The Tinware

     As I've mentioned before the tinware, that is mudguards, headlamp, rear chainguard, toolboxes and fuel tank, was in a fairly poor state. The front mudguard was a non-Panther guard, holed with rust and chopped up when we loaded the van. The rear mudguard was a deeply valanced Panther type but upon dismantling it turned out to be a Panther front guard with a rusty extension bolted on to make up the length. The rear chainguard was the correct one although it had been repaired with the lower section replaced and fixed with pop-rivets. I decided to reuse this as is, just clean and paint. The toolboxes had both lost their lower third to the rust worm and were put to one side for later consideration. The headlamp was rusty on its lower half but recoverable, the fuel tank was beyond salvation. The rear number plate and the seat pan were both rusty and a little moth-eaten but usable.


Remains of the front guard.

Rear mudguard as taken off.

The fuel tank beyond repair



Seat, foam, pan and cover

       The mudguards were stripped of paint and the numerous drilled holes and the odd rusted thin area were welded up and filled. The replacement back mudguard from my shed appears to be from a BSA as it had a recess at the bottom for the swinging arm. This was dressed out (for which read hit with a large hammer!) All the parts were rubbed down, sprayed with a primer filler then a couple of coats of top coat. I used a cutting compound and polish on this for a decent finish but went through to the primer on the rear mudguard so had to start again on that. Finish is not concours but looks adequate to me so the parts were bolted to the frame.

 

Front mudguard and headlamp shell.

Rear mudguard, number plate and chainguard.

Seat pan.

     The replacement fuel tank is on its way and there is still work to do on the toolboxes but I shall turn to the engine next after a longish break during which I hope to lace up some wheels..

The Mysterious Trail.

     This Panther came with a set of leading link forks which look to be home made as the welding is pretty lumpy. This type of fork has been likened to fitting power steering to a motorcycle combination. Unfortunately in this case the pivot blocks on the leading link arm had completely rusted away so I had no idea where they should be. This meant a little research into the arcane laws of TRAIL.

     The contact point of the front wheel of a motorcycle should trail behind the steering axis where it meets the ground to give a castor action. That is the wheel will return naturally to the straight ahead position after a turn, thus a bicycle can be ridden 'hands off' due to the trail of the wheel. This is positive trail, a lot of which makes for a stable machine at high speed but a sluggish one at low speed. Negative trail with the tyre contact in front of the steering axis leads to an unstable and very dangerous machine as the wheel wants to return to positive trail. Try pushing a bike backwards 'hands off.
 

Trail for the late Panther fork (Dimensions are approximate.)

     
      On a motorcycle combination a lot of trail makes for very heavy steering giving a tiring ride with a lot of hard work so the trail should be reduced but remain positive. The front wheel needs to be moved forwards to reduce trail and backwards to increase it. P&M did this on their own forks and on Dowty forks by offsetting the axle from the centreline of the stanchion. Reversing the fork would change the trail but to a fairly minimal degree. I've ridden Panthers solo with the trail set in both positions, it seems to make little difference. Note that with late Panther forks you need to change the sliders to the other side so for solo use the brake is on the left hand side of the machine. Generally the bikes left the factory set for sidecar trail.

      I set about measuring the trail on my bikes, not easy when it's all together. The late heavyweight Panther fork gives trails of 3.7" sidecar and 5.1" solo, Dowty forks, 2.2" and 3". My Douglas Dragonfly and Panther 10/3 have Earles forks, a form of leading link, with solo trail only 4" and 3.5" respectively. All measurements are approximate. Apparently Harleys have trail of 6"! The old bible 'Motorcycles and how to manage them,' suggests a positive trail of 1.5 inches for a sidecar outfit so I intend to aim for that but provide several mounting points to give an option for solo use. Drillings are provided for trails of 1.5”, 3” and 4”.
 

Setting out of leading links (Dimensions approximate.)


      First I assembled the headstock bearings and fitted the yokes to the frame. The compound, braced, fork leg pair was put into the yokes, a tricky job as both legs have to go in together. I used two lengths of studding, nuts and washers to draw them into place. I put the rear wheel and a shock absorber into the swinging arm temporarily and adjusted the scissor table to give the correct ride height at the front using a dimension obtained from my M120.

      A length of steel rod was passed through the crown nut and down the headstock stem to touch the bench. It was centralised in the bottom yoke by a drilled wine cork, (of course the wine had to be drunk first!) This gave the position of the steering axis at road level and the bench was marked accordingly.

Steel rod giving steering axis.

       I fitted the original front shocks fully extended to their lugs and jacked the leading link up to contact my new saddles. This gave the original setting out more or less and gave a trail of about 2.5 inches. To move the wheel forward to a trail of 1.5 inches I had to disconnect the shocks to avoid the angle of the link changing. For solo trail the wheel is moved backwards so that the shocks are then too long when fitted between the welded lugs.

Original set up. approximate. (Saddles not fixed at this stage.)

       My main concern, apart from whether the bike handles ok or not, is that in the maximum trail position the back of the link may foul the exhaust pipe. I've taken a check dimension of my other heavyweight and it is going to be tight.
        The prepared saddles and bolts were tacked in position to the link and the whole assembly was fitted to the fork legs to check the setting out before they were fully welded in place. The welding was done professionally as I don't trust my own; a failure here is not to be contemplated.
 

Saddles located and tacked in place.

       As mentioned  above this setting out is different to that originally fitted so the shock absorbers will not fit between the lugs provided; these are welded to the fork legs and the link. The top ones were cut off and some sidecar clamps were prepared with new bolts and shims to provide adjustable top fittings to the shocks. Time will tell if the trail is correct!



Upper clamp fittings

       The shocks were cleaned up and painted and the springs plated. the lower rubbers looked ok but the upper ones were replaced.

Front shocks cleaned up and plated.

         The fork was assembled using new stainless bolts and self-locking nuts. I have checked the fit of the mudguard and it is clear that the setting for maximum (solo) trail will need to have a different or modified mudguard, if indeed the rear of the fork will clear the exhaust pipe. I used the central hole for assembly as I shall run the bike solo at first while I prepare the sidecar chassis. The first ride could be quite interesting!

Final assembly, the red wheel is temporary.

Ready for a mudguard and wheel.

       Now I need to sort the tinware and the wheels.