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I’d love a test done better
Also not only output for the given X force of 40nm
But also choose 10 and 20nm to show the force required by the x brake system to achieve what power
And even, x nm at the caliper, how hard do you have to squeeze the lever to get there
And he’s, making sure everyone is running the same pads ( metal or organic ) and then a nice sinter green or what not and same rotor for everything to see the difference given by pad shape and brake system
Ehm, brakes comes with random pad choice from the factory, who's fault is that? They were testing STOCK brakes, if manufacturer opts to undersell their brake by cheaping out on pads, it's their reliability. Better pads and rotors make any brake better, after all those are the actual braking surfaces, of course they make a big difference.
Pads and rotors are both things easily changed by the end consumer.
For the lab data, they should have used either control pads and rotors from someone like Galfer, or used the best available from each OEM. If they wanted to use whatever OEM pads were fitted for subjective on-trail testing that would be fine but you don’t get meaningful lab data with a random spread of pads.
Another note that makes me question their testing too: their setup photos for the Maven on the lab test make it look like they may not be applying force to the correct point on the lever. This wouldn’t matter for testing different pads in the same brake but would invalidate comparisons between brakes.
I do testing for a living. This shit drives me nuts.
Edit: what I’d also really have liked to see is a graph of brake torque vs lever force and another graph of brake torque vs lever displacement. I think it would give some really interesting insight into why certain brakes feel the way they do.
Agree completely, I'd also like to see the amount of lever throw it takes to achieve a given power point.
IMO this is partly why brakes like the Trickstuff and Hope did so well, their levers put down a larger amount of power for a given input force, but require a longer lever throw to get there. These two brakes have very light lever feel, so a brake test that is only based on force at the lever is going to be jaded in favor of these two because the lever will keep moving for a given input force but there's no indication of how far it went. Compare this to Mavens, which put more power down in a shorter lever stroke (arguable on the Hopes moreso than the Maximas), you kinda don't get the whole picture. I run levers closer to the bar and Maximas just do not do as well like that compared to others.
Both are great, I'm not saying they don't deserve their place, just that using a constant input force doesn't tell the whole picture.
What part on the bike is not easily changed? (Forget headtube routing for a second). While we all would appreciate more detailed test and deeper analysis of braking performance, it's hardly something any online magazine is going to do for us, same with damping rates of different suspension products, wear rates of cassettes etc. Plus, I think more often than not we empirically know very well that is you want more mechanical advantage in a brake you have to either compromise lever feel or compromise pad rollback. That is unless you go for variable cam mechanism in a lever (even though that messes up the lever feel as well just in a different way).
I've been a bit curious about how most people center their calipers. I initially would center based on the gaps in the pads, but when I worked at a shop, I learned to center the rotor between the caliper gaps and ignore the pads initially. Then if the pads made uneven contact (assuming the pistons had been cleaned and lubed), you could work the brake lever and use a small flat head to massage fluid from one piston to another to get them dialed in. If I've helped someone trail side with brake rub, I just center to the caliper and it seems the fluid in the pistons balance out after some braking
Not sure if it's an odd way to do it but I've found its been simple and effective compared to other methods I've tried.
super cool POV with Brake Ace data laid over top - Dante Silva and Tyler Ervin on Telonics - figured it goes best in this thread.
Absolutely, I believe if the force to the lever was 1/3 the mavens and codes would’ve dropped with Hayes, Maxima and Hopes at the top
There’s a ton of Variables
I remember a while ago in the red site podcast they said they would’ve done a test like this but done better
I’m waiting
Compromise lever feel in what way? I've been running the Hayes Dominions for a few years now and they have felt great and really delivered on the power. They don't feel compromised in any way to me. The mechanical advantage comes from how easy it is to increase the pressure in the system. Think of Bernoullis equation. Removing the energy we won't really be considering in a brake system like this, kinetic and potential, (p1 +1/2pv1^2 + pgh1 = p2 +1/2pv2^2 +pgh2) We are left with P1=P2. Pressure at one end is equal to the pressure at the other end. Pressure is equal to force/area, so we can increase force at the caliper end by increasing the area the pressure is applied to, and we can increase force at the lever end by increasing the length of the input arm relative to the output arm. You can use cams in the lever arm to change the mechanical advantage through the stroke, and the feel of the lever.
