Saturday, September 1, 2007

The Frame Enjoys A Nice Cup Of Tea And A Sit Down With Motor And Gearbox

The engine and gearbox were finally introduced to the frame today. Impatience got the better of me, and while the frame still needs to be sent off to be checked for trueness, I thought it would be fun to have a little assembly time! Still a lot missing, but at least it looks like something now.

A quick cup of tea while I admire my work, take some pictures, and then dismantle it again to get the frame ready to send off.

Saturday, August 4, 2007

The Primary Chaincase

I managed to score a Triumph Thunderbird outer primary cover for a reasonable price a couple of weeks ago. Its foot rest hole had been welded up, but badly and with no blending of the shape attempted, and a patch had been done at some point when the clutch had made a bid for freedom.

I blended the the foot rest area to match the top side with a disc sander attached to my drill. Several times I broke through the old welded patch and had to reweld the holes that I made. Once that are was looking about right, I welded up the two lower screw holes that were cracked, and then set about polishing.

First the wet sanding - 240 grit in one direction, followed by 320, 400, 600 and finally 1500, all in opposing directions making sure to totally remove the previous sanding marks. This was followed by buffing on the polishing wheel and finally out with the Mothers Mag and Aluminum Polish . Overall I am pretty chuffed with the results. There is a slight ripple where the patch was done, but I don't think it will be noticeable when it is on the bike. Now I just need to find the matching inner cover - back to Ebay....

Unfortunately no before pictures, but here is the finished cover...

The Gearbox - Revisited

Well the gearbox is now complete. All new bearings, bushings and stainless steel hardware. With the engine and gearbox ready to fit into the frame I feel like the project is finally moving along. You can read more about the gearbox in an earlier post - The Gearbox - Polishing The Outer Cover

The next job that I will have to farm out is the frame which needs to be checked to make sure it runs true, and then the assembly can start in earnest.

Monday, July 2, 2007

The Rear Hub - A Frustrating Weekend In The Tool Shed

After a long and frustrating weekend in the tool shed, I finally have something to show for the better part of a full weekend's work.

Two weeks ago, while getting some parts that I will never use ready to sell on Ebay, I had an epiphany, a revelation on the direction to take this project. Up until now I had been planning on running a belt drive for the primary, and as a result I was going to have to buy a fancy rear wheel with an enclosed cush drive - about $500 dollars worth of kit. If you add that to the $800 dollars for the belt drive and I have thrown away a lot of dosh just so that I don't have to adjust the primary chain or worry about oil drips. Among the pile of parts was a complete AMC clutch that I had picked up in the early stages of planning parts, and then promptly forgotten about. With about $100 dollars of parts it will be better than new, and I can spend the rest of the saved money on other bits that will move the project beyond the pile of parts stage.

So with the primary figured out, it was time to sort out the rear hub so that I have something to align the gearbox to when I get there. The choice was either the original Norton rear hub or a Triumph conical hub, both of which I had among my parts pile in the shed. The Triumph hub is the better brake, lighter and looks like a Norton Manx racing unit. However, it isn't a Norton Manx racing unit but a later knock off and I am trying to keep this project as original as possible. So with that in mind, I decided to use the Norton hub - a full width alloy hub with cast iron drum bolted onto it. Looks nice but really heavy, and therein lies my weekend's work - trim down some weight and make it look a little less stock.

