Nerding out on Brakes shall we? Not another tech deraliment

I think Im getting at both A & B, TRP & Shimano brakes feel way more consistent For a few rides After doing a few hours of strapping it to the bar.

I've ridden many 'shop bled' TRP/XT brakes on other peoples bikes and they always feel odd or inconsistent when you start getting any kind of heat into the caliper.

Mavens have a wandering point similar to XT ONLY if you dont swing off the lever with the 2 rotor or 4mm spacer massage untill the seals/pistons settle together

It's 2024, surely we can have a simple to bleed brake that is powerful and consistent.... I guess Shimano's new brake at the end of year Will tick those boxes right? 

Aren't they pretty much Galfer Shark rotors with more holes and less shark ? And thicker. I would expect those to perform very similarly to the Sharks... Which from my opinion is pretty good. Not as cheese grater-y as the Galfer Wave, not especially noisy (unless used with Trickstuff Power+ pads, but then every single rotor on earth is super loud as far as I know). Just super expensive unless bought at a big discount if you can find them.

Yeah TRP's version of the Shark. 

The wave & shark setup is pretty good - which is what im running... just dont use Resin pads on wave's, they bite hard but wear fast.
I've been using  galfer purple ebike pads and they are damn good.
( my ebike setup with XT 4 pistons.)


 

Yep. They seem pretty good. I feel like it's a pretty optimum rotor shape. Everything I've tried similar works well too. 

I have one real brake burner of a run that'll be good to give them a real hiding on once it opens again. 

I just ordered a pair of Waves to experiment with in combination with my current Sharks.  I saw that Frameworks was running Waves front, Sharks rear.  Is that what you're doing too, or vice versa?  I have noticed that Sharks gobble through brake pads, I'm guessing due to the sharp laser cut holes.

Im running 223 wave up front with shark out back.

Purple ebike pads in my ebike are holding up damn well. way longer than any resin, i wouldve been through 2 or 3 sets of shimano resin by now.

I'm using the TRP S05E 203 front and rear and they are doing great (with Galfer green or Trickstuff Power+), no issue so far. The best part of them is the 2.3mm width which I was looking for (mostly for there solidity, I always bend my disk one day...).

No issue with the Trickstuff PO+ pads either, there are always been dead silent to me ?

I have to say that Trinity + S05E + Trickstuff PO+ is the golden ticket for me, absolutely tremendous breaking power, no fading even after complete days at the bike park and 8000m D-, no wandering bite point, easy to modulate, very light lever, and completely silent. Not the less expensive though...

Haha I have the same combo to try! I had a hunch it would be the ticket! 

The Lewis parts have arrived!

Fitting was straight forward, aside from the lever needing a tiny bit of filing to make it clear a part of the master cylinder body. I now have adjustable bite point on my Maximas. The adjustment range is really good, when maxed out there's only about 10mm of free stroke. In the photos both levers reach has been set to the same distance from the grip. On the front is the Lewis lever with the bite point set to the maximum and on the rear is the original Trickstuff. There's a good 15mm of difference in bite point distance.

The brakes now have a much more defined bite point and the power feels like it doubled since the power comes on with so much less pull. Gonna give these a go in the bikepark tomorrow.

They're not knockoffs, they just copied most of the dimensions (from a product that clearly works) and very liberaly borrowed the design language. And added some features 😜

I've seen a proto crank from them and it was a "for the love of God, after all the comments about the brakes, another straight copy?". It's like they have no imagination... 

One thing to pay attention with those levers, the free stroke adjustment is just "push the piston in" while the lever stays in its stock position. 

So make sure the circuit isn't closed from the reservoir when the lever is at its resting position, otherwise it'll be problematic when the brakes heat up and the liquid slightly expands, or just when pads wear out and there's not enough oil in the circuit to compensate. 

If when the adjuster is all the way in, you can still bleed the brakes fine, all good.

Which is why on the Hope brakes you can only reduce the free stroke so much with the BPC screw before it bottoms out, or on the Beringer you can actually close the circuit and have 1mm of free stroke but then as it's closed, you have to open it again from time to time.

How much was the whole kit if you don't mind? Might be interested to try out

All of the parts in the first picture cost me 108$+30$shipping+local tax. Your mileage may vary.

I was aware of this and with the Lewis pushrods the system is closed. The brakes have little to no pull after heating up. This isn't a big deal since in Finland there's not that much elevation to cause any real problems. It might also be due to me using the Trickstuff free stroke spacer instead of the Lewis one which is much thinner. The free stroke spacer sits between the circlip and the end of the pushrod setting the "resting" point of the master cylinder piston.

So if I changed the spacer to the thinner Lewis spacer, the piston would not be as compressed and the main piston seal would maybe clear the reservoir hole. I installed the pushrods with the Trickstuff spacer to get the minimum free stroke possible but now the brakes are "sealed".

