Anyone know anything about disc brakes?

yep

There's no reason they shouldn't work together.

something I'm doing wrong then. Will have another go tomorrow.

It's always possible that the IS mount isn't straight or is painted which is twisting the adapter

So I need to replace pads on my commuting bike and am taking Shimano j02a out - any reason to look at any alternatives? I don't do much maintenance these days so wonder if metal would last longer, but am also fed up with noise....

I switched to swiss stop but that's not saving any money or increasing pad life.

Current version is J05a which are supposedly longer lasting than the longer lasting j03a you skipped, you can get the K05s-rx if you don't need fins, which you probably don't fit commuting.

Ooh useful, cheers - yeah didn't think these lasted long, upgraded versions would be good

I've always found them to last OK anyway, but they now apparently last 40% longer + 40% longer than that, whatever they works out to with maths.

whatever they works out to with maths

To a close enough approximation, 1.4²=2

Can’t find anything on here about the Juin Tech cable discs. Leaving aside hydro vs hybrid vs cable, anyone got any experience with them? Much difference between the 2 pot and 4 pot (F1 vs GT). Compressionless housing essential? Thanks

F1s were the best brakes I'd had before GRX, never tried the 4pot. Compressionless housing isn't essential for anything but it makes a really big difference, especially if you've got a full run of outer, so is highly recommended.

I’ve got 105 hydro levers which I like and work, and had 105 callipers which were fine but leaked. Tried Hope callipers which are too fiddly to set up for my lack of patience. Should I get new 105 calliper or upgrade to an ultegra, or is there another aftermarket hydro caliper that works nicely with shimano levers?

Apparently I haven’t had a disc brake related question for 9 years, but I enjoyed this.

Anyway, I have a road bike, 160mm front and back, flat mount, shimano 105 currently. I want to achieve the best braking possible (I’m tall, I always weigh too much to be any good at cycling and currently weigh even more).

What is my best plan of action? Buy mtb callipers, bigger discs and adaptors, if the discs will clear my frame? Am I restricted to Road callipers? Am I right to feel that road callipers are less powerful than mtb, and if so why….?

Please and thank you in advance.

How big are you? I've run 160mm front and rear Ultegra and have ridden everywhere with that setup. What pads are you using? How do you brake? Are you scared and dragging the brakes or doing 100kph and wondering why you don't stop in 10m?

Missus has had 105 calipers on her Sequoia from new and has gone from cable to Di2 shift levers (so there's been at least one bleed in that time) and never had issues. Maybe you just got a bad one or maybe someone got a bit frisky with a screwdriver during the install? Anyway, I'd just stick 105 or Ultegra on (I have Ultegra but I don't know the difference between them and 105 calipers)

The braking power is similar across all the Shimano calipers, you could get some hope rx4 calipers which seem more powerful but are a bit more awkward to set up. Easiest is 180 front rotor but you might be limited by the fork. TBH they should work plenty well enough as is if they're working right.

Big statement but bigger [/fatter] than you 🤗

6’6” and 124kg at last count, ideal weight is normally 110-112kg.

I had it serviced and he put shit pads on, which I accepted because I didn’t know better. First proper downhill they stopped doing anything much at all which was terrifying, I stopped by wearing down my heels on the tarmac.

Took it to another shop immediately who replaced the pads with shimano, checked the fluid, and gave it a once over and they’ve been ok ever since, but I got discs because I wanted them to be good not ok.

I am more at the doing 80kph and wanting to stop asap end than the dragging the brakes end.

First step sounds like servicing them properly, myself, so I learn more about them, and then maybe swapping to hopes and a 180 front (which I think I have room for).

Am I naive to think that mountain bike brakes plus the biggest rotors I can fit would give me better stopping? I don’t mountain bike and haven’t found anyone asking the same question really. Are MTB discs “better” or are they just “different” somehow.

And is it wrong to want the best possible stopping power? It means I can go faster 😬

What road bike do you have? The frame and fork will determine how big a rotor you can run.
What make and model of brakes are you running?
Not all bike shops are created equal, you might have a shitty bleed that's stopping you getting full power.
Bigger rotors will give the most benefit but you probably won't be able to get bigger than 160mm on the frame but the fork might be able to take 180mm.

I'm 100kg give or take a kilo or two depending on which way the wind is blowing.
I run 160mm discs on my road bike with hope rx4 calipers and they stop me ok.

Articles say eg “I can’t imagine needing the same stopping power on my gravel bike as on my trail bike” or “as gravel bikes get more aggressive they will need more mtb-style brakes” but why not just have the “best” brakes possible - what am I missing!

Thank you! [and thanks @hippy and @snottyotter too]

Levers and callipers are I think 5800 (105).

Bike is a random custom steel I bought second hand. It has a 38cm tyre on it currently - it’s not a proper gravel frame but can fit 35s with mudguards front and rear. I think it will have enough clearance for a bigger disc on the front, I assume it depends on the angle the fork “leans in” towards the headset, ie how vertical the forks are vs the centreline of the bike?

Good to know they work for you, they are probably what I will get but want to work out if they’re absolutely the best first.

When I’m back in shape/a bit lighter it may matter less, but 100kg to 125kg is still a big leap!

Bear in mind that I'm 90+ kg but I'm also riding around with a loaded bike (touring, racing, etc) so system weight is more likely well over 100kg.

Were the brakes you used actually bedded in? Disc brakes don't work if the rotors are fresh, they need some hard stops to work properly.

I'd check the frame and fork can actually take bigger rotors before thinking that will solve things. Are there actually adapters for flat mount that will do bigger than 160mm?

The other thing is - I can lock up the wheels with 160mm front and back so the limitation here is tyre traction, not brake power.

It sounds more like you had a shit set of brakes or perhaps the brakes weren't bedded in and it's put the willies up you.

Get an MTB with huge rotors and 4-pot calipers and you're just gonna lock the wheels up and now you're not stopping because the tyre is sliding down the road (or more likely, you're on the deck)

The rotors weren't changed in the service, and the pads were disintegrating! I can’t at all remember what they were, I think two people’s names, not a brand I’d heard of.

I think you can get the right adaptors (hopefully for less £ than that is I go that route) and that site is the first I’ve found that suggests I’m not entirely crazy