[slyfink]

Good explanation of why my car brakes worked on the way to the trailhead, but my bicycle brakes were shit. Granted, not everyone rides in the cold, but the wandering bite point seems like a bigger problem in just a little chillier weather when you are on steeps, something with the replenishment orifice size in the shimano brakes and how quickly that is overwhelmed by the mineral oil. I remember distinctly the issue at Darrington down those trails in the Fall, one of the last times I was on those brakes in any normal-ish conditions.

I guess I was referring more to the conversation discussing SRAMs assertion that DOT fluid is better in situations where there is rapid heating of the system, because the seals for DOT fluid handle heat better. Or something like that.

The descents typically aren't long and sustained enough where I normally ride to really push a brake's heat management capacity, so I find that is a moot point for me. hence the horses for courses analogy, since my horse wouldn't benefit from that advantage on my courses.

That said, about your point... I wonder how much of that is a Shimano design issue, and how much is down to the fluid? I got tired of weeping calipers contaminating my brake pads, but wanted to stick to mineral oil, so I switched to Magura on my fat bike. Haven't had any issues in two years with those brakes. But I didn't ride much this year, and not much at below -20°C.

edited to add: this sat unposted overnight and the conversation continued in the mean time...

 

[StiHacka]

Pick brake fluid and be a dick about it

 

[sethimus]

Pick brake fluid and be a dick about it

but is it vegan though?

Bionol - Trickstuff

Wer die beste Bremsfunktion der Welt möchte, der sollte eine erstklassige Hydraulikflüssigkeit benutzen. Bei Trickstuff gibt es ein in Deutschland entwickeltes und gefertigtes Bremsöl. Es wird aus Pflanzenöl – also nicht Erdöl – hergestellt und weist einzigartige Eigenschaften auf.

trickstuff.de

 

[Cerberus75]

There’s more than just “dry” boiling point, wet boiling point is important because DOT can absorb water and not leave water in its separate form. Water will boil at 100C and turn into gas. That’s what we don’t want. Water makes its way into all systems over time, so the longer you run the fluid, the more stable DOT is and the more and more mineral gets affected by water in the system. I’ve had mineral oil brakes feeling like crap under tons of heat. I thought they were overheating due to the 203 rotors not being enough, but the brakes were baking in all ways possible. For car racing, you want the best high temp fluid you can get. They’re are some other problems, as not all your other parts like brake lines, seals, etc. can deal with that heat, even though the fluid can handle it. Some people use titanium shims for the pads to provide a little more insulation.

Correct and eventually you have water in the caliper since the mineral oil will rise to the top. So water is near the hottest point.

 

[rideit]

but is it vegan though?

Bionol - Trickstuff

Wer die beste Bremsfunktion der Welt möchte, der sollte eine erstklassige Hydraulikflüssigkeit benutzen. Bei Trickstuff gibt es ein in Deutschland entwickeltes und gefertigtes Bremsöl. Es wird aus Pflanzenöl – also nicht Erdöl – hergestellt und weist einzigartige Eigenschaften auf.

trickstuff.de

“Animal, Vegetable, Mineral”

 

[toodles]

I reckon you've got other problems if you're getting that much water into the system hey.

 

[canadmos]

Correct and eventually you have water in the caliper since the mineral oil will rise to the top. So water is near the hottest point.

That's a moot point, because you need to bleed shimanos before the fluid ever has a chance of separating.

 

[Toshi]

"moot"

not mute

 

[buckoW]

There’s more than just “dry” boiling point, wet boiling point is important because DOT can absorb water and not leave water in its separate form. Water will boil at 100C and turn into gas. That’s what we don’t want. Water makes its way into all systems over time, so the longer you run the fluid, the more stable DOT is and the more and more mineral gets affected by water in the system. I’ve had mineral oil brakes feeling like crap under tons of heat. I thought they were overheating due to the 203 rotors not being enough, but the brakes were baking in all ways possible. For car racing, you want the best high temp fluid you can get. They’re are some other problems, as not all your other parts like brake lines, seals, etc. can deal with that heat, even though the fluid can handle it. Some people use titanium shims for the pads to provide a little more insulation.

I didn’t know about the ti shims. nice trick!

For sure, i use all sorts of fluid and sometimes even prototype stuff in unmarked bottles occasionally. When you are already using good fluid it seems to make an unnoticeable difference, maybe marginal gains at some point. Very true about the fluid not being the weak link at those heat levels. I have had a caliper seal let go at the worst moment 4 times in 20 years of riding Champery. Scary but fun af if you don’t die. I think pad and rotor condition greatly varies the heat buildup.