I will try it with the lewis spacer to see if it that will help.

I installed the Lewis spacer. The Trickstuff spacer is 2mm thick and the Lewis is 1.2mm. Unfortunately I forgot to take measurements with the Trickstuff spacer installed but with the Lewis there is 14mm of actual bite point adjustment range. Max is 32mm and min is 18mm. I put a syringe to the lever and tested if fluid was able to travel between the reservoir and the rest of the system. If I open up the freestroke completely, fluid can move freely but adjusting the freestroke to the minimum will close the system. So not a perfect system by any means but still way better than stock.

Thanks for checking ! That will be a problem for me, between the caliper heating up and fast pad wear, I'd have to wind the adjustment out pretty much every run.

I'll just leave it at that for now. I'm using 612parts calipers on one bike and the freestroke is slightly shorter than with regular Maxima calipers. The 612 prototypes were even shorter, but had a problem of using the pads in a wedge (like if the pistons weren't as guided as on the more recent caliper), and that was a big problem for me. Either I had to swap the pads around every day, or I'd get less days off those pads ..

I glazed this setup riding park yesterday. Pads are MTX gold, very heat tolerant. Don't think I contaminated them, no fluid leakage visible. For context, I've run the pads since November with great performance, but swapped rotors recently because I was having trouble getting the old one trued. I sanded the pads, cleaned with alcohol, bedded them properly and had a few local rides with good results before the park day.

Could the floating rotor and ceramic pads have worked together to trap heat in the pad track, making the friction surfaces unusually hot without the fade you'd normally feel at the lever?

Is it just me or are the rotors really really shiny? Basically polished? 

Yeah, the rotor is basically a mirror - see my glove texture reflected at the bottom? I haven't actually pulled the pads out yet, but I can't imagine them not being shiny. Will check soon.

Good point about the lack of discolouring, suppose that could point to contamination after all.

Heat is my prime suspect because it was 28°C with steep terrain and a cautious rider haha 😅

To have a rotor that shiny tells me your pads are contaminated. Make sure you don't also have a fluid leak somewhere, a bit of brake fluid or bearing grease can definitely help "polish" a rotor like that. 

Interesting with the Lewis lever on the Maxima. Out of the box my Direttissima were a perfect bleed, and after a few days of riding, bedding in, I have no reason to want a bite point adjust, or at least I don't feel like i'm missing anything. With the T4V4 Hope's, I definitely dialed it in given how long the lever blades are. 

Once I get my Maxima's and Piccola HD in, maybe my opinion will change? Will be ordering some Radic Kaha as well to try out. 

I think the other posts about the mirror like finish possibly indicating contamination are great advice, but I just wanted to add that, given that the pad-swept surface of your rotor goes right to the outer edge, and the rotor is relatively new to you, it would be good to double check that you don't have any pad overhanging the rotor. I'm sure you would have noticed it, but I've seen people who swapped rotors to one that seemed like it was the same size, but was actually a few mm smaller, leading to pad overhang, and, over time, the pads wore to the point that the little strip of unworn meat on the two pads met in the middle. The braking in those cases felt very similar to glazed pads at the lever, and it was only upon pulling the pads out that we saw the true cause of the problem.

Thanks to you guys who took an interest in my problem. Tonight I had a chance to take a closer look. I can't find any contamination nor pad overhang. The inside of the caliper is dry. Pads do look shiny, but on a test ride the brake has normal power, unlike when I glazed Sram metallics and half the power was gone.

What I did find is visual evidence of the pads moving forward and back a lot, consistent with the shudder I could feel. That's not brake fluid you see outlining the piston shapes, it's just the finish worn off.

 My new idea is that some property of this specific pad & rotor pairing causes a grip-slip condition at higher temps. The MTX golds have more grab with some heat in them, so maybe there's a point where this interacts with the floating aspect of the rotor, even though said rotor doesn't seem loose.

Any smart people able to support or deny that? I'm just curious at this point - a pad and/or rotor swap seems like a likely cure if symptoms persist.

Are you sure that the two rings are not from accidently having put the pads in the other way round? Pads typically wear unevenly and so 4 piston brakes often use 2 different piston sizes or position the pad off center to compensate for that. If they have been taken out and put back in reversed then the brakes will feel a bit strange and probably squeal until everything wears in a bit.

That's a very good question. No, I can't be certain the markings aren't from putting pads in opposite to the previous way. But I did scuff and clean them and install a new rotor on July 20, last time I had them out (which is why I didn't pay attention to orientation). I followed that up with a bed in process, so I don't think the heavy shudder I could feel was a symptom of badly bedded pads this time. Especially given I had full power whenever the brakes were cool and the shudder was not happening.

I also observed clean fore and aft edges on the pistons that could support pad movement as the culprit, but I don't know whether that pattern is normal.