@Andrew Breckon - the stem question on the Spectral:ON is a fair bit more involved than on most bikes, so worth understanding what you're dealing with before buying anything.
The core issue is that cables are routed through the stem for complete integration on the Spectral:ON, which means you can't just unbolt a standard stem and swap it like you would on a conventional bike.
The internal routing of cables through the stem is the real headache, and
Canyon themselves weren't forthcoming with answers on what replacement stems are compatible, mainly due to this cable routing situation. The knock block itself isn't the obstacle here - that lives in the headset/frame area and doesn't directly affect which stem you can fit. The bigger constraint is that Canyon uses a proprietary cockpit design.
You can't change the stem or bar individually and will have to replace both to adjust the fit on some versions of the bike.
That said, it's not completely hopeless. Canyon indicated there are parts that can be ordered through them to make a stem swap possible, though they may take some time to source. Your first call should be directly to Canyon's customer support - give them your year and spec level (CF, CFR, AL) and ask what they can supply. Also worth knowing: standard round spacers can be used by removing the Canyon-specific ones and placing the round spacers above the top cap with rubber plugs, and it works fine
- so the spacer stack side of things is manageable. Which year and spec is your Spectral:ON? That'll narrow down what options actually exist for you.