Saturday, April 9, 2022

Panther 1935 Model 50. 6. The Wheels

 The wheels were in a rusty condition but appeared to be sound. I dismantled the brakes and removed the bearings from both. The back wheel had several bent spokes one of which I managed to unscrew as a pattern. Central Wheel provided some replacements in butted 6 gauge steel zinc plated. I then had both wheels, the front brake plate and the speedo drive gear powder coated in silver.

Front wheel as received

Back wheel as received.

        The front wheel has a WM2 rim and 40 spokes as per Panther wheels but it doesn't look Panther to me although it may be earlier than those machines with which I am familiar.

Front wheel powder coated.

      It took a while to remove the bearings as the whole assembly seems rather unusual. There is loose half-inch diameter axle inside a sleeve which carries the bearings. These are taper rollers which face outwards, the cups being fitted last. Adjustment is provided by a sleeve threaded into the hub and this is held in place by a lock ring. I had to make a special tool to remove the sleeve. Grease is retained by felt washers, large steel washers and a circlip.

Front wheel bearings.
Top, axle, centre, lock ring, threaded sleeve, bearing cup,
taper rollers on inner sleeve
Bottom, felt seals, washers and circlip/

       The threads on the axle are also odd at 24 tpi on 1/2 inch diameter. I could find no standard reference for this and had to screw cut the nuts, something I find fairly difficult. Having taken ages to do that I though to check Tracy Tools website. They of course can supply taps and dies. Apparently the thread is UNS, Unified Special.

The brakes I had relined at Villiers Services. The shoes came back beautifully cleaned with bonded-on linings.

Front brake parts

Speedo drive gear, screws, plates and locknuts.

     The back wheel has a standard 1930s Panther rear hub but it is laced to a WM3 rim. No real problem. I can use either a 3.50 or a 4.00 tyre. To set up the wheel I needed to check the chain lines and to do that I had to start with the engine sprocket which is on a taper and not adjustable sideways. I have yet to build the engine but I did have an assembled crank so I put that into the cases and slid it between the engine plates. With a clutch basket and centre fitted to the mainshaft of the gearbox I could align the sprockets and make spacers to locate the gearbox laterally.

       With the rear wheel bearings and axle in place, and the rear sprocket fitted temporarily against some cush rubbers I could align the rear chain. Everything looked fine until I noticed that the rim is half an inch off centre. This is a real pain as I know that the spokes are not adjustable as most of the nipples are rusted tight. The wheel will need to be cut apart, new spokes sourced and the wheel rebuilt so back to Central Wheel for another set of spokes. One step forward, two back!

The rebuilt wheel ended up centred in the frame and this gave me a rolling chassis.


Rear wheel complete and centred



Front wheel.

Speedo drive, front wheel.


     The large speedo drive gear came attached to the front wheel and I found I had the gearbox in the cupboard.where it had lain for many years. This had a large fibre gear attached which gave the wrong gearing. I calculated that I needed a twelve tooth gear to give the right ratio having run the speedo head at a known speed in the lathe and noted the reading. I cut this from a piece of Tufnol, a similar material to the original gear and time will tell if it is man enough and if the gearing is about right. The mounting bracket was made up to fit a handy lug on the forks.

      I needed to press ahead with the engine but was stalled as the cam followers were badly worn. These had to be built up and reprofiled but this of course took time; all praise to our Mr.Fox. To keep on track I turned to the electrics which would originally been Miller. However  as with all things this machine I turned to what I had, generally Lucas stuff.

        I had a dynamo with the correct tapered shaft for the chain drive sprocket, cleaned and tested it and ran it up in the lathe whereupon it produced about 18 volts, so all well there. A Lucas CVC unit with regulator and cut-out also proved to be functional and when connected to the dynamo, an ammeter and a headlamp produced a good stable output at 7.8 volts. Hopefully it will perform similarly on the bike. I made up a loom and checked out a Klaxon horn I had. This proved to be a bit reluctant but eventually emitted a satisfying squawk. 

The new pattern parts I needed for the lights proved to be a real problem and took ages to solve. The new eight inch headlamp takes a prefocus bulb and I found that the bulb holder fitted to the reflector could rotated which messes up the dip. Also the pattern Lucas prefocus bulbs were crap. I bought a box of ten and they all have the same fault. the ring which locates them in the holder is a press fit but it is not tight and can rotate on the bulb which means the terminals in the connector miss those on the bulb. Also some of these rings are slack enough that pushing on the connector against the springs in the terminals can push the bulb into the lamp. I soldered the ring in place once I realised what was going on but still could not get a connection. The problem only revealed itself when one of the terminals in the connector fell off and I saw that it was crimped over the insulation! How the Chinese got a rocket into space is beyond me!

      I then spent ages making a rear lamp based on the Miller two lens effort. Finally everything works off the battery, lights, stoplight, and horn. I'm sure some of this pattern electrical stuff will self destruct once the engine is running, so that is the next step.

Rear lamp based on a Miller design.




Panther 1935 Model 50. 7. The Engine

 As noted before this 500cc engine was incomplete and badly mauled. The crankcases and rocker box are the only parts I can reuse and the for...