[QUOTE=Schwinnsta;23180221]
Originally Posted by
Duragrouch
Most rear racks are centered over the rear axle, so nearly all the payload weight goes there, the rack stays just hold it from tipping over forward or back, very little load, if there was, most flat stays would buckle, especially since most people curve the stays (I don't).
Yes, but the stays take the load to frame and dropouts. Most of the load does go to the rear wheel as you say, but the racks front stays carry a portion of the load and most of that too goes to the rear wheel. The rack stays must carry the load, or what else holds it up? And if the rack stays don't buckle, then they are structurally adequate.
Our comments crossed while each other were writing. Please see my additional comments in my last post.
The rack stays don't take load to the dropouts, but to the seatstay braze-on eyelets, and I engineered things so the tension load there is small, as those welds are not large. I could replace my rack stays with cooking twine and the rack wouldn't move when static. Only under hard braking, might the rack stays take any compression load, and it would still be small, especially if I place the most dense things at the bottom of the panniers, to reduce the vertical moment arm. I also did not attach the rack stays at the normal forwardmost position on top of the rack, but went lower with structural clamps (seen in folded pic), to get a more favorable force angle on the rack, to reduce loads further.