Thick rotors seem to be a noticeable change. Ice Tech rotors looks to be shite. DOT is much more stable for my uses (600-1000m descents) however the new Cura 4 is almost convincing me otherwise. They do have a special fluid they use.

I have had almost all the brakes at one point or another and friends often pull brakes out of my melted stash and rebuild with varying degrees of success. Here’s the pile currently. Brakes are a wear item round these parts, imo.

My current favorites are the Hayes A4 and the new Cura 4.

 

[jstuhlman]

I didn’t know about the ti shims. nice trick!

For sure, i use all sorts of fluid and sometimes even prototype stuff in unmarked bottles occasionally. When you are already using good fluid it seems to make an unnoticeable difference, maybe marginal gains at some point. Very true about the fluid not being the weak link at those heat levels. I have had a caliper seal let go at the worst moment 4 times in 20 years of riding Champery. Scary but fun af if you don’t die. I think pad and rotor condition greatly varies the heat buildup.

Thick rotors seem to be a noticeable change. Ice Tech rotors looks to be shite. DOT is much more stable for my uses (600-1000m descents) however the new Cura 4 is almost convincing me otherwise. They do have a special fluid they use.

I have had almost all the brakes at one point or another and friends often pull brakes out of my melted stash and rebuild with varying degrees of success. Here’s the pile currently. Brakes are a wear item round these parts, imo.

My current favorites are the Hayes A4 and the new Cura 4.

View attachment 174947

curious: how are new cura4 different than older? i like my older ones up front but honestly don't notice much difference from the cura2s out back other than a bit of lever feel...

 

[Jm_]

I didn’t know about the ti shims. nice trick!

I have had a caliper seal let go at the worst moment 4 times in 20 years of riding Champery. Scary but fun af if you don’t die. I think pad and rotor condition greatly varies the heat buildup.

Yeah, the caliper seals is definitely one of those areas that can fry. Some cars w/o will upgrade to vented pistons, to further attempt to control this.

 

[rideit]

That's a moot point, because you need to bleed shimanos before the fluid ever has a chance of separating.

“It’s a feature, not a bug!”

 

[englertracing]

Good explanation of why my car brakes worked on the way to the trailhead, but my bicycle brakes were shit. Granted, not everyone rides in the cold, but the wandering bite point seems like a bigger problem in just a little chillier weather when you are on steeps, something with the replenishment orifice size in the shimano brakes and how quickly that is overwhelmed by the mineral oil. I remember distinctly the issue at Darrington down those trails in the Fall, one of the last times I was on those brakes in any normal-ish conditions.

Have you tried redline like water?

 

[englertracing]

I reckon you've got other problems if you're getting that much water into the system hey.

PreSSurE WaSHerZ are Geud MAIntenenZe

 

[Jm_]

Have you tried redline like water?

I have the: https://www.putoline.com/en/catalogue/product/371/hpx-r-25w/1735/

It helps a little...but not much. Not anywhere near how the Hopes on DOT feel pretty much like normal no matter the conditions. The putoline 2.5 still has the on/off feeling and crazy pump-up/bite point getting further out issue in the cold. It does seem better than the stock mineral oil...but the degree is not huge.

 

[englertracing]

Cst @100c puto 2.85, redline 2.34
Cst @40c puto 6.61, redline 4.0
Pour point puto -39, redline -50

Maybe redline would improve

 

[Flo33]

Have you tried redline like water?

I have after Udi recommended it and won't go back to anything else.

 

[Bikael Molton]

What is your concern with Ice Tech rotors?

I’m on A4s with Shimano and Hope rotors now and am figuring out which rotors to go with when I need replacements. Probably something thicker…

thanks!

I didn’t know about the ti shims. nice trick!

For sure, i use all sorts of fluid and sometimes even prototype stuff in unmarked bottles occasionally. When you are already using good fluid it seems to make an unnoticeable difference, maybe marginal gains at some point. Very true about the fluid not being the weak link at those heat levels. I have had a caliper seal let go at the worst moment 4 times in 20 years of riding Champery. Scary but fun af if you don’t die. I think pad and rotor condition greatly varies the heat buildup.

Thick rotors seem to be a noticeable change. Ice Tech rotors looks to be shite. DOT is much more stable for my uses (600-1000m descents) however the new Cura 4 is almost convincing me otherwise. They do have a special fluid they use.

I have had almost all the brakes at one point or another and friends often pull brakes out of my melted stash and rebuild with varying degrees of success. Here’s the pile currently. Brakes are a wear item round these parts, imo.

My current favorites are the Hayes A4 and the new Cura 4.

