Trek Slash+ 9.7 SLX/XT Electric Mountain Bike Review: Oh So Quiet

To take up the slack, Trek routed the chain through not one but two idler pulleys. The result looks a little like a three-ring circus near the chain ring, but that added idler pulley allows the derailleur to do what it’s supposed to do, which is keep the bike shifting well.

Love at First Ride

I loved this bike off the bat because it felt nimble and fast and gave me the confidence to sail over a few steep lines that I normally avoid. On trail, I never felt the need to ride beyond level-two power, even on climbs, which added to its acoustic feel. The only place I could have used more of a boost was when riding home straight uphill on city street with a 13 percent grade.

After multiple subsequent tests, I felt the same joy with one caveat: There was a consistent and nagging rattle that sounded like a loose wheel, but I could never isolate the source of the noise, which likely indicates that it was internal and perhaps coming from the battery or a cable rattling in the downtube.

To give the Slash+ a more robust test, I passed it on to Samuel Hayden, a former collegiate gravity rider at Fort Lewis College in Durango, Colorado. After a 20-mile ride in mostly turbo mode on the double blacks of Piedmont (stuff I never ride), Hayden returned with a huge grin and with more than 65 percent battery power left in the tank.

On its weight and handling, Hayden reported that the Slash+ melded substantial power with a surprising lightweight build, noting it had a solid and reassuring connection with the trail and maintained stable flight during jumps.

His only major gripe? The 9.7 lacks a SRAM transmission, which tends to be more reliable for e-MTBs. But that problem is easily solvable, if you have an extra $4,000 on hand, by upgrading to the Slash+ 9.9 XO AXS T-Type.