Seeley Norton Done (or almost)

springer · Oct 2, 2020

After more than 2 years planning and working on it , here is my almost finished Seeley Norton. Still few details to add. Photos are about one weeks old, now i have front fender and headlight bubble. Done so far about 520 kilometers. Two track events to attend this month, more photos to follow.
The bike will be used both on track and in some occasions road use.

New item by Con Man

photos.app.goo.gl

New item by Con Man

photos.app.goo.gl

New item by Con Man

photos.app.goo.gl

Fast Eddie · Oct 2, 2020

That looks fabulous, well done!

maylar · Oct 3, 2020

Do tell us about the motor in that beauty

lcrken · Oct 3, 2020

Looking good. Two years is actually pretty good compared to how long some of us take for our projects.

Ken

springer · Oct 3, 2020

Here are some specs:
Frame Roger Titchmarsh MK2
Cases norton 1972, cylinder Andover Norton 750
Rods Jim Schmidt ultralight Carillo Rods. Pistons Jim Schmidt, cam JS1. All valves lifters springs followers etc are from Jim Schmidt.
Exhaust Steve Maney with titanium silencer and rear cup modified to accept Supertrapp discs
Carbs Keihin CR33s Special from Jim Schmidt,
Ignition Tri-Spark, Coils Dyna
Shocks and forks (Ceriani GP) are from CR Suspension in Hungary.
Front Hub Norvil. Rear Hub, disc and sprocket, Seeley made by Dick Hunt.
Brake Calipers are Original NOS AP 2195 Lockheed. Both master cylinders original AP lockheed .
Primary belt and clutch from Bob Newby Racing. Front Discs Are original Norvil semi floating lightened by my machinist.
Clip- ons Tomasseli Adjustables
Dry (from Fuel) weight 148 kgs (with alternator, headlight, kickstart lever and kickstand)

Fast Eddie · Oct 4, 2020

Oh yes, the words are even better than the pictures!

All we need now is a video WITHOUT hideous over dubbed music...

Schwany · Oct 4, 2020

Yeah, I'd like to hear that running. Nice work

How do you like the JS CR carburetion?

Any port work? Sorry, I'm not familiar with Seeley specs in case port work is understood. I'm thinking all Seeley bikes built today are one off replicas.

Steves · Oct 4, 2020

Very nice, I have a similar plan for my race bike when I stop racing it. The only thing I would say is the tyre sizes look a little out. Just an impression looking at a photo of course. Not so important on the road but if you take it to the track and and get at all exuberant then it is.

springer · Oct 4, 2020

Fast Eddie said:
Oh yes, the words are even better than the pictures!

All we need now is a video WITHOUT hideous over dubbed music...

I have two track events this month , although it will need some tunng and sorting out of some things , i will surely have some video.

springer · Oct 4, 2020

Schwany said:
Yeah, I'd like to hear that running. Nice work

How do you like the JS CR carburetion?

Any port work? Sorry, I'm not familiar with Seeley specs in case port work is understood. I'm thinking all Seeley bikes built today are one off replicas.

JS CR carbs worked pretty well out of the box, not even a screw needed something. Cold start needs to be a bit better but that will take some time along with overall tuning. I have about 600 kilometers on the clock so far, mixtures seems good, response also up to 5500 RPM ... we ll see . Well not some specific port work except for matching, Still needs some fiddling with the manifolds and their extensions.

springer · Oct 4, 2020

Steves said:
Very nice, I have a similar plan for my race bike when I stop racing it. The only thing I would say is the tyre sizes look a little out. Just an impression looking at a photo of course. Not so important on the road but if you take it to the track and and get at all exuberant then it is.

Hmm Tyres are front 100/80/18 and rear 120/80/18. This is a first set of BT 45s just to start and do the first Kms on the bike. From what i know these dimensions are commonly used on classic bikes racing and there is not too much you can do especially with the rims that you can fit to the Seeley frame and fork. Especially the fron fork with dual Norvil discs is a pain... Next set will be AVONs 10/80/18 and 130/65/18 racing compounds AM 22 And AM 23

Steves · Oct 5, 2020

Ignore what I said, just a random thought looking at photos. You will like the Avons, plenty of grip and warm up quick. 110 on the front. Cantilever rear depending on rim size.

