hi all, I have a query about the front riders footrest that hopefully someone can answer.
the bike I'm rebuilding has just been boxes of bits for decades, the bike was stripped nearly 40 yrs ago for rebuild and the frame got nicked along with obvious things like footrests, electrics etc so I have been gradually getting the right bits together again.
My question relates to the LH thread stud which holds the left footrest. On the earliest frames the stud was just plain LH thread both ends, it screwed into the tapered boss in the frame and just had a nut and washer to clamp the footrest onto the taper as it showed on my original parts catalogue.
Please correct me if I am wrong in my assumptions here. it seems that after the first year BSA introduced a stud with a spline (4817?) so stud still screws into frame lug with spline sitting at the end of the taper. The footrest has a flat machined into one side on the outer face A splined washer with one flat face slips over the splines, engages with the flat recess on the footrest and the clamping nut locks the rest onto the taper with the splined washer stopping the footrest rotating on the taper.
I initially got a plain LH thread stud which works but is obviously a design weakness. Having looked at some different sites the later stud seems to have a short thread at on end, a splined section then a longer thread at the other end. a later parts catalogue shows in the exploded view the short section seems to be oriented toward the frame so short thread into frame lug then unnecessarily long thread sticking out beyond spline for washer, plain washer and nut which seems a bit weird as I would have expected the long thread to go into the frame lug for max purchase.
What has further confused me is that Draganfly list the stud, 4817 and their illustration is of a stud which is equally long either side of the spline and they seem to be saying that 4817 is a shortened version of 4819 which seems to be for a B40.
So my question is, for a 61 bike, which I have now got the correct fotrest for with the notch for a splined washer, should the stud have a shorter thread on the outer end and a longer thread into the frame or should it be the design with an equal length thread either end of the spline (and does that leave lots of thread sticking out beyond the nut)>
if anyone knows the length of the thread into the frame boss it would be helpful, my frame had the stud snapped off flush and the first 3/8" of the thread was a little damaged getting the bit out so it would be good to know if the correct stud will safely engage in the undamaged threads.