Nerding out on Brakes shall we? Not another tech deraliment

sprungmass
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Calgary, AB CA
2/20/2025 10:40am

@Slavid666 Thanks for the Sinter Green suggestion. I did a big ride in the snow and they were dead quiet the whole time. Even after a nice crash in powder which got the rotors/calipers soaking wet and it only took 5 seconds for the noise to go away. With the Hayes metallic pads, they would be insanely loud for at least 5 minutes if not the rest of the ride. Great modulation and power to boot. Excited to run them on my summer bikes too.

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2/20/2025 11:14am
As someone who went from bleeding shocks by hand to using a vacuum pump about 10 years ago, a brake bleeding and pad bedding machine are...

As someone who went from bleeding shocks by hand to using a vacuum pump about 10 years ago, a brake bleeding and pad bedding machine are 2 things I would immediately buy if I was running a general workshop. The time saved plus consistency (which saves even more time on parts coming back to be redone) is crucial for a sustainable workshop. I only occasionally do brakes but I'm still planning on building more tools for pad bedding when I get the time. 

Actually the same goes for wheel building - I used to do about as many wheels as I do shocks but the reason I stopped is I couldn't invest in dedicated machines for both jobs. Look at Wheelworks in Wellington, NZ for the kinds of stuff I mean. https://www.wheelworks.co.nz/?srsltid=AfmBOooE6xOR6S3PT9hMztNxJQiCKBytlFTaQxgyXLGz_M1V2wYOaGln

In my opinion if a shop is hoping to do technical work like brakes, suspension and wheels they absolutely need to invest in modern tools. The productivity rapidly pays for itself, making life better for customers and the workshop more sustainable/profitable. The trend I see is if bleeding brakes is too much of a hassle then a mechanic will convince themselves its "fine" and doesn't need to be done, whereas if the service is super easy you'll be much more likely to get it sorted then and there without much thought

TEAMROBOT wrote:

https://www.wheelworks.co.nz/what-makes-us-unique/

Pretty cool read for anyone who's curious. A lot of very expensive, very cool tools and machines.

ballz wrote:
IDK about the whole expensive tools necessity spiel. If you have good pitch perception, you can tension wheels like a champ. I understand that an amateur...

IDK about the whole expensive tools necessity spiel. If you have good pitch perception, you can tension wheels like a champ. I understand that an amateur like me has infinite time to fine tune their wheels unlike a shop that has to optimize time budget to make a profit. But like in many other crafts, a talented and skilled wheel builder likely doesn't need fancy technology for superb results.

You can definitely build very good wheels just by pitch - I'm basically tone deaf and can still achieve adequately even tension by plucking. The problem becomes after a month of riding - can you verify the pitch is still the same? And theres no way to quantify the absolute tension of each spoke in different wheels - a CX-ray in a carbon rim will sound very different to a thicker round spoke in an alloy rim. if a wheel comes back after a month with a broken spoke, you need some way of confirming that it was built to the correct tension so you can be sure its not your fault that it broke. When people are charging thousands of dollars for a carbon wheelset they need to be doing every possible to make sure its as reliable as it can be.I know for a fact most wheel breakages or spoke breakages are due to the tension being too low, uneven or spokes being the wrong length. The only way to do that consistently every time is with good tools. It's sadly become too common for when someone breaks a spoke they get blamed for doing something wrong or "must have got a stick in it" when actually the wheel wasn't built properly. Thats why I linked to wheelworks - he didn't want to accept that spokes always break so learned how to prevent it and has proven its possible. Another example of how low the bar has gotten is Brian Cahals revent video on ENVE wheels - he seemed genuinely shocked that they lasted a year when really that should be a realistic expectation! Wire spoke bicycle wheels are very good so you shouldn't need to touch them outside of a World Cup DH weekend (DH is a bit of an exception - its pretty tough to be invincible to full blown rock strikes, but the typical enduro rider shouldn't be seeing that)

 

If you only build the occasional wheel then you don't have to go all out on tools, but if you are regularly doing high end builds then I think its essential, and a shop should at least be aware of its limits and maybe leave the most expensive & lightweight builds to someone better equipped. Or be prepared to suck up the repair cost if it comes back after a month and not put it back on your customer. People got trained to accept things like spokes coming loose after a few rides, or brakes needing a few squeezes to "pump them up" when really that is totally preventable and not really that hard to do! 

