I have completed my modification of the brake lever. This is what I did:
First I measured. No point in experimenting if I have nothing to report back. Just for reference, I measured all the positions. 6 is, of course, the most important. So stock, it became the "0" reference for both the inbound (index finger) and outbound (at the ball, nearest the pinky finger). All measurements are, of course, in mm. First measurement is inbound second is outbound:
6: 0 0
5: +2 +4
4: +4 +8
3: +6 +12
2: +8 +17
1: +11 +21
I removed the lever assembly by removing the bottom nut and then unscrewing the top bolt. To my dismay, I learned the two parts of the lever assembly are held together with a pressed-in tube. You have to remove that tube to do anything, and it is tricky. I spent considerable time finding just the right stuff to use with my bench vice to get that sucker out.
Once it is out, you can see how it works. The wheel has a bunch of different surface depths and it presses against a tiny rectangular steel block on the other part of the assembly, that is held on there with a small pin. I used a bench grinder to grind as much material as I could while still leaving enough for possible wear and to prevent that pin from having to little material to anchor into. I should have measured but didn't. I am guessing I took about 1mm. I put it back together again (yeesh) so I could measure on the bike. Improvement, but not all that much:
6: -2 -3
So I took it apart again and went after the wheel. Caution: when you pull the wheel out, there is a small spring and a pip that are inserted into the bottom of it and they are easy to lose! I then took the grinder to the #6 flat surface, which happens to be the largest surface. Unfortunately, I noticed copper color, then silver under it... so this is likely heavily plated steel. That means now I can look forward to rust. Oh well... too late now!. The limit to the grinding is the tube that holds the spring and pip. So I ground about 1 to 1.25mm off that surface also. While I was at it, I ground away a little on the #5 surface too. Reassembled and measured (remember, this is all relative to #6, stock):
6: -4 -6
5: -2 -3
So there you have it. About an hour of work, and I gained only 4mm closer inbound and 6mm closer outbound, plus I risk having future rust problems with the adjustment wheel. I am not sure I would recommend this procedure, but it did cost nothing and did gain some. I am not sure if the gains are enough, but I will find out when I ride tomorrow. I don't think it is possible to gain more from the stock lever without resorting to somehow bending it. Various pictures below...
