As far as my knowledge goes and in simple layman's terms, all the replacement brake lines have the real line itself in PTFE (teflon) doing all the real work and in itself being darn close to inexpandable.
What's on the outside is only for protection against chafing and such things and of course for looks and the only "advantage" for the Kevlar lines is that they will be a bit lighter than braided steel but the amount of weight difference is of course ridiculously small.
There's even a French brand called TEID that used to sell DIY parts to make your own from scratch and I've been using this on my bikes for many years with ONLY the (black) teflon line and no cover whatsoever, the sleekest lines possible with rock-hard brake-feel to my utter satisfaction but recent legislation in my and the surrounding countries has called for pressure-testing at factory (or something like that) for complete finished lines, so that option has gone for good.
Hope this helps and if anyone thinks I'm wrong in the inside of all these lines being the same and thus "performance-wise" no differences, please feel free to correct.
What's on the outside is only for protection against chafing and such things and of course for looks and the only "advantage" for the Kevlar lines is that they will be a bit lighter than braided steel but the amount of weight difference is of course ridiculously small.
There's even a French brand called TEID that used to sell DIY parts to make your own from scratch and I've been using this on my bikes for many years with ONLY the (black) teflon line and no cover whatsoever, the sleekest lines possible with rock-hard brake-feel to my utter satisfaction but recent legislation in my and the surrounding countries has called for pressure-testing at factory (or something like that) for complete finished lines, so that option has gone for good.
Hope this helps and if anyone thinks I'm wrong in the inside of all these lines being the same and thus "performance-wise" no differences, please feel free to correct.