I know I'm being overly simple on this, but I'm still not sure what exactly would be compromising the brake feel of you go higher power, especially since feel is a personal preference.
Long free stroke is part of overall brake feel for me?Dominions are pretty extreme in this aspect. From the top of my head I don't know about any other brake with that much free stroke, even brakes that are more powerful (on paper at least) like t4v4, both of them feel nicely linear though. On the other hand you have servo wave shimanos with very wooden feeling initiation that gets ok ish once you get to the pad contact point, and they get there quicker while also running a lot more pad rollback so disc clearance is good.
How many people actually change pads and rotors? Testing brakes as they come stock is 100 % the right way to do it.
I was more surprised that the caliper was bolted to the carrier from the bottom (no friction taking up the load) and maybe that the force applied to lever was an overhang, not sure if us grabbing the bars and the lever makes any changes or not...
As for different braking forces, as long as the flex of the system is at least close to linear (should be), the torque response will also be linear. Where changes would have been seen is where flexibility of the hose and caliper would make a difference in lever throw (against the master, not the handlebar) and would disproportionately increase the braking torque at higher braking forces because of the lever to piston cam improving things.
The people who are interested in these test results are the ones changing their pads and rotors! (Edit: although it's pad compounds I'm concerned about, per the original comment)
The test wasn't even internally consistent. In some cases they have different OEM compounds within the same brand, meaning all that effort was a waste.
Although given this is page 51, I doubt I'm adding anything new here.
Of course a long post typed on my phone gets eaten by the system...
Testing brakes as they came is the only logical way of doing it. If they come with different pads within the manufacturer, that's how it is. If they were to test with a spec rotor and pad, which one? Why the one you say and not some other one? Should they test all of them available on the market? Even the aliexpress ones? See the issue? Also, said test was not aimed at this thread.
Brakes are, as anything these days, being sold as a system. They should be evaluated as such. Aftermarket pads and rotors should be tested separately as an upgrade option.
The only case where a spec rotor and pad would make sense is if brakes were sold without either in the kit. For rotors this is the case, but then you should evaluate them with rotors from the list of compatible ones. Which they did - OEM ones. Otherwise, where do we draw the line? Should frames be tested using spec components and bearings to filter out the differences? Put Cascade links on all of them to I don't know, level out the kinematics and only test flex and other ride characteristics?
Dominions are extreme with free-stroke?
I just went and measured mine. All four are running at 15mm free stroke before a pretty solid/obvious bite point, measured just before the hook on the lever. Is that a lot? It's less than my twin pot shimanos (which are theoretically less than the 4 pot shimanos I think, due to less piston area?)
One pair is 2 years old and has not been bled since new, other pair is probably 5 rides old, and i don't do any tricksy stuff like advancing the pistons. Just set and forget.
Its a well known characteristic of the brake as documented in quite few threads on multiple forums. I have tried 3 sets, all of them have longer throw than any other top competitors. Can they be fettled with to improve this aspect? It looks that way as per page 12 in this very thread. However apples to apples (or Stock to stock), they have longer free stroke than any other brake I have tried, code rsc with bite point adjusted all the way in is comparable I guess, haven't measured it so not sure, adjusted all the way out it's noticeably shorter though. They are good brakes, no one is doubting that so no need to be butthurt. Just not a perfect one.
I'm not butthurt, this is just the third pair that has been the same for me and less than my shimanos out of the box. I measured because I'm curious to compare it to others!
edit: reading page 12, he managed to reduce the free stroke by 12mm. Given that I have barely more than that to start with, it sounds like an assembly issue rather than a characteristic of the brake.
The beauty of testing with a spec rotor and pad is that it doesn’t matter which one you use as long as they’re all the same. Even if you use a bad pad, it’s equally bad for all of them.
If a Maven with a shitty pad from aliexpress makes 30% more power than a Code with the same shitty pad from aliexpress. Then you know definitively that the Maven makes 30% more power than the Code.
If you test a T4V4 with a Hope Green pad against a Maven with a sram “organic” pad and the T4V4 has more power on the dyno, does it actually have more power? You don’t know because you have a really good pad in the Hope and a mediocre one in the Maven. Is Hope green even the OEM pad? Well yes and no. They come with green in the box but they also come with two other lower performance option in the box too.
It’s like testing sports cars but some of them are on all season tires and others are on r-compound tires.
Edit: to compare it to your bike test analogy, it would be like putting all the bikes in a group test on the same tires. Something that the media outlets frequently do for group tests.
