Friday, March 25, 2011


Finished up the fabrication on the tank, including the hinge, rubber mounting and latch.  The ignition and seat lock came in so I'll be working on finishing up the seat next. Tried test fitting up a fender for the rear, but I will fabricate a new one instead, something wider that will extend to the swingarm pivot in the front.

Tuesday, March 15, 2011


Lots got done on the XS this weekend, the battery was located and a mount built so that it will sit inside and under the rear of the tank, keeping it's weight centered, as opposed to some builds which thoughtlessly stuff it under the seat, where the extra mass is at exactly the wrong place.  The rear frame hoop was sheeted in so that the electronics can be mounted, some of the wiring was cleaned up and all the remaining sockets were replaced with gold plated connectors.  The seat was also built for the most part, it will end up being covered in leather or vinyl, so the aluminum wasn't polished.  

 The tank still needs to have the bottom welded in, mounts fabricated and then matching frame tabs welded on to the frame, now that the battery is mounted, building the bottom of the tank can go ahead.  The seat will be hinged and lock as well, so some more work needs to be done there as well.  The kickstart relocation is almost done, and once finished, the exhaust can be built and routed so that there is no interference.  Shocks, chain and swingarm should be on the menu for this week.

Monday, March 7, 2011

XS Manx

I started carving the tank from a built up block of insulating foam over the weekend, and when I was happy with the shape, I cut the pattern at intervals and used it to build a plywood buck for the final tank.  The pieces are interlocking so it's very strong for clamping your pieces as you fit and form the next section of metal. 
This shows the beginning of the forming process, the pattern is broken down into workable segments which are then cut from aluminum and formed to fit the pattern, then clamped so the next section can be formed and fit, the two kneewells have been formed in this picture and will be finished up and tacked to the main section before moving on to the tank sides.  I tend to form both the left and right parts for tanks before tacking, as this keeps things more symmetrical.

Toby spent the day on the lathe working on our elegant solution to the interference problem caused by the kickstart lever and the rearset controls.  I didn't have room to take pictures of this, but the finished mechanism will be documented.

Wednesday, March 2, 2011

XS Manx

I spent the better part of an afternoon making a hanger for the new brake caliper, to adapt it to a 320mm rotor and the fork tube from the 1100.  I also machined a spacer for the rotor because the caliper was very close to the spokes.  Seems to have all gone well, though we discovered that the rotor is actually warped, and since the setup is all done, we'll have to replace it with the same type.

Toby and I worked Monday to get a lot done on the bike, starting with getting the engine back in the frame.  That took some bubble wrap and wrestling, but it went in and mounted up well.  The wheels are back on for now, so we can check the swingarm and neck angle, and see what kind of offset to build into the fork yokes.  
Some $5 angle finders come in really handy.

With the length of the xs1100 forks, the swingarm angle came in about 11 degrees and rake was about 26, which is pretty good for a stable but agile bike without much squat under power.  The swingarm will be replaced with a box section steel arm, though the length will likely be kept the same.  The offset on the stock yokes is probably too high, and will be decreased by about 20mm when the new yokes are machined. 
I spent a good amount of time getting the riding position set before starting to design the tank, I first machined plates to bolt to the frame, and accept the bolt for the footpeg, then moved and moved it around until it was right, and matched well with the position of the handlebars, which also got moved a lot.  Right now the position is very good, no weight on the bars and feet under the rider c/g.  I'm using some of my adjustable stainless rearsets on the project as well, along with my adjustable clipons.  Good combo in my opinion.  
While Toby was machining a part for a special kickstart relocating mechanism, I decided that I could go ahead and work on the front fender, since the front end won't change from here on out.  This took me a couple hours and draws on vintage racing fenders for the look.  The masking tape will hold things in place until I can screw the bracket into the fender. 

Sunday, February 20, 2011


We're running xs1100 forks on the front of the bike for additional stiffness, but before reassembling the forks and putting them back on the bike, some changes were made.  Compression blowoff valves were machined and installed to allow for tuning both the low speed and high speed compression damping rates, rebound rate will be controlled mostly by the choice of fork oil.  The stock fork caps were also tossed and replaced with new caps which allow full variation in preload.  New fork clamps will also be machined with an offset designed specifically for the bike.

Friday, February 18, 2011

XS Manx

I pulled some long hours in the shop the last few days to get the wheels for the Manx bike built, we're going to use H profile 18x2.15 rims laced with Buchanan stainless spokes to the stock hubs for this bike.  The smaller front wheel should make the front end a bit more nimble, alloy rims came stock on the XS650, but the stock spokes were in poor shape, so it made sense to go with stainless, polish everything, and rebuild the wheels properly.

