A Streetfighter For The World | The Sunburst Seeley Commando


As featured on the #1 custom bike website www.bikeexif.com/nyc-norton/

In early 2014 we got a call from an overseas number on the shop phone.  On the other end of the call was a pleasant voice with an unidentifiable accent who introduced himself as “Joe”.  He was calling from his home in a small country nestled in the middle of the Mediterranean Sea.  He had just purchased a pristine Norton Commando in the States and asked if we could add some performance and reliability mods to it before ultimately shipping it across the seas to him.  Sounded easy enough.  This was the humble beginning of a relationship that has circled the Earth many times.  Having already in his stable a bone-stock Commando, as well as other vintage bikes of various marques, Joe wanted this Commando to have a bit more “oomph”.  This is our specialty and we were very happy to comply.  Soon more and more components started to arrive at our door, but as we mapped out the process of what it would take to optimize these bits it became clear his beautiful Commando would need to be torn down and key internals changed (camshaft, pistons for compression, etc) to get the bike up to the state of tune and reap the benefits of the components laid out in front of us.  And while we love this kind of work, we both agreed this Commando was just too nice to tear down.  Our discussions quickly turned to an entirely new concept.  Joe was very familiar with our other builds, and asked if perhaps we could do up a Seeley Commando 750cc Streetfighter, starting with the bits that were initially earmarked for the stock bike.  Hmmmm.  How quickly could we say yes!??

Fast forward to present times –  NYC Norton has built up what we believe to be one of the most beautiful, radical, fast, vintage-based street bikes out in the custom world today.  To document it after completion our first call was to our friend, fellow racing competitor, and talented artist and photographer, Doug MacRae (www.douglasmacrae.com), who arranged to travel to New York City to photograph this machine.  Doug’s photos are interspersed here, illustrating the build’s story line:

NYC 07-15_4598-Douglas MacRae

A beauty, but all business

Once we had a template and punch-list in place for the new Seeley Streetfighter the next matter of business was obtaining the platform to build up this phoenix.  After a few weeks of all parties searching ’round the world we were able to source what appeared to be a ratty 1970 donor Commando from everyone’s favorite auction website.  Outward appearances showed us it was missing lots of bits, but the fundamental components looked to be intact. The idea was we rebuild the motor from the bottom, up, and work to upgrade the internals and get the specs up to a tuned street bike, rebuild the gearbox, and adapt some of the suspension, etc. to the Seeley Chassis.  Unfortunately, after its delivery, it was quickly discovered this poor baby had lived a rough life; rougher than the well-placed auction photos revealed.  The crankcases had a very sloppy weld on the drive side half – a tell-tale sign a rod had broken through in its past.  The crank itself had large chunks taken out of  the cheeks, and the journals were so undersized the rods knocked if you sneezed near them.  There was a lot of moon crater looking damage to the combustion chambers in the head.  Damn.  Caveat Emptor, indeed.  Taking a step back, we decided to use as much of the donor as we could while sourcing some very robust (reliable) racing motor bits usually reserved for the track.

Version 3.0 was about to take place.

Back to the drawing board, we sourced a Maney lightweight crank, set of Maney crankcases and alloy cylinders, and a Fullauto head.  These all but replaced the unusable components from the donor.  All the timing side bits were checked and were very usable, thank goodness.  The oil pump looked brand new (it probably was). All the timing side gears/sprockets were pristine. We chose to go with Carrillo rods and our favorite JE 73mm forged pistons.  The crank was balanced to 74%, the same factor our own multi-championship-winning Seeley Commandos use.  A Web racing cam was used in concert with one of the last Maney exhaust systems ever to be made.  We kept the compression close to 10:1 – high enough so the bike could be ridden aggressively on the street, but still able to run on hi-octane pump gas.  A TriSpark electronic ignition was installed which has one of the best street Commando curves, making kickstarting a beast like this possible.  We machined the cases to accept a Comstock reed valve breather giving the ability to breathe all through the RPM range.  But why go through all this effort and not help the flow of air and fuel?  Keihin FCR35 twin carburetors were fit and manifolds were adapted to get the perfect inlet tract length to the head.  Oh, about that head…the Fullauto Norton cylinder heads are a work of art, and adding one to this motor was the cherry on top.  Kibblewhite Black Diamond valves and R&D springs were fitted.  These heads with standard valve sizes have much better flow characteristics right out of the box than stock.  Achieving comparable flow numbers using a stock head would require extensive porting, bigger valves, reangling, and a lot of development.  This is the single biggest boost of power one can add off the shelf for your Commando.  Proof is in the pudding, and the eating is good.