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sspomer
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Fantasy
2/20/2025 2:19pm

figure putting brage's latest AK insanity in here is appropriate 🤣

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mannebask
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2/21/2025 12:36am
sspomer wrote:

figure putting brage's latest AK insanity in here is appropriate 🤣

Impossible, Shimano brakes are terrible according to a majority of this thread. 🤠

4
1
Evil96
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2/21/2025 1:18am
sspomer wrote:

figure putting brage's latest AK insanity in here is appropriate 🤣

mannebask wrote:

Impossible, Shimano brakes are terrible according to a majority of this thread. 🤠

They still are

Get the job done but they’re nothing special, plus, he could do all that on v brakes 

1
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mannebask
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2/21/2025 1:40am
sspomer wrote:

figure putting brage's latest AK insanity in here is appropriate 🤣

mannebask wrote:

Impossible, Shimano brakes are terrible according to a majority of this thread. 🤠

Evil96 wrote:

They still are

Get the job done but they’re nothing special, plus, he could do all that on v brakes 

Another way of saying "it's not the bike, it's the rider" 😉
My point being, if Saints are good enough for a rider of the skill of Brage, it will do for most of us mortals.

Different strokes for different folks, i was joking a bit, this is a tech derailment thread in the end. 
 

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2/22/2025 1:06pm

How is pulling a vacuum supposed to be done? 

Clamp the syringe and try to degas the fluid the fluid that you will be bleeding with. Is this useful for both for and mineral fluids?


Attach the syringe to one end of the brakes and pull while leaving the other end closed to pull out small air bubbles. How do you prevent bubbles from going right back into the system ones you release the vacuum?

2
2/22/2025 1:21pm
How is pulling a vacuum supposed to be done? Clamp the syringe and try to degas the fluid the fluid that you will be bleeding with. Is...

How is pulling a vacuum supposed to be done? 

Clamp the syringe and try to degas the fluid the fluid that you will be bleeding with. Is this useful for both for and mineral fluids?


Attach the syringe to one end of the brakes and pull while leaving the other end closed to pull out small air bubbles. How do you prevent bubbles from going right back into the system ones you release the vacuum?

Correct, close the opposite end of where you're trying to pull a vacuum. With the syringe vertical hold the slight vacuum and you'll see bubbles rise past the "surface" of the fluid in the syringe. Poof, gone forever

I mostly tap on the syringe with the oil level below the tube/fitting to move the bubbles up and let them sit for a few minutes before use too. Then slowly advance the fluid through the tube to the fitting. That seems to get most out and keep it out
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2/22/2025 3:41pm

My apologies if I'm way late to the party on this one, but I was pretty surprised.  Want to make 110% sure I've got it right, and post may be a nice PSA if I do.  

SRAM "Dot Grease" is now labeled "hydraulic brake grease," and even though seals only play well will DOT or mineral oil, the hydraulic brake grease is what you us for all of their brakes, DOT and mineral oil.

The formula / chemical makeup of this grease has never changed.  SRAM says, "The formula for Hydraulic Brake Grease has remained consistent since it was branded under AVID or PitStop"  

The bottom line is that it appears I can use the ancient tub of SRAM brake grease labeled "DOT" on my Maven's and it's just fine.  It just seems heretical, given how much everyone freaks out about not using anything DOT with anything mineral oil and vice versa.  

Is this right?

1
2/22/2025 4:18pm
My apologies if I'm way late to the party on this one, but I was pretty surprised.  Want to make 110% sure I've got it right...

My apologies if I'm way late to the party on this one, but I was pretty surprised.  Want to make 110% sure I've got it right, and post may be a nice PSA if I do.  