Lacing the rims takes the better part of an hour, truing takes the rest, but the result is definitely worth while.  Polishing these parts up from the snotty stock parts took hours and hours, but again, was well worth it for what will be a show stopping bike.

I got the wheels to Toby yesterday and he was able to mount the new tires, and balance the wheels.  He chose Continental "ContiGO" tires, because of the sticky compound, and modern performance design.  I think they look great on the wheels, the front wheel is being stopped by a modern two piston sliding caliper on a 320mm Ducati rotor.  

XS Manx

Toby finished the engine and brought it to the shop tonight, looking great, it's definitely the nicest engine I've seen.  He went through the entire engine, piece by piece and inspected everything, replacing any parts that were worn or damaged.  The cylinders were honed, valves lapped, all the goodies to make the engine run better than it did when it came from the factory.
Toby bead blasted all the engine parts and put on a fresh coat of enamel too, much better looking than the stock black muck that came from the factory.  
Detail shots of the engine are impressive.

Monday, February 7, 2011

 Toby is finishing up stripping the extra junk from the frame, quite a few hours went into just getting all the tabs, mounts and hangers off before we can add a flat rear hoop and some bracing.  The frame will be sandblasted next so any welding can be done on clean metal.
 The frame is looking better, some extra bracing will be designed and welded on once the motor is back in, so we avoid interference with it.
 The carbs have been cleaned and the old paint stripped off, the bodies have been ultrasonically cleaned and Toby has gone through and inspected and ordered replacement parts where needed.
Carb bowls have been ultrasonically cleaned too, and polished.

While waiting for the engine to finish up, I machined a titanium rear axle to replace the stock steel unit, for a savings of 10oz of unsprung mass.  The front will get one too, as well as rebuilt forks and custom cartridge emulators.

Saturday, January 29, 2011


We got the tires off the old rims, and bought a Borrani 18" rim for the front wheel, along with stainless spokes to lace both 18" rims to the hubs.  An order of needed engine parts will come in this week, so the engine can be buttoned up better than new. 

The spokes were removed and the hubs will be polished and lightened where needed, the rear drum may or may not end up being resurfaced.  The front wheel and hub are fairly light and strong, and the Ducati rotor being used on the front end won't add much to the unsprung weight either, which will be good.  The back wheel assembly however, was awfully heavy and is going to make the back end suspension a touchy subject.  I took apart the assembly and decided I could start to shed some weight at the axle.  So I decided to make the axle again in titanium, as I still have about 20 feet left from a surplus find.

Titanium isn't much fun to machine, especially with a very old lathe, and no steady rest either.  The amount I could take off per pass was really limited by the need to keep the piece from flexing, so about an hour and a half after starting, I was doing my finishing passes.  Without the steady rest, I had to divide up the shaft and manually compensate for the remaining flex in the piece.  Not too bad really, wound up with an axle +/- .001 over the length, plenty precise for this old beast.  And it saved 10oz over the stock steel shaft, and is stronger too.

Monday, January 17, 2011

Building the XS Manx

Despite getting the business end of a screwdriver in his eye last week, Toby is back at the 650 engine, which is certainly a well engineered piece of metal.  The cam came out with little trouble, the manual specs a chain breaker to split the cam chain and extract the cam, but he managed to remove the end bearings and find enough wiggle room to get it out with ease.  The frame continues to shed weight, another hour of grinding left me with a pile of dust and useless crap to clean up, better on the floor than on the bike in my opinion, useless weight has no place on a real cafe racer.  We're planning on swapping the front forks for a set of larger XJ1100 units, the top and bottom triple clamps will be machined after we mock up the bike to measure some of the critical geometry.  The trees will likely be built with an eccentric adjustment for fork offset, to allow some fine tuning once the bike is on the road.  I'll likely be machining some cartridge emulators and building them into the fork damping system too, there's no reason to leave better roadholding out of the equation.

Wednesday, January 12, 2011

Building the XS Manx

This will be the story of the transformation of a cruddy old '83 XS 650 into a custom Norton Manx style roadracer.  My friend Toby Zeigler, a professional mechanic and excellent engine builder, and I have teamed up to complete this build.  With our unique skill sets, we'll have a machine that runs and handles better than it did the day it came from the factory, and looks as good as it performs.  This bike will be built to sell to a worthy buyer when completed, and we hope to be finished before the riding season really kicks in.  Of course we'll have it in ridable shape by the time the weather gets just warm enough to do a few hundred miles of shakedown rides before stripping the bike again for final polishing and powdercoating, etc.

We spent Monday afternoon getting all the extra junk off the bike and removing the engine for a complete professional overhaul.  Once apart, I realized just how ugly the stock frame is...