Originally Posted by
DropBarFan
I hadn't realized that, does seem a bit odd to combine alu fork & steel frame. The expedition-style front rack is a bit of overkill IMO, they're very heavy. Trek should break the mold & make the 520 all-aluminum with suspension seat-post & fork. Germans/Dutch make many such bikes (flat-bar), Trek could carve out a new niche with a drop-bar version.
Trek has clearly abandoned the traditional touring bike with the 2019 520. I suspect the LHT/DT and other competition ("adventure" bikes) forced the transition to a trendier bike which appeals more to younger consumer demographic. If they added suspension post and fork it would probably make it a bit too much like the 920 and 1120. Yes, the 520 front rack probably weighs as much as 3 or even 4 Tubus Tara lowrider racks.
WRT ThruSkew, a 9x100mm QR equipped
Shimano HB-M475 hub with 5mm skewer rod cannot be readily converted to a 10mm through-axle mount. Trek has seemingly adapted a QR skewer to TA mounting, which
looks like TA without the apparent strength and retention advantage of true TA. ThruSkew is likely no more secure than QR + lawyer-lips on the traditional steel QR-mount touring fork. Also, Alivio/M475 is a pretty cheap choice of hubs for a fairly critical component on a bike that will cost ~$1700 with sales tax. Surly has specified XT 756 hubs (three component group levels higher) on the Disc Trucker Complete bike since it's introduction in 2012.
The 2019 520 replaces Dura Ace barcons with Sora brifters, mated to TRP Spyre brake calipers (short cable pull). Disc Trucker uses Microshift index/friction barend shift levers and Avid BB7 MTB/long pull brake calipers, controlled by Tektro 520 levers. The advantage of Surly's approach is that the index/friction shifter is more versatile for use with MTB cassettes, cranksets and deraileurs, and the MTB calipers permit LBS/owner to swap to MTB-style handlebar without added cost for brake swap.