BB7 Q: 160 G2 or 185 Roundagon
I'm currently pricing out my BB7 build, and have run into the dilemma of choosing between a 160mm G2 and a 185mm Roundagon for my front brake. This raises a number of questions for me that I'm hoping you can help me out with . . .
1. Do I really need the 185mm in the front, or will the 160mm suffice?
2. How superior is the G2 rotor design to the roundagon? Enough to make the size difference in rotors a wash?
3. Will it be problematic if I run the front brake with a roundagon and the rear with a G2?
Here's the way the build is going to look:
Rear: 160mm w/ G2 rotor
Levers: Speed Dial 7's
Cables: Jagwire ripcords
I'm about 200#s geared up btw.
The BB7s are terrific brakes. You will love this upgrade from rim brakes. I think for your weight, you would find having a 185mm upfront much better with braking control. I'm <180lbs with full gear and have tried running 160mm on both but just feel much more confident with a larger rotor in the front. Using less effort to brake helps me keep focused on technique much better.
Don't have an opinion on Roundagons or Clean Sweep G2. I went from BB7s w/Roundagons to Juicy 7s w/G2 to Elixir w/G3. Each brake was progressively better but couldn't tell you about the quality of the rotor performance. The Clean Sweeps are, however, lighter than the Roundagons and every little thing helps with rotation weight.
Go for the Clean Sweep G2 rotors 185mm front and whatever in the back (definitely don't need more than 160mm). You will have no issues with running different types and sizes of rotors either.
the G2 rotor is a bit lighter, usually quieter, and is less prone to heat fade. The Roudagon is certainly a serviceable rotor, but the G2 is just better. I've run both with BB7s and much prefer the G2. At your weight I'd also recommend the 185 front/160 rear combination. The larger lever moment of the 185mm rotor produces better braking power, and will also increase heat fade resistance. A larger rotor simply takes longer to heat up. And since most of your braking should be taking place with the front brake, that's where you'll need both of the above traits the most.
Now you might be able to get away with a 160 on both ends. But it would depend heavily on your riding style and terrain. If the trails you ride are fairly flat and flowing with no long down hill runs, switch backs that require heavy braking before entering, steep descents, etc., and you use good braking technique, and don't ride to aggressively, then you could likely get away with 160s. I weigh in at 220lbs and my commuter bike has a set of BB7s with 160mm G2s and works just fine. But my off road bike has a 185/160 set up on it. If it didn't I'd likely roast the front brake nearly every ride.
Your call, but for a 200 pounder I'd recommend a 185/160 set up with just about any brake you care to name. And for Avid brakes the G2 rotors. They do perform better than the Roundagons.
"I do whatever my Rice Cripsies tell me to!"
Thank you both for your help. I ended up going with 160mm G2's front and rear, since I just couldn't find 185's with G2's at a reasonable price and by all accounts the G2's seem better than the roundagons. I don't ride terribly aggressively, nor on especially steep trails, so I think that's the best compromise for me. If it turns out not to be I can always just get a larger rotor for the front.
Thank you both for your help.
I'm curious how you like 160/160 setup- any heat fade or lack of stopping power?
Originally Posted by ccarbot
I am 190#, had been running 185F/160R G2's on both my 29ers (Juicy 7's and ElixrCR) for quite a while. Just switched the front on my double squish (ElixrCR) to 160. What prompted me to mess with it is that front brake stopping power feels like overkill at times and one of my MTB cronies (who's been riding for many years more than me) keeps saying that 160 is more than enough.