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I have found when setting up v-brakes that adjusting the brake cable to ensure the brake pads do not touch the rims is a bit of trial and error affair, and the instructions with a Shimano brake set I bought say the brake pads should be a millimetre away from the rim on each side. (The docs actually say a combined total of 2mm)

After some frustating unsuccessful attempts I came to this strategy which seems logical to me but may not be so in practice.

  1. Clamp the brake pads firmly against the rim with the cable pulled as tautly as possible and tighten the pinch bolt. If done right it should be impossible to pull out the noodle from its holder and brake pads should keep the wheel locked

  2. Release the cable by the minimum length plus a millimetre or so needed to enable the noodle to come out of the holder, then tighten the pinch bolt. It may not be actually necessary to tighten the pinch bolt at stage 1 if you have an eye for the required length. Just pull it taut and release it accordingly.

I also follow the Park Tools advice on loosening the barrel adjuster to the last two turns to use those to loosen the brakes at the end of the process if they wind up too tight without having to adjust the cable again at the pinch bolt.

I estimate that if there is no slack in the cable, the gap between the pads and the rim should be somewhere near the combined total of 2mm required, but this assumes that the length of metal at the end of the noodle holder must be the same on all noodles, and all brake levers pull an equal length of cable dependent on the degree of rotation.

So, is the amount of metal that sticks out of the noodle holder a set standard on noodles or does it differ between manufacturers and models?

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Noodles vary a little in their design and dimensions, including the tip area you are referring to that projects past the cradle or holder of the brake. The most important differences in noodle dimensions relate to their overall length, angle, and how much they project out the sides, because there are frames (particularly small ones) that need specific sizes to avoid clearance issues.

However, the dimension you are referring to does not have the kind of effect on brake adjustment you are implying, or really any effect beyond what kind of boot it will play nice with. For example, SRAM/Avid noodles are smaller and shorter in this area than most others and need specific boots.

The procedure you outline would leave a previously anchored area of cable in the loaded span of cable, which in some circumstances can lead to the cable fraying and in turn creates a risk of brake failure. It's uncommon for it to get to that point, but a goal of any procedure for setting up a brake should be avoiding the possibility completely.

A good method that applies to virtually all linear pull brakes (other than short-pull ones like the Tektro/TRP Mini V) is to adjust the pads how you want them, run the cable, and extend the barrel adjuster 5mm from fully threaded in (which in most cases is 5 complete turns because most applicable barrel adjusters have a 1.0mm thread pitch). Pull the cable tight with a fourth hand or plier, then anchor the cable. Screw the barrel adjuster back in all the way. For most brakes and levers, this 5mm distance of cable travel is a good default adjustment. If it's a new system, after some hard test squeezes you may find you have to re-anchor the cable 2-3mm "tighter" to take out slack from the system breaking in, but the previously anchored spot won't be in the loaded span of cable so it is not problematic. If you're working on the same or similar systems repeatedly, you can further refine your technique to have an educated guess on how much the system will slacken after the initial squeezes, and you can use that to go straight to an appropriate amount of barrel adjuster extension. For example, when most of my working life was assembling the same 3 models of comfort bike over and over, I would do about 2mm of extension for the rear and 4mm for the front, which quickly and consistently one-shotted the adjustment.

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  • When the brake pads wear out and need to be replaced the parts of the cable crushed by the pinch bolt are bound to come under load again as the new pads are wider and the cable is relaxed again. What is the remedy for this condition other than changing the whole brake cable regularly, especially after long rides in hilly environments?
    – vfclists
    Jul 10, 2023 at 3:10
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    @vfclists Typically, a good initial setup that makes minimal (ideally zero) use of the barrel adjuster will allow you to run through the wear life of the pads and keep the brake adjusted using only the adjuster, likely along with some positioning adjustments via the pad mounting bolt. Then when it's time for new pads, you reset the barrel adjuster, and never have to touch the cable anchor bolt. Jul 10, 2023 at 4:51

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