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  1. #1
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    2007 XTR Pad clearance X post

    I have just built a new bike with m975 discs and have noticed that the pad clearance is more than on any of the XTR M965 calipers I have on other builds. I have noticed this b/c there is much more lever travel to engage the pads (M975 XTR levers) than with my M965/XT lever set up. The brakes work well it just takes more pull on the lever to engage them.

    I have adjusted the reach on the levers to just clear my knuckles with the brakes locked up so I am just looking for feedback from anyone else who may be able to tell me if there is a way to reduce the clearance a bit.

    Since the M965 calipers were notorious for rubbing and lazy piston perhaps this is by design that the clearance has increased.

  2. #2
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    could be down to incorrect bleeding.

    my friend has saint brakes same as mine but i have to pull more also,dunno how it works but theres a difference for sure.

  3. #3
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    The XTR 975 calipers do have more pad retraction. I expect it's to make sure there's no residual brake drag for the World Cup racers. It sure keeps them from squealing and rubbing in the mud.

  4. #4
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    I just set up my new xtr front brakes last night and noticed the same thing as the op. I would really prefer for the brakes to start engagin further out. I am pretty sure that the bleed is good. I have been bleeding MC brakes for years, and the lever is quite firm once it engages. I am trying to figure out if there is a way to alter the bleed process to reduce the space. Like maybe using a narrower spacer when bleeding so that the start point is closer together.

    I must say the pad retraction is excellent and there is zero drag. But I really need my brakes to engage sooner. I have long fingers and big hands and this late engagement just feels wrong.
    FWIW its a post mount caliper and I am using m975 dual contols.
    Any suggestions would be appreciated.

  5. #5
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    two suggestions...
    the first one is cheap and easy to do. when bleeding the brakes, make sure the pistons are NOT pushed all the way into the caliper. in doing this, you may not be able to use the yellow bleed block. you want to create a higher oil volume in the caliper for quicker engagement. the downside of doing this is that if you do long downhills and you use your brakes a lot, up will have less room in the master cyclinder for oil expansion at high temperatures and there is the possibility for the levers to firm up.
    second choice will cost money... use XT (or Saint or SLX) brake levers with the XTR calipers. those levers have what is called a Servowave mechanism. this will engage the pistons faster during the initial lever travel and then ramp up to a higher power (leverage ratio) after pad contact. the reason XTR levers do not have this feature is that it adds weight to the levers.

  6. #6
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    Quote Originally Posted by onespeedfreak
    two suggestions...
    the first one is cheap and easy to do. when bleeding the brakes, make sure the pistons are NOT pushed all the way into the caliper. in doing this, you may not be able to use the yellow bleed block. you want to create a higher oil volume in the caliper for quicker engagement. the downside of doing this is that if you do long downhills and you use your brakes a lot, up will have less room in the master cyclinder for oil expansion at high temperatures and there is the possibility for the levers to firm up.
    second choice will cost money... use XT (or Saint or SLX) brake levers with the XTR calipers. those levers have what is called a Servowave mechanism. this will engage the pistons faster during the initial lever travel and then ramp up to a higher power (leverage ratio) after pad contact. the reason XTR levers do not have this feature is that it adds weight to the levers.

    I am planning on doing the first one as soon as I have time. I spent all weekend putting hardwood floors in the den so no time left for the new build.
    I will probably file down one of the yellow blocks to make it narrower. I am really wishing my vacuum pump brake bleeder thing wasn't at my dad's house an hour away. I imagine that could help too.

    Choice 2 isn't much of an option as I am using xtr dual control.
    Thanks for the suggestions.

  7. #7
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    Yup I do the first one as well cos I like very fast pad contact. You can also just use a large allen key to space the pistons when bleeding the brakes.

  8. #8
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    Re-bled the front brakes last night. BTW be careful with the screws on the reservoir covers. They strip easily. and you will need to take them on and off repeatedly so go easy on the torque. (guess i'll be heading to the lbs tomorrow for replacements).

    Anyway I used an 8mm allen wrench for the pistons to bear against while re bleeding. Now the lever is firm and engages really soon. Unfortunately I have lost some retraction and the brakes now drag a little. So for anyone else wanting to do this something about 9mm thick should be the sweetspot. The factory bleed block is a little over 10mm.

    Also bled the rear last night which took forever. It will probably need a second bleeding as well. I think when these systems are shipped dry it just takes a while for the fluid to penetrate all the nooks and crannys and for the seals to get re lubricated. If you don't have a lot of patience then you shouldn't try to install your own xtr brakes from scratch.

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