Originally Posted by
Trakhak
Redbullet's rings are 50/39/30, so probably 130/74, as was standard for Shimano road triples and apparently others. Your point stands, though.
That said, like you, I thought it strange that chainrings had worn out, especially after only the equivalent to 3,000 km or miles or whatever he said.
Redbullet, assuming that the cassette and chain are not fairly new, I'd suggest checking them for wear before buying the chainrings. It's far more likely that those are the culprits, or one of the two.
Especially if the reason that you think the rings need replacing is that the chain slips when you're pushing hard with the chain on the middle or big ring and on the smaller sprockets. Those are the gear combinations you'd naturally be pushing hard in. It can feel as if the chain is slipping on the rings, but it's almost always actually from worn small sprockets (and usually a worn/"stretched" chain, too).
It is about 30000 km, not 3000 on the crankset. Still low mileage, indeed. They don't slip yet and the actual chain and cassette are ok after some 7000 km so far on them. But the profile of chainrings teeth on the large and middle is not fully circular anymore, they look like small circle parts on sides, linked by a straight line at the bottom. I would rather extend the life of the drivetrain with 5+ years at 40 EUR price, than waiting a few thousands km to have slip and wear the chain and cassette.