUMPH ENGINE Go Lightly ! . ( of course ' we ' want to see pictures of THAT , and Everything Else . )

If the bike is ' very very incomplete ' Id tend to take it as a liscence to do something differant , and save a pile of dosh on overpriced unobtainium .


500 twin ' manx '; es ( they wernt ) were raced in the U S of A in the 50's on .
Often its more fun to find fings that WORK , and let it find its own maitre .

Hasit got a GOOD front end ? ( Forks ) There SHORT Roasdholders , But if wheels & suspension are MISSING Id use horrible late jap. stuff , maybe monoshock .
and a Honda 750 tank , with a new bottom ? ( A old cheap dented one ) as it were a copy , more or less .

A young whippersnapper had a 750 roadster at the wet 2002 Pukekohe CRMC meet . Custom Aluminum engine cradle , NS 25 Honda suspension F & R ,
Dunstal Pipes with the latest style F1 ' cans ' , was light fast smooth & leading effortlessly In the WET . As it was his everyday ride to work motorcycle ,
PRACTACALITY was the First Order .

The 500 would get you a quieter ride ( Tho ' SS ' spec. build ? ) Whereas a Triumph will fair howl , if its built with a late & crack tested crankshaft .
Modern Filtering & both'd last forever .

Er . Wot was the question .

Photos Please , Photos ! . And set the FRAME on a bench , and check over carefully & closely for dings and straightness , as to verify your not wasting your time .

This might be some use . The numbers are just sequential production order/series .

BORROWED FROM ' Elsewhere '

Much will depend on the positions of the numbers and letters to give a positive identification.

Early Twin Engine numbers up to the first model 88were usually bashed into the metal on the top left crankcaseabove the crankshaft end. Usually, but not always, there is a model number and the engine number. From around 1956 onwards, the engine number appeared under the camshaft tunnel bulge. About 6cm further back most (pre-1961) twins also had a model number and year identification letter stamped. If the letter P is stamped here then it means the engine is a 1959 build. If 122 or 14 or 15 are also in this area then the capacity and model type and hencesize of engine will be denoted by this.

If the letter P appears as a suffix immediately after the engine number then it usually denotes a Plumstead built item; post 1963. As Dominic states that his engine begins with 44*** this is too early for any 1963 twin engines which by then were being stamped 100000 plus. The number 12 by itself suggests a model 7; which would be 1949 to 1956 and engines numbers of 44*** were produced in 1952/3. generally with a letter G stamped near to the 12. So my money goes on a 1952/53 Model 7 for these crankcases.

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Norton Owners Club do a I D thingo , if it were a rarity , you might restore it STOCK . But ifits one of millions Id make it One in a Million . Updated Custom .

Fritzer_108 said:

The bike is very very incomplete and was most likely a candidate for a Triton build (also came with a 650cc unit Bonneville engine). I am very familiar with Triumphs, but not Nortons, so any resources would be appreciated. Are most parts interchangeable between models?

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When you ask, "are most parts interchangeable between models?", do you mean engine parts, or running gear?

Running gear:
In 1960, Norton went from the Wideline frame to the Slimline frame, so the tanks (fuel and oil), seats, etc are specific to those frames. The front ends changed widths to accommodate a front brake change. There were other more minor changes, but I can only assume you're not rebuilding back to stock (because that would be insane), so that's the big change to worry about. Your frame is probably a "bolt-up" with a bolt on subframe.

Engines: Some of the parts are interchangeable, but anything to do with the bore or stroke (barrels, pistons, pushrods, conrods, crank, are mostly specific to the capacity of the motor, but there is some interchangeability between the 600/650, with some adaptation of the individual parts. There are a seeming million variations to the heads, and a few variations of the cases. Earlier parts will generally work with larger capacity cases, but not the other way around. There was a big change in top end oiling, from return puke (like the Triumph) to pressure fed with some minor (yet important) component changes to make it all work. The Atlas (750) is a whole other ball of wax from the smaller capacity motors, and most parts are not interchangeable at all.

Gearboxes: There were two (main variants of) gearboxes from the date of your bike's manufacture to Norton's demise, the laydown (what your bike [frame] had) and the AMC. The AMC is regarded as the more robust of the two. There were a variety of mainshaft lengths to make the primary chainline copacetic on different motors, ie Domi/Atlas vs Commando vs Singles. Parts for the AMC 'box are much easier to come by.

The earlier the Norton, the harder it is to find old stock parts for, particularly in the States. You've got a pretty early Dominator, so it'll be a tough row to hoe. Building from the ground up is expensive. I'd budget $10-$15k, for a current resale value of about $7-8k. The Dollar and Pound are currently almost at a 1:1, so now's a good time to import parts. Norton owners enjoy great new part support. Not as varied as Triumph, but higher quality in general.

