Should there be any washers or distance pieces between the Dowty fork ends and the alloy brake castings on a 1947 FS or do they just clamp up tight ??? Thanks in advance.
The wheel spindle, fork legs, brake shoe carrier casting, inner hub and any other gubbins should be regarded as one piece when tightened up, only the wheel and brake drum should be free to rotate. That said the fork legs should not be strained inwards or outwards when the spindle nuts are tightened.
To be sure I think I’d let the air out, fully compress the forks and then take a reasonably accurate measurement, + or – 5 thou should do. Measure the spacing at full extension too, hopefully it will be very nearly the same, if not you are fully authorised to first beat your breast and then panic for in that case you are into quite another ball game!
If there is a big enough difference between the fork legs and the wheel hub width then you will need spacers. The most critical measurement, the “worst case” position, is the fully compressed one because in that position there is the least tollerance to misalignment, use that one if there is any doubt. I’d expect the wheel to be equally disposed between the legs but the Mk.I eyeball, a length of string and a correctly positioned rear wheel will get both wheels nicely in line.
If you need spacers and can’t make them, scribble the dimensions on a fag packet, (preferably a full one), and I’ll knock a couple out for you.
The “Dowty” forks fitted to Birmingham Scotts (they were Dowty converted to springs) employed the conventional telescopic fork system of clampling the wheel, bearings and brake plate all in one direction to one fork leg, and the other fork leg was free to float about, but then clamped around the wheel spindle having found the “neutral” position.
Are you saying early Scotts with Dowty forks had two clamping nuts either end of the wheel spindle same as early machines with girder forks????
Tis a good idea befor finally tightening up the wheel spindle nuts to “bounce” the machine up and down a few times (or wheel it into a wall to compress the suspension- thus “settling out” any slight mis-allignment.
There are no spacers on the brake plate assembly.The spindle is 17mm.
dia.with a 0.750 ins. dia.shoulder on the LH.end this passes through the
LH.fork leg LH. brake plate ,hub bearings ,RH. brake plate and screws
into the RH.fork leg. When the spindle is tightened the shoulder butts onto
the steel insert on the LH.plate and clamps the whole assembly to the RH. fork leg. First nip up the spindle then slacken half a turn apply the front brake, while the brake is on lock up the spindle this centralises the shoes
to the drums then as Stan said bounce the forks up and down a couple of
times to align the forks and tighten up the 5/16″ unf. bolt on the LH. fork
leg clamp and job done. If the hub bearings have been assembled correctly the wheel will rotate freely.
Best wishes Ted Robinson.