All about Bosch
Bosch have been making eBike systems for over ten years. Their premier mountain bike motor system is the Performance Line CX motor (Gen 4), which provides 85Nm of torque, and has four modes of assistance. Bosch have a supporting app called Bosch eBike Connect, however the app doesn’t allow for motor customisation like the Shimano and Specialized apps. This means you’re stuck with the standard four modes of assistance. Luckily these modes are pretty good from the off!
The first mode on offer is the ubiquitous Eco mode. Eco mode is as the name suggests, economical. This mode offers 50 percent additional assistance on top of what the rider is putting in. How this feels in practice compared to a regular bike is like you’ve got really good legs that day. Eco mode definitely allows you to ride with riders on regular bikes, but it would be nice to be able to tune this mode to offer even less assistance on mixed rides.
The next mode is Tour mode. Tour mode offers an additional 120 percent of power. It’s a noticeable step up from Eco, however in my experience it’s my least used mode on a Bosch motor. The reason for this is that if I’m needing to reserve my battery, I’ll use Eco, and the higher assistance modes are better in just about every other situation.
EMTB is the third mode offered by Bosch, and this mode is the way to go for when you’re riding on the dirt if you want to get the most out of your eMTB. EMTB mode offers progressive assistance from 120 percent (essentially Tour mode) all the way up to the maximum 300 percent assistance offered by Turbo mode.
On the trail EMTB mode works fantastically. When you’re soft pedalling to maintain traction on a tricky climb, the motor doesn’t spin you out like it would in Turbo mode. If you’re putting down the watts on a flat section of trail though, the motor gives you everything it’s got.
On top of the variable assistance, EMTB mode makes use of Bosch’s 85Nm of torque with a feature called Extended Boost. Extended Boost works by keeping the motor engaged for a fraction of a second longer after you’ve put a crank in. This works wonders on technical climbs where you’re half cranking to get up and over obstacles by pulling you over the top.
The last mode is Turbo, which offers a laughable 300 percent assistance on top of what you’re putting in. Whilst it’s fun to whizz up steep roads at 25 kilometres per hour, on the trail that amount of unrestrained power can be really dangerous, which makes EMTB mode a much better choice once you’re off the tarmac.
Overall, Bosch’s four modes of assistance offer a broad spread of options. Whilst these four modes don’t leave me wanting much more, it would be nice to see Bosch’s app give you the ability to tinker with their modes like Shimano and Specialized.