...the nice front rack is way more rack for the same price tag,have you seen the bag of fittings for the nice front rack?
<nods> Agreed, Bill, but had to sell mine on,due to lateral instability. The brackets are a delight for vertical loading, but proved to be too thin to support a heavy load without swaying unduly for me. I seem to be alone in this, but it happened and made it unsuitable for my needs.
For that matter, the Surly Rear rack proved the least resistant to lateral loads in my instrumented tests. The culprit was the squashed-tube lower and upper mounts. Capturing the ends between large-diameter washers definitely increased resistance to lateral deflection. Similarly, brazing up new mounts with machined spools at the bottom helped even more.
The Thorn EXP rear rack had the greatest lateral stiffness of the four racks in my tests, then a Tubus Logo Evo followed very closely by a Cargo Evo and then the Surly Nice Rack (Rear).
For testing, I mounted the racks in turn to a single bicycle with very beefy seatstays and chainstays, then used a digital luggage scale to apply a traction side load to the upper-rear corner of each rack (in each case the same distance from the dropout mount so the moment-arms were identical) and noted the lateral deflection of each in mm. I then repeated the tests tugging on the corner of the top deck. I wish I had kept the precise figures ready to hand. I still have them, but misplaced. Between the Tubii, the Logo Evo was stiffer than the Cargo at the lowered bag mounts (due to a shorter span of tubing). the Cargo Evo had better less lateral movement than the Logo Evo at the top deck, thanks to the more angular plan-form of the last strut, which had better bracing angles.
I borrowed a friend's Tubus Cargo Classic to compare and found it marginally more flexy than the Evo version. The Classic uses a lower mounting tang made of stamped sheet steel, while the Evo series uses an investment cast 3-D mount with recessed well for the mounting bolt, but at the expense of a second mounting point for rear mudguard stays.
I kept the rear Surly for mounting to the tandem because I already had the rack and the tandem is built with an unusual design that precludes ready mounting of most rear racks. As it was, I had to trim a bit of the rack tubing at the lower forward flare to gain adequate clearance (No longer in production, this bike, has seatstays and chainstays that form a continuous, very large-diameter "hoop" and there is minimal clearance -- ~1mm -- between a vertical rack mount and the seat-chainstays). For that application the Surly Nice Rack (Rear) is about the only ready-made option. I brazed my own racks from cro-moly steel for my folder, but it is a time-consuming operation. Lots of bends and miters to make, but quick to braze once you have built a fixture to hold all the tubes in alignment.
Best,
Dan.
