Author Topic: FSA brake callipers  (Read 239 times)

Feanor

  • It's mostly downhill from here.
FSA brake callipers
« on: March 06, 2019, 06:16:56 pm »
I've recently acquired a TT bike from someone at work who is giving it up.
It's a Cervelo P2.
I did some fettling last night, and there was one thing that was tweeking my mechanical OCD funnybone.
The FSA rear brake calliper.
Now, I know these don't get much use on a TT bike, but it was irritating me.

The Zipp pads were rammed in to the pad carriers, but not fully. They were sticking out of the back by about 5mm, which looked shit.

Two things became apparent:

1) The pad carriers on these FSA calliper are not compatible with regular Shimano-pattern pads like the Zipp ones. The Shimano-pattern pads are slightly curved to match the rim curvature. The FSA carriers are straight, and so the pads just jammed part-way in.

2) I noticed they were assembled incorrectly: The correct order is pads - concave washer - calliper arm - flat washer - nut.  So the concave washer allows for pad angle adjustment.
But they were assembled pads - calliper arm - concave washer - flat washer - nut, ie the concave washer was on the wrong side of the calliper arm and was useless.

The reason for this became apparent.

Took a new set of SwissStop Shimano-pattern carriers with new SwissStop carbon blocks and tried to fit them.
No go.
The FSA calliper does not open wide enough to accommodate standard Shimano-pattern carriers and pads between the arms and rim.
The previous owner had bodged this by shifting the concave washers to the wrong side of the arm.

Found a spare Shimano brake calliper, and indeed it opens by several mm more.
Replaced the entire calliper and fitted the new SwissStop carriers and pads and all is well.

There must be FSA-specific pads which you need for this calliper, but I want to use the Shimano-pattern carriers and pads so the FSA calliper is now in the junk box.


zigzag

  • unfuckwithable
Re: FSA brake callipers
« Reply #1 on: March 06, 2019, 07:31:34 pm »
perhaps the calipers were from an era when narrow rims were the norm?..

Re: FSA brake callipers
« Reply #2 on: March 06, 2019, 07:44:06 pm »
^

But apart from this FSA stands for Fucking Shit Apparatus.

Re: FSA brake callipers
« Reply #3 on: March 07, 2019, 12:54:40 pm »
more than one type of FSA caliper, so it isn't clear what the issues really are.


FWIW shimano-fit road inserts are usually handed (i.e. curved externally) but the holder slots are perfectly straight, as are the inserts themselves where they fit in the holders. A little soapy water helps if they are a tight fit but if they are simply the wrong thing then they will need cutting down/making thinner to fit.

XTR type inserts are straight or slightly curved; however they assume the curved shape of the holder either way; rubber is quite squishy stuff.

FWIW XTR inserts can be cut down and used in 'road' holders; the interface to the holder is very similar but the net result isn't as secure. Note that XTR inserts are usually ~1mm thinner than other road inserts (which are BTW available in different thicknesses from shimano amongst others anyway) so I would imagine that you could make your brakes work this way if push comes to shove. Obviously you will have to cut a slot in a cut-down XTR insert  so that the retaining screw still works properly.

Note also that non-toe adjustable shimano pattern holders usually have a washer between the holder and the caliper arm too, but this washer can be safely moved to the other side of the caliper arm if needs be, leaving a holder that needs less space to work properly.

cheers