Hi Carl,
Yes I realised they changed (that year?), however, I have seen something written that they were still fitting the older type forks through 1920 until they were used up? Added to this, I want to build the bike in 'TT Rep' fashion, based on the pre-war TT bike (1912/13/14 era), and they are more correct for this spec than the post '20 type. I have seen earlier forks with both straight and curved side links, not sure which were fitted for which years or models? (still got a lot to learn about Douglas's - but that's half the fun!).
Incidentally, I stripped them this weekend for a trial fitting - what a lovely time warp, they look like they have not been used or stripped for very many years. As well as looking to have the original castellated nuts, I also found what looked to be the original wasted fork spindles with 'flats' which I assume was to aid the flow of grease. Not sure they are good enough to re-use though, will wait until I refurbish. the forks even have 3 of the 4 original grease nipples, very dinky and different from modern ones - will try to carefully clean these up as they have a few knocks
Incidentally, for anyone restoring a set of these type of forks - as well as traces of nickel on the side arms there was also traces on both the bottom yoke (which surprised me) and the top yoke.
Another very interesting feature was the bolt/pin for clamping top yoke to bottom yoke spindle. It has a mushroom head - but is drilled just under the head, which I assume is to hold wire that secures it into the corresponding slot in the top yoke, interesting. On later bikes I restore I normally make up new bolts if less than perfect, but will try to save as many as practical on this.
This weekend I also cleaned up and checked the little 2 speed gearbox (which I believe is 1920 from the number). I made up new (stainless) studs and top nuts. I chased the gearbox threads before fitting, but the casing, threads and condition look pretty good. I might have made studs fractionally too long, but want to fit thick spacer washers top and bottom to ensure secure clamping to frame without risk of flex.
Incidentally - while cleaning I found a small 'P' stamped on the side of one of the geabox lugs, does anyone know what this stands for, if anything? (the main gearbox number is preceded 'LG').
Final thing - I do have a tank top gate for the bike, but it is the later 3-speed gate, if anyone has the 2 speed top gate (which I believe had 'Low'/'High' cast on it) surplus for purchase, I would be very interested.
Cheers
Paul Norman
www.racingvincent.co.uk