How do those aliexpress pads compare to pads that I will actually buy and use in the brake at some point?
I find brake tests with a controlled pad and rotor combo are far more valuable… it allows you to standardize some variables and compare the actual brakes performance. Brakes sets are hardly ever shipped with rotors and the brakes will far outlive the stock pads so you certainly aren’t stuck with them. I’ve run codes, trp, and dominions over the last several years most often with galfer rotors and have always moved to galfer or mtx pads if I even bothered to wear through the stock pads. Sure a test with both stock and controlled pads/ rotors would be ideal but if we can only have one I’m taking the control.
Having them this tight and then screwing in the crosshair screws... have you not had issues with this wearing away at the brake mount / adapter surface? I did and I swore that was causing issues with getting them aligned in the first place, eventually I gently hit the area w/ sandpaper and started ignoring the crosshair system.
When I had a couple pairs of Dominions, I had the same thing happen on both. (The top of the mounting surface got scoured by the bolt washer and led to the bolt loading up the top unevenly, or trying to push back into the lowest wear groove.) Also the grub screw wore down the threads of the mount bolts.
They're just tight enough to not move by hand, which isn't really any meaningful tension on the bolt, only really enough to squish the compressible stuff and hold everything square... Im sure I could make it move if I reefed on it. Haven't seen any wear. I guess it depends how often you realign them? I'm with the other guy a few posts back, align rotor to caliper and any pad misalignment is a piston problem.
I'll keep an eye on that though, thanks.
I did some freestroke measurements out of interest as it came up earlier on this page, I found across my two sets of code rsc how I have them adjusted I'm looking at about 20mm measured in the middle of the finger spot. I had a measure of 3 different shimano 2 pots (m785 xt x 4 and slx x2) and they were all around 22 to 24mm. What I found interesting was that all of the brakes I had engaged at basically the same point from the bar even with them all done by feel rather than a deliberate attempt.
Anyone else got any data?
Wait I thought it was a well known and reliably documented characteristic that Dominions have extreme amounts of free stroke compared to Code RSCs. Are you telling me that that's not correct, and that they appear to have less?
Yeah I may or may not have tried to align my way out of a bent rotor problem more than a couple times 😅
Definitely keep an eye on it and don't tighten your bolts too much before using em. I'm glad they're working for you, it was initially a decent part of the reason I was psyched to buy em (after that I just didn't care because they feel amazing and work great).
I mean, both of them have contact point / free stroke adjustments, are we measuring at the extremes?
I'm just poking fun at Jakub for telling me I'm wrong about my own experience with my brakes.
I've just left the free stroke as it came. Code RSCs can easily double the amount of free stroke I have, but I don't know how little they can adjust down to.
Question for you all nerds
Back from when I was on Maguras I never had to think about this rotor size and spacing as it was perfect pm180 frame/fork pm +40 or 23 adapter and run 220/203 pads were biting perfect at the top of the rotor, great match.
Switched to Hope, running the same bike and fork, 203 rotors so the H adapter +23mm
Noticed the pads were biting quite low and on their “tech book” Hope states there should be 0.5 1mm max of un “bitten” rotor.
While it seems a bit odd I measured mines and I was 1.76mm off, and on another bike I installed some 200 rotors today It was sitting so low the rotor was actually touching the top of the caliper with the proper +20 adapter, had to move it to +23 to have the pads at the correct height.
Now back on my bike, I put some 1.47 washers under the caliper and now the pads and rotors are a perfect match,
So I’m wondering where’s the issue here?
Hope caliper sitting too low?
I’d love to run everything flush with no washers especially since they don’t have any proper facing or anyrhing, thankfully these brakes are easy to align but ideally I’d have the calipers flush on the adapters and nothing else.
If you have em, I'd try another brand of adapters and see if the problem is still present. The calipers are near net forged, so I'd be hard pressed thinking they'd get terribly outta tolerance during machining. What I could see happening is an L adapter being mislabeled/machined with an H on it, since the needed amount of spacers pretty well perfectly aligns with the radial difference between a 200 and 203mm rotor.
***Edited for clarity. Will no longer post/reply before coffee kicks in****
Only one of them is meant to be adjusted and actually does good job at that. The other one, well, not so much.
Post a reply to: Nerding out on Brakes shall we? Not another tech deraliment