Fast Eddie · Oct 5, 2020

Steves said:
Ignore what I said, just a random thought looking at photos. You will like the Avons, plenty of grip and warm up quick. 110 on the front. Cantilever rear depending on rim size.

That’s what I used when racing. But there were plenty of fast lads who swore by 110 front and rear.

SteveA · Oct 5, 2020

springer said:
Hmm Tyres are front 100/80/18 and rear 120/80/18. This is a first set of BT 45s just to start and do the first Kms on the bike. From what i know these dimensions are commonly used on classic bikes racing and there is not too much you can do especially with the rims that you can fit to the Seeley frame and fork. Especially the fron fork with dual Norvil discs is a pain... Next set will be AVONs 10/80/18 and 130/65/18 racing compounds AM 22 And AM 23

I run a 90/90 18 on my Rickman and prefer the way that steers. I happen to like Heidenaus and also use a 130/70 18 rear and personally I am comfortable with that. Heidenaus warm up quickly and are good in the wet. They can get too hot in the height of summer in Southern France. The Heidenau rear has the added benefit that I don't have to carve large sections of the tyre away on both sides to clear the swinging arm as the Avon 130/70 tends to be oversize!

However most of the Seeley Nortons running in France are on the 90/90 18 AM26 front and 110/80 18 AM23 rear or the Contis using 100/90 front and 110/80 front reversed on the rear, avoiding the larger rear. The 110/80 front seems less popular now.

There are those who will point out that the narrower rear improves turning in as well.

Technically you bike will be notes as overtyred and over braked! Storm 42 (Ralph) originally fitted twin discs to his 920 Seeley and has removed the second disc on the basis of far too much weight. This will also improve steering. He can certainly tell what tyres he is using. Race compount tyres will not be a lot of fun on the road as you will not get enough heat into them. But I have assumed you plan track use.

I don't really recall a 750 with twin large/lockheed discs, 920s/1007s yes! Those twin disc set ups in use on 750s tend to be Marzocchi front ends with smaller discs and small Brembo calipers!

Schwany · Oct 5, 2020

springer said:
JS CR carbs worked pretty well out of the box, not even a screw needed something. Cold start needs to be a bit better but that will take some time along with overall tuning. I have about 600 kilometers on the clock so far, mixtures seems good, response also up to 5500 RPM ... we ll see . Well not some specific port work except for matching, Still needs some fiddling with the manifolds and their extensions.

Thanks for the info. I'm trying to get some real world information about the Keihin CR and FCR carburetors on a Norton. I've worn out the search here and got very little. I'm sure there is information here, it's just hidden in threads about something else.

I'm going to be making a set of manifolds for an Atlas oriented motor in a P11 frame to work with either the Keihin CR or FCR carburetors. The P11 Matchless frame drops quick behind the motor and space is very limited. I can use straight Triumph spigot manifolds, but they end up having to be really short, and it puts the carburetors at a slightly steeper angle than I think is optimal. So I'm reworking some MKII spigot manifolds (when they show up) to bring the level of the carburetors down and use as long a set of intake extensions as possible to start with.

My guess is the FCR carburetors with the accelerator pump and choke might make starting easier on any motor configuration, but of course one pays for it. I'll probably always have a little bit of a cold start issue with my fueling configuration without some sort of tickler or accelerator pump, because I have longer than stock horizontal extensions on my intake manifolds. Of the few images I've seen of the Seeley intake tract, I think your extensions are about 2.5x longer. Must take a lot of leg to get that started when cold.

Excuse my going off topic. Building your own is definitely the most satisfying to me, but usually comes with a good helping of fiddling. Enjoy the project.

springer · Oct 5, 2020

Schwany said:
Thanks for the info. I'm trying to get some real world information about the Keihin CR and FCR carburetors on a Norton. I've worn out the search here and got very little. I'm sure there is information here, it's just hidden in threads about something else.

