Nerding out on Brakes shall we? Not another tech deraliment

Moving air bubbles to lever.

I don't want to derail this into a "what brake should I get" thread, but also, what brake should I get? 

My past three bikes I went from Avid something (pre-SRAM) and they were not great. Then Shimano Zee's and now Shimano SLX 4-pots with Galfer wave rotors (220/200) and (usually) Galfer pads on a RM Slayer 29. They've been reliable and easy to use and pretty good and I'm a big fan of having a short pull and there hasn't really been much to complain about. 

That said, it's time to upgrade. Kitted up, I typically weigh 120kg-ish, they've got some mass to slow down. I ride some park, but mostly lots of steep, tech dh stuff in the Canadian Rockies, interior BC and a couple trips to the Sea to Sky (Squmish/North Van/Pemberton/etc) each year. 

I'm going back and forth between Saints (lots of power and that ol' familiar Shimano feel) or Domains. As good as Maven's seem to be, I don't like the feel of SRAM levers/pull, so not really considering. Maybe Hope's, but might be a touch more than my budget (even though they're not THAT much more). Obviously Maxima's would be the move with an unlimited budget, but just isn't possible. Ha ha 

Any other big guys on here with some good insight?

I'm a bit lighter than you but I think once you hit the 210lb mark, you end up with a lot fewer good choices. A lot of people don't really experiment much with brakes either, so people will describe a brake they've used for 8 years as having amazing power but they haven't tried any of the latest gen brakes to compare.

As I said before, I didn't find the Saints that powerful. The data Hayes posted (I understand and agree this is likely biased) showed the Dominions having more overall power and that is my experience. The problem with the Dominions is the short brake lever combined with the way they ramp up means they require more hand strength to put power down and I could readily fade them on some long downhills. 

I also don't think Maximas are a good solution for heavier riders. They have the power available but it comes on very linearly and so you would have to run your lever blades far out. Every review of these is done by 160-180lb riders, so their experience is going to vary vastly.  

I agree the Mavens don't have the most refined lever feel, but of all the brakes I've tried, they are the ones I would suggest to riders above my weight. Eventually you need to recognize there are just going to be tradeoffs due to the design requirements to make them work with that much power and progression, a stiff lever is a side effect of that, but I will say that I feel they felt different than other SRAM brakes I've had in the past fairly significantly. If you can get past the stiff lever feel, this would be my #1 choice for anyone above say 225lbs. Even being 220, I could've gotten away with 180 rotors and possibly smaller, they ramp up the power that quickly.

Hope T4 V4 may be another choice, but I would up to 220 rotors and possibly try different pads. The power with them is there, but like the Trickstuff, it takes a longer lever pull, although not as light and not as linear. I also do not like the bleed process. 

Intends would be another good option, but they are hard to get ahold of. I found they had ample power for me and ramp up fast even with 200 rotors, going to 220 may boost that for you further. 

I would straight up skip Magura. Good brakes, great consistency, power comes on way too late in the stroke for heavier riders. 

Haven't tried TRP or Formula yet, nor Beringer or 612 on the niche side. Being blunt, you may need to accept "not perfect" to get the power you want.

Enjoying the conversation from afar, hoping it twists into more rotor talk. Where are we actually with oversized rotors, why arent we all running 223mm? Spend 50% of my riding trying to find new stuff, low tier 180mm has been great dragging through brush and staying true. Thats my greatest hesitation, what about everybody else?

I'm around 105kg, and in my experience, Saints and the current XTR 4-piston are amazing for steep terrain. I was surprised the SLX brakes are as far off from the power of every other Shimano 4-piston brake as they are. I assumed weight was the only difference until I found myself pulling the lever as hard as possible frequently. That being said, I dislike the wandering bite point on Shimano brakes and prefer to run SRAM brakes. Mavens have had ample power in every scenario I've put them through, I would suggest downsizing the front rotor to 200mm in order to make the power more usable as it does come on quite strong with a 220 up front. 

Resets the piston seals so you get closer bite point.

Cura 4 w/ FCS: 

I got these in today. The FCS install was janky as all hell but mainly because my snap ring pliers wouldn't close enough for the snap ring to seat. I managed to get it in, but it wasn't pretty. The lever appears a bit shorter and has a more defined hook on the end than stock, reminds me more of Shimano or Hayes levers. The bite point adjuster seems to move the lever fore/aft slightly to change progression, but it feels super subtle when you pull the lever. 

