Zzbog

Hello,

I'm having a problem with Tektro RL520 brake lever:

I can pull it a bit before the brake reacts to it.

It feels like there's more cable slack remaining, after I pull the lever...

Here's the video:

https://www.youtube.com/watch?v=EzFkHrqFEoE

The second lever is absolutely fine.

I suspect there's something wrong with the cable (the housing is brand new), but I'd hate to recable the thing only to learn that wasn't the problem.

zzyzx_xyzzy

possibly the housing wasn't pushed all the way into the lever when the housing went on, or there's a kink in the housing or cable somewhere.

Chris_W

Or maybe there is a problem with the tension/spring in the brake mechanism itself.

xenologer

The short distance of initial movement is you pushing against the lever's return spring while the cable is sitting slack.
So shorten the cable.

Zzbog

It can't be because of the lever, right?
I doubt it's the length of the cable, since it's really pretty short..

mzeffex 

Dunno, but I gave it 5 stars

xenologer

What matters is the Relative length of the cable versus the housing.
Shorten the cable, or lengthen the housing.
The adjusting barrel acomplishes this, however for the amount of slack shown in the video I'd undo the cable clamp bolt and shorten the cable.