SRAM "Dot Grease" is now labeled "hydraulic brake grease," and even though seals only play well will DOT or mineral oil, the hydraulic brake grease is what you us for all of their brakes, DOT and mineral oil.

The formula / chemical makeup of this grease has never changed.  SRAM says, "The formula for Hydraulic Brake Grease has remained consistent since it was branded under AVID or PitStop"  

The bottom line is that it appears I can use the ancient tub of SRAM brake grease labeled "DOT" on my Maven's and it's just fine.  It just seems heretical, given how much everyone freaks out about not using anything DOT with anything mineral oil and vice versa.  

Is this right?

I would have to look up the data sheet to be sure but its probably right - mineral oil systems and their seals are fairly tolerant of a wide range of grease/oils so grease made for DOT brakes will usually be fine in mineral oil. Its the dot fluid itself that can be harsh on some rubbers. The biggest issue is using anything mineral oil based (ie 99% of greases) in a DOT system as the seals will rapidly swell and ruin the whole thing

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2/22/2025 4:34pm
How is pulling a vacuum supposed to be done? Clamp the syringe and try to degas the fluid the fluid that you will be bleeding with. Is...

How is pulling a vacuum supposed to be done? 

Clamp the syringe and try to degas the fluid the fluid that you will be bleeding with. Is this useful for both for and mineral fluids?


Attach the syringe to one end of the brakes and pull while leaving the other end closed to pull out small air bubbles. How do you prevent bubbles from going right back into the system ones you release the vacuum?

2
2/22/2025 4:36pm Edited Date/Time 2/22/2025 4:39pm

people missing the part that Brage is scrubbing the speed.....  
When sponsored... you tend to make do with what you have.

Pretty much every single person i've spoken to who have changed away from shimano to brands from TRP, SRAM to trickstuff all enjoy how much better they are than shimano.
Shimano have the benefit of being easy to setup... perfect for pinkies to say "they are better" because they can lever bleed with a cup.

5
TheKaiser
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2/22/2025 4:41pm
Primoz wrote:
@Digit Bikes mentioned that pulling a vacuum might make the bubble too big for them to be able to move through the hose. I'd say pulling...

@Digit Bikes mentioned that pulling a vacuum might make the bubble too big for them to be able to move through the hose. I'd say pulling a vacuum with the other syringe opened (there's enough restriction in the line or complete system that there still will be a vacuum) will enable the oil to flow under a vacuum, so pulled through the system, thus the bubbles will enlarge and flow together with the oil.

That's why I was saying here about using a vacuum machine connected to both ends of the brake system with a Y plumbing system and pulling a vacuum on a reservoir then maybe even having a pump or something flowing the oil from the caliper to the lever (and back towards the caliper through the external plumbing) to promote this flow of bubbles. The only reason for this is to a) be able to tune the level of vacuum (0,9 to 0,8 bar absolute pressure, so 0,1 to 0,2 bar vacuum might be enough and prevent ingress of air past the master seals) vs. how you're able to control it with a syringe and to be able to plug the system and have the machine run instead of standing there and handle the two syringes back and forth, pulling vacuum, holding it there, holding your hands up above your head, etc. etc.

You've probably already seen them, but there are a lot of very inexpensive vacuum bleeders available for automotive work that might be good for any experimentation you wanted to do with mechanizing this a bit more. They don't all have gauges but here is one with a gauge for under $30: https://www.harborfreight.com/brake-bleeder-and-vacuum-pump-kit-63391.html

I'd used one without a gauge many years ago, to bleed some Hope brakes, back when no one in the bike world was offering anything like the nice "Pro" bleed kits that exist now. Compared to the crap syringes that we were working with at the time, it was a step up, but we didn't really have it dialed in terms of getting a good enough seal at the fittings, so air leakage could be a problem. That really isn't any different than pulling a vacuum on syringes though, so if you already have good airtight fittings to use with your brake system now, then splicing them into the vacuum bleeder shouldn't be a big deal. The neat thing about these devices vs. a syringe is, even without a power source, they can maintain a vacuum and leave your hands free to do other work, and they also have a large catch can, you don't run out of capacity if you are needing to move a lot of fluid.

