I have just made up a set of these dampers and one of the things I though I would do is to make the rods longer so as not to have to put so much oil in to cover the valve with the forks fully extended. But I soon found out that you can't, as when I checked to see if the valve would go right down (e.g. forks fully down) the valve hit on some thing, so had to make the rods so as the overall length was as the drawing, 16 1/4", I did creep a bit I made mine 16 3/8" that gave me about 5" of movement before it would bottom out, not sure just how much movement there is as I did not check that when I did the forks up some time ago, but I suspect that it is about 4" some one might be able to correct me on that?
One of the things that concerns me is the fact that the oil comes so far up the stanchion to cover the valve it leaves not much space for the oil when the forks bottoms out, I put 260ML of oil in to cover the valve, adding a bit at a time (Fork oil 10W)and the last bit took only about 20ML to raise the oil level about 3"! (without the valve in there) so that makes me think that when the forks bottom out there can't be much space left at the top of the stanchion for the displacement of the oil, the pressure must be very high at the bottom of it travel, what do you think?
Haven't taken it for a test run yet, its been a bit wet and I'm allergic to water! but on all accounts it's makes a big difference.
Peter