Does anyone own a Canyon?

did they say its your fault @benjam ?

100%

The cable stops on the frame are bonded aluminium, what you can see occurring is paint lift due to oxidisation.

We see this occur as a result of corrosion caused by lack of or improper cleaning and maintenance. Corrosion can be accelerated if the bike is often ridden/kept in coastal areas, ingress of salt from the roads in winter or sweat falling onto the bike during use. As this issue is not due to a material/manufacturing defect but is a wear and tear/maintenance issue it would therefore not qualify for warranty or guarantee replacement.

As the issue is cosmetic in nature you can continue to ride the bike.

I would suggest ensuring that after cleaning your bike thoroughly a corrosion resistant product is applied to the bike to disperse/drive out moisture and protect the bike. There are a number of products available on the market, we recommend Muc-Off products.

The bike was ridden, stored and cared for by me in Bath and I am fastidious with bike care. This is the bike after 4 years of ownership: