Brake caliper not springing back all the way

Question

I've got got some road caliper rim brakes which don't spring back all the way after pressing them. They go back 95% of the way but there is a tiny bit of left after that they can travel. (without the cable attached this is)

Video here: https://imgur.com/a/aAFg9VZ

Is this likely to mean the brake needs lubing or some limit screw isn't set quite right? This particular brake I accidentally took the spring out and reassembled it myself, could I have made a mistake putting it back together?

How should I go about fixing this?

Edit I have realised that this is not actually a problem when the brake is connected up but don't know how to delete a question.

Answer 1

Based on the text and your edits, the caliper doesn't have enough spring force to open itself up fully.

When its connected to the lever on the handlebar, there's a bit more tension added via the inner cable, and that combination is enough to pull the caliper open.

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While it works now, I'd suggest that you might want to disassemble the caliper and clean out all the sliding surfaces, then lubricate and reassemble.

Some brakes have teflon or plastic bushings, which are low friction but also tend to mash or wear over time. You may get away with rotating a bushing so a worn spot is elsewhere.

It is also possible for small knicks/dings/burrs to interfere with each other in sliding surfaces, so honing and sanding and gentle filing can help make sliding things slide easier.

Lastly it is totally possible for springs to loose their springiness over time. You can often restore their sproing by overcompressing them, at least for a few years more. Do be careful with this, springs can store a lot of energy and if something slips in the vise, that energy can throw them surprisingly fast into you.

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When reinstalling, consider new inner and outer brake cables too. They do rust internally, and a nice new cable set can help with modulation and lowering the power losses to friction.