I had seen some pictures of a Velocette Thruxton with a scalloped hub and thought it would be a good look. So with some careful measurements, a calculator and remembering that π (pi) was about 3.141 I set about marking the hub up. It took me a while to get the technique down, starting with various files, grinder bits and then I came across a set of small sanding drums that were the right diameter for what I needed, slow going but the results looked good.
The first side took the better half of Saturday, but I was more than a little chuffed at how it was looking. Not necessarily any lighter but very Mad Max. I decided to call it a day and do the other side on Sunday.
Sunday morning I return to the shed and mark up the remaining side. With it all pre-marked, and knowing now what I am doing it races along; enough so that my mind starts to wander and I am not really concentrating but thinking about the next job. Two scallops left and..... BOLLOCKS!!! I misread my own marks and sand the wrong bit - right over the spoke hole leaving so little metal that the strength is going to be more than a bit suspect.
I decide to finish it off anyway and give it a clean and try and figure out if it is repairable with some clever welding. When all was done I was even more mad at myself because it really did look good and painted up it would have looked even better. I decide to set it aside and mull over my options and have a beer to refresh my soul and well being. Second beer in and I start to like the looks of that conical hub a little more. After all, it is the better hub and it is a lot cleaner a design. You can also change the sprocket without replacing the whole drum, which I needed to do with the Norton hub, and they don't come cheep. The hub I have on hand has a brand new alloy sprocket and new break shoes - I can fix this up without being anymore out of pocket.

So with another new direction decided, it was time to break out the hole saw and attack the next hub. Two inch holes fit nicely between the stiffening ribs and don't affect the strength of the hub. So once again, with some careful measurements, a calculator and remembering that π (pi) was about 3.141 I set about marking the hub up. Happy that I had the marks all equidistant and where they were meant to be, I put the hole saw in my drill press and started making holes.
The first hole went without to much trouble other than a lot of vibration. I started in on the second hole and the chuck on my drill press decided to disintegrate throwing bearing around the shed and leaving the drill inoperative. Just not a good weekend. Refusing to be beaten, I pull out my trusty old hand drill and attack the hub to finish it off.
After all five holes are drilled, it is time to smooth them out and remove all the sharp edges that will encourage stress fractures to start. A good clean up later and I am pretty pleased with the results and I think it will look good on the bike. I am tempted to scallop this hub too, but after the last unmitigated disaster I am thinking I might just leave it as is.

The next job is to powdercoat it black and fit gauze in the holes to stop rocks, birds, small children and the like from falling in and jamming the brakes. But that can wait until I am ready to get it laced to a rim.
And if I change my mind again, it really will make a lovely lampshade.

Friday, June 8, 2007

The Gearbox - Polishing the Outer Cover

So with the motor pretty much finished, it is time to turn my attentions to the gearbox - a 1958 Norton AMC 4 speed. First job is to get the outer cover polished so that I can send it off to have the leaky O rings replaced by proper oil seals, as was standard on the much later Mk3 Commandos - this is a service that Fair Spares America Inc ( in San Jose, CA undertakes at a reasonable price.

Once this is done, I will take the gearbox to Steve at European Cycles ( to check out the mechanical condition and see what is needed to make a reliable box out of it.

So, without further ado, on with the polishing. You can see from the photos that the old cover isn't in the best condition, with some deep gouges and scratches. First job is to give it a good clean with degreaser.

Once it was all clean, I attacked it with a fine file over the worst areas, and then 60 grit wet and dry paper attached to a disc on the drill.
Once I was happy that all the scratches and gouges were smoothed out, it was time for the jar of elbow grease and many grades of wet and dry, right up to 1500 grit. After a fair amount of back and forth between grits (my patience isn't the best) it was time for the buffing wheel and polishing compound.
I was actually pretty chuffed at how well it came out. There are still the remains of a couple of the deeper gouges, but they give it the character that a 50 year old piece of aluminium should have!

Saturday, May 26, 2007

The motor is finished (for now)...

The motor is back from being rebuilt and is just about complete - a few parts left to finish which I will collect in the next few weeks.

