Disk Brakes - how much 'free stroke' is normal?

galwayguy85

I've got with the times and now have a road bike with disk brakes. My old bike, which I'll continue to use has the good ol' fashioned rim brakes.

Rose Reveal AL 105 - https://www.rosebikes.com/bikes/road/endurance/reveal-al

SHIMANO 105 ST-R7025 Brakes (hydrolic)

PDF https://si.shimano.com/en/pdfs/dm/RADBR01/DM-RADBR01-09-ENG.pdf

When I gave a display model a test ride I was freaked out by how scarily responsive the disk brake levers were.. so much so that I was afeared of getting flung over the handlebars!

I ordered the bike online and it came quickly. When I mounted the front wheel I was a little surprised to see how far I need to bring the brakes levers back to gain any traction on the brakes. Once I get some traction it all stops very safely.

Is it normal for the levers on disk-brake bikes to do this??

There is no 'free stroke adjustment screw' with these particular brakes. The levers have to come back to about 2cm from the bar tape. I can adjust the reach adjustment but I am still a bit uneasy

I've been to the local bike shop and they've told me that this is perfectly normal.

On my rim brake bike I'd be telling myself something is not right and that the barrel adjusters need to be looked at.

Various 'hacks' online suggest removing the wheel, applying some pressure to the brakes and then putting the wheel back on? This seems to be taboo?

https://www.youtube.com/watch?v=thGBWhfIaB8

Why are 'lower end' groupset brakes denied what would otherwise be a given on rim-brakes?

Please put my mind at ease 😀

Thanks.

Mefistofelino

When the lever reaches the end of its travel, is it spongy or firm?

CramCycle

Tie the brakes closed, leave over night, job done,maybe check and top up fluid if necessary.

galwayguy85

Hi folks, thanks for tips.

@Mefistofelino, I can't say for certain what 'mushy' is, it's my first bike with disk brakes. I'm starting to feel like rim-brakes are better!

@CramCycle, thanks. I might give that a crack, but it shouldn't be necessary on a bike that's only out of the box a few days (and from a company with a good reputation)?

They're mainly online, but they also have 2 retails stores in Germany (where I live these times). When I was taking the test bike for a few trips around the car park I was almost afraid to pick up too much speed as the brakes seemed a little bit 'too' responsive to light pressure.

The 105 groupset doesn't have a free stroke adjustment screw - a possible explanation. Only Ultegra (and upwards) have this bloody screw... I didn't know that when I committed to buy it - the online consensus being that 105 is good enough for those who are not using their bike at a competitive level. The Ultegra groupset would've cost me another two or three hundred euros.

https://www.rosebikes.com/

galwayguy85

Brakes 'open'...

Brakes making contact with the rotor - seems to be a crazy degree of rotation around the lever 'fulcrum'...

And fully closed... at least when just sitting on the ground. At full speed it surely closes a lot more.. but seems very far back relative to rim brakes...

Mefistofelino

The free stroke adjustment screw is not equivalent to the barrel adjuster on cable brakes. It doesn't remove the slack in the system - it moves the starting position inwards so the levers can be more easily reached by riders with smaller hands. The pad contact point remains unchanged even if the reach is adjusted.

That fully closed position doesn't look too bad to be honest. Sometimes bleeding / topping up of the system can improve the reach.

bwdbwd

Moving starting position inwards is the reach adjustment.

Free stroke is how much you pull the lever before the brakes engage.

Having this problem myself. Would be worth bleeding the system to remove air bubbles or change pads, although not relevant on a new bike.

At a guess bubbles

triggermortis

Sounds like a bleed is required to me. I just got my first hydraulic disc brake bike and the levers don't need as much pull as yours to start working. I thought 105 did have adjustments for reach and free stroke. Mine's 105 as well, but I haven't looked for any adjustment screws yet as it seems ok so far.

Mefistofelino

https://www.boards.ie/discussion/comment/121768948#Comment_121768948

For Shimano, the Free Stroke is the reach adjustment. The pad contact point remains unchanged

https://bike.shimano.com/en-EU/technologies/component/details/free-stroke.html

galwayguy85

It all seems a little ambiguous .. a screenshot directly from the manual (PDF link in OP)

Here a distinction is made about free stroke and reach adjustment - some levers have the functionality to alter both. And some (such as mine) don't. Can't fathom why?

In any case, it looks like it's pretty much normal to have to pull the levers so far back (in relative terms).

Will have to get used to it. 😀

My years old ROSE Gran Fondo has many years ahead of it yet. Coming and going to work (and any hilly rides I may plan).