Large Rotor size

[Triaxtremec]

I'm building a XC Santa Cruz Nickel with a 650b conversion. Picked up a set of nice Avid brakes from a buddy of mine that came with a 203mm front and 180mm rear rotors. I'm used to running 180mm front and 160mm rear. Is it necessary to run a 203mm rotor?

[TheSchwagman]

No. Too Heavy. 180/160 gives plenty of power, unless you're doing hardcore DH.

[Triaxtremec]

Kinda what I was thinking. Thought about doing 160 f/r to save some weight with some XX rotors but I've always had good luck with the Alligator windcutter rotors too.

[phlegm]

Just to double-check, what is your weight with gear?

[phlegm]

Oh, and I suggest you contact "madsedan" in this forum. From memory his signature listed a 650b Nickel and he listed his height/weight in a thread in the Weight Weenie subforum. Could be an ideal resource.

[kidd]

Avids are usually 185mm.

[Triaxtremec]

Just to double-check, what is your weight with gear?

I'm 185lbs. With gear I have no idea, I don't ride with any crazy gear other than clothes, a helmet and clothes.

[jredling]

Just picked up my enduro expert which came with a 200 front and a 180 rear. I'm going to do some enduro racing this season so I think that the large front rotor will be nice as far as heat dissipation on the downhill sections. If your mainly into xc riding you may not need that big of a rotor.

[madsedan]

Agree with some other recommendations, I run my nickel with 180/160 and I'm 230+ depending on my beer intake
At your weight a 180/160 is plenty good and 160/160 would be fine as well honestly. I'm running Magura's with their storm SL rotor and have plenty of brake at my weight with no overheating/glazing or fade.
I've run Alligator windcutters in the past but I really like the Magura rotors I have now, they make a little noise occasionally but nothing too obtrusive, I got lucky and they came with the brakes otherwise I'd probably still be on those light Ashmia Ai rotors on my last build.

[shiggy]

Avids are usually 185mm.

Not anymore.

[NYrr496]

I weigh 255 and I run 203 front and 180 rear. Works for me.

[trmn8er]

220 lbs here and I love the 203/180 Magura Storm SL rotors. I find the larger rotors allow my pads to last way longer than when I had 180/160 size. And they stop the bike super well.

[Mtn-Rider]

Big rotors are great but not for free. Being bigger in size but not thickness makes them fragile, they bend much easier than smaller rotors.

Large rotors require extra care during transportation and storage. Anything pressing against a 200mm rotor can easily warp it. Not a big deal but at least good to know.

[Learux]

230 lbs, 180mm front and back, works great.

[ashas]

on all my bikes front 203/200, rear 185/183/180

I just don't believe small rotors. plus - bigger rotors do look better.

[offroadcmpr]

I have a 29er with avid elixir CR. I have 185 on the front and 160 on the back. When I moved to 185 from 160 it didn't make as big of a difference as I thought it would. I can also still get them overheated to the point that they start to fade and scream.
But they work well enough that I am comfortable for one finger braking on any terrain. I think I would like a little bit more. I am also about 200 pounds loaded up.

[006_007]

All these posts about "extra weight" and "fragile" for 200mm rotors - I dont really get it. I have run 200 on one of my bikes for years and I have never had any issues with either. I guess I could save 40g and switch to a 180mm rotor...

With the extra leverage a 650b tire would have over a 26" I really dont think I would be happy on a set of 160mm rotors - pretty sure at my weight (185lbs) and what I ride (lots of climbs, with lots of potentially steep descents) that I will be opting for the 200mm front 180mm rear option when I build a 650b.

[libretto]

I ran a 203 front and a 180 rear on my fsr for a few seasons. I could never seem to get the front rotor to stop whining at high speeds and switched back to a 180 and the issue went away.

For what its worth the difference between the 203 and the 180 in stopping power was not really noticeable on most of the trails i was riding. Save the weight and go with the smaller rotor

[Triaxtremec]

Think I might drop to a 180/60 or 160/160 combo. The 180/160 combo on my hardtail seems more than enough for the local trails.

[coxodoina]

I'm going to do some enduro racing this season so I think that the large front rotor will be nice as far as heat dissipation on the downhill sections

[brandaopj]

i have a 29er and have 160 front and back

[millertm]

I'm closer to 300lbs and my XT BR-785's work great with the 180/160 Ice Tech rotors. No noise and enough stopping power to put me over the bars if I am not careful. I too think that the larger rotors look cool but could not get anything over a 180.

Mark