Fullauto head is casting artistry

Fullauto head is casting artistry

It was time to turn our efforts to the gearbox.  Like the motor, the box had lived a tough life.  There were signs some kind of debris had run itself through the gears.  We were able to salvage most of it, but the 2nd gear pair was junk and replaced with a later, taller type.  All bearings, bushings, and seals were replaced as is standard with a NYC Norton gearbox rebuild, as well as our very reliable kickstart shaft seal modification.

Once finished with the motor and gearbox it was time to focus on the larger bits.  Our tried-and-true metal bending artist Roger Titshmarsh supplied for us a mint Seeley MK2 Replica Chassis.  Once in hand we set out on fabbing up custom engine plates to house the Commando motor with the thick-walled Maney cases so to obtain good clearance from the T45 Seeley frame rails.  Jon and I spent a lot of time spacing the AMC gearbox over to the left 5mm from the motor centerline to give better chain clearance for the back tire, while determining rear offset for perfect sprocket alignment between the countershaft and the rear hub.  A pair of NYC Norton custom alloy fork yokes were set up with pinch-bolt top for quick geometry changes, as well as Cosentino shim-stack cartridges in the front Commando forks.  Falcon shocks were fit to the rear and made a nice slim fit with fantastic damping characteristics for both aggressive street and racing.

NYC Norton has always had great success with our uprated version of the classic Norton Production Racer recipe for the front wheel, and this was where we took the build.  Twin 11.5″ disks were bolted to a 6-bolt hub using AN aircraft bolts, fit to Norton Production Racer fork sliders.  The disks were drilled in the same NYC Norton pattern used on all our performance street and racing bikes, taking off over 1.3lbs from each brake rotor.  AP Racing 41mm twin-pot calipers were used with Ferodo Platinum pads and all is pumped by a Brembo master cylinder and twin stainless brake lines.  The front rim is an 18″ WM3 unflanged alloy laced up with stainless spokes and nipples.

Classic but updated Norton Production Racer front end

Classic but updated Norton Production Racer front end

The rear wheel was built up using our two-piece Triumph T140 replica billet hub along with a Maney cush drive to give the stock gearbox a little relief from quick shifts and exuberant throttle use.  A drilled T140 disk, fabbed caliper hanger, torque arm, Brembo caliper and master cylinder, and stainless brake line were put in charge of stopping on the rear.  This setup allows for quick sprocket changes and is a perfect fit within the Seeley swinging arm.  The rear was laced to an 18″ WM4 unflanged alloy rim with stainless spokes and nipples.  Both front and rear wheels were mounted with Bridgestone BT45 Battalax performance DOT tires.

Shifting and braking are handled by our exclusive NYC Norton rearset controls, alloy shift arm, and stainless linkage.

NYC Norton rearsets take control

NYC Norton Rearsets take control

The primary side of the bike was built using a 30mm belt drive that increases the primary ratio (less torque shock to the AMC gearbox – a good thing).  The clutch features machined and lightened Commando drive plates and Barnett friction plates.  A super trick high-output alternator was adapted outboard the belt drive, the mounting of which is a work of art in and of itself, keeping a low profile hidden behind the alloy belt guard cover.

Primary side detail

Primary side detail

Now was time for the jewelry. Whether a stock Commando or custom Seeley, this is always the part that outwardly distinguishes one NYC Norton build from the other.  Being the well-traveled bloke he is, Joe turned us on to FlatRacer in the UK, where we agreed their Sprint 1/2 fairing would fit perfectly in structure and philosophy.  This is a robust piece; heavier than our racing bodywork we often use, which allowed us to alter the shape the fairing considerably while maintaining its structure, achieving the custom fit we needed for the Seeley chassis. We used our favorite custom lightweight headlight protruding through the fairing nose in an endurance racer style, keeping the street-legal functionality based in a racer’s vision.

