I have no idea what is inside of Momentum original cable, but take a quick look at this picture:
So I can clearly tell what is inside of HD570 cable. It contains inside three stranded cables, and each single strand! is covered in isolation paint. On the box it says it is Kevlar reinforced OFC cable. Sounds great doesn't it? Well, not for me at least! That paint can be easily scratched and you can potentially get short circuit. Also if you play too much with cable, these strands may break and you will get different resistance of left and right cables. While cables for left and right should be identical (otherwise you will get imbalance), the ground cable should have twice as many strands, which is not the case here - ground is (at least as far as I can see with my eyes) identical as left or right.
The HD570 are higher impedance headphones, but their cable is thicker than cable of Momentum, however it is also longer. Also on the Momentum's box I don't remember any mention of Kevlar or OFC.
If you read this forum you will find people replacing their cables for more expensive models like HD650. So if you take all that into account you probably should not assume that stock Momentum cable is all these headphones would ever need. For me the replacement cable is nice alternative, because it is longer, and thus I can stretch on the couch when listening to the music from my laptop. With the original cable I would have to bend over my laptop...