thisisnotaspoon – Member
Yes, for the reason Cougar explained, 140mm wasnt enough anymore!
Awaits cougars response to see if thisisnotaspoon can look into the future!
What are Fridays Euro lottery numbers? 😀
The answer surely depends on what is the limiting factor – energy dissipation or mechanical force.
If it’s energy dissipation then there is no difference unless the combined weight of the bike and rider are different as you are still dissipating the same energy.
If it’s the mechanical force that can be applied then a bigger wheel has a larger moment arm so is thus more capable of overcoming the friction that can be applied by the brake (depends on the Coef. of friction and pressure).
However there is also the mechanical grip available so if both bikes had the same mechanical grip that was unable to sustain full braking power then no difference. But if the 29er has more grip (most/all of the time) then it can take more powerful brakes but is this still up to the limit of the smaller rotor?
Another question is will the rider be going faster on the 29er?
In all honesty I would still choose brake diameter based on what the bike is used for. DH – 200ish, trail etc 180, XC race bike 160 and a size smaller on the back and this is due to a combination of energy dissipation and braking power.
That is my view anyway.