[Closed] Brakes. Can you have too much...?

Hope V4's with 180 and 203mm rotors. But that's on a fox 36 equipped, 150/150mm 29er.

Zee's, 203 rotors front and back and a fox 32 is a strange combination...

Not really. The 'bigger' the brakes are the less hard they have to work at any point which means they will feel sharper and better generally. But weigh more. Pads would probably last longer though.

Sounds about right. Enduro mag had a test a few years ago and the difference between 2pot deores and zee was 5nm average torque (70/75nm) so not a massive difference. I have 203/180 with 2 pot deores and it's fine for me at 63kg on my big bike.

Presumably you have a beefier fork on the bird?

I'm 85kg.

I'd say go as big as you want/need. I've bought a 220mm front rotor as an experiment. Haven't been able to fit it yet as it won't go on my front hub but RS 35 forks don't deflect anywhere near the same extent as old 32mm forks did.

The advantages of small rotors are weight (the difference between 160/160 and 200/180 can be about half a lb depending on the brands). And heat in winter, I found small rotors would remain bedded in even in the sloppiest conditions so pads lasted longer.

In the dry, with my weight right back I find the rear will only just lock up and the front certainly doesn't.

So in summer I've tended to use 203/180 Shimano Ice tech rotors, and winter 205-160 Hope Rotors.

Personally I dont think so.

Depends on where and how you ride, what surface and what tyre.
Recently I was going down a long steep hill and begun to run out of stopping power. Front tyre DHF Minion, brakes 203 rotors Guide ultimates, me 86kg. Being chased by my mates I threw caution out of the window. It got sketcy 🙂

But for general XC messing about its not an issue.

Im looking to upgrade to some of those Trickstuff brakes.

I think there is something in @TINASs point about pad glazing - that a bigger rotor doesn't get as hot unless you are working it hard. I'm 70-odd kg and only ever run 180/160, even with a fully laden bike.

I’ve got Codes in both my fs and hardtail. They don’t lack anywhere and I’ve never found myself thinking I have too much stopping power.

200/180 on the Bird Aether
200/160 on the Vitus Sentier - although that’s just because I found cheap secondhand rotors in those sizes at the time.

No, IMO. Either brake later or don’t squeeze as hard.

20x F&R for me on all my MTBs, save for a rigid XC bike, but even that is 180 F&R.

That said, the fork stanchions are all 35 or 36mm.

Only reason I haven’t gone bigger rotors is potential warranty issues, though I know the current generation are allowing up to 220.

I'm about 100kg and run Hope tech3 E4. I originally set them up on a 160/160 bike with 183/160 rotors with the thinking being that they get hot enough to keep them working well but not too hot. Never had any fade issues but did need to squeeze pretty hard.

Now running 200/180. They work just as well, I just don't need to squeeze as hard.

Thinking 203/180 for the Bird and dropping the Anthem to 180/160.

Curious about what other folks run.

Whatever is spare and allows the easiest wheel swaps.

Mega has 203/180 and 4 pot and uses a +20 PM/PM adapter ... my old Aeris has 203/180 2 pot and uses a +40 PM/PM .. Jnr's Aeris has 180/180 so I can use his back wheel it's total overkill for his 35kg... I don't have a +20 spare so he's only 180 on the front.
XC is 160/160... cos I've a stack of 160 rotors from when he had smaller wheels that rotors caught on uplifts

I’m 120kg, i use 200/180 on my fs ebike with 2 pot xt. No issues.
200/160 on my surly, with older 2 pot slx, no issues.
180/160 on my cx bike with cable pull something or other, no real issues, but lacks power.
Imo, yes you can be overbraked, if you weigh 45kg and use 200mm rotors you may struggle to get them hot enough to actually work properly.
At the opposite end of the scale, I would overheat 160mm discs quite quickly on a long descent.
A mate has 4 pot zees with 180/160 discs on a genesis tourer, no issues.

My disk choice has crept up over the years from 160/160 to 180/160 to 200/160. Now it's 200/180. Can't see a down side at all.

Yes.

I've had to downgrade the rear rotor on my winter roadie to a 140mm as it was impossible to judge the (typically poor Shimano) modulation on a 160 and there was negligible difference in feel on greasy tarmac between "not slowing down" and "locked", especially when in big thick gloves. Even now, its still a bit more marginal than I'd like.

Years ago I ran a set of early Hope Tech V2s. Bought them for an Alps trip, where they were mighty, but back in the UK in winter, I just couldn't get them hot enough to work properly for a typical "steam down a hill, haul brakes on at the bottom to stop" effort. After a couple of proper close misses I swapped the calipers for E4s and all was fine again.

Bike brakes, big rotors. And bed them in properly.

I've never wished I was less in control/had to pull the lever harder/my brakes overheated easier. I've also never wished my callipers or rotors were 20g lighter either.

Let's be honest, any decent brake can lock either wheel at any point nowadays. A more powerful brake just lets you control it better, while getting less arm pump/fatigue.

No doubt 6pot w 300mm disks will become the latest industry trend now. Brings those face plants alive.....

Not so much "too much brake" but you can definitely have not enough subtlety- the ancient Formulas that I like have all the power I want but can also put down a tiny whisper of that power when I'm teetering on snow or whatever. Same as the brembo setup on my motorbike.

But by and large, the more power you have, the harder it is to use well- like trying to tap in a nail with a sledgehammer. Some people like that, others don't, which is fair enough. Some people like to use a little tacking hammer, because it's lighter and easier to carry around, even though it's really bad at putting bigger nails in...

Thinking 203/180

I'm similar in weight to you and have this set-up with Zees (and Codes) on all my MTBs.

I never feel I have too much brake, or not enough modulation.

So it sounds like you have a trail focused Giant with powerful brakes. I would say, take the rear 200mm rotor off that, and put it on the front of the Bird.

For the rear, I’d go 160 on the Giant, since the Zee has plenty of power(and rear doesn’t need much anyway).

For the Bird it would depend how hot you get them? If you do summer time Alpine descents, the bigger the rotor the better, put 200 mm in rear.
But, it might be harder to modulate, and harder to get them up to good working temps on terrain with shorter descents, so for more all around use I’d go 180mm in the rear of the Bird. You should still have plenty of power on the rear.