by Adam_Winstone » Thu Dec 04, 2014 6:44 pm
The disc links allow for a much better interaction with the hub backplate. You should consider that even the drum hub fitted to SI and SII TV175s made an expensive (if you consider that they had to make 2 versions) change to the backplate, corresponding to the incorporation of dampers. You then need to think that there have been a number of cases where the early drum backplate has sheared the link stop off and resulted in the bike locking up the front wheels on the cables (sometimes they give, other times they don't). Without doubt, the additional loading of dampers and a decent motor deserve the more secure fitting offered by the sturdy locking nut/stud of the disc (or early TV175 drum) links. Yes the later drum was beefed-up to stop this from happening, however, better brakes and bigger motors mean that even the beefed-up later drum backplate is on its limits.
If I was fitting a hydraulic disc then I wouldn't even consider the drum type link version as I've had an early backplate shear on a cable drum, as has a fellow clubmate that lives in my county (so 2 examples close to home!).
Adam