Originally Posted by
Duragrouch
I read the article. I'm not sure lowrider rear now means the same as what is indicated as tested. My rear rack has a lower tier for the panniers that is maybe 2" or slightly more below the top platform, and this greatly improves putting the trunk bag on and off, as well as less interference between the trunk side pockets and the rear pannier top flap/pocket. This is a full-size rear rack, mounted on a 20" wheel bike so sits about 3" lower overall, and thus the panniers about 5" lower overall. The rack platform is about 5" higher than it needs to be for tire clearance, but this helps keep the big panniers high enough to clear tall curbs when pedaling near them, but it also means the trunk bag (heavy, full of tools and spares) sits high for the bike. The rear panniers are both completely behind the rear axle, to provide pedaling heel clearance. This sounds contrary to Blackburn's recommendations, but this is a stable setup, even when heavily loaded. Ironically, it's a Blackburn rack, TRX-2, I chose it specifically for the far-aft pannier position, and lower tier setup. However, in the article, Blackburn doesn't show the lowrider rear rack, just the standard rear rack (centered over the axle), and mentions "frame whip" with the panniers that far aft, but that may be due to insufficient rack lateral rigidity and not the mass position with respect to the bike overall. My rear rack and stays are rigid laterally. My front panniers hang from a "sixer" front brakepost rack, and thus, due to the small (20" wheel) fork length, the panniers end up being "lowriders" even without a proper lowrider rack. Again, stable setup.
The point of the article was assessing different locations for pannier center of gravity placement with the limitation of adequate heel clearance, and how that may impact handling. They compared a very high center of gravity where the bottom of the pannier was far above the axle against another setup with the center of gravity at the axle height.
Both setups that were compared are not really practical by current standards. Generally today the bottoms of the panniers are at about axle height, or higher. Nobody puts panniers so low that the pannier could impair derailleur function. Current racks and panniers are designed to be in between those two extremes that they described. (I am not considering the small bike packing racks for this discussion.)
And their testing was done on full size bikes in an era where almost all bikes were steel framed with smaller diameter tubing that made the frames quite flexible compared to today standards for tubing diameter. My rando bike has a frame very much like those older frames, and when I have a bag or two of groceries on that rear rack, it really impairs the handling, which is why that frame was never sold as a good frame for load carrying.
And they certainly are not practical to compare to your small wheel folding bike, which I assume has an aluminum frame and has all the weight well aft of the rear axle.