3
Nobble
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2/22/2025 8:59pm
My apologies if I'm way late to the party on this one, but I was pretty surprised.  Want to make 110% sure I've got it right...

My apologies if I'm way late to the party on this one, but I was pretty surprised.  Want to make 110% sure I've got it right, and post may be a nice PSA if I do.  

SRAM "Dot Grease" is now labeled "hydraulic brake grease," and even though seals only play well will DOT or mineral oil, the hydraulic brake grease is what you us for all of their brakes, DOT and mineral oil.

The formula / chemical makeup of this grease has never changed.  SRAM says, "The formula for Hydraulic Brake Grease has remained consistent since it was branded under AVID or PitStop"  

The bottom line is that it appears I can use the ancient tub of SRAM brake grease labeled "DOT" on my Maven's and it's just fine.  It just seems heretical, given how much everyone freaks out about not using anything DOT with anything mineral oil and vice versa.  

Is this right?

2
2/23/2025 2:02am
people missing the part that Brage is scrubbing the speed.....  When sponsored... you tend to make do with what you have.Pretty much every single person i've...

people missing the part that Brage is scrubbing the speed.....  
When sponsored... you tend to make do with what you have.

Pretty much every single person i've spoken to who have changed away from shimano to brands from TRP, SRAM to trickstuff all enjoy how much better they are than shimano.
Shimano have the benefit of being easy to setup... perfect for pinkies to say "they are better" because they can lever bleed with a cup.

Bs. Shigura is best bang for the buck if you know how to set it up with plutonline and like the hard bite point.

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2
Evil96
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2/23/2025 10:38am
tabletop84 wrote:

Bs. Shigura is best bang for the buck if you know how to set it up with plutonline and like the hard bite point.

i can argue in the long run Hope is the best bang for buchk, shigura is dogshit, if the master leaks it goes in the bin, levers are made of cheese so every couple crashes you need a new one, if something happens to the caliper side you can't service that one either, so no, definitely not good value

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3
2/23/2025 11:13am

does anyone have any hint of media release date for the new shimano brakes?
In november I was told End of Feb but not sure if still the case?

 

1
Primoz
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2/23/2025 11:50am
tabletop84 wrote:

Bs. Shigura is best bang for the buck if you know how to set it up with plutonline and like the hard bite point.

Evil96 wrote:
i can argue in the long run Hope is the best bang for buchk, shigura is dogshit, if the master leaks it goes in the bin...

i can argue in the long run Hope is the best bang for buchk, shigura is dogshit, if the master leaks it goes in the bin, levers are made of cheese so every couple crashes you need a new one, if something happens to the caliper side you can't service that one either, so no, definitely not good value

Are you talking about Magura or Shigura? 

1
Evil96
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2/23/2025 5:05pm
tabletop84 wrote:

Bs. Shigura is best bang for the buck if you know how to set it up with plutonline and like the hard bite point.

Evil96 wrote:
i can argue in the long run Hope is the best bang for buchk, shigura is dogshit, if the master leaks it goes in the bin...

i can argue in the long run Hope is the best bang for buchk, shigura is dogshit, if the master leaks it goes in the bin, levers are made of cheese so every couple crashes you need a new one, if something happens to the caliper side you can't service that one either, so no, definitely not good value

Primoz wrote:

Are you talking about Magura or Shigura? 

Shifura, but it’s the same on both, on Magura you get the 5 year leak proof, on shimano you get the normal warranty and no parts to fix/service the brakes 

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2/23/2025 6:12pm
That makes sense to me.  Thanks for taking the time to reply.If you could wave a magic wand, would the brake bleeding machine also be able...

That makes sense to me.  Thanks for taking the time to reply.

If you could wave a magic wand, would the brake bleeding machine also be able to pressurize the system at a consistent and repeatable pressure - like the trick of pressurizing Codes from the bleeding edge fitting at the caliper before closing it off.  Sometimes I do end up letting a touch of fluid out of one or the other.  I can definitely see the value of doing that consistently and quickly in a shop setting.

