Originally Posted by
idiq
Quick question... I have a 2008 Bianchi Sok (Easton Ultralite Tubing) and I'm looking to upgrade the rotors and braking system. New to mountain bikes, have done road for a while...
Currently has Avid BB7 Mechanical 160mm rotors
From what I can tell all disc brakes have the same 6-bolt pattern... So what's the biggest downside to upgrading to 185mm or 203mm rotors? I'm sure I stop faster and with more torque on the frame, but are there any other downsides?
That being said, I was looking at the Avid Elixir Code R (or just plain Elixir R) at the 185mm rotors. I'm not that familiar with the Elixir line, is it a relatively good bang for the buck? Would those rotors be overkill on my SS 29er? Any help is appreciated...
Its very common for 29ers to come with a 185 front rotor and 160 rear. The larger rotor in the front provides better stopping power, as you aluded to. Many people (like myself) will run 160 front and rear, even for a 29er, for a cross country set up. But 185 is completely acceptable if you want more torque on the front brake.
You start to see larger rotors on bikes built for All Mountain, Downhill, Freeride, etc because the faster speeds make a higher need for increased stopping power. The major downside to large rotors is they are more prone to damage from crashes, etc. since they are larger. I wouldn't go with a 203mm personally, it is unecessarily big for your purposes (at least from what it seems, I assume you are riding mostly cross country seeing as your are running a SS 29er). My suggestion would be 185 front, 160 rear.
The Elixir brakes are really good, IMO, especially for the price. I have the Elixir 5 (nothing special) and like the lever feel, especially after it has been rebled. The higher end elixir's are even nicer with more adjustable features.