531colin wrote: But I do think theres a random bit of nonsense going on....
Colin, I think you might be right. I ran some numbers through the applet and -provisionally anyway- I now believe his definition of MA applies to a single arm
not the whole caliper
. If correct then (because the main cable tension is shared between two arms, not just one...) the applet gives MA values which need to be halved in order to be compared with the other brake values.
Re lever MAs (LMA);
A- V levers are about 2:1
B- V levers set for 'canti' pull are about 2.75:1
C- DP dropped bar levers are typically about 3:1
D- Old style dropped bar levers are about 4:1
E- Old style 'four finger' MTB levers are about 4:1
If unknown, measure the lever travel where you pull with your fingers
and divide this by the cable pull acheived.
[2019 edit; 'New Super SLR' (NSSLR) levers (most new model shimano STIs from 2008) have a MA of approximately 2.5:1]
Re caliper MAs (CMA)
F- short reach side pull 1.1:1
G- DP caliper 57mm reach 1.3:1
H- DP caliper short reach 1.5:1
I- old style cantis (& many centre pulls) 0.8:1 to 1:1
J- medium profile cantis with optimal geometry 1.5:1 to 2:1
K- mini Vs 2.5:1 to 3:1
L- full v's 3.2:1 to 4:1
If unknown, measure the cable pull and divide by the 'squeeze' or total pad travel (left and right).
[2019 edit; 'New Super SLR' (NSSLR) calipers (most new model shimano DP brakes from 2008) have a MA of between 1.5:1 and 1.75:1]]
System MA (SMA) is the multiple of the two; some examples-
Full V setup; AL ~8:1
Mini V with DP levers; CK ~7.5:1 to 9:1
DP setup with 57mm drop; CG 4:1
Old school cantis and levers; DI 3:1 to 4:1
DP levers and old school cantis; CI 2.5:1 to 3:1
70s/80's race brake; DF 4.5:1
DP levers with optimal cantis; CJ 4.5:1 to 6:1
If SMA is unknown, measure the lever travel where you pull the lever with your fingers, and divide by the total pad travel.
[2019 edit; 'New Super SLR' (NSSLR) levers/calipers (most new model shimano STIs/brakes from 2008) have a SMA of approximately 2.5 x (1.5 to 1.75) = 3.75:1 to 4.4:1]
The numbers above tally reasonably well with my experience.
Obviously a higher SMA value also gives a proportionally reduced pad clearance all being equal, and will need more frequent adjustment.
Note that the same SMA value will (at a lower cable tension) give a slightly more effective brake, because cable friction losses will be lower.
Note also that a 'flexy' feeling brake may need to be run with closer pad clearances, otherwise the lever might bottom out before the brake come on with any great force. Thus stiffer brakes can be run with higher SMA (and reasonable clearances too) vs a more flexy brake.
2020 edit; More information about which STIs and which brake levers are NSSLR and which are not.
As of 2019 the following models are listed as NSSLR type brake pull
ST-R9100 ST-R9150 ST-R9160 ST-9070 ST-9071 ST-9001 ST-9000 ST-R8000 ST-R8050 ST-R8060 ST-6870 ST-6871 ST-6800 ST-6770 ST-6700 ST-5800 ST-R7000 ST-5700 ST-4700 ST-4600 ST-R3000 ST-3500 ST-R2000 ST-2400 ST-R460 ST-R353 ST-R350 BL-TT79
are both current and use the older brake cable pull suitable for original type DP calipers.
listings for 2012 show the following NSSLR levers
ST-7970 ST-7900 ST-6700 ST-5700 ST-4600 BL-TT79 BL-4600 BL-R780
and the following with shorter cable pull for original DP calipers
BL-TT78 ST-3400 ST-2300 ST-R221
NSSLR was new for 2008, in Dura-Ace only to start with. Thereafter new model STIs in groupsets nearly all use NSSLR cable pull. AFAICT the only 'groupset' (i.e. not non-series) STI model introduced after 2008 (i.e. 2009 or later) with the old brake cable pull is ST-2300.
The quickest way of checking the introduction date of groupset parts is to look at this pagehttps://en.wikipedia.org/wiki/Shimano