I would pretty much just use a shock vacuum bleeder - only smaller and with seals made for DOT fluid (and a separate machine for mineral oil, or even the same one used on dampers). Maybe have a split hose to tap in to both ends but the machine itself wouldn't need much changed. I don't pressurise the fluid at the end, other than to make sure there is a bubble of fluid in the bleed port and air doesn't get sucked back in. The bladder compensates for extra volume anyway, and any firmer lever feel will disappear once the pads have worn slightly. If you wanted something like that I would rather use a product like the @CascadeComponents brake adjuster

Also if anyone is interested, you can get push-loc and threaded fittings off ali express dirt cheap, along with syringes and luer adapters if you want to play with bleeding techniques (or rebuilding 4 ohlins TTX25 shocks at once....) 

https://www.aliexpress.com/item/1005002817631533.html?spm=a2g0o.store_pc_home.promoteWysiwyg_6000894952908.1005002817631533 (just an example)

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Primoz
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2/23/2025 9:19pm
Evil96 wrote:
i can argue in the long run Hope is the best bang for buchk, shigura is dogshit, if the master leaks it goes in the bin...

i can argue in the long run Hope is the best bang for buchk, shigura is dogshit, if the master leaks it goes in the bin, levers are made of cheese so every couple crashes you need a new one, if something happens to the caliper side you can't service that one either, so no, definitely not good value

Primoz wrote:

Are you talking about Magura or Shigura? 

Evil96 wrote:
Shifura, but it’s the same on both, on Magura you get the 5 year leak proof, on shimano you get the normal warranty and no parts...

Shifura, but it’s the same on both, on Magura you get the 5 year leak proof, on shimano you get the normal warranty and no parts to fix/service the brakes 

But Shimano levers are not cheese to the level Magura are... 

Feels a bit like ranting for the sake of ranting... 

8
Primoz
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2/23/2025 10:03pm Edited Date/Time 2/23/2025 10:07pm
That makes sense to me.  Thanks for taking the time to reply.If you could wave a magic wand, would the brake bleeding machine also be able...

That makes sense to me.  Thanks for taking the time to reply.

If you could wave a magic wand, would the brake bleeding machine also be able to pressurize the system at a consistent and repeatable pressure - like the trick of pressurizing Codes from the bleeding edge fitting at the caliper before closing it off.  Sometimes I do end up letting a touch of fluid out of one or the other.  I can definitely see the value of doing that consistently and quickly in a shop setting.

I would pretty much just use a shock vacuum bleeder - only smaller and with seals made for DOT fluid (and a separate machine for mineral...

I would pretty much just use a shock vacuum bleeder - only smaller and with seals made for DOT fluid (and a separate machine for mineral oil, or even the same one used on dampers). Maybe have a split hose to tap in to both ends but the machine itself wouldn't need much changed. I don't pressurise the fluid at the end, other than to make sure there is a bubble of fluid in the bleed port and air doesn't get sucked back in. The bladder compensates for extra volume anyway, and any firmer lever feel will disappear once the pads have worn slightly. If you wanted something like that I would rather use a product like the @CascadeComponents brake adjuster

Also if anyone is interested, you can get push-loc and threaded fittings off ali express dirt cheap, along with syringes and luer adapters if you want to play with bleeding techniques (or rebuilding 4 ohlins TTX25 shocks at once....) 

https://www.aliexpress.com/item/1005002817631533.html?spm=a2g0o.store_pc_home.promoteWysiwyg_6000894952908.1005002817631533 (just an example)

FWIW, based on a tightness testing fixture we have at work (measuring pressure drop at 50 mbar pressure levels and the like), I'd use compression fittings instead of push in fittings. Somewhat stiff hoses so they don't buckle and close off under vacuum is a good choice too. 

As for luerlock fittings off Aliexpress, I don't have the best experience... I've had to crank down on them with pliers to make them seal at least somewhat reliably... 

EDIT: as for separate machines, what about using the machine just to apply vaccum and pressure and using external fluid tanks? That way you can have separate tanks for mineral or dot fluid. There is still the chance of vapour getting pulled further into the system and mixing with the other fluid though... 

