Joined: Jul 2015
Posts: 7,501
Likes: 3,302
From: NW Oregon
Bikes: 1982 Trek 930R Custom, '91 Diamondback Ascent w/ XT, XTR updates, Fuji Team Pro CF road flyer, Specialized Sirrus Gravel Convert, '09 Comencal Meta 5.5 XC, '02 Marin MBX500, '84 Gitane Criterium bike
your bike has horizontal dropouts... is the QR lever steel or aluminum? Horizontal dropouts require the old steel quick releases... the aluminum, "external cam" type QR's will slip for sure under heavy load!
and if the wheel/axle is a replacement, then there is a chance that the QR is bottoming out on the SPRINGS, not allowing clamping on the plain steel dropouts!
being an older bike, there is also the chance that the rear wheel is now wider than the original, and that the frame was not properly realigned to fit the wider wheel... the dropouts may now be at an improper angle to the hub, which can also cause what you mention......
Last edited by maddog34; 11-04-17 at 10:24 AM.