You've damaged it previously.
A few people have reported chromoplastics failing around the fittings under the fork and seatstays, possible due to cracking caused by vibration. I think you'd need a starter crack though, either due to a knock or over-tightening.
@ffm started
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A few people have reported chromoplastics failing around the fittings under the fork and seatstays, possible due to cracking caused by vibration. I think you'd need a starter crack though, either due to a knock or over-tightening.