Mountain Bike Action Bike Test: KHS Sixfifty 6555+E Trail Bike


e-specific but designed for high rigidity and lightweight, and a SunRace cassette that makes for a 1×11 setup that never runs out of useful range. The derailleur hanger is replaceable.

“It climbed up the hill like a sprightly mountain goat!”


A relatively long-travel, 100mm dropper seatpost gets the seat out of your way for descents and technical stuff and raises back up for the climbs. Although, we found this one to be very slow in actuating. It’s been better than getting off the bike and manually dropping/raising the seat, but not as instantaneous as we’d like. This is a better setup for when you know the trail like the back of your hand and can anticipate the adjustment a few seconds ahead.


There are a lot of e-mountain bikes using the Shimano E8000 motor. It’s a good choice for many companies because it’s small, light and powerful, and Shimano is very flexible about battery choices. KHS has used a standard 504 Wh battery in the 6555+E.

The front end of the KHS is very forgiving on trails.

We made a big mistake by trying to tweak the settings for the E8000 via the E-Tube app in the field. Turns out that the bike needed a firmware update, and on a cellular connection, it wasn’t about to happen. We canceled the firmware update and rode the software stock. When we got back to the office, it was handled quickly via Wi-Fi. Make sure you check that before you leave to see if there are any updates, or you’ll regret it when you get to your trail. As always, we tweaked the Trail mode setting to make it higher and closer to the middle range. Every E8000 motor we’ve ridden has needed this.

While we’re on the subject of the app, in case our friends at Shimano happen to be reading this, the user interface leaves something to be desired. It wasn’t clear that we have to be in the app to connect, not first connecting via the phone’s Bluetooth settings. Once in there, it’s hard to tell how to change the settings. We’re familiar enough now after riding dozens of bikes with E8000 systems, but the average consumer who is using one for the first time may get stuck.


The 6555+ is a solid, trail-oriented bike with…

You might also like