A Triton offers more of a fabrication challenge, but is obviously a well-worn path.

The Featherbed bikes handle great. Full stop. The best of its era (the entire 20 year production run, and beyond). With better (than stock) suspension and braking components, it will surprise a modern bike owner with its competence. You'll not be hunting modern Ducatis by any means, but they do just fine and definitely go fast enough to kill you.

On that note, welcome to the forum! A lot of answers to questions can be found.

Cheers,
Todd

As a friendly counter to the late model Domiracer pic @Matt Spencer offered, I'll add this, which is the 50's version, which might be more appropriate for the era of your frame:

Here are some pictures of it as it is. I mocked it up with the P-11 motor for now (it has cylinders but I removed them to do some cleaning). I'm planning to use that motor to build the bike and discovered that the gearbox is a laydown from a Model 7. The pictures are somewhat out of order so use the arrows to cycle through them

Matt Spencer said:

Hasit got a GOOD front end ? ( Forks ) There SHORT Roasdholders , But if wheels & suspension are MISSING Id use horrible late jap. stuff , maybe monoshock .
and a Honda 750 tank , with a new bottom ? ( A old cheap dented one ) as it were a copy , more or less .

Click to expand...

I am not sure what forks are on it, but they are definitely British and the legs look really similar to some Roadholders I found on eBay.


It has Borrani rims on the front and back and double twin leading drums on the front. Both drums have a Suzuki logo stamped in them so I don't know what they're from, but they fit very well and everything rotates freely. It also came with a oil tank similar to the one in the posters of the racers.

My biggest concern right now is finding all of the parts for the primary (clutch, sprockets, etc. ). I found a mostly complete primary on eBay and a brand new after market kit from Lowbrow Customs (Both are pretty pricey). My concern is whether they will fit because I have a later engine (1967 Atlas P-11) coupled with a earlier laydown gear box as opposed to the AMC gearbox. Thanks for the help!

t ingermanson said:

. You'll not be hunting modern Ducatis by any means, but they do just fine and definitely go fast enough to kill you

Cheers,
Todd

Click to expand...

Objection. The featherbed Nortons has a habit of trying as hard as they can to stay with the wheels down., Even if you makes mistakes.
If I'd bought a Triumph instead of a Dommie back in 1965, I'm pretty sure I´d not been on the forum today. Quite a number of my Triumph friends I raced the streets with did not make it.
My first impression of the Ninja was that it handled like a Norton.

I think that you've found a great basket case. Will handle well, great stopping power for road use, slightly better power than a stock Bonnie and decent weight.
The laydown gearbox should handle the Atlas power. The Manxes used laydown boxes long after the AMC box was introduced. As you say, primary chain lining is your main concern.
Though I would contemplate fitting a belt drive if it lines up.

Mike40M said:

Objection. The featherbed Nortons has a habit of trying as hard as they can to stay with the wheels down., Even if you makes mistakes.

Click to expand...

Totally agree on the handling, however the extra 120hp and 2 extra gears make themselves known.

The Newby belt kit works on the laydown or the AMC. Same mainshaft spline, just make sure you've got the correct length mainshaft. I think RGM has a list of lengths within their listings. The serial number and the protrusion on the case where the clutch cable enters will tell you what came in the 'box originally, but it's been a while and may have been changed. The Newby is an excellent piece of kit, and worth the extra money, if you're starting with nothing. Finding oil tight primary cases will get you up to even dollars with the Newby. It's also reportedly the best belt kit for the laydown's required clutch lift. The shift spline is different (larger) than the AMC, and harder to find levers for, particularly for rearsets. Newby is in the UK, and may be cheaper to buy directly with the current exchange rate than Lowbrow or Frank's Classic Cycle. Frank's is cheaper than Lowbrow in my experience, stocks parts and is very helpful.

A good source for all the small bits is Kevin at Nortonraceparts.com. He's very helpful as well.

The front brake is a from a GT550 or GT750. Having it already adapted to the forks is a big bonus.

Appears as all the expensive chunks are there, it'll just be the classic "death by a 1000 paper cuts" for all the "small and cheap" parts. Looks good already though!

Not fast enough to kill you:

Fast enough to kill you:

Mike40M said:

As you say, primary chain lining is your main concern.
Though I would contemplate fitting a belt drive if it lines up.

Click to expand...

