Semi Hydro discs help

DeVlaeminck

My Genesis CDF has semi hydro discs and the braking on the front is weak - the lever doesn't bottom out on the bar but it just doesn't seem to stop the bike very well at all.

Can anyone give me a brief checklist of things I should work through to get this thing working as it should ?

ugo.santalucia

Does it have compressionless cables?

Is your caliper set up correctly (meaning the rotor is fully in contact with the pads)?

Are your pads new and need a bit of bedding in?

DeVlaeminck

OK thanks will check cables but they are the ones it came with so I would guess not but the rear works pretty well with same cables.

Pads aren't new so would have bedded in but not old enough to be worn - was wondering if they'd been glazed/contaminated and whether that could be remedied by light sanding ? Rear pads were replaced as they went missing in an accident - whoever put the bike in a car when I went to hospital which I assume was my wife lost them when they took the wheel out so they may not be the same type. It's possible the bike has also been left upside down when that happened could that be a problem with hydraulic brakes - worth bleeding them ?

Will have a look at the rotor - I haven't adjusted it since purchase but I guess that doesn't mean it is straight.

meanredspider

It would be useful to know what calipers they are.

Were they once working and now they aren't?

Cleaning the pads up or, better still, replacing the pads then doing the proper bedding-in process will be important.

DeVlaeminck

TRP Spyre on a 2015 Croix de Fer 20. Out of the box I found the brakes a little underwhelming but they seemed to get worse over the month I had it before getting rear ended by a car.

I got a shop to fix the damage and that included the new rear pads which seems to have made the rear brake better than it was so I guess that points to the pads being the problem. However the impression I get is that the front is worse even than it was - I've not ridden it for 6 months so could be wrong but either way it's pretty poor and definitely not giving me the kind of power some of you seem to be getting from those brakes.

I'll give the pads a clean up and see what happens - suppose I could swop the rear to the front and see what happens - assuming that is possible it would tell me if the pads are the issue or not.

ugo.santalucia

DeVlaeminck wrote:

TRP Spyre on a 2015 Croix de Fer 20.

Spyre are not semi-hydro, they are conventional mechanical disc brakes. Might have contaminated pads or poor caliper alignment

meanredspider

ugo.santalucia wrote:

DeVlaeminck wrote:

TRP Spyre on a 2015 Croix de Fer 20.

Spyre are not semi-hydro, they are conventional mechanical disc brakes. Might have contaminated pads or poor caliper alignment

Yes this or glazed pads: if not bedded in properly, they gradually get worse - I think it's a bit of a viscous circle.

My advice would be as I suggested before: get new (suggest organic) pads and do the set up from scratch including a proper bedding-in process. Also give the disc a good clean before putting on the new pads.

DeVlaeminck

OK they aren't spyre they are HyRd. Will try the pads

meanredspider

DeVlaeminck wrote:

OK they aren't spyre they are HyRd. Will try the pads

That makes more sense. With the HyRd it's important to use the lever pin when setting up the cable tension. I think it's covered well enough in the manual but it is a really important step to be sure they operate correctly. My LBS screwed this up and I found myself on the 12% bit of the Alpe with no front brake...

ETA - this won't be the cause of your issue but it's key to changing the pads.