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 Post subject: XTR v-brake help
PostPosted: Sun Jun 02, 2013 10:51 am 
Gold Trader / PoTM Winner / RB Rider
Gold Trader / PoTM Winner / RB Rider
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Joined: Wed May 19, 2010 11:32 pm
Posts: 2151
Location: Bristol
First off I will say that maybe I am being thick :lol:

I havent had parallel type v-brakes before so maybe it is me but I am having trouble getting any spring tension in some M950 v-brakes I bought recently.

If I use the middle hole on the frame (at the canti stud) everything lines up as it should but there is zero spring tension unless the screw adjuster is fully in. Even then it is not enough to provide enough to reset the brake when you release the lever????

If I use the upper hole on the frame the parallel linkage of the brake is no longer parallel to the wheel meaning the blocks don't line up with the rims. But there is plenty of spring tension.

There is significant rotational movement in the brake, Im wondering if there is a problem with them?

Its all difficult to explain so I will try and get some pics up if people have any ideas what Im doing wrong or is wrong with them.


The brakes I bought were mis-matched and came with a pair of M951 ones as well. These seem fine (but they do have an extra spring incorporated into the parallel linkage)


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 Post subject: Re: XTR v-brake help
PostPosted: Sun Jun 02, 2013 11:31 am 
PoTM Winner / retrobike rider
PoTM Winner / retrobike rider
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Joined: Wed Feb 17, 2010 8:02 pm
Posts: 1171
Location: East Yorkshire
I have similar issues with my vbrakes on my 1993 Kona Lava Dome, are they the rears youre having bother with and ill guess if yes, then its a skinny steel frame?

If you look at the back of the V 'arm' the spring comes out of the pivot and up the back to a stop, is this spring arm straight, as a common way to fix spring issues on the trail is to bend it manually, if this has been done then you will have way too much spring power on the top hole and the spring will be visably bent, try straightening it by bending it back till it runs straight.

If this is not the issue and that spring is straight, then slacken off the spring adjuster screw as much as you possibly can and try them on the top stud hole on the mount, you may find this is the only way you can run them with enough return power on the spring, but it may still be too much spring tension for your liking!

Another one to look at is your pad adjustment, if you have the spacing shims set up wrong then the arms of the brake will be diving in too far and causing your issue, i try to set my arms up so they slant outwards as you look at them (resembling the 'V' shape they get their name from) this gives you good power from them and also seems best for the parallel push linkage to work correctly, if you set the pads wrong, then you will end up with the arms resembling an 'A' shape and could almost certainly be the culprit of your issue!


I think thats about the only couple of issues i can think of (if all that hungover babble makes sense to you) that i can think of, but if you can, pics will help diagnosis and assistance further!


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 Post subject: Re: XTR v-brake help
PostPosted: Sun Jun 02, 2013 2:38 pm 
Retro Guru
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Joined: Tue Nov 14, 2006 8:11 pm
Posts: 1181
Location: Hobbiton-on-the-Water
They might be 'sticking' internally. Problem I had with my rear XTR 961s. The tension spring can stick due to water ingress and also the grease 'drying out' (can't think how else to describe it).
Use a thin blade to prise the rubber cover off, then use cone spanners to dismantle the brake. Clean, regrease and rebuild. You will notice the difference. Quite an easy job to do, just make a mental note of how they came apart, particularly the parallel linkage arms


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 Post subject: Re: XTR v-brake help
PostPosted: Sun Jun 02, 2013 4:54 pm 
Gold Trader / PoTM Winner / RB Rider
Gold Trader / PoTM Winner / RB Rider
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Joined: Wed May 19, 2010 11:32 pm
Posts: 2151
Location: Bristol
Thanks guys.

Yes Spudly it is the rear, and yes it is a skinny steel frame. The spring arms are actually a bit bent so I will try and straighten them to see if it helps :D


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 Post subject: Re: XTR v-brake help
PostPosted: Thu Jun 06, 2013 7:27 am 
retrobike rider
retrobike rider
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Joined: Fri Aug 08, 2008 2:36 pm
Posts: 16736
Location: Yorkshire, England
M950's I'm guessing then.. Probably bend springs, just reshape it. Off the bike though are they nice and smooth, if not give them a god strip down and service.


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