Originally Posted by Phil from VA
I have Julies on my single- don't waste your money. They are not of equal build quality. My Gustav's have zero drag. I think the drag issue was fixed 2 or 3 years ago.
Can't comment on the Julie brakes that came on your single but would otherwise agree that the Julie is clearly not as robust in appearance as the Gustav. However, I've taken a test ride on a tandem fitted with the Julies and was impressed and am otherwise passing along what someone who sells Hope, Grimeca, Magura, Avid and Formula brakes for tandems has observed and received as feedback from satisfied customers who purchased the Julie Tandem and Julie Tandem Plus models for their off-road tandems. Certainly not as definitive as an actual owner's report would be so take it for what it's worth.
As for the Gustav M's and drag, I'll just paste-in what Magura has on their Web site:
"Note: with the floating calliper system of a Gustav M a slight drag between rotor and pads is absolutely normal. Correct installation will reduce this to a strict minimum. The Gustav M is by the way the only disc brake on the market for which the manufacturer has given OFFICIALLY green light for tandem use."
http://www.magura.de/english/bremsen/gustavm.htm
This is consistent with what I experienced in '99 and what I've seen as recently as two weeks ago on an '03 Ventana being built-up with '03 Gustav's. Floating calipers, they are what they are but they work quite well.