I'm new to Bromptons but I think so. Don't think anything ever comes attached to it on stock bikes so it's a bit weird. I thought maybe it was from bottle dynamos back when they were popular but I think it's simply for the cable rub attachment. Some of them face backwards which might help keep the cable away from the tyre on bikes with no mudguards
When you spec a Brompton without mudguards they come with a little disc attached to that braze on which pushes the cable away from the tyre when steerering, not very commonly seen
I'm new to Bromptons but I think so. Don't think anything ever comes attached to it on stock bikes so it's a bit weird. I thought maybe it was from bottle dynamos back when they were popular but I think it's simply for the cable rub attachment. Some of them face backwards which might help keep the cable away from the tyre on bikes with no mudguards