It started out as a 1958 Triumph T110 bottom end, complete but in need of a total rebuild. The cases were stripped and bead blasted, with all threads checked and repaired where necessary. A late sixties two piece crankshaft from a TR6C with the lighter flywheel was used, with reground journals to first undersize, polished conrods and all new bearings.
Later NOS nitrided E3134 camshafts were used with all new bushings, and R cam followers running in Morgo tappet blocks. The cylinder is a Morgo 750cc kit and topped off with an early twin carb 9 stud head. The alloy pushrod tubes join the late style blocks to the earlier head, and house lightweight performance pushrods. The rocker boxes house lightened dural tappet adjusters and solid spacers instead of the original springs to reduce friction. They are joined by an original finned Webco oil rail.
Other goodies include a finned sump plate complete with drain plug, timing cover with tachometer drive and oil seal conversion and a Morgo rotary oil pump to keep the whole lot lubricated. The magneto is a Lucas Competition model (K2FC) but with all internals removed. They will be replaced with a Boyer electronic ignition unit which will be fitted further down the line.

Still needed - Oil pressure release valve, intake manifolds, finned rockerbox caps and a dynamo blanking plug to switch to later alternator electrics.

Monday, May 21, 2007

Dreaming Of A Bigger Tool Shed...

At the bottom of the garden stands the tool shed. This is by no means a tool shed to boast about. It's roof leaks, the floor is rotten, a family of squirrels takes refuge from the elements inside, and I am forever having to prune back the ivy that seems to like the darkness of the shed.
Now while it serves its purpose as a place to keep my tools and various projects, it is both a little cramped and a little too damp for restoring old motorcycles. This isn't all bad. I have come to an agreement with the girlfriend that as parts get restored, as long as they don't smell or leak oil, they can live in the warmth and dryness of the house. Sadly the old BSA does not fit into either category so it has to fend for itself in the tool shed. Maybe when I am done with the Triton, the old girl will get an engine overhaul and come stay in the living room. Or maybe we will move to a place with a garage. We will see, but for now, a visual tour...

These actually make it look quite tidy... The Honda Monkey Bike sitting in the corner - I have to finish this by the time my girlfriends nephew has long enough legs to ride it - don't they grow up quickly nowadays.

Time for a nice cup of tea and a sit down, and ponder the meaning of stuff...

Sunday, May 20, 2007

Alignment woes...

So with the motor's pending arrival it is time to start thinking about fitting bits together - the gearbox will be a reasonably quick job to refurbish, it is time to start planning ahead on engine plates, spacing and drive trains.

Using a Norton gearbox, this will be the only part that will be fixed laterally. The engine, having its mounts narrower than the engine plates, has room to adjust side to side in order to align the clutch and engine sprocket. With the plans to use a belt drive, this has to be spot on to stop the belt wandering off. I will be using a double sided gearbox adjuster to stop the gearbox twisting under load. As well as the engine and gearbox being lined up laterally they must also be spaced suitably apart for the primary chaincase to fit, and using a belt drive, the belt must fit within spec - belts are not made in every conceivable number of teeth and the permutations are not limitless. The gearbox centre should also be below the centreline of the rear swingarm when the rear suspension is loaded. This is so that when the power is applied, the force on the rear sprocket is such as to pull it down more in contact with the road rather than pull it up away from the road. Also the nearer the gearbox shaft is to the swingarm pivot, the less the variation of the distance between the gearbox and rear sprockets as the suspension extends and compresses. This is kinder to the rear chain. So that is the gearbox.

The rear wheel has some movement side to side by fiddling with the axle spacers, and adjusting the rim offset to suit. Things to be careful of are compromising the rear brake plate torque stay mechanism, and the chain clearing the swingarm. The Gearbox sprocket also has some lateral adjustment by using shims or offset sprockets, so even though the gearbox is fixed, the sproket alignment is not. Of course, the same is true with the clutch. It is also true with the crankshaft sprocket.

So, if I haven't confused myself, I put in the gearbox, adjust sprocket to rear wheel, adjust rear wheel to gearbox, put in engine and adjust to gearbox, shim sprocket to get spot on and Bob's your uncle, I will have a drive train.

So with all this thinking about alignment, I am going to have to get my frame trued before I start putting things in it, or all will be for naught. I guess I am going to have to make my mind up on my rear wheel too. And who I am going to get my engine plates from. Should probably figure out my primary cases and order my belt drive while I am at it. And then I have to decide what sprocket sizes and chain guage to use. I guess I should quit worrying about alignment for now, and go back to collecting parts and upsetting my bank balance...

