My original calipers both started having sticky piston issues after around the two year mark.I switched my wife’s bike which had an aging XT 2 piston to the latest SLX 4 piston.
There was a noticeable power increase. She’s not that great at modulation so can’t talk about that aspect.
Just replacing an aging component with a new one is an advantage
I'm just over 100kg kitted up, I suppose that extra 25kg makes a difference.I tend to be a "don't fix it if it isn't broke" type of person so I'd probably just leave it if it was me. I am 77kg fully kitted, so my 2 pot XT brakes (2 bikes) and Avid BB-7 brakes (3 bikes) stop me fine with a 185 rotor up front and 160 rotor in back.
I do like the instant bite feel I get now. Did a really long steep descent a couple of weeks ago and had rear brake fade for the first time but realised it was in need of a bleed so maybe it wasn't brake fade after all?I wouldn't. If you start noticing fade, go with a bigger rotor. In my experience 2 pots are sharper and grabbier (instant bite) while 4 pots are more powerful and have more modulation. This is coming from my testing with Shimano, Magura, and Formula.
Yes, good point @2021Mach6 and would have blamed a bad set up or worn pads etc. but Buddy's Zee's are all good. He's not into bike maintenance so I did a lever bleed on them and replaced the pads recently so I'd say they were 'normal' with nothing that would effect their true performance.What size rotors and what kind of pads are you currently using? And do you know what condition those Zee brakes were in?
😆 Yes it's a month after Christmas, it's winter so I've not been putting as many miles in so my 100kg is a conservative estimate. That time of year when pads wear down quicker and brakes feel less powerful. 😃Brake pad replacement costs may rise, lol.
I am a fairly 'late' braker and rely on an immediate and predictable lever response, so good ole 2-pot XTs with metallic pads on a 180 rotor worked well for me. However I seem to have gained a wee bit of weight and a slightly smaller bit of my old downhill speed back, and found I needed brakes with moar powwwwwwweeerrrrr!
So I just* upgraded my rotor and swear I got at least that paltry +10% in braking power that switching to 4-pot gets you.
It's also a consumable that was fraction of the cost of new 4-pot brakes without the built-in added cost and potentially reduced reliability of 2x the pistons/seals and pads.
I'm running a Magura 203 MDR-P rotor now, so it's a Mag-mano setup.
Stopping power is noticeably improved, and I am getting zero fade over some fairly lengthy descents.
Plus it looks pretty bad-a$$, imo!
View attachment 1967667
*I also 'just' flushed my lines and installed fresh metallics with the fancy fins. But it was really all about the rotor!
Edit: Qualifying my 'nah don't bother' poll response to acknowledge that if you are on the biggest rotor your fork can take and are using metallic pads and still want more brake, then 4 pot may be the last best option.
Your right of course and this upgrade would be the first time I've contemplated replacing a fully working component without really having a good reason to.Nope... unless you have overheating or other issues.
I built up a 150mm FS 29er a few months ago and put XTR 9020 2-piston (with 180mm Ice Tech rotors and metallic pads) on both front and rear. 2-piston are lighter in general. These brakes, a set of older XTR 8020's plus SRAM ones I run on other bikes slow down my ~200 lb / 91 kg jolly carcass quite effectively. With a fluid replacement on occasion (couple years or longer) none of gotten sticky or wear pads unevenly.
I tend to agree with this (2 pots sharper than 4). I've swapped XT 2 pots for XT 4 pots and experienced exactly that on two different bikes.I wouldn't. If you start noticing fade, go with a bigger rotor. In my experience 2 pots are sharper and grabbier (instant bite) while 4 pots are more powerful and have more modulation. This is coming from my testing with Shimano, Magura, and Formula.
Could be wrong but more piston surface area pushing on bigger pads with more friction material is the only reason for the small power gain and better heat dissipation?I don’t think you will notice a night and day difference. I think the biggest gain is heat management given double the pad area to absorb and dissipate heat. I often wonder about the physics: given same master piston and two different sizes of slave piston, force should be the same? How does more friction surface area play in if at all? I’d like to hear analysis on this.
to this point i have magura trail sports on my fat bike with 160 rotors. I run 203s on other bikes but don’t get going nearly as fast on my rigid fat bike plus mainly winter/ snow riding conditions. They have 4 pot front/ 2 pot rear and i never notice a difference. Although the recent magura interview on Down Time claimed 4 pot has more power and 2 pot has more modulation. Maybe i am not sensitive enough to notice.
final thought: i love my 8000/mt5 shigura setups (so much i run it on 2 bikes). But discovered the hard way, if you buy magura calipers only they don’t come with hoses and more importantly no banjo. That adds $100 to the pair so it’s probably more expensive to buy magura mt5 calipers and brake lines (to get the banjos) a la carte than it is to just buy the entire brake assembly.
That's some willpower right there. I wish I had you discipline! Couple unnecessary splurges, but mostly tires and brake pads.Your right of course and this upgrade would be the first time I've contemplated replacing a fully working component without really having a good reason to.
