Frame options

BrianG · Apr 18, 2017

Examination of my newly acquired 1969 Commando has revealed some significant frame concerns. I am thinking of building it up from an aftermarket frame. Some time ago I saw an article on a trellis frame that carried a monoshock swingarm.

I wonder what current frame options are available. Any ideas?

cjandme · Apr 18, 2017

BrianG said:
Examination of my newly acquired 1969 Commando has revealed some significant frame concerns. I am thinking of building it up from an aftermarket frame. Some time ago I saw an article on a trellis frame that carried a monoshock swingarm. I wonder what current frame options are available. Any ideas?

Check out JSMotorsports Norton website. the frame you pictured looks an awful lot like his old race bike frame. He sell blueprints for just 10 bucks and I believe he can even have one custom made to order. (don't quote me on that part) Super nice guy and great to do business with. (He shipped out the manifold and carb to me on very short notice).

Rohan · Apr 18, 2017

Bear in mind that a lot of the cycleparts (tank seat sidecovers possibly wheels brakes) won't fit if you go with a trellis frame. And it won't look like a Norton, other than the logo on the tank.
And you won't be happy with the standard engine's performance after having spent all that dosh on the fancy cycleparts. ?

Remind us, whats wrong with your frame.
Unless its scrunched into a ball, a good repairer can make them new again.
Although if its too bad, it may be easier/less expensive to find another....

It would have a lot of bling with that trellis, IF you are prepared to spend....

grandpaul · Apr 19, 2017

Yeah, you could end up with something ugly like this one...

peter12 · Apr 19, 2017

Wouldn't want that in my drive.

Dances with Shrapnel · Apr 19, 2017

BrianG said:
I wonder what current frame options are available. Any ideas?

Norvil offers (offered?) a lowered Commando frame and may offer a standard frame.
NYCNorton can fix you up real pretty with a new Seeley Replica - badass option!
There is always the used featherbed (not after market) or a McIntosh Featherbed Manx frame.

BritTwit · Apr 19, 2017

BrianG said:
Examination of my newly acquired 1969 Commando has revealed some significant frame concerns. I am thinking of building it up from an aftermarket frame. Some time ago I saw an article on a trellis frame that carried a monoshock swingarm.

I wonder what current frame options are available. Any ideas?

Norvil does offer replacement frames for Commandos.
The benefit going this route is that you can retain the isolastic engine mounts.
The trellis frames are rigid mounts, not really suited to smooth, comfortable street/road use.

gortnipper · Apr 19, 2017

BritTwit said:
Norvil does offer replacement frames for Commandos.
The benefit going this route is that you can retain the isolastic engine mounts.
The trellis frames are rigid mounts, not really suited to smooth, comfortable street/road use.

Well, a dynamic balance tuned to the frame would go a long way to helping with that.

ashman · Apr 19, 2017

gortnipper said:
BritTwit said:

Norvil does offer replacement frames for Commandos.
The benefit going this route is that you can retain the isolastic engine mounts.
The trellis frames are rigid mounts, not really suited to smooth, comfortable street/road use.

Click to expand...

Well, a dynamic balance tuned to the frame would go a long way to helping with that.

Yes a good balanced Commando motor and no need for isolastics at all, I went this way 35 years ago with my hot 850 in a Wideline Featherbed and have no problems at all with vibrations even to this day and at 58 years old I can still ride it all day every day and the best thing I ride a well set up and one of the best handling frame of old.

Ashley

jseng1 · Apr 21, 2017

BrianG said:
Examination of my newly acquired 1969 Commando has revealed some significant frame concerns. I am thinking of building it up from an aftermarket frame. Some time ago I saw an article on a trellis frame that carried a monoshock swingarm.

I wonder what current frame options are available. Any ideas?

Yes that's a JS Motorsport frame. Currently owned by Ken Canaga. JSMotorsport with the help of Frame Crafters can build you a copy (street version available). For smooth cruising you'll want the lightweight pistons (1/3 lighter than stock). Frame Crafters can make you a smoother looking fuel tank with rounded corners. Definitely the best handling Norton frame available. The last Norton to get on the National AMA podium and the only Norton that could compete successfully against aircooled monoshock Ducatis.

Early version with spoke wheels:

Ken Canaga's version with mag wheels:

Another customer constructing his frame & swingarm:

Rohan · Apr 21, 2017

What would a typical build cost, $$ wise ?
Would you get any change out of say $10k or $20k , or ??

Std engine/gearbox unit etc already on the garage floor....

Does anyone run one on the street ?
Would this even be legal, within the strict letter of the law.

acotrel · Apr 21, 2017

Whatever you build will probably be expensive, so it is always wise to keep in mind it's ultimate resale value which depends on it's end use. (If it fits an historic road race class, you might have more potential buyers.) If you build a Seeley or Rickman framed bike, you will probably get max return when you eventually come to sell it. And the bike's functionality might be better than with the trellis frame you are looking at. 'Racing improves the breed'. How much race- winning was done using that trellis frame and on what sorts of circuits ? If it is slow-handling, you might build yourself a pig and you will only find out when you ride the bike on public roads.
This is an expensive bike, however from where you are at present with your project, it's build is completely achievable . It's price would be somewhere near $30,000 US. So perhaps you might calculate your project budget from there ?:

jseng1 · Apr 22, 2017

Rohan said:
What would a typical build cost, $$ wise ?
Would you get any change out of say $10k or $20k , or ??

Std engine/gearbox unit etc already on the garage floor....

Does anyone run one on the street ?
Would this even be legal, within the strict letter of the law.

Here is a quote I got from Randy at Frame Crafters years ago. It probably needs to be updated.

One frame $3600
engine Plates $400 to 500
Gas Tank $1200
Oil tank $450
Brazing instead of tig welding - add $300
50% deposit required

I know of one that was run on the street and there are many that have bought the plans but I've lost track. It is legal to "create" a bike and its much easier if you already have the registration for the number on the motor and just go with that and change the frame. You would go through the same process as the street Seeley owners.

If anyone wants to know about the handling of the JS monoshock frame. The person to look up is Rob Tuluie - he placed on it at a National BOTT race in the 90s and later worked his way up to the head of the Renault F1 race team.

gripper · Apr 22, 2017

A friend of mine has a 920 Commando engine in a BSA bandit frame. The front down tube is down the back of the timing case right next to the revcounter drive and the gearbox is almost touching the oil pressure relief valve. It's tight. I believe it was originally built by Pete Lovell.

Rohan · Apr 22, 2017

Pic ?

As a road bike, or a race bike ?
How does it handle, with a fair bit heavier engine in it ?
(The bandit was a 350, although the frame looks like it was intended for something bigger.)

gjr · Apr 22, 2017

So, what's wrong with your original frame ?

Greg

acotrel · Apr 23, 2017

The Seeley frame was originally intended for 500cc British singles. Before I owned it, mine had a very heavy 750cc Laverda motor in it. The answer to the handling differences due to engine weight lies in the steering geometry, and changing that a few times can be expensive. A while back, I saw a cheap BSA Gold Flash frame, however the Commando engine might be too tall. With 60's' 650cc Triumph fork yokes, the Gold Flash frames handle beautifully, otherwise they can be dangerous.

lcrken · Apr 24, 2017

If anyone is interested, there's lots more info on the JS monoshock bike here

monoshock-and-daytona-1990-t8194.html?hilit=jim schmidt monoshock Norton

The freshly painted frame is still hanging in my rafters, waiting for me to get it back together again. Still have a couple Norton projects ahead of it for now, but I do plan to eventually get it up and running again.

Ken

Frame options

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