Bleed went fine. Install easy enough. 

I pedaled around and can pretty much tell right away they are going to last like 3 rides for me, if that. The bite point is super far into the lever stroke, I'd go as far as to say the power comes in slower than any other brake I've tried and that's with Trickstuff pads and 203 rotors. You pull through a shitload of deadstroke to get any stopping power, I'd go as far as to say the deadstroke is almost longer than any other brake I've tried except my wifes TRPs. I'll try riding them, but I'll probably end up back on the Hopes. I've heard the 2s have a faster bite and I ordered a set to try, so we'll see how those work out. 

They do look nice, though. Power is just weak sauce, but maybe I'll feel differently on the trail. They do seem to get decent power at the end of the stroke, but the amount of lever stroke to get there is too damn high.

Excellent nerding nerds. I've enjoyed reading this thread.

The thing I'd like to see more nerding out about is brake lines. In my experience if you want a balanced feel front to rear you need to do something to balance your lines or make them much stiffer than stock shimano or magura lines. A rear line on a long bike is 2 or 2.5x as long as a front brake and it makes a big difference in how much expansion you get in that length of line imo.

It seems to me that if one brake line is going to be twice as long as the other and you want to achieve the same lever feel in both hands then you'll need to find a rear line that is twice as stiff. Goodridge or similar perhaps. When are bikes with internal hard lines arriving? Surely that's the 2025 version of headset cable routing?

I tried 220 HS2s for a bit last year on my ebike and went back to 200s/203s.  They definitely have a ton of power but I was having issues with keeping them straight (front and rear) and also warming them up enough (front) (I'm like 172-175 lbs with gear).  I switched to Galfer Sharks at 203 F/R and their power is somewhere in between a 200 & 220 HS2, but seem to stay straighter better for me.

Damm now I feel bad about recommending them. I assume you tried both the full open and full closed setting of the FCS dial ?

Don’t feel bad! I have been wanting to try them for a while and they may come out a bit on the trail. It’s all good.

On FCS yes, I did. The dial makes a difference but the bite point is still longer than I prefer. I am going to ride and rebleed like I usually do then see how they feel on the trail, parking lot feel for me isn’t always a good indicator 

Although I have never found the dead stroke to be as long as you describe it I would recommend pulling the rear wheel out and press the lever a couple of times to get the pistons closer to the rotor. The poor mans contact adjust. It's finicky and takes some patience but could fix your problem. 

I have done this couple times because I like very little dead stroke, works like a charm.

Another thing i am curious aboust is how ling should a brake last?

1 season, 5 seasons, forever?

I got me thinking because i crashed and needed to replace the lever body, and bought a complete brake, and man its was a massive improvement!

3 years old MT7 that was upgraded.

Improvement in what sense? 

I replaced all the pistons and seals in my code RSCs last year after four seasons and it was an improvement too (lever feel mostly). 

Ideally you would want to do a clean up and rebuild yearly but I personally do everytime they feel a little lazy. Really depends on the conditions too. Fine dust or muddy conditions followed by a bad bleed job (pushing dirt towards the lever) would increase the service intervals.

Hi guys, long time lurker first time poster. Wondering if anyone can comment on the insanely long lever throw on Hayes Dominion brakes.

Haven't seen it mentioned anywhere else but mine have about 50mm of dead stroke before finally biting after a day in the park. After resetting them they still have about 40mm of dead stroke. The bite point is solid though and no issues with power either. Running 2.3mm thick rotors and bleeding with the standard Hayes bleed block.

Any advice or experienced on this would be appreciated. Unpopular opinion but the Code RSC levers on my other bike feel much better overall right now. 

Basically everything. From lever feel, pad retraction and smoothness of each piston. 

So i think brake maintenace should be higher up on the service list from now on.

This is one of the main flaws of the Dominions IMO, the lever throw is way too long and gets longer as the pads wear. It's borderline too long but within reason, I just hate that feeling of useless stroke and the way the lever pull changes so much in the stroke of the lever. 

Either way, try making sure they are aligned and centered properly. I usually do this visually, the setscrews help but they can also get in the way. You can also take the bleed block, flip it to the side that's a half bleed block, insert it and work the pistons out. You can then drip a few drops of DOT onto the pistons and press them back in, then work them out again, then in again and that'll make sure they are properly lubricated. That'll take care of any potential retraction issues, although I doubt it'll help you here, it's worth doing. Also you can fiddle with the bite point adjuster, maybe it was set wrong? Make sure your pads aren't roached as well.