View attachment 174947

 

[buckoW]

What is your concern with Ice Tech rotors?

I’m on A4s with Shimano and Hope rotors now and am figuring out which rotors to go with when I need replacements. Probably something thicker…

thanks!

They wear out and glaze much quicker than other rotors. Keep in mind I’m only riding DH.

 

[buckoW]

curious: how are new cura4 different than older? i like my older ones up front but honestly don't notice much difference from the cura2s out back other than a bit of lever feel...

I’m not sure. But they work nice.

 

[Andeh]

They wear out and glaze much quicker than other rotors. Keep in mind I’m only riding DH.

My experience with them is that they also bend or warp if you so much as look at them funny. I didn't run them for very long, but a few of my friends are Shimano fanboys, and their rotors are ALWAYS rubbing because they can't stay straight.

 

[HAB]

My experience with them is that they also bend or warp if you so much as look at them funny. I didn't run them for very long, but a few of my friends are Shimano fanboys, and their rotors are ALWAYS rubbing because they can't stay straight.

Yup.

I'm having good luck with Galfer rotors.

 

[Cerberus75]

What is your concern with Ice Tech rotors?

I’m on A4s with Shimano and Hope rotors now and am figuring out which rotors to go with when I need replacements. Probably something thicker…

thanks!

The Magura 2 piece rotor has been working very well with my A4s. Icetech warp very easy. You can't sit holding the brakes while resting. Makes them warp pretty bad.

 

[Cerberus75]

Yup.

I'm having good luck with Galfer rotors.

How thick are they? I was thinking about trying those next.

 

[rideit]

They wear out and glaze much quicker than other rotors. Keep in mind I’m only riding DH.

How do you keep your girl-ish figure?

 

[jonKranked]

They wear out and glaze much quicker than other rotors. Keep in mind I’m only riding DH.

custom title: "I only ride DH"

 

[canadmos]

I didn’t know about the ti shims. nice trick!

For sure, i use all sorts of fluid and sometimes even prototype stuff in unmarked bottles occasionally. When you are already using good fluid it seems to make an unnoticeable difference, maybe marginal gains at some point. Very true about the fluid not being the weak link at those heat levels. I have had a caliper seal let go at the worst moment 4 times in 20 years of riding Champery. Scary but fun af if you don’t die. I think pad and rotor condition greatly varies the heat buildup.

Thick rotors seem to be a noticeable change. Ice Tech rotors looks to be shite. DOT is much more stable for my uses (600-1000m descents) however the new Cura 4 is almost convincing me otherwise. They do have a special fluid they use.

I have had almost all the brakes at one point or another and friends often pull brakes out of my melted stash and rebuild with varying degrees of success. Here’s the pile currently. Brakes are a wear item round these parts, imo.

My current favorites are the Hayes A4 and the new Cura 4.

View attachment 174947

Is that a polished chrome XTR brake lever? Do you have the left one and does it work?

 

[Carraig042]

How thick are they? I was thinking about trying those next.

The Wave rotor is available in 1.8mm and 2.0mm.

 

[Udi]

If you have a problem with your MTB brakes, the type of fluid (glycol / oil) probably isn't the cause.

My current favorites are the Hayes A4 and the new Cura 4.

Can we have your mini review of the Cura4?
Have you run the pads from new to spring-scraping on a single bleed?
Wondering if they've addressed the inadequate MC fluid volume issue - knowing Formula they do make quiet updates. I've liked both the A4s and Cura4s I've ridden for stopping but the Hayes are too heavy (for the bike I want to put them on) while the Cura4 is refreshingly light. Meaningless unless they fix(ed?) the volume issue though.

 

[jonKranked]

Have you run the pads from new to spring-scraping on a single bleed?

 

[englertracing]

I didn’t know about the ti shims. nice trick!

For sure, i use all sorts of fluid and sometimes even prototype stuff in unmarked bottles occasionally. When you are already using good fluid it seems to make an unnoticeable difference, maybe marginal gains at some point. Very true about the fluid not being the weak link at those heat levels. I have had a caliper seal let go at the worst moment 4 times in 20 years of riding Champery. Scary but fun af if you don’t die. I think pad and rotor condition greatly varies the heat buildup.

Thick rotors seem to be a noticeable change. Ice Tech rotors looks to be shite. DOT is much more stable for my uses (600-1000m descents) however the new Cura 4 is almost convincing me otherwise. They do have a special fluid they use.

I have had almost all the brakes at one point or another and friends often pull brakes out of my melted stash and rebuild with varying degrees of success. Here’s the pile currently. Brakes are a wear item round these parts, imo.

My current favorites are the Hayes A4 and the new Cura 4.

