Anyone know anything about disc brakes?

Earplugs?

Actually it's the correct length, so small drill bit and good to go? Shimano make out like you just connect and pull the lever and all is well.

The seal isn't particularly strong so I'd imagine that fluid would burst it when you pull the lever, never tried though.

Ta for the advice, think I'll pop the seal and go for it. Wil update with the outcome.

In the OEM factories they don't break the seal before installing the lever, that's why on your first brake bleed you'll often see little white bits floating in the fluid.

Ah okay, so just assemble and tighten up, press the lever and all good 👍 haven't got spare olive and brass thing plus the tool to install and bleed kit etc and just want to be sure I can install without all that as I don't want my bike out of action while waiting for stuff if it doesn't work.

Personally, I use a pick or knife to take out the seal, if you're careful and do it just before installing the lever, then you won't lose any fluid.

I just let the seal get punctured during fitting - the needle just pushes through it. Looked like some kind of hard wax. Doing anything with the seal increases the risk needing a bleed.

Ultegra r8000 series calipers. One piston seems not to be moving. Anything I can do to sort it?

Yeah, you basically hold one piston in while pressing the lever to advance the stuck one and clean it. (Be careful, you don’t want the piston to pop out completely!)
This park took video explains it well

https://m.youtube.com/watch?v=vQXFFgRButo

https://m.pinkbike.com/news/tech-spotlight-brake-caliper-piston-service-assessment-2014.html

For my current post-mount gravel bike the last few years I've been running a set of GRX levers hooked up to some M7100 post-mount calipers with BH90 hoses.

Moving soon to a flat-mount frameset I'm trying to decide whether I should get a set of GRX flat-mount calipers or possibly something else such as the flat-mount version of the M7100 brakes.

Seems to me the MTB brakesets have much cheaper brake pads and as I've been quite happy so far with the M7100 brakes.

So, am I missing some strong reason to go with the road/gravel standard brakes and pads?

Flat mount ones all use the same pads K without fins or L with in shimano codes, they're essentially the same brakes across road/MTB with the usual small material/finishing difference as you pay more money.

I'll get MTB as the bloody road pad retainer pins are shite.

Ah right, that does make sense that they do actually use the same pads. I guess I'll just go with whatever's in stock and reasonably priced.

Folks can anyone ID what brake pads I need for these brakes? Front is Shimano Deore, unsure what the back is, might be the same, on a 2018 Urban Arrow. Hydro brakes. Ta

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There's a code on the other side of the caliper.

Front: should be M6000 IIRC.

Either G05A-RX Resin (w/o fin) or any G coded pads or J05A-RF Resin (w/ fin) or any J coded pads.

Rear: MT500

B05S-RX Resin (w/o fin)

Do also check the rotor if it is resin only before switching to sintered.

Noobie question, but trying to fit new pads and they touch the rotor because obvs much thicker than what was there before. Tried to reset the pistons but they won't recede enough to make it all fit. Does that mean there's too much fluid in the system? Is it a good idea to open the shifter screw (Ultegra) and reset the pads, so a bit of oil bleeds out?

That can help, yep

does anyone find the r8170 lever throw absolutely huge? or have I just got massive bubbles in both brake lines

All the Shimano hydros have somewhat large throws if you're used to rim brakes set up tight, but it shouldn't feel massive, and the servowave ones like those don't feel that big at all. I vote for better bleed.

i adjusted the reach and free throw and it is much better - but seems the rear definitely needs a bleed!

Noob question please.

I've got some new Deore M6100 brakes. They are bled but not connected up. If I'm not cutting the hoses, what do I need to do to get the juices flowing. They have come capped with some sort of capped-barb-thing (see pic), not with the simple pull-off cap shown in the instructions.

Do I remove the capped-barb-thing and replace it with a normal barb? Or leave it in place and pierce it with the new barb? Or something else?

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Ah ignore me this was answered a page ago - answer is pierce it with a small pokey thing, or even just leave it there and let the brake fluid push it out the way

I'm after a bit of advice please.. I was bedding in some new front pads this morning on the way into work, on Sram Force brakes and shifters. After 3-4 hardish stops along a flat bit of road, the brakes lost bite and I could pull the lever back to the bars. After a short while it went back to normal. Any idea what causes this? Heat? I wasn't exactly working them hard.

In general I've never found them to be great in terms of stopping power. Is the Shimano equivalent thought to be better or are road hydro brakes of all brands inherently less powerful than low-end MTB (my only comparison point)?

I know with Shimano that but master and slave cylinder/piston sizes are the same for both road and MTB twin pot brakes so they are as powerful as each other. The real difference IME is hand position on the levers, your hands can pull MTB levers more easily.

Any idea what causes this?

Sounds like they need a bleed.