After some more digging, I discovered that the gearbox is from a pre-featherbed single. Assuming it hasn't been tampered with, it should have a 8.625" mainshaft. I still need to do some digging and take some measurements to see how everything would line up.

t ingermanson said:

The Newby belt kit works on the laydown or the AMC. Same mainshaft spline, just make sure you've got the correct length mainshaft. I think RGM has a list of lengths within their listings. The serial number and the protrusion on the case where the clutch cable enters will tell you what came in the 'box originally, but it's been a while and may have been changed. The Newby is an excellent piece of kit, and worth the extra money, if you're starting with nothing. Finding oil tight primary cases will get you up to even dollars with the Newby. It's also reportedly the best belt kit for the laydown's required clutch lift. The shift spline is different (larger) than the AMC, and harder to find levers for, particularly for rearsets. Newby is in the UK, and may be cheaper to buy directly with the current exchange rate than Lowbrow or Frank's Classic Cycle. Frank's is cheaper than Lowbrow in my experience, stocks parts and is very helpful.

A good source for all the small bits is Kevin at Nortonraceparts.com. He's very helpful as well.

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Luckily, some type of homemade shift lever came attached and it should work well with the rearsets I have. Thanks for the resources...I've been looking for parts diagrams/shop manuals and was pretty happy to find them on the RGM website. I was able to find a cheap original shop manual for the Atlas motor on Ebay...I hope that will be a useful aid.

Mike40M said:

If I'd bought a Triumph instead of a Dommie back in 1965, I'm pretty sure I´d not been on the forum today. Quite a number of my Triumph friends I raced the streets with did not make it.

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You don't need to be racing to make that happen. Just 3 weeks ago, I was driving my 1970 T120r back from classes at my college when a girl pulled out right in front of me with her brand new Mini Cooper. I was able to swerve in the last second to avoid a head-on collision, but she still clipped me and bike and I went flying. Luckily, I ended up with no broken bones or head/spine injuries. The Bonnie is very much salvageable and I'm in the process of rebuilding it. The most awkward part about the whole incident is that we both study engineering at the same school and will probably be in some classes together down the road

Fritzer_108 said:

Here are some pictures of it as it is. I mocked it up with the P-11 motor for now (it has cylinders but I removed them to do some cleaning). I'm planning to use that motor to build the bike and discovered that the gearbox is a laydown from a Model 7. The pictures are somewhat out of order so use the arrows to cycle through them



I am not sure what forks are on it, but they are definitely British and the legs look really similar to some Roadholders I found on eBay.

1962 Norton Dominator Atlas 750cc P11 Manx Model 20 *2559 FORKS ROADHOLDER | eBay

Find many great new & used options and get the best deals for 1962 Norton Dominator Atlas 750cc P11 Manx Model 20 *2559 FORKS ROADHOLDER at the best online prices at eBay! Free shipping for many products!

www.ebay.com

It has Borrani rims on the front and back and double twin leading drums on the front. Both drums have a Suzuki logo stamped in them so I don't know what they're from, but they fit very well and everything rotates freely. It also came with a oil tank similar to the one in the posters of the racers.

My biggest concern right now is finding all of the parts for the primary (clutch, sprockets, etc. ). I found a mostly complete primary on eBay and a brand new after market kit from Lowbrow Customs (Both are pretty pricey). My concern is whether they will fit because I have a later engine (1967 Atlas P-11) coupled with a earlier laydown gear box as opposed to the AMC gearbox. Thanks for the help!

1962 Norton Dominator Atlas 750cc P11 Manx Model 20 *2559 CLUTCH PRIMARY | eBay

Find many great new & used options and get the best deals for 1962 Norton Dominator Atlas 750cc P11 Manx Model 20 *2559 CLUTCH PRIMARY at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Bob Newby Primary Belt Drive & Clutch Norton Dominator 88 99 650ss & Atlas | eBay

Find many great new & used options and get the best deals for Bob Newby Primary Belt Drive & Clutch Norton Dominator 88 99 650ss & Atlas at the best online prices at eBay! Free shipping for many products!

www.ebay.com

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Just a safety note on 2LS front drum - be careful or you may suffer the same fate as I did, with potentially far worse results!
Please read the link.
Cheers

Nov 11, 2016

For parts, there are two very reputable suppliers who supply a lot of the retailers in the US



In the US (and Canada)

Yr Avg Norton Forks . Likely early Commando ?
Triple Clamps , has it got the two handlebar rubber mount bolt holes in the top one ?

' Short ' roadholders - the front guard ( if early commando ) taps the lower steering damper fitting . If fitted .
SO , fork top nuts Off - Does it ' collapse ' so the tyres within say 3/4 inch of the triple clamp .

