What's this for?

[zzpza]

I've just picked up a freebie bike. I've stripped it down (as I'm going to paint it) and noticed something weird. What are these flanges for? There's one either side of the bearing cup.

[Adam]

I think that's the new "Nanny" bike. It means you can't ever turn the handlebars too far, thus preventing you from doing a u-turn.  You won't see a politician riding one of those though.

[clarion]

I thought it might be some kind of steering limiter, but it doesn't turn, does it?

  *baffled*

[Jurek]

Does it turn?
Outer cable guide, perhaps?
 

[Ian H]

Outer cable guide, perhaps?

Homemade perhaps? For handlebar mounted changers?

[tatanab]

I thought it might be some kind of steering limiter, but it doesn't turn, does it?

  *baffled*

It could be.  If the bike had centre pull or cantilever brakes then the nut on the back of the cable hanger would stop against the projections.

[Fixedwheelnut]

 Could they be to protect the paintwork from the cables rubbing, before the day of sticky back plastic?