I've always thought of it as a modulation thing. With a larger rotor I find it harder to keep the rear wheel just below the point of breaking traction. Last year I was running a 200f/180r setup and never felt like the rear didn't have enough power and was very satisfied with being able to control the rear wheel locking up. My current rig has 200s front and rear (and the same brakeset) and I find myself skidding around unintentionally a lot more even after 4 months with the larger rotor.
The reason why has nothing to do with engine braking or looking cool. When brakes are applied weight is shifted forward. When the weight moves forward, you will have more 'weight to stop' at that point (others would say more traction, hence bigger brakes equals faster stopping). Hence larger rotor - better heat dissipation and more net "power".
Either way, this is why cars, motorcycles etc. go this route.
That said, I'm a run em big on both wheels kinda guy.
The rear brake might be used More but never as Hard. And one can see obstacles that might damage rotors and be able to steer the front around while having less control in the rear due to not having eyes on it.
DH rig has 180mm rotor in the back here, less likely to hit rocks and when it does its cheaper to replace. Smaller rotors taught me to not use them as much and overheat them so they work when I need them to work. I ride steep trails and you learn to not cook them to the point of failure. In my early years of riding disk brakes I learned on 8'' Hayes Mags, brake systems have come a long way since then.
LLLLL
3/5/2019 4:35 PM
Jeffrey6675
3/5/2019 1:11 PM
7willmorris
3/5/2019 12:44 PM
kleinblake
3/5/2019 4:36 PM
7willmorris
3/5/2019 5:35 PM
jeff.brines
3/5/2019 11:17 AM
C'mon Marshy!
The reason why has nothing to do with engine braking or looking cool. When brakes are applied weight is shifted forward. When the weight moves forward, you will have more 'weight to stop' at that point (others would say more traction, hence bigger brakes equals faster stopping). Hence larger rotor - better heat dissipation and more net "power".
Either way, this is why cars, motorcycles etc. go this route.
That said, I'm a run em big on both wheels kinda guy.
jeff.brines
3/5/2019 12:59 PM
"Sources"...
https://physics.stackexchange.com/questions/143823/why-are-a-motorcycles-front-brakes-more-effective-than-back
https://www.quora.com/Why-are-front-brakes-always-larger-than-rear-brakes
http://knowhow.napaonline.com/front-brakes-vs-rear-brakes-whats-the-difference/
That's just via a quick google search
Big Bird
3/5/2019 10:56 AM
Scrub
3/5/2019 10:45 AM