Id clean ( strip ) the frame to bare metal . CAREFULLY - not sand blast . to inspect for cracks .
tank . Being Snoty , id try'n pawn it on a real ' manx ' or Domi copy . To quibble .

Mine ran PROGRESSIVE RATE external spring forks . they should be at say 1/3 travel , feet up , laden ( elbow against a wall )

and yes , if the whole primarys awol , A mesh guard on a custom inner , but there must be plenty of Ex Commando primarys around from someone fitting belt drive .
If you fall over a 75 triumph rear hub with the female bearing retainer cup . Grab it . the Conical triumphs almost a alumn. copy of a real Manx .
dont think youll find a cheap 7r AJS front brake in a hurry .

Was a ducati 450 heading west through medlowbath today . Not even on a trailer . Little light Orange thing . GOOD for a objective / subjective comparison . KEEP it LIGHT .

theres my ' home built ' cow . shoulda used alumn. for the seat base , & woulda bin all alloy . almost .
Triumph squab & cover with a wedge of hi density from 1/2 back . I made the oil tank , & engine plates .
Triumph ( 68 ) swing arm .. Keep it basic 7 save the loot for later !

gortnipper said:

For parts, there are two very reputable suppliers who supply a lot of the retailers in the US

Andover Norton Spare Parts Drawings - Genuine Andover Norton Factory Parts - Commando Parts

Genuine Andover Norton Parts created from the original drawings.

andover-norton.co.uk

Primary Categories

Primary Categories

www.rgmnorton.co.uk

In the US (and Canada)

Norton Commando Parts

Keep your Norton Commando on the road running strong by installing the best parts. Here at CBS we stock Andover Norton parts to fit all Norton Commando models.

www.classicbritishspares.com

Walridge Motors – Welcome to Walridge Motors

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Also for parts I'd throw "Norton Race Parts" into your browser NRP

Their website is a bit frustrating to scroll through, I don't recommend it on a cell phone. Also, need a sheet of paper and a pen to build a cart. I personally find they sell really top notch stuff, and all their pieces that would require instruction, come with instruction.

Shipping is what it is, but at least the pound is much lower than it has been.

Fritzer_108 said:

Here are some pictures of it as it is. I mocked it up with the P-11 motor for now (it has cylinders but I removed them to do some cleaning). I'm planning to use that motor to build the bike and discovered that the gearbox is a laydown from a Model 7. The pictures are somewhat out of order so use the arrows to cycle through them



I am not sure what forks are on it, but they are definitely British and the legs look really similar to some Roadholders I found on eBay.

1962 Norton Dominator Atlas 750cc P11 Manx Model 20 *2559 FORKS ROADHOLDER | eBay

Find many great new & used options and get the best deals for 1962 Norton Dominator Atlas 750cc P11 Manx Model 20 *2559 FORKS ROADHOLDER at the best online prices at eBay! Free shipping for many products!

www.ebay.com

It has Borrani rims on the front and back and double twin leading drums on the front. Both drums have a Suzuki logo stamped in them so I don't know what they're from, but they fit very well and everything rotates freely. It also came with a oil tank similar to the one in the posters of the racers.

My biggest concern right now is finding all of the parts for the primary (clutch, sprockets, etc. ). I found a mostly complete primary on eBay and a brand new after market kit from Lowbrow Customs (Both are pretty pricey). My concern is whether they will fit because I have a later engine (1967 Atlas P-11) coupled with a earlier laydown gear box as opposed to the AMC gearbox. Thanks for the help!

1962 Norton Dominator Atlas 750cc P11 Manx Model 20 *2559 CLUTCH PRIMARY | eBay

Find many great new & used options and get the best deals for 1962 Norton Dominator Atlas 750cc P11 Manx Model 20 *2559 CLUTCH PRIMARY at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Bob Newby Primary Belt Drive & Clutch Norton Dominator 88 99 650ss & Atlas | eBay

Find many great new & used options and get the best deals for Bob Newby Primary Belt Drive & Clutch Norton Dominator 88 99 650ss & Atlas at the best online prices at eBay! Free shipping for many products!

www.ebay.com

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Might be Suzuki GT750 drum brakes, before they went over to discs

Definitely go for the belt drive..the original tin cases will never hold oil. Try RGM for a belt drive using a Commando diaphragm clutch. They have many options and I do not know about an early gearbox like yours. It should be cheaper than a Newby set up.

When you make the engine plates, put the motor as far forward as possible. Your bike will never handle as good as a Manx, but it will be at it's best with the motor forward. With Tritons, most guys have an inch between the front mount on the motor and the frame mounts. The handling is less positive.