An arduous day today but it was ultimately almost a success. Almost, because I did not finish what I started but the task to manufacture the forks to engage with the bridge on the frame was difficult and but for further electrical problems would have got done.
It started badly with my Dremel replacement going “phut” and refusing to turn more than one revolution each time it was turned on and finished with my heat gun going “phut”. Both are terminal cases.
I had to spend about an hour and a half working out the positioning of the seat and the shape of the hook, First I established a datum on the frame and measured everything from that point or rather the line drawn on the frame to correspond with the bottom edge of the seat then I cut a cardboard template which looked OK when I offered it up. The first attempt on the LH side hook for which I used the 10mm nylon as suggested by Utopia turned out to be too long by about 20mm but was relatively easily modified and is now just about a perfect fit.
The RH one was more difficult as the plate bonded into the seat has the threaded holes too far inboard by about 10mm and in consequence the hook clashes with the rear suspension rocker casting. At this point I had 4 options:
a) remake the plate already bonded to the seat – too much work
b) make a fillet that bolts to the existing holes and bolt the hook onto the outside of it – may still come into play but would be an untidy way to do it
c) drill and tap new holes in the plate – not the best position because the plate is only 3mm thick aluminium and I do not see the threads holding in the long term
d) put an S bend in the nylon hook to allow clearance on the suspension rocker hence the heat gun and why progress stopped until tomorrow