2021 Trek Marlin 7
The 2021 Trek Marlin 7 is an immensely popular bike in the Trek lineup. The 2021 Trek Marlin 7 is among the most affordable aluminum mountain bikes and it’s a great entry level bike for those who are just getting started.
This particular model has a geometry that is a cross between an XC bike and one with a more upright position which makes it comfortable to ride on those long bikepacking trips.
The frame of the Trek Marlin 7 is made from what Trek calls their Alpha Silver Aluminum, although it’s not the same aluminum from the Excalibur series, it’s still a great material. Using this slightly lower grade aluminum, Trek has found a way to keep the price point low by still allowing for features like a threaded bottom bracket and an integrated headset. They even welded up mounts for a rear rack!
On the XS and S size frames you’ll find a slight bend in the top tube to allow for a bit more stand over clearance for shorter riders but the size mediums and larger will have a straight top tube. Another great feature of the different frame sizes is that the smaller frames get 27.5-inch wheels while the larger sizes get the 29er, something I feel more manufactures should adopt.
The wheels are wrapped with the Bontrager XR2 Comp tires sporting a width of 2.2 inches. Referring to the medium size frame, the 2021 Trek Marlin 7 has a standard geometry chart for an entry level mountain bike. Chainstays are 438 millimeters, a headtube angle of 69 degrees, and a seat tube angle of 71.9 degrees.
The stack and reach dimensions are what give this Marlin 7 the upright riding position. The stack is a respectable 602mm and the reach is 418mm.
The front fork is the Judy from RockShox and allows for 100mm of travel which would most likely be sufficient for bikepacking on most types of terrain. The Judy for also has a turnkey lockout feature so you can make adjustments on the go when riding mixed terrain.
The drivetrain for the 2021 Trek Marlin 7 is a 1×10 setup from Shimano. You get the Shimano Deore M5120 long cage rear derailleur that is matched to the 11t-46t M4100 cassette. The tiny 28t front chainring is turned by an FSA Alpha Drive crankset sporting a 170mm arm length on the smaller frame sizes and a 175mm crankarm length for the medium and larger frames.
A nice surprise from this entry level 2021 Trek Marlin 7 are the Shimano MT-200 hydraulic brakes. Weighing in at 29lbs this aluminum frame mountain bike is a bit on the heavy side though but would make for a great entry level mountain bike as well as a great tool for some weekend bikepacking adventures.
