Making an internal cable throttle for the 1957 Triumph Freebird bike.

These are the brass reverse levers going on the bike. They are made by hand in Ukraine and are a BMW knock-off. The holes for the screws had to be enlarged to allow the cams to slide enough to tighten them up and the cable perches needed filing out, but hey are otherwise strong serviceable units. This particular pair was chosen because the cable exits toward the back wall of the inner handlebar, allowing room for the throttle mechanism.

The Honda components that make up the internal throttle cable mechanism. Made for a 1969 Z50 minibike, they were chosen because they leave the interior of the handlebars clear enough to get the brake cable through. The longer piece at the top of the pic is the slide that pulls the cable end, and the other piece is the cable sheath holder. The cable sheath has a threaded end that screws into the holder, making for a solid joint that can’t back out like most cable holders.

The hardest part to make was the internal spiral that drives the slide.. getting the angle of the slide was not hard, but getting the spiral to lay down perfectly flat and getting the right tolerance between the bar was tricky. Although the throttle is based on the Honda design, it was changed a little by adding the ring at the bottom to act as the flange that rides against the bar. A thinner outer tube will cover the spiral.

The inner workings of the throttle mechanism can be seen in place. The cable holder is held in place a couple of different ways. There is a round keyed portion at the top of the slot that keeps the top located correctly, then a flange that slides over the bar and keeps it from being able to come out the top, and finally a screw that secures it from the bottom. The slot for the slide was cut by hand and made a few millimeters longer than the stock Honda one to accommodate the longer travel of the Amal carb slide.

This is the flange that slides over the cable holder. It also is the spacer the outer throttle tube rests on, and the ring at the end keeps it from sliding inward on the bars. A stopper screw was turned from a hex bolt. In addition to anchoring the bottom of the cable holder, it keeps the throttle tube from being able to slide off the end, and limits the range of the throttle twist. The exit hole for the cables can be seen on the underside of the bars. A shroud (seen below) was made to go around the hole to support the cable and keep it from resting on the edge of the hole.

Other than the cable for the brake, this is all that will be on the right side.

That is about as clean as it gets on the handlebars.

The exits for the cables were given some shrouds that were brass-brazed on.

Because there are two cables exiting the handlebars on the right side and they are not as fat as the left-side clutch cable, a thinner, taller shroud was made.

1993 FXR Softail custom and 1978 CB750 updates.

The lines of the backbone will give the rigid frame appearance the owner is after.

Using some 6mm clip-nuts on the seat brackets to hold the rear hump down. They are self-centering and hold in place nicely till they can be welded on the inside, and then the rest of the bracket can be ground off. Also nice not having to strip zinc plating off prior to welding. The cross-piece will be used to mount the electronics tray.

Some anodized grommets dress up the rear hold-down screws.

The cross brace profile was kept low to keep the rear triangle open. For strength , the attachment points were kept low on the tubes and close to the swingarm and motor mounts. The owner wants to try and fit a Cognito Moto oil bag in the front of the triangle. It is placed so that the air filters are shielded from rear tire spray.

Still a long way to go, but the lines of the bike are starting to take shape.

With the rear shock pre-load dialed up to the max, it makes for a perky tail. A 4 into 1 exhaust system is coming next, and will help fill the rear of the bike silhouette.

All welded up, the shock mounting plates run through the box and are welded internally to make a complete box.

With no roadmap to make this monoshock conversion, it was meant to be over-engineered strength-wise while still leaving room for the shock reservoir.

1978 Honda CB750 monoshock mount, 1993 H-D FXR update, mandrel making.

There are more pieces that will go on to strengthen the brace, forming a complete box. The attachment points on both frame tubes should spread out the pulling forces and also give the brace the leverage it needs.

Decent welds. Too bad they are inside the brace where they will never be seen.

The frame and oil tank for the 1993 Harley Davidson FXR custom build came in from England. Custom built by Jeremy “Briz” Witt of CCD, it uses the Harley FXR motor/tranny mounts, while giving the appearance of a Harley Softail frame. He has worked out the geometry so that the motor mounts do not get trashed by swingarm flex.

The work on this frame is superb, with beautiful TIG welded joint. CCD will do any rake, stretch or swingarm width you want at no extra charge.

The frame came with an MSO (Manufacturer’s Statement of Origination) and a VIN stamp, so it should be easy to register. The swingarm uses spherical bearings and is as beefy as the rest of the frame.

One last thing. While doing some deep cleaning around here, I came upon a segment of an old Honda ATC70 axle that was rusted and nasty, with a long sleeve covering it and rusted in place. Just like all the crap I save, it has to be proven useful at some time or it is just crap, so…This is the product of some time with the grinder and lathe. Made entirely from scrap, this mandrel will be used in metal forming. Prior to this, I would clamp pieces of rod in the vise, which was less than ideal.

The second mandrel in the background was made from a piece of the same axle.