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Not exactly. The loads are high due to the diamter the braking loads act over the hub flange. If you had a symmetrical disc brake hub the situation would be the same. the tension changes on the rotor side is not proportional to the static spoke tension. The tension changes will be dependant on the torque applied just like on a rim brake rear wheel with the exception that unless your chris hoy you cant apply disc brake torque when pedalling.
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The kinetic energy removed maybe the same but due to the rotor size difference between a rim and the disc brake rotor the forces on the spokes are quite different. The higher forces on the spokes applied at the hub flange (set by the hub flange diameter to rim diameter) do not mean higher retardation force on the bike. I have corrected my first post on this. There is a glaring error.
As I have shown torque = force applied * diameter of rotor.
Energy in one revolution is actually work done=torque*2*pi
Assuming tangential spokes
So W.D = (braking torque)2pi = force(rotor diameter). That could be rim or brake.The work done here is fixed. The rotor diameter is not. It's 10 times larger for the rim than the hub flange pcd ( assuming 62mm Shimano 6 bolt flanges) so the force on the spokes has to becl different. Small disc brake hubs just make matters worse.
So bringing energy into this changes nothing.
So when you apply physics/naths the answer falls out. I used to teach this subject and maths too.
The problem is you are misunderstanding the relationship between torque and energy.
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Disc brakes do place more braking loads on spokes than rim brakes can. You can work out what the difference is by taking the ratio of the rim diameter to the rotor diameter.
Force(rim) x d(rim) =force(rotor) *d(rotor)
So for a 160mm rotor a disc brake thd braking torque goes through the hub fglsnge. Braking forces on spokes are therefore 10 times as much load on the spokes as a rim brake can at the limit of tyre adhesion.
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Danstuff as you have realised you can't get a spoke length calculator to work out the spoke length.
It is possible to do mathematically for the four rows of spokes.
I normally guess the lengths then work out the fractional crossing in spocalc for that hub.
For a hope pro 2 32h and a kinlin tl29 the lengths were 296/298mm. I guessed right first time. 297/298mm would have been better but I lacked 297mm.
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Nothing has happened for the past two years apart from bickering which has got louder.