40-50mm of pull is a lot more than I'd expect for them, but they do have a longer deadstroke than most other brakes I've tried. 

Ive been on A4's for about 2.5 years now, I cant remember how much dead stroke I have but its much less than 40-50mm. Are you talking about initial pad contact or pulling until the power wall hits? I'll measure mine tonight but the dead stroke on my A4's is equal to or less than the XT's on my other bike. There is an adjustment that can be tinkered with to tailor the bite point, I hesitate to recommend it as its not called out by hayes and its easy to get carried away, I had set near instantaneous bite with this method but it bit me when I was up at 7K feet and the pressure/temperature change caused the brakes to drag to the point of needing to burp the system. If you have ever disassembled the lever and know how the linkage/piston actuator works you probably know what I am talking about. 

I mean pulling until there's resistance at the lever. I've already tried all these suggestions too (lubricate the pistons, re-bleed, wind the contact all the way in then all the way out, wait for them to bed in, elastic band on the levers etc). No luck, front and back brake both feel identical, but both with massive throw.

Otherwise the brakes work great but since I like the lever to bite about 40mm from the bar to begin with it means the levers are wayyy off the bar under my last finger pad when I'm not pulling them. I'm wondering if there's some internals that were set up wrong from the factory? 

 I have heard that rational before regarding keeping the system pressurized helping rid it of bubbles, and I just don't get how that would be helpful. In my experience, the opposite is what you want, as with a vacuum bleed the bubbles expand hugely and therefore have greater buoyancy. Going up/down in pressure rapidly could maybe help, as can vibrating the brake system, as it helps jar bubbles loose to allow them to float upward, but this constant pressure thing just doesn't make sense to me.

I just inquired with someone on PB in a thread about this same photo, and he suggested that shrinking the bubbles by putting them under pressure could allow them to fit up the hose more easily, which I guess does make some sense, although it seems like there would be a sweet spot with shrinking vs. buoyancy. Is that your theory about why pressurization helps or do you have some other ideas?

Are you saying that the flexed piston seals, which would normally roll back the pistons when the lever is released after a short pull, will slowly creep back along the piston under a long sustained pull as is done by strapping the lever down for an extended period? So it is kind of like advancing the pistons by squeezing the lever with a thinner bleed block or rotor removed, to reduce the lever throw? 

I've always heard the claim that strapping the lever is to somehow help rid the system of bubbles, although I don't understand how it would actually help in that regard, but your suggestion makes some sense if the piston/seal interface does actually creep over time.

Maybe we’re measuring differently but the tip of the hook on my leaver measures 55mm from my grip statically. If I spin the tire I hear drag with the lever 46mm from the grip and the lever stops moving at 38mm. To me I would say my dead stroke is 17mm, but that’s just how I calculate it. Here is a picture for reference. If wanted I can probably put together a little write up on how I tune bike point at the lever, or at least what works for me… I will say that what people refer to as the contact or bite point screw does absolutely nothing. It contacts nothing and adjusting is accomplishes nothing. But there is another adjuster that makes quite the difference but it’s not labeled and requires disassembly of the lever blade to adjust it. 

I'd say higher pressure would help precisely because the bubbles are smaller and can float through the line. I guess this should help with Shimano style brakes where you use a cup at the top. If you use two syringes like with Sram brakes I don't think this would be needed as much as you can pull or push the fluid through the system from either side. 

I think the straps on the levers are about dissolving any remaining gasses into the fluid, which will improve brake performance until the air degases out again; which will take some time. Henry's law stuff probably, but I don't know how long reaching the new equilibrium would take, hours or days probably. The idea is that dissolved gasses are better than entrained gasses in your braking system.

Or I could be wrong and it's about getting the bubbles to be smaller and thus move more easily in the system to help degas the system. But if that is what's going on in the picture the bike/brake levers/lines are angled wrong, the foam grips and velcro straps don't seem to be the best way to put more than 1-2lbs on the lever instead of a more ideal squeeze of probably 15-20lbs. F for effort.

I could get behind this is about letting the caliper piston seals creep into a new resting position, but I've never tried it.

The force has already been applied the strap is just holding it in that position.

If you want to make the bubbles smaller to move, you don't want too much pressure. 

FWIW I always degas the fluid before bleeding, both braking and for shocks.