The eye of the storm

The eye of the storm

The Seeley MK2-style alloy petrol tank required a bit of extra relief to the underside achieve clearance for the throttle linkage on the Keihins.  We added some extra padding to the MK2 seat to provide some comfort beyond what a typical racer would ask, and it was reinforced with added bracketry which doubled to mount the LED tail lights.

Cat's eyes and pins

Cat’s eyes and pins

The lighting and horn are controlled by minimal low-profile switch gear housed on the clip-ons, with all of the back roads tomfoolery reported back to the rider via the MotoGadget nestled tightly in the dash.

Pilot's view

Pilot’s view

Now… no one can look at these photos and not notice the very vibrant color scheme of this bike.  It is certainly a departure from the more conservative natural alloy, silicon bronze, and occasional black and gold livery most of our customers’ NYC Norton Seeleys roll out of our shop with.  Joe knew he wanted something bold, but he wasn’t sure exactly what.  We danced around many ideas in the process.  I would shoot the bike in its natural colors and Photoshop in different ideas, emailing them across the world for consideration.  But after much back and forth, we seemed to stall a bit.  It needed to be perfect and we both hoped the right idea would fall into our laps so we rested on the concept for a while.  It was later while sitting in my home recording studio that an idea dawned on me…  as I sat plunking out some parts on my guitar I realized this was a motif that was very important to me – the cherry sunburst of a vintage Gibson Les Paul.

A cherry sunburst indeed

A cherry sunburst indeed

I have played many different guitars over the years, but the Les Paul is without question my favorite.  And while I don’t discuss it much in the motorcycling world, I have a long, involved history with the music world, and this just seemed like such an obvious confluence of two very different pieces of my own personal life.  There it was, sitting (falling) right in my lap.  I waited a few days for this to metabolize in my own mind before presenting it to Joe.  I didn’t want to hurriedly suggest such a concept without a little time to let it process myself.  It was a loud scheme (just like the guitar can be!) and it was certain to create a strong reaction.  But the initial build of the bike was all but done and it was time to get it painted and the final touches completed, so I had to put it out there.  I made the call, and like the very first conversation we ever had, Joe’s upbeat nature was positive and he was 100% on board.  Wow.  Really?  How about that!?  This made it very personal.  Yep.  The Sunburst.

The last philosophical hurdle had been cleared.  And there was only one person I knew who could paint such a thing and be able to communicate with me clearly through what was certain to be a complicated process and get this done as I needed – our go-to guy Brent Budgor from the Vintage Vendor.  So off went the fairing, mudguard, tank, and seat to Brent.  And as we worked through the gentle shading process of the sunburst motif I learned that Brent too had a Les Paul that he had once stripped and painted, so my concept was understood implicitly from the get-go.  As he does, Brent laid out the Norton logo and pins in a gold undercoat, then spraying the major color over.  After several mockups and photos back and forth, Brent said it was time to close my eyes and trust him.  I stepped back and let him go with it.  When I received the final photos of the motif from Brent I was over the moon.

'Burst

‘Burst

Once the bodywork was back, the bike was buttoned up in short order.  In hindsight it has been such a pivotal bike build for us because of the way something small evolved into this final, beautiful result.  This is a serious bike…  Yes, it’s pretty, but its foundation is based on a very tractable but top-spec competitive 300-pound 750 Seeley Norton racer, adapted for the street.  The bike starts on first kick and is an absolute blast to ride.  It has all the famous Seeley handling and Commando torque without any sacrifice.  Its break-in runs and dyno numbers do not lie (more on that in a future post).  No, it is not Papa’s Norton.  Yes, perhaps the cobblestones in the NYC streets might rattle its tight suspension a bit.  But there’s not a back road in the world this bike can’t eat alive.

Timing side

Timing side

Drive side with sunburst

Drive side with sunburst

NYC Norton Sunburst

Full Right

NYC Norton Sunburst left

Full Left

And while our friend Joe remains at the back of this story at his request, I must say without his long view and patience we could not have built something this spectacular.  Thank you, Joe.

KC and the Sunburst Band

KC and the Sunburst Band

 

-Kenny Cummings
NYC Norton
October 2015

 
 

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