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I'd like to see more vids of components being torture tested.
Good grief the new brembo brakes have to be the ugliest things I've ever seen, it makes the mavens look like a piece of art. After looking at my intends, the brembos make my eyes recoil and blast backwards in the brain.
There are so many people that work on the development of a brake, can't imagine there wasn't at least one guy that said what in the f is this aesthetic. They could be two times better than my intends at half the price, won't ever put those on my bike
Exactly. Probably begins losing elasticity as the molecule chains get cooked.
I'm bored at work and reading Brembo's article about the new brakes, and one thing definitely stands out to me (besides the higher hydraulic leverage than Mavens !!!):
"The braking system, both front and rear, includes an axial brake master cylinder that, in addition to the two common adjustments (lever distance and free stroke), also features center-to-center adjustment, allowing riders to customize the braking feel according to their preferences."
Center-to-center adjustment?? Is this Brembo's terminology for a leverage ratio adjustment like the Lewis LHT? If this is the case, it's hidden in the lever very well. Looking at the lever, there's no visible pivot point other than the main lever pivot, which leads me to believe there's no cam mechanism in there. In that case, I'm at a loss for what else this adjustment could be on a direct-link master cylinder.
I'm surprised more brands haven't done that yet it seems very useful on the Lewis. Coming from someone who likes their brakes touchy.
On the topic of those Brembos has anyone come to a conclusion on fluid in that system? It's not DOT since it's red.? Any ideas if it's mineral oil or their own formula?
Formula fcs lever has similar system and it's very well Hidden.
Hi brake nerds! I'm looking for a sanity check on a brake mount I've designed. Does this look sane or insane? Thanks in advance!
SRAM and some others would say sane.
https://www.pinkbike.com/news/sram-patent-hints-at-universal-brake-moun…
That looks to be skinnier than the one I've designed. I'm hoping that means mine won't fail hahaha
I like both your thought experiments and proposed real world experiments. I did not know that brake fluid was such a poor conductor of heat, that is really interesting.
Having said that, am I crazy to think that getting even a small layer of the fluid up to the boiling point could be problematic? In other words, these hypothetical hot pistons will transfer heat fairly readily to the fluid layer in direct contact with them, I would imagine. The fluid may then not as readily transfter the heat throughout the rest of the hydraulic system, but it doesn't seem like you'd need to boil the whole system for it to be a problem. It seems like just the immediate layer right around the pistons would be enough. I am thinking of when one is boiling a pot of water, and before it reaches a full rolling boil, you start seeing bubbles coming of the layer of water in direct contact with the heated surface at the bottom of the pot.
I haven't looked into aluminum piston properties myself, but the great thermal conductivity of aluminum (when compared to steel) is why Shimano sandwiches it in their Icetech rotors. On the other hand, while aluminum may conduct well internally, it also has fairly high reflectivity and low emittance, which is why aluminized materials are often used in radiant heat barriers in construction and HVAC systems, so if Brembo had a piston face that minimized surface contact between the piston and pad backing, that might work in their favor.
Considering they call them “isolated” pistons and there’s a visible line inboard of the edge of the piston, I think they are using an insert for insulation like a lot of brands are. You can see a very real increase in caliper temp using stainless pistons. I would not want aluminum with no additional insulation.
Right. Part of the joy of All Clad cookware is the aluminum core that helps heat the pan evenly. Brembo looks to be using a phenolic insert.
I just use side cutters or diagonal cutters and send it. It's worked sweet for all my braided. You could also use a cutting disc and wrap some insulation tape around your cut point.
I feel you. We should go in together on some "contact adjust is cheaper than therapy" shirts.
For me, my one set of Mavens has a shorter throw and I don't need to cheat pads as much. I've run Codes forever, and still have them on my other two bikes. I always end up cheating the pistons out some when the pads have worn to about 3.5 total width. I can generally get them back where I've got some room in the contact adjust band to get them feeling the same and keep them there as the pad finishes its life. But maybe I'm not overfilling/pressuring as much right from the start as you are?
SRAM is not cool and boutique, but you can set them up just how you want them and the parts availability is fantastic. I love being able to rebuild MC and calipers and always get whatever I need.
Could it be that people who brake hard for shorter distances and let the levers fully return to resting position get along better with SRAM brakes whereas people who tend to hold the lever within the dead stroke more get bothered by SRAM?
Im just going to comment on the last part.
IMO I feel like every single person i've ever met that has complained about Sram brakes I notice they are always brake draggers - which are the same ones who Grip their Grips as hard as possible all the time... then they complain they get sore hands/Arm pump.
Im not going to lie, When I first Used The Code RSC brake I used to get sore hands/arm pump alot easier and it wasnt untill I met a really good rider on the Chairlift he just said "do you brake when driving at the speed limit? Brake when you actually have to, If it feels to fast for you - ride some slower trails to get muscle memory"
I ended up learning how to ride Harder trails, my arms werent as tired, I actually went alot faster than before and as a bonus, my pads lasted considerably longer.
A side note to above, I believe this is Why some people destroy Those Green Race pads galfer/hope(galfer)/sinter etc The constant dragging just destroys them with heat.
Most people moaning about Codes a few years ago also ran Rs from my experience. Very few people running RSCs complained about them. Maybe today when more powerful brakes are available, but not 5+ years ago.
I think Sram did themselves a big disservice by even offering a Code R, they should have just started the lineup with Code RS.