1
Evil96
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2/23/2025 11:42pm
Primoz wrote:

But Shimano levers are not cheese to the level Magura are... 

Feels a bit like ranting for the sake of ranting... 

the blades on Shimano are as strong as the lip on a can of beer, crash once and they're fatigued, crash twice and you need a new one, on magura the sort of carbotecture master is more of an issue, it not ranting, it makes sense, both options, especially when paired together are a worse combo bang for buck in the long run than say Hope as you miss both companies warranties and get both levers and calipers that are officially un serviceable

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Primoz
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2/24/2025 12:28am

Servicability wise Sram is probably the best option. 

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Evil96
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2/24/2025 12:50am
Primoz wrote:

Servicability wise Sram is probably the best option. 

i'd say so, but if you take performance and value for money then it's quite horrible as well

1
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Jakub_G
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2/24/2025 1:15am
Primoz wrote:

Servicability wise Sram is probably the best option. 

Formula offers every single part needed even for brakes that are 20years old 😉

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29
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2/24/2025 4:23am
Primoz wrote:

But Shimano levers are not cheese to the level Magura are... 

Feels a bit like ranting for the sake of ranting... 

Evil96 wrote:
the blades on Shimano are as strong as the lip on a can of beer, crash once and they're fatigued, crash twice and you need a...

the blades on Shimano are as strong as the lip on a can of beer, crash once and they're fatigued, crash twice and you need a new one, on magura the sort of carbotecture master is more of an issue, it not ranting, it makes sense, both options, especially when paired together are a worse combo bang for buck in the long run than say Hope as you miss both companies warranties and get both levers and calipers that are officially un serviceable

you have made your opinion on Shimano known, repeating it every time someone talks about it won’t change anything


I want more digital photo forensics instead please

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ballz
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2/24/2025 9:58am
Primoz wrote:

Are you talking about Magura or Shigura? 

Yes.

2
boozed
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2/24/2025 7:45pm Edited Date/Time 2/24/2025 7:48pm
Primoz wrote:

But Shimano levers are not cheese to the level Magura are... 

Feels a bit like ranting for the sake of ranting... 

Evil96 wrote:
the blades on Shimano are as strong as the lip on a can of beer, crash once and they're fatigued, crash twice and you need a...

the blades on Shimano are as strong as the lip on a can of beer, crash once and they're fatigued, crash twice and you need a new one, on magura the sort of carbotecture master is more of an issue, it not ranting, it makes sense, both options, especially when paired together are a worse combo bang for buck in the long run than say Hope as you miss both companies warranties and get both levers and calipers that are officially un serviceable

I think you've just encountered the concept of a "mechanical fuse".

2
HexonJuan
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2/25/2025 6:42am
people missing the part that Brage is scrubbing the speed.....  When sponsored... you tend to make do with what you have.Pretty much every single person i've...

people missing the part that Brage is scrubbing the speed.....  
When sponsored... you tend to make do with what you have.

Pretty much every single person i've spoken to who have changed away from shimano to brands from TRP, SRAM to trickstuff all enjoy how much better they are than shimano.
Shimano have the benefit of being easy to setup... perfect for pinkies to say "they are better" because they can lever bleed with a cup.

Shimano seems to always be in a weird spot. I've friends who've had no issues to report and others who quit the brakes due to too many issues, myself included. When they were new they were damn good, but they didn't age well. Every brake is easy to set up as they're all just a variation on a theme, you just have to find their note differences to interpret their take right. Where I think Shimano gets things right is their fluid paths. Every unit I've worked on has had air in the reservoir, whether that was new on a bike or from a box. When mounted, you would never notice it til you came to near the end of the pad life or flipped the bike upside down. Their fluid paths guide the air up out of the active part of the system really well. I've bemoaned the issues I've had with em here and elsewhere so I'll just say where they're wrong is service parts availability, and arguably that some brakes are strictly designed not to be serviced at all due to permanent fasteners (lookin' at you, non series Deore).

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