Anyone know anything about disc brakes?

I meant buy some shimano brakes.

cantis?

Obviously.

They're on my other bikes.

SM-RT76-M, much overhang.

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What's the height of the pad? My Avid G2 rotors have more metal than the Shimano ones, only have 160s but could measure for comparison...

Pad is 20mm.

Superstar rotors all have a 17mm track depth. Apparently Hope V2s are 20mm whilst Hope M4 are 14mm... But Hope V2 is an old design and comes in 183mm, not 180mm.

Hope Mono Trials rotor would be OK, but since I'm not actually doing trials I'd rather not use a rotor that's made of holes.

Avid G2 is 16-17mm so not much use either.

Hope V2 and some washers?

IS mount caliper, IS Mount fork, no adapter for 180mm...

Buy a shimano brake.

You're running Echo right? Match it with their rotors?

£19 here, but as per the Hope Mono Trials rotor, I'd rather a rotor with more metal and less hole.

Anyone got a SRAM bleed kit in SE they fancy lending me? Cleaning the piston the fucking thing fell out. That'll teach me to do any sort of bike fixing whilst hungover

Be very careful when you push the piston back in - you can damage the seal and end up with a perma-leaker

Why?

I gently pushed it back with a tyre lever, it's moving but now with not enough fluid to push it all the way out. Total crash course, sigh.

Less bite, but more power and less pad wear.

Probably heavier, stiffer rotors too.

We'll agree to disagree but my current setup - Shimano M615 with original organic pads is more than adequate.

The pads do wear out quick compared to sintered ones but they offer better modulation/feel.

Rotor wise it's an Avid and the only time I've ever replaced one was after a bad crash.

The holes are there for a reason, it allows for better dissipation of heat and the Echo rotor is quite likely designed to work with your caliper.

You sure less holes won't cause your caliper/fluid to heat up? Point to ponder...

Intrigued to know what these weigh... It has to be very close to the specs of the ksyrium pro to be considered.
http://www.chainreactioncycles.com/mobile/shimano-rx830-road-disc-wheelset/rp-prod121497?gs=1&gclid=CKC1tNuRkMsCFQoCwwodjHcISg&gclsrc=aw.ds

Bike Radar review says "Our set weighed 1860g for the pair (840g front, 1020g rear) excluding quick releases"

That's pretty disappointing when aksiums cost £400 less and only weigh 100g more...

Shimano are wider and proper tubeless though... Assume the hubs will be pretty hefty, but easily serviced...

Fair points. I'm focusing on weight too much.

There are two types of friction at the rotor-pad interface, abrasive friction and cohesive friction.

Abrasive friction is destructive and is what gives you brake dust and worn rotors.

Cohesive friction happens between similar materials, hence the need to bed-in new rotors and (ideally) to clean the rotor and bed-in again when changing pad compounds. Heat causes the face of the pad and the film of pad-residue on the rotor to become sticky creating bonds which break as the rotor moves. Cohesive friction doesn't work at low temperatures (no stickiness, no bonds to break) or at high temperatures (bonds break too easily).

Further reading: "Cohesive Friction vs Abrasive Friction", Bendix, 2007.

You need surface contact for cohesive friction, whereas edges give you more abrasive friction. Trials riders say edgy rotors give you more bite, wheras smoother rotors give more hold. Trials riders don't have heat problems, so having less metal to sink the heat away isn't a problem for them.

I'm not too fussed about rotor weight since the radius is so small, so I'd rather have a smoother track with more cooling nearer the hub (like the Shimano RT99 FREEZA).