Anyone build a DIY range extender for an Bosch Performance SX maybe the same like CX Gen 5?

[Markus_W]

Hello, I'm thinking to buy a bike with Bosch performance SX Motor, but only when it's possible to build a DIY range extender.

For the CX Gen 4 I think there is no issue, but I haven't seen a SX oder CX Gen 5 build.

Thanks Markus

 

[Greg Watts]

Hello, I'm thinking to buy a bike with Bosch performance SX Motor, but only when it's possible to build a DIY range extender. For the CX Gen 4 I think there is no issue, but I haven't seen a SX oder CX Gen 5 build. Thanks Markus

Officially, yes - practically, it's complicated. There's a real difference between "Bosch built a range extender for this motor" and "you can actually bolt one onto your bike."

The official route (PowerMore 250): This one was actually purpose-built for the SX system - the Powermore battery was developed for the new Bosch SX system, specifically for the Bosch Performance Line SX motor and for bikes with this motor. It also works with CX Gen 5 - Bosch's newer 600Wh and 800Wh PowerTubes both are capable of being paired with the PowerMore 250 range extender, so regardless of which size battery comes fitted in your e-MTB, you have the option of increasing capacity. On a CX Gen 5 bike that gets you towards 1050Wh combined, which lines up with what we've got on file for bikes like the Santa Cruz Bullit and Vala.

The catch: for this to work, your ebike manufacturer must have previously activated the "Powermore Range" option in the software of your ebike, and you cannot find out whether the option is activated via the Ebike Flow app - only a specialist dealer can do this. So it's not a universal bolt-on - it's a per-bike software flag the brand has to switch on, and if it hasn't been, you'll immediately get an error message stating your ebike is not "Powermore Range" and that you cannot use it. Worth asking the dealer of any specific SX or Gen 5 bike you're eyeing whether that box is ticked before you buy.

True DIY (non-Bosch battery): This is where I'd be honest that the trail goes cold for SX/Gen 5. There's a well-documented DIY parallel-battery hack for CX Gen 4 - one forum build reported with less than 50€ built his own range extender, reaching 625Wh plus 229Wh from the range extender for 854Wh in total with zero errors, though others attempting similar dual-battery tricks on other Bosch systems have hit errors and shutdowns. I can't find a confirmed working DIY build specifically on SX or Gen 5's newer electronics - that doesn't mean it's impossible, just that nobody's posted a proven one yet.

So the honest steer: if a genuine plug-and-play extender matters to you, buy the bike on the strength of the official PowerMore compatibility (and confirm it's enabled) rather than betting on a DIY hack materialising for the newer motors.