View attachment 174947

I always wanted to attempt pairing the formula the one non radial master cylinder with a formula oval caliper.

 

[buckoW]

If you have a problem with your MTB brakes, the type of fluid (glycol / oil) probably isn't the cause.


Can we have your mini review of the Cura4?
Have you run the pads from new to spring-scraping on a single bleed?
Wondering if they've addressed the inadequate MC fluid volume issue - knowing Formula they do make quiet updates. I've liked both the A4s and Cura4s I've ridden for stopping but the Hayes are too heavy (for the bike I want to put them on) while the Cura4 is refreshingly light. Meaningless unless they fix(ed?) the volume issue though.

Hey Udi!
I haven’t had enough time on them yet to burn through a set of pads. I’m half way through so I’ll have to come back for that part. For now they are pretty good but I prefer the Hayes still. I got them for free so full disclosure and all.

I always wanted to attempt pairing the formula the one non radial master cylinder with a formula oval caliper.

I might have some fresh oval seals to try that combo.

 

[William42]

If you have a problem with your MTB brakes, the type of fluid (glycol / oil) probably isn't the cause.


Can we have your mini review of the Cura4?
Have you run the pads from new to spring-scraping on a single bleed?
Wondering if they've addressed the inadequate MC fluid volume issue - knowing Formula they do make quiet updates. I've liked both the A4s and Cura4s I've ridden for stopping but the Hayes are too heavy (for the bike I want to put them on) while the Cura4 is refreshingly light. Meaningless unless they fix(ed?) the volume issue though.

I'm up in the pac NW riding 2000ft+/600m+ descents pretty regularly on Cura 4's. I'm at 3 sets of pads 1 bleed (post setup) for my rear brake and 2 sets of pads no bleeds for my front. Using Formula brands semi-metallic pads. Also do a decent amount of shuttling on them.

I only weigh 173lbs though, so make what you will of any brake review by my skinny ass. I think the lever shape and pull is mediocre and I've never been able to get a bleed even half as crisp as I have with any other brake i've ever owned. That said, the important factors like strength, raw stopping power, and consistency have been pretty solid - I like them only a tiny bit less than saints, which I won't run because of the excitement factor of a variable bite point that sometimes just lets you send it by surprise when you're trying to slow down. I'll happily run them until I'm able to get a hold of some maximas which at this rate appears to be on the horizon for 3022 delivery date.

 

[Udi]

I'm up in the pac NW riding 2000ft+/600m+ descents pretty regularly on Cura 4's. I'm at 3 sets of pads 1 bleed (post setup) for my rear brake and 2 sets of pads no bleeds for my front. Using Formula brands semi-metallic pads. Also do a decent amount of shuttling on them.

Awesome, cheers.
Does the lever stroke stay pretty constant towards end of pad life, esp on the rear brake? Got a rough buy date on them?
I wonder if they updated em. Similar to you I didn't get a super crisp bleed on the set I installed either, but it was good enough.

I always wanted to attempt pairing the formula the one non radial master cylinder with a formula oval caliper.

Got a pile of both in a box, but the oval calipers suck for large wheels due to the tiny fast-cook pads - same with T1, Cura 2, etc. The Cura 4 is the first Formula brake with a decent sized pad.

 

[englertracing]

Got a pile of both in a box, but the oval calipers suck for large wheels due to the tiny fast-cook pads - same with T1, Cura 2, etc. The Cura 4 is the first Formula brake with a decent sized pad.

I see,
But what does the mix master himself think about how they would feel and work(powerwise)?

 

[Lelandjt]

Aktually…

(anyone run a fall line? ). The 125 is 440g with cables and housing, so um, yeah.

1/2 a pound savings over my Fox.
hmmm.

The new Fall Line R is the world’s lightest dropper seatpost

9point8 pushes the boundaries of dropper weight

www.bikeradar.com

I've had that on my XC bike since 2017. Works perfectly with only some wiper seal lubing.

 

[rideit]

Hmmm.

 

[Lelandjt]

Every time I hear people whinge about AXS I recall all the roadies who fought disc brakes so hard. "but rim brakes are fine!"

I'm still riding a rim brake road bike. At the 100+ person tour I'm currently on my bike is by far the lightest and cost less than $3000. My Dura-ace brakes on DT alloy rims work great.

 

[rideit]

I’ll race ya on a super steep downhill in the rain!

 

[Lelandjt]

Thats a shame, I didn't notice that. I actually squeezed some the other day, they felt nice and solid. Hefty though..

BuckoW uses them on all his bikes and the one I borrowed last week felt great. Good power and modulation, short throw, firm enough at the end.