Bicycle Mechanics - Need input on XT brake calipers

I just replaced my AVID brake calipers on my GT xcr-4000 with Shimano XT units. These have the parallel-push pads and the brake action is awesome! But I have a question; are the brake arms suppose to stick out so much? I know the parallelogram linkage takes up some room but these arms are like 3/4" farther out on each side. From the noodle to the cable clamp is about 2-1/2" (about 64mm) when adjusted for 1-mm pad clearance. I am using the 3-mm shim (thinnest) between the pad and arm and even filed that shim down to bring the arms closer together but it still looks goofy. Are they suppose to be like that? My old AVID's had about 1-3/4" (about 44mm) clearance from the noodle to the clamp. If this is normal then I'll just leave it alone; would like to hear from anybody with XT or XTR calipers as to what their caliper mounting position/measurement looks like. Thanks all......

http://www.parktool.com/repair_help/howfix_linearbrakes.shtml

http://www.shimano-europe.com/cycling/phpimages/productserie/service_pdf/B870A.pdf

JimB,

Check out those sights that Hunter suggested. I installed my XTR V's quite a while ago, but I believe in the installation instructions it said that there had to be at least ?64? millimeters clearence between the end of the noodle and the pinch bolt. I can't find my installation instructions. Double check this though. I measured mine and the end of the noodle to the center of the pinch-bolt mechanism is about 70mm. The rear measures longer because it is a different rim. Make sure your brakes are balanced side to side with the tension adjustment screws. If I'm measuring correctly, 64 millimeters is not excessively wide for the length of the cable between the noodle and the pinch bolt, from my experience. Hope some of this helps.

-Moab

All I know is XT is supposedly quite loud!

JimB,

Just to correct my earlier post, I checked several of my repair books and found that the minimum allowable distance from the end of the "rectangular box" holding the end of the noodle to the center of the pinch bolt mechanism is 39 millimeters.

I think that you are just used to the straddle wire length of your old set of brakes. I also noticed that the caliper arms seemed farther apart on my XTR's when set up than did my old avids. The distance between the two braking surfaces (width) on your rims could also make the calipers appear to be farther apart at the top, as the calipers must be spread apart farther, lengthening the distance of the straddle wire, and making the calipers seem like they are set funny. You still would have noticed this with your old brakes.

Make sure your tension adjustment screws are used to center the calipers properly. This could allow you to pull more cable through the pinch bolt, pulling the tops of the calipers closer together.

-Moab

Originally posted by WorldIRC
All I know is XT is supposedly quite loud! Not if toed in properly

Thank you everyone for your responses. The instructions stated that a minimum of 46mm clearance between the noodle and pinch bolt; didn't say anything about a maximum. That is a good point about a wide rim will force the brake arms to tilt outward more that skinny one will; I have Mavic D521 rims. The brakes work very well but just look odd. I guess I'm just used to seeing the brake arms vertical from the pivots where as the parallel-push arms sit outside the pivots. Because I have so much exposed wire between the noodle and pinch bolt do I need to get an extra long "grub" to cover it?

The "grubs" aren't even truly necessary so I wouldn't worry about it.

my older xt vbrakes have less than 2" gap between the noodle and the bolt. my rims are not that fat though, mavic 217 sup. the newer gens of xt vbrakes do look wider apart though.

Are your "older" XT brakes parallel-push type?

OOPS! Sorry, I missed the "v" in front of the word "brakes". Would be weird to see parallel-push v-brakes.

Sorry again everyone. I wish I could this "v" brake / cantilever brake squared away. I always get the two confused as far which is which. By the way, why is it called a "V" brake anyway. I know Shimano brought it on the market in 1996 but why is it called "V"?

Originally posted by JimB
Are your "older" XT brakes parallel-push type?

my older xt vbrakes actually are parallel push. might be one of the first gens though.

cantilever brakes use 'levers' and thats the type that looks like a triangle.

vbrakes are also known as linear-pull brakes, though i have no idea why they are called vbrakes.

Thank you to everyone for your responses. What I did was I removed the 3mm shim and replaced it with a 1mm shim (acutally a 1/16" thick stainless steel washer) between the pad and arm. I was lucky in that 3 out of 4 pads hit the rim parallel and flat. One pad had some toe-out so I had to file the washer to a slight taper to make the pad sit parallel to the rim. This set up has NO adjustments possible but everything is just perfect and locked in solid. The arms now sit almost vertical (slightly bowed out) and are vertical when the brakes are applied. Clearance between the noodle and pinch bolt is adequate. According to everything I've read this is the ideal setup. AND it looks a hell of a lot better, not bowed out to the max. Only problem now is that these calipers generate so much clamping power I have to install brake boosters as my frame and fork are spreading when applying the brakes.