Code RSs still uses bushes for the lever pivot and they always just wear and feel crap very quickly. I have no problem with bushes in Shimano levers but SRAM ones just don't last well. Code RSCs are on another planet in terms of longevity/performance just because of that IMO.
I have a "BMX background" (lol) and often don't even cover my brakes let alone drag them. Still don't like the SRAM feel and prefer extremely light levers, will not use anything other than Dominions now. Still get arm pump 🥲 even when I'm climbing/bouldering fit. But the lighter lever feel definitely helps it.
I changed my setup so that the lever is super close to the bar and I stopped getting arm pump instantly, and I’m on Code RS.
I would venture to say 75% of arm pump occurs bc of brake lever setup, 10% how the brake is used and 25% bc the brake system itself. That's 110% true.
I've talked about my hand problems a lot, but brake setup plays a huge role. It's part of the reason I've tried so many different brakes.
What I found is that brakes with a ton of power but super linear pulls (Maxima, MT7, Code mainly) don't help and/or make issues worse for me. This comes down to power delivery but also ergonomics and how that power delivery influences power delivery. Some brakes just can't be run close due to the lack of power early in the lever pull. If the lever has to be shot out into space to get power from it, it'll change where your hands engage with the bar and where the pressure points are. Further out and your hand rotates more inwards towards the stem, closer in and it rotates further outward. How this helps or hurts depends on your hands/bars/arms/etc. You can experiment with this somewhat by putting the lever out at extreme angles, pulling it, and noting where your hands feel tense against the bar, move it all the way in and repeat to note the difference.
This is where very grabby, very strong (Maven, Intend, T4V4, Radic) brakes make a big difference for me esp if they have contact adjust. You can tune the lever position based on where it feels best and make adjustments to mitigate or reduce arm pump. Everyone has different hands/arms/wrists/etc, but also bars have different sweep and riders use different roll on the bar (which influences sweep angles also). For the average rider without issues, it may seem pedantic or fiddly to mess with this, but for people who have problems or issues, it can be a remarkable change in how you feel riding. I wish I had an objective way to measure and map this out, but being sensitive to it - it's pretty easy to feel.
Point being, I find a direct correlation to brake lever position / braking power delivery and how bad my hand issues get aggravated. If you experiment with lever positioning and pull, you'll probably find that the pressure points on your hands move as the lever position is moved in/out.
I don’t know about all of that I just know that the more outstretched your index finger is, the more strain there will be on your forearm. Being able to ride with that index finger curled closer to the bar reduces that strain immensely.
190 kitted out and my Guide RSCs are right at the limit. I just love the ergonomics, though.
Yeah that's brake setup 101 IMO, people who run their brakes half a mile away from their bars are cooked.
I wouldn’t put my 45kg beginner rider wife on those things
Hayes Dominion A4 weirdness - looking for advice.
One of my dominions keeps losing bite point. I bled the brake it an the bite point was feeling sharp and where I wanted it, after a couple rides the bite point kept pulling in towards the bars further and further to the point where the lever was pulling all the way into the bar. I did another lever bleed to get the air out of the system, which returned the bite point to perfect. Riding around the parking lot it felt mint. Again on the first ride the bite point completely disappeared. It seems like there is an air gap somewhere into the system, but no brake fluid is coming out of any of the ports or elsewhere. The system seems completely sealed so far as I can tell. Looking for advice - front brake lever pulling into the bar is scary! Thanks
Likely that there is air elsewhere trapped in the system. You may need to do a full bleed instead of just a lever bleed.
Dislikes very pinkbike, it’s a brake nerds thread not a crap brakes, let’s be honest with ourselves
As Jaloypj said, do a full bleed. Also, double check that the hose nut at the lever is fully torqued. When I had them, at least once I thought I had it tightened up enough, but the bleed felt like crap. I put an actual torque wrench to bring it up to whatever value they say, and ended up turning the nut like at least 2 full rotations more, and the problem went away.
Clean the calipers really, really well and make sure they are completely dry. Go ride and inspect afterwords to verify that they are not leaking anywhere. I have both heard and seen that the newer Dominions have been prone to leak which can cause issues similar to a bad bleed even when there is no air in the system. But first make sure that there is no air in the system, full bleed and work the pistons out to make sure nothing is trapped behind them. Hayes has been quite good, from what I have heard with the warranty process if that is the issue, leaking.
https://youtu.be/yKDVB37AOic?si=UjivGrJdZkxmFB-Y Interesting video regarding brembo’s DFM methods for F1 brakes. I’ve heard some anecdotes about how F1 brake fluid is vastly superior to DOT fluid, but after looking at the composition details it’s still poly- glycol ether based fluid, same as DOT. Will try to get my hands on some as I have some connections to a LMP race team with a few Rolex wins.
I have a feeling that as I have theorized, system fluid pressure is key to management of the fluids boil point, and the idea that using phenolic or other thermoplastic inserts are more armchair theory vs having any practical application in high performance applications especially considering that F1 or LMP car brakes operate at temperatures that no mtb brake would ever hit, >800c. I have a few phd chem eng. at work and will have to pick their brains on the idea of localized boiling and if that’s an actual fluid phenomenon that could cause degradation but I have a feeling that the heat flux isn’t high enough to cause that to happen even if the thermodynamics support the idea. Pretty wild to see how little material is used regardless of the forced induction aero being used for brake cooling. Interesting stuff nonetheless.
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