A silly question I think but, I guess that the cartridge pad holders are not universal ie, my koolstop holders will only take koolstop pads?
I think there are only two patterns on anything made ~this century~, Campag and Shimano. Someone with detailed knowledge might be able to correct this.
in (short) 'road' inserts this is pretty much true. SRAM uses the same fitting as shimano and most aftermarket inserts. Campag is different to that and I believe there are one or two aftermarket brands which use the same pattern as campag.
MTB brakes and some cantis use a long 70mm insert often called an 'XTR pattern' insert. These are all meant to be interchangeable and mostly, they are
From 2016 (2017 in the case of Centaur callipers) Campagnolo brake callipers also now use the same insert shape as Shimano/SRAM (with the screw), so newer Campagnolo brake pad holders can use Swissstop Flash ProbBXP inserts, older ones the Campagnolo-specific Race Pro BXP
Not strictly accurate.
Campag SR, RE and CH brakes have historically all come with Campag fitting shoes to accept Campag fitting pads.
The pad design was modified to move away from a strictly held-in-by-friction design, to being retained by a clip in 2012. You can use the friction retained pads in the shoes designed for a clip but I'd not advise the reverse - it's not that the blocks will come out under braking (assuming the shoes are fitted the right way round), it's that if you pull the brakes on and pull the bike backwards it's possible (though, TBH, not that likely) that you'll pull the pads out.
The same was true of Campagnolo entry level brakes (excepting some older brakes that had a flirtation with integrated fixing bolts, and some of the TT and Flat-Bar brakes which had their own pad varations), until 2015 when Campagnolo launched the "un-ranged" brake, basically a lower-cost Chorus 2015 unit. These brakes are generally now matched to Potenza and Centaur groups (and occasionally, as the cut-price merchants see the opportunity to <shock> make a profit on what they sell this way), Chorus groups. The pad holders are Shimano style, with a screw to retain a Shimano-type block.
The pad holders on the current Chorus brakes are likewise Shimano style.
SR and RE brakes are unchanged in this respect and use a Campagnolo spring-clip retained pad, as do the DM brakes.
As a generality, where users are running Shimano rims, we recommend Shimano pads. Likewise Campag with Campag (Campag compound for Shimano holders can be had - BR-CA500 - which helps out all the Shimano and SRAM riders running Fulcrum or Campag wheels), Miche with Miche, Mavic Exalith with Mavic Exalith etc. Pad compounds are developed by wheel makers in tandem with the rim materials and generally they are a good match in terms of wet and dry performance, as well as in terms of maintaining the condition of the brake tracks. In each manufacturer's case, they may well have a specific pad recommendation from within their range, for a specific rim material or treatment.
We see people assuming that (say) just because Mavic Exalith pads are made by SwissStop, they can run a SwissStop pad of similar appearance - this is not necessarily the best pad for the job and can compromise braking as well as rim wear rates. This reflects the fact that OE product is often different to after-market product. At the Campag Service Centre, we've seen Campag alloy rims destroyed by third party pads as well as Shimano rims (yes, we see those in our workshops too) damaged by third-party pad compounds that are too hard. Likewise we've seen too-soft pads disintegrate as a result of heating - not to mention the much-vexed problem of inappropriate pads being used on carbon rims with very negative results for the rims.
A few years ago I was at a wheel manufacturer (not, this time, Campag) where after market and incorrect OE pad materials were being lab-tested on alloy and carbon rims from the manufacturer concerned. Some of the results were positively scary and made me very glad that I wasn't trying to ride some of the tested combinations down a mountain, or in heavy traffic ... the maker's own pads performed flawlessly, even up to circumstances that produced 300-325C at the pad-rim interface (not as uncommon as you might think).
