Brakes not opening? (Velo Orange grand cru dual pivot)

[tylercheung]

I have a set of unused Grand Cru long reach brakes that admittedly has sat in their box on the shelf for a while. Recently, mounted them on a frame - the front works fine, but the rear, when tighted up to ~ 6 Nm or so, won't really open up/reset. I don't t think it is the cables or housing; am worried maybe it's the spring or something to do with the pivot joints or something. How to trouble shoot this - would I have to take apart the brake itself?

Unfortunately, could not find much technical manuals on the VO grand cru brakes.

[Joxster]

take the cable out of the caliper as test the spring by squeezing the brake pads together, if they release it's your cable thats the problem and if not back off the bolts to 5nm and see if that helps. If that doesn't help it's a spring issue.

[HTupolev]

Originally Posted by tylercheung

How to trouble shoot this

Go through the possibilities.

You mentioned that you don't think it's the cables or housing. Disconnect the cable from the brake and just try it out. Make sure that that pulling on the brake lever smoothly pulls cable; make sure that when you release the brake lever, the cable can freely return. Make sure that the brake lever itself also moves freely.

Now just check the brake with your hands. If you push on the brake's arms with your hands so that the pads contact the rim, does it freely return?

You mentioned that this occurred after securing the brake to the bike with 6nm of torque. If you unsecure the brake from the bike, and again actuate the brake arms with your hands, do the arms rebound freely?
(If it moves freely when unsecured, but not when secured at 6nm, then try securing it with less than 6nm.)

[fogrider]

So loosen the attaching bolt, and if it still doesn't open up, pull it off and do they open up when not attached? I had some brakes get that way, I had to disassemble as much as possible and spray WD-40 into the pivot points. You may need to let it sit and flip it around to get the WD-40 to flow around. That should loosen things up, then lube with lithium grease and reassemble.

[El Chaba]

Is it too late to return for a refund?...Quality control is not a hallmark of Velo Orange...

[tylercheung]

I did chat w/ some folks at VO. At the moment, things seem to work fine if I loosened this black bolt along the centerline just so; if I loosen it too much the brake pivots around the centerline . My best guess is that when I torque up the mounting bolt, this compresses the center pivot assembly, as this is the only explanation why it works fine w/o torque and not to fine when torqued up.

[bobin2]

Hey can I jump in here and ask a question? I just got this set and I'm confused by why the quick release dial/mech rubs against the caliper when completely open. I'm thinking of sending back cause this quick release dial just doesn't seem intuitive - or I'm stupid which is more likely. Just seems like those things should not be rubbing together.