Saturday, May 19, 2007

A trip to the bike shop...

So I took at trip to the bike shop ( today where my motor is being assembled to drop off a big box of motor parts, and to give the man some hard earned cash - seamed like an odd exchange and definitely very one sided. The bottom end is now complete and I have to say it is a thing of beauty. The top end is ready to be worked on and from his reports, I should be seeing the completed motor by the end of the week. So it is time to clear some space in my wardrobe until the Norton frame is ready to be its new display cabinet. Photo's to follow....

Sunday, May 6, 2007

Dreaming of brakes...

So one of my hardest decisions I have come across so far is what brakes to go for, the possibilities are endless and range from thrifty to possible bankruptcy. My original plan for the rear was a Triumph conical hub, drilled to look like a Norton Manx hub at a tenth of the price.

As for the front, I have been totally clueless and still am. My first thoughts were a full width Norton hub with a Norton Commando twin leading shoe brake plate, but I went off the thoughts of this because the Commando didn't come about until 1968/9 which makes it a little late for my build specs.

And then I came across a strange company called Disco Volante and discovered what only can be described as cafe racer porn - let me introduce you to the 250 mm Fontana four leading shoe front brake and its little brother, the 210 mm twin leading shoe rear brake. Time to start saving, I think I am in love...
Well, a lad can dream. Think I will put this decision off for a while, maybe I will make my mind up next year - for now, back to the motor and start on the gearbox...

The Motor...

I decided that the plan for this bike should be to construct it entirely from period parts available to the sixties builder and any concessions away from this should be hidden from view. I decided that a pre unit motor was the way to go, and settled on a 1958 Triumph T110 motor - 650cc vertical twin. I managed to find a bottom end in reasonable condition, well, that is how it was advertised, and surprisingly I didn't get raped over the price as so usually happens on Sleazebay.

The motor as bought...

So next came the long and arduous task of collecting overpriced motor parts. The list so far...
  • Morgo big bore kit - 750cc, complete with pistons and gudgeon pins
  • Morgo rotary oil pump
  • Morgo tappet blocks - later style
  • Mid sixties two part crankshaft - light version from a TR6C
  • Polished conrods
  • E3134 nitrided cams with R followers - this is Triumph's racing set up
  • 3 key way timing wheels
  • Alloy pushrod tubes - late style tappet block to earlier head
  • Performance push rods
  • Timing cover complete with rev counter drive
  • Finned sump plate with drain plug
  • Bonneville twin carb head (9 stud)
  • Rocker assemblies
  • Lightened tappet adjusters
  • Finned oil rail for rockerboxes
  • All new bearings and bushes and gaskets.

The motor is currently with Steve Giblin of European Motorcycles ( who is doing the engine assembly for me, including dynamically balancing the cranks and rebuilding the head, as well as repairing stripped threads from previous heavy handed owners. Hopefully it should be ready in a few weeks time so that I will have something complete to look at and to build a bike around. I am trying not to keep a tally of how much money I have in this motor already, or else this bike is going to end up as living room furniture.

The motor in its original surroundings...

The Frame...

When I first decided that an old cafe racer was the direction I wanted this project to head, it didn't take long for me to decide that a Triton was going to be the object of my desires. First built in the early sixties they were a marriage of the Norton featherbed frame, accepted as the best round handler of the day, with a Triumph twin 650cc engine which was well known for being the most reliable and easily tuned, but in a frame that has been described as a hinged camel.

After a fair amount of searching I came across a 1956 Norton Dominator 99 Featherbed frame - this is the wideline version of Norton's featherbed. It was a complete rolling chassis complete with its Roadholder forks and fullwidth alloy hubs laced to some rusty but original rims. I exchanged it for my tax return and the project begins...
This is how the frame would have looked in the motorcycle it was intended for...