Brake Caliper Mounting & Adjustment - Linear Pull & V Brake

In this video, we will walk through the mounting and adjustment for the Linear Pole Rim Caliper Brake. Make sure you're watching the caliper mounting and adjustment video that matches your brake type. If you're not sure what you're dealing with, watch this video. The linear pole brake may be found on the rear or the front of the bike. Pivots for the brake are located below the braking surface. Left and right arms are pulled together by a single primary wire. A housing stop is attached to one arm. The cable extends to the other arm with a pinch bolt. Pulling the lever brings the pads to the rim. Typical tools and supplies may include hex wrenches for brake caliper mounting and pad adjustment, a fourth-hand cable stretcher, torque wrench and bits to make sure things are properly tight, a screwdriver for brake centering, a cable cutter to trim the brake cable and to install the end cap, grease, a rag, and a thread locker. The linear pole brakes mount to the same frame fittings as the cantilever brake. The outside of this surface should get some grease to help them run smooth and not bind. Do not grease or lubricate the inside threads. There is typically a thread locker on the bolt or, if there's none here, thread locker could be put inside. Grease on the threads would eliminate the purpose of the thread locker. The brake calipers have a spring that will insert into one of three possible fittings. The topmost fitting provides a lot of spring tension. It is common you may have to twist the pad to get past the fork. Here, it almost feels like there's too much tension. The bottommost hole provides very little tension. Typically, select the middle hole and make sure that both sides are symmetrical and in the same middle hole. Mounting bolts are now threaded into each side. If there is pre-installed Loctite on the bolt, it is normal to feel a little resistance as it threads in. That is the thread locker doing its job. A typical torque for the mounting bolts is 8 to 10 Newton meters. The arm should still swing freely. After the arms are secured to the frame or fork, the pads are now adjusted. The common linear pull will have a threaded stud system. There is a series of convex and concave washers that create a ball and socket system. This will allow for alignment in several planes. It will allow for toe. It will allow the vertical face of the pad to be squared to the rim. We can move up and down in our brake arm for height. Everything is secured with a single nut at the back of the brake stud. It's also very common to notice the slight curve in your brake pad. This curve will match the curve of the rim. Loosen the pad mount, bring the arm and pad to the rim, and adjust. Because we're traveling downward on an arc, we want to be to the top edge of the braking surface, not to the top edge of the rim, but the top of the braking surface. As the pads get thinner, it will travel down the rim more and more. Never have a pad so high it would hit a tire. With the mounting nut loose, the pad won't want to move in lots of different planes. Bring the pad gently to the rim and push with some mild force and secure the nut. The pad will tend to be self-aligning and put the convex concave washers where it needs to be correctly aligned with the two flat surfaces the rim and the pad align. Toe can be had a couple of different ways. Loosen the nut and bring the wrench forward or back as needed to gain toe. Toe is useful to help reduce brake squeal. As the rim rotates forward, the pad and the arm are going to pull back and forth slightly. That can cause a squeal, which is a harmonic resonance. By introducing touch at the front and a slight gap at the back, we are reducing the tendency for the arm and pad to move back and forth quickly. That reduces squealing. We begin with the correct height. We check that the front and back edge are square and even to the rim. So for toe, we loosen the nut, pull the wrench forward in this case, and secure. Here, far too much toe. With huge amounts of toe, you're reducing braking performance as it flexes to come in and apply force to the rim. So a slight gap is what we're looking for. Bring the wrench to the back slightly. Hold and secure. A slight gap at the back, front edge and back edge even or flat to the rim. Typical torque here, six to seven newton meters. Hold the pad as you tighten the final tightness so it doesn't twist as you tighten the mounting nut. Repeat the process on the other side. A second useful technique to get some toe is to put a shim at the back edge of the pad, align our pad fully to the rim, secure the nut, and remove the shim. A rubber band closed up can act as that shim. We'll place this on the back of the pad, loosen the mounting nut, and proceed to adjust our pad as normal. Just some mild force to the rim is going to move the stud and the washers to allow toe. Secure pad fully, remove the shim, and we have a slight gap at the back from the shim. Repeat the process on the other side. The brake cable passes through the housing and the housing will be stopped at what is called a noodle. The noodle acts as a stop for the housing and the cable will pass out to the other arm, allowing us to draw arms together. The noodle typically consists of a liner underneath the housing stop. This is a common place to get a lot of moisture and corrosion. Consequently, it's a good place for some lubrication. Install the wire through the noodle and out. The noodle will engage in the linkage off of one arm and pass over to the pinch bolt on the opposite arm. It is common to see a dust boot attached at this point, the idea being it's going to keep dirt out of the system. So from here, we feed through the pinch mechanism, and before we draw the pads together, back out the barrel adjuster three or four turns so we can have some fine-tuning adjustments at the lever. With our housing fully secure in the noodle, the noodle is secure and seated in the linkage, we are ready to draw the arms to the rim. We can do this with a fourth hand such as the BT-2. It's only necessary to touch the rim or even get really close. Don't go all the way and squeeze with force. You won't have enough adjustment to make a good setting. So it's simply to the rim, then secure the pinch bolt. If you don't have a fourth hand, you typically can just pull the arms together just with your hand and pull the cable out. You have a lot of leverage on these arms. It doesn't take a lot of force to pull the pads together. So typically just using the hand is enough. And here again, we're tightening the pinch bolt. It should flatten and crush that cable. Here, six newton meters is a good average torque. We'll now set the pad clearance at the rim by the feel at the lever. If the pads are too tight, the lever is going to pull and immediately engage. That is simply too close. If the wheel comes out of true at all, it's going to rub the pads. Additionally, it really doesn't give us good braking power. Third problem, it's difficult to disengage the quick release mechanism. We should be able to pull out the linkage from the noodle and here we are having trouble doing that. This brake is set too tight. Here, we'll bring the barrel adjuster in toward the lever, giving us more slack. Here, we have more travel. That's good for our leverage at the hand. We are well greater than an inch clearance when we're contacting, so we have plenty of brake power. And here, we can disengage and re-engage our quick release easily. This brake is not too loose. It is not too tight. We would set the rear brake the same way. It's time now to center the brakes. Centering is done by subtle changes in spring tension. One side, or commonly both sides, will have a screw adjacent to the return spring. By tightening the screw, you're increasing tension on whatever side you tighten. Here, we are not centered. We have a large gap on the rider's left and touching on the right. Both pads are going to move together. But here, the right arm is weaker compared to the left. So, I'm going to loosen this screw, making this one a little more equal in strength. And if we went too far, we can tighten. And if it looks good, it is good. We could have done over here, we could have tightened the screw to draw the pads to the right. We could tighten this screw to draw both pads to the left. Again, both pads are going to move if you're just dealing with one of these screws. So you don't need to do both. It's time now to trim the cable and install a cable end cap. It's also common on many of these brakes to have a little place to tuck the wire away so it's tucked cleanly. So we actually want to cut right about here where the thumb is. I'm going to pull that out. We're going to trim that. We'll put an end cap on and we will crimp it. Then, tuck it back. It's clean and out of the way. These brakes are ready for the road. And that concludes the process for brake caliper mounting and adjustment. If you're looking for help on a different procedure relating to rim brakes, we've got a whole series. And watch this video for an explanation how we've organized our rim brake video content. Thanks for watching, and be sure to subscribe for the latest from Park Tool.