With the teater-totter rear suspension you guys will need to keep the track tensioned properly. If you don't, the clips will miss the rail tips and try to derail. What you are hearing is the guide clips hitting the bottom of the hyfax instead of sliding down the sides. That is why it goes away when you tension it properly, it takes the rotationally induced belly in the track out coming off the drivers.
This is plausible however when on a flat, straight, downhill the twist should be minimal, and as the design allows the rear to pivot, the front is still held in place by the two piece h arm, which would transfer the rear "twist" to the more up and down motion at the tip of the rails. The noise does not seem to change from a freewheel down hill to one applying the brake, or under clutch engagement and compression. I noticed this on the first hill I went down after only 10 miles, I don't think the track would have stretched much after that short a distance. It does sound like a "normal" ice build up, but after inspecting the tunnel, and not finding any, it's something else. Under power, the top of the track is pulled tight as we are sort of pushing the track under the sled. During braking, or downhill, the bottom of the track is tight, as we are dragging it against the drivers, and the top is allowed to float if you will. Is it possible that the taller lug is hitting the tunnel as it's being loose on the top, and sort of being flipped into it? Which would indicate a tighter adjustment should correct it. I know most of us like to run things on the way loose side, and perhaps with the taller lug, this will not be possible. Did the in-season versions have the shorter lug? If so are they seeing the same noise?? Wow, that's more thinking than I normally doo on a Monday night. I figured on running it up in the shop to look for the noise, however not having the ability to maintain the same suspension loading on the rack may not produce the noise. ???? Hum....
Yella..:face-icon-small-dis
