Goo, I'd had 2 Combat front disc brakes that took a lot of strength to drag down speed, till I poked out the tiny pin hole restrictor fluid resistance in the big rubber boot in the master cylinder and got excellent lower effort braking, enough so I have to be careful of locking the nice new rubber on front below hwy speeds and get scary squeals over hwy speed. After feeling the difference between re-sleeved new master cylinder and just poking the factory hole open, I now think that the main advantage of all the narrower master cylinders is mostly that None of the re-sleeves have any restrictor hole at all. To me about the only reason to resleeve m/c is to repair bore damage pitting. I have not heard of others doing this significant upgrade, **knowingly** as all that upgrade all have no restriction orifice, but only the increased hydraulic leverage is mentioned. My buddy Westley is dang fast rider when he wants to be - tells me he has to hang back a lot because his drum brake just ain't up to it on our steeps and 90' Mt. hwy turns. Its a bit of a drag to ride with him in the steeps/twisties d/t his drum brake slowing him up so much he says. If ya like to fly up to sharp turns and pull down harshly as cars threaten to pull in front of you, i highly recommend the disc brake. I started collecting most the items to convert Wes's '71 drum brake, which the cable brake light switch grieves him a lot to work and still actually brake somewhat, but he's says nope he likes the drum appearance and keeps him going milder, so I gave up. Ping me if interested in what I got to be rid of.