quote='jim beam'notryt said:I did a review of the rx40 a couple years back. compared them to DA and
105
they took the middle position. all doing with spring tension difference
the da was the most responsive and the 105 the least.
how do you figure that? the shimanos share the same spring and have the
same length lever arms.
besides, "responsive" implies reaction time, and that means momentum. i
defy you to detect the momentum differential for the slight mass
difference between the moving parts of the different models.
Quoted message said:the rx40 weight is
about the same as the ultegra. as everyone else has commented its all in
the pads. the salmons wear to fast and are usually a couple bucks more
but braking is more significant.. not recommended on a racing bike more
for commuting.
the pad is not the caliper, buddy.
Quoted message said:Comment on single pull vs dual pull. dp brakes are quicker
responding,
how do you figure that? their velocity ratio for activation is lower.
Quoted message said:they also are easier to feather. (racers know what Im talking
about)
well, i used to race and i haven't a clue what you're talking about.
Quoted message said:also they wear the pads more evenly than single pulls.
no they don't. the "c" arm has significant "cosine error" [to quote
jobst brandt] and it wears very unevenly.
1. I believe I did state that braking ability had more to do with the pads than the brake calipers themselves.
2.when it comes to physical strength of material all 3 are basically the same wouldnt matter if they were forged in the fire of Mordor and the spring strength or more acurately, the tension IS different you can feel on the release allthings like brake handles/shifters being equal.(I can also tell if my my bike seat has been moved up/down 2mm or if Im using a 42 or 44mm handlebar or a 100 or 110 stem)
3:Wrong again, single pulls wear more on one side more than on the other,
specifically the non-pulling side (the side away from the brake cable).
Of course with anything your results or amount of wear may very.
4: Feathering is gently touching a brake to slow down slightly while
attempting to maintain a constant rhythm. (not cadence)
(30 years of experience.. Cat:3) This is why I know!!! 😉