Thanks MrC.
One of the inherent problems with the pannier racks (IMHO) is that they are aesthetically pleasing (in either black or chrome) but quite weak structurally. This was strengthened by a (home) welded gusset in the lower front join and a bar across the lower back.
As we tended to carry everything I found that the center of gravity in the panniers was in line with the rear wheel or behind it which would have contributed to the pannier racks flexing. Generally when travelling solo and all this weight towards the rear of the bike any pothole tends to lighten the front end causing a little shake of the handlebars. One way to prevent this was to jack up the rear shocky but when combined with the plastic frame never really gave the R65 a good reputation down here.
I have had the bike start to wallow in big sweepers when cranked over above the speed limit when fully loaded. Usually the result of a small bump and any idea of backing off the throttle was to be avoided. The smart people were usually on a R100RS or R80G/S.
Once I manufactured a rack for a fuel tank over the back seat. It was from a lawn mower and increased my range out to about 500km. Pre-digital photo era but I still have the rack. I also scratch built a pair of engine pot racks but never really found them useful over long distance, apart from drying racks for wet gloves.
Anyway the R65 was my first long distance tourer and coped reasonably well to the abuse that was dished out to it.
