Quote:
Originally Posted by Thompo
I have been struggling with my front brake on my 2011 too.
Its been bled forwards/reverse/on the bike/ off the bike etc with both DOT4 and 5.1.
100% no air in the system.
My Master cylinder is 11mm Ive tried my 2011mc and friends 2005mc and feels the same.
As you have noted, when pulling the lever excessively hard you can see the caliper flex.
I had CNC aftermarket levers, ive found the standard lever to give better feel and as previously mentioned fit a solid banjo rather than brake switch to firm it up slightly.
As for the rear both my bike and my friends 05 needed rear calipers.
The solid side (opposite piston) has either worn or been bent over time leading to the pads (and disc) wearing like this /| rather than parallel ||.
I noticed this slighty on the front too when swapping pads last night 
EDIT# Pic of rear caliper attached. Mine was very badly worn, might have been run with pads on the wrong side or something (previous owners spanner work was woeful!)
Mates 05 was similar but to a much lesser extent. |
I'm glad you brought this back up, because I forgot to post up my findings.
First off, a new bleed nipple made zero difference. I'm still quite confident that I've never had any air in the system.
Secondly, I got around to measuring the caliper flex. I was seeing around 0.015" of flex when I squeezed the lever all the way to the bars (that's about 0.4mm for y'all metric folk), which was a lot in my opinion.
I checked my XR400R with a very similar Nissin brake system, and didn't see more than 0.002"-0.003" (0.05-0.075 mm). That's a pretty sizable difference in the two.
Upon closer inspection, I realized that the two calipers mounted in the exact same fashion, so I decided to swap them. Having both of them side-by-side, the reason for the additional flex became obvious. See the pictures below.
So with the XR caliper fitted on the EC250, and everything bled properly, I checked the flex again and saw about 0.005" (0.125mm). A very marked improvement, but still not quite as good as the XR. A closer look at the master cylinders gave me a reasonable explanation: the distance between the pivot bolt and piston is about 25% smaller on the GG than the XR, which means that the lever has more leverage on the GG.
Real world riding results? Noticeable improvement. It's still not as firm as what I'm used to riding. That said, that doesn't mean that there's anything wrong with it, just that it's different. After riding it for a while and getting used to it, and then riding friends' bikes, I've actually really come to like it. It has more than enough power to lock the tire and throw you over the bars with a good 2-finger squeeze, but it has a very wide modulation range in the middle, compared to some friends' bikes (ahem, orange ones) that transition from "off" to "throw you over the bars" with very small changes in lever force.
I also noticed that the pads / rotor were wearing at a bit of an angle, almost certainly due to the abnormally large amount of flex in the caliper. This probably accounts for some of the lack of firmness that I still feel today even after putting a more rigid caliper on. I plan on replacing the rotor whenever I wear out the pads, probably sometime later this year.