I'm going to be making a set of manifolds for an Atlas oriented motor in a P11 frame to work with either the Keihin CR or FCR carburetors. The P11 Matchless frame drops quick behind the motor and space is very limited. I can use straight Triumph spigot manifolds, but they end up having to be really short, and it puts the carburetors at a slightly steeper angle than I think is optimal. So I'm reworking some MKII spigot manifolds (when they show up) to bring the level of the carburetors down and use as long a set of intake extensions as possible to start with.

My guess is the FCR carburetors with the accelerator pump and choke might make starting easier on any motor configuration, but of course one pays for it. I'll probably always have a little bit of a cold start issue with my fueling configuration without some sort of tickler or accelerator pump, because I have longer than stock horizontal extensions on my intake manifolds. Of the few images I've seen of the Seeley intake tract, I think your extensions are about 2.5x longer. Must take a lot of leg to get that started when cold.

Excuse my going off topic. Building your own is definitely the most satisfying to me, but usually comes with a good helping of fiddling. Enjoy the project.

Well as far as cold starting , i ve developed a routine of priming it with a couple of kicks with switch off and full gas and choke. This starts it second kick with switch on . When hot it starts with 1/4 of a kick , but you ve seen my kickstart lever it s huge!. I am used on kicking a 1200 cc harley so The Seeley is a toy compared but as i told you no tuning yet whatsoever. I expect it to improve. My manifold extensions are 48 mm. In the future i plan on making one pieve longer manifolds with my machinist. There is a horizontal tube on the MK2 frame that prevents carbs from going closer than that, but i ve heard opinions that the motor needs long intakes. However i still have some problems of the carbs vibrating and touching the underside of the tank but i am working on this too.

springer · Oct 5, 2020

SteveA said:
I run a 90/90 18 on my Rickman and prefer the way that steers. I happen to like Heidenaus and also use a 130/70 18 rear and personally I am comfortable with that. Heidenaus warm up quickly and are good in the wet. They can get too hot in the height of summer in Southern France. The Heidenau rear has the added benefit that I don't have to carve large sections of the tyre away on both sides to clear the swinging arm as the Avon 130/70 tends to be oversize!

However most of the Seeley Nortons running in France are on the 90/90 18 AM26 front and 110/80 18 AM23 rear or the Contis using 100/90 front and 110/80 front reversed on the rear, avoiding the larger rear. The 110/80 front seems less popular now.

There are those who will point out that the narrower rear improves turning in as well.

Technically you bike will be notes as overtyred and over braked! Storm 42 (Ralph) originally fitted twin discs to his 920 Seeley and has removed the second disc on the basis of far too much weight. This will also improve steering. He can certainly tell what tyres he is using. Race compount tyres will not be a lot of fun on the road as you will not get enough heat into them. But I have assumed you plan track use.

I don't really recall a 750 with twin large/lockheed discs, 920s/1007s yes! Those twin disc set ups in use on 750s tend to be Marzocchi front ends with smaller discs and small Brembo calipers!

Well the configuration of brakes and tyres starts with this one, i ve talked with Ralph Storm 42 about many things , he s been a great help. i like these brakes and also this hole pattern saves me about 450 grams each disc. we ll see in the future how it will develop.

Chris · Oct 5, 2020

Hi Springer
I use Steve Maneys curved manifolds with a central extension piece ie rubber mounted both end. Supported with a rubber band under the trumpets tied over the frame tubes. The curve allows the carbs to sit slightly lower below the tank than straight manifolds.
Chris

springer · Oct 5, 2020

Chris said:
Hi Springer
I use Steve Maneys curved manifolds with a central extension piece ie rubber mounted both end. Supported with a rubber band under the trumpets tied over the frame tubes. The curve allows the carbs to sit slightly lower below the tank than straight manifolds.
Chris

Thank you Chris , i ve seen Steeve's manifolds, they are certainly an option to consider. what kind of carbs do you run? any photos of the setup?
This month i ll run tha bike as it is and then make the improvements

springer · Oct 12, 2020

From what i know rear Seeley MK2 shocks should be 13.9 inches , anybody could help me with the front fork length from wheel center to bottom of lower fork (or top of upper fork) because i have lost my notes on that.

Seeley Norton Done (or almost)

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