That's what I first thought and with standard rearsets and clevis fitting there may be just enough play there to get the required adjustment.Adjustment is normally done as below by undoing the lock nut and then turning the push rod:-
With the Harris rearsets the master sits higher up requiring a longer threaded bar/pushrod ideally to reach the pedal lever point. As it happens the rose joint gives a bit more length than with the clevis fitting and more room for adjustability. One should be able to loosen the two said nuts and spin the threaded bar inside of the rose joint to adjust the height without disconnecting the rose completely. But seeing as the rose joint sits higher up along the bar with the nuts almost touching there is little room to get in there and spin the rod.
I don't think the top lock nut gives much adjustment from that end. IIRC when I fitted my rearsets I was intending on replacing the pushrod with a longer bit of threaded bar. I ended up peeling back the rubber boot and trying to work out how to remove the pushrod only to find out it does not thread in or out as I thought and the end of the threaded bar is a flared nodule. If you know what I mean
and just spins around inside the orifice once past a point. The top locknut basically locks it off to stop it from spinning and stiffens it up so it don't flop from side to side and wobble about.If I want to adjust the pedal height I simply undo the lower locknut, Undo the rose at the pedal, spin it a few turns up or down the bar. There's plenty of threaded bar inside the rose joint so loads to play with. Obviously the more threaded on it is the more secure it is so I wouldn't un-thread it say..... more than around the half way mark. And don't forget the locknut.
(:-})
I get it now 
