Engagement adjustment with hydro disc brakes?
 

Hi all,

Incoming new bike that I will be running hydro discs for the first time. Is there an adjustment for engagement or is it just what it is? I like a lot of throw ( I guess that would be considered lots of modulation ) on my rim brakes. Will I have that option?

As always, thank you all in advance!

Steve

on campy hydro system you can adjust the throw, you have 2 options... not sure about the other 2 systems

This will be ETap hydro.

You might not care once you try them.

Hydraulic discs behave differently so it might not matter once you're adjusted.

If they are a good system the modulation will be fantastic even if there is very little throw, no different than a really good system on a motorcycle or a sports car.

That said I have rode some road systems with what felt like too much slack before they start working for my taste. I have had several MTB systems that have almost no slack & minimal lever travel compared to rim brakes and yet still have way more modulation feel & tons of power. Kind of best of all worlds, and I expected the road systems to get there really fast too.

A good hydraulic system requires less effort, and your fingers + brain can be more precise when less effort is required. Modulation is all about calibrating that effort just right.

The amount of pad movement for a given amount of lever is dependent on the size of the cylinders in the lever and caliper respectively - so modulation in that sense is fixed.

Free stroke is the amount of lever movement that occurs before pad contact on the rotor (think your barrel adjuster or cam on a traditional caliper) and is adjustable on some brands, not on others. Sram road hydro doesn't to my knowledge though you can partially hack it by overfilling the system (do at your own risk). The latest shimano road stuff does have free stroke adjustment so you can tune the initial contact point to your liking.

I'm just installing Shimano ST-RS685 hydros and there are both stroke and reach adjustments, and so far I only messed with the reach.

what group?

You're in luck! eTap HRD has adjustments for both reach (where the lever's default position is) and free stroke (how much lever pull is required before pad engagement).

Specifically for eTap HRD: Proper bleeding technique requires the free stroke adjustment to be set to minimum. Once you've bleed you can fiddle to your hearts content.

As others have noted, hydraulic disks have a very different lever feel so it's worth giving the default settings a try. I love my eTap HRD setup, good luck!

I know where the reach adjustment is ( I assume it’s the same on the HRD ETap shifters ). Where/how is the free stroke adjustment?

Great news, btw...I’m a fiddler!

Thank you!

Check this vid out that shows the two adjustments:

https://youtu.be/HVc88EG5YOM

So awesome! Thank you so much for this!!! This answered my question and more.

Steve

I've got them on my gravel Coconino. The setup has the reach at minimum and I just left them that way since I'm in the drops a lot on that bike. Set them up in September 2017, haven't messed with them since.