Some manufacturers forcing pros onto disk brakes for the 2019 season

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wolfesquire
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by wolfesquire

#NoBraques

Just to give a 3rd option.

by Weenie


fxx
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by fxx

wolfesquire wrote:#NoBraques

Just to give a 3rd option.
After you.

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ND4SPD
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by ND4SPD

Lewn777 wrote:
Thu May 16, 2019 6:26 am
Yes on paper DOT fluid is better than mineral oil.
Not just on paper.
Lewn777 wrote:Like ceramic bearings a bicycle can't make use of the extra heat dissipating performance gains.
Ceramic bearing are another subject, they are not used in the brakes, and therefore can't be compared with DOT fluid or mineral oil.
Lewn777 wrote:Shimano mineral oil brakes are the best in the business, simply look at any round of the mountain biking world cup and you'll see how well mineral oil performs in real life on a bicycle.
Sram (which uses DOT fluid) is not used in mountain biking world cup?

3Pio
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by 3Pio

fxx wrote:
Thu May 16, 2019 10:24 am
dastott wrote:In my area of Japan I don't know any serious cyclists (regular racers or Strava KOM hunters or big mileage guys) that have discs on their road bike. Almost all ride carbon wheels though.
Asian cyclists seldom want disc because the riders are light around 60 kgs so they feel that disc brakes are unnecessary.

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Im not Asian, not that light (74 kg at a moment), riding plenty of hills on carbon tubulars... And feel that disc brakes are unnecessary, and just marketing gimmick for road bike.. And no, really dont feel that need stronger brakes even in wet and even im surrounded with mountains (grades from 5% to 20%)

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Lewn777
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by Lewn777

ND4SPD wrote:
Sat May 18, 2019 4:26 am
Lewn777 wrote:
Thu May 16, 2019 6:26 am
Yes on paper DOT fluid is better than mineral oil.
Not just on paper.
Lewn777 wrote:Like ceramic bearings a bicycle can't make use of the extra heat dissipating performance gains.
Ceramic bearing are another subject, they are not used in the brakes, and therefore can't be compared with DOT fluid or mineral oil.
Lewn777 wrote:Shimano mineral oil brakes are the best in the business, simply look at any round of the mountain biking world cup and you'll see how well mineral oil performs in real life on a bicycle.
Sram (which uses DOT fluid) is not used in mountain biking world cup?
For bicycles there are a list of advantages and disadvantages for both mineral oil and DOT fluid. DOT fluid often needs degassing, DOT fluid absorbs moisture, DOT fluid can't be left in a can to be used later without going bad from moisture absorbtion. The advantage of DOT fluid is it's heat dissapating performance gains, but those aren't needed in the application for bicycles.

I've used both Shimano and SRAM mountain bike brakes and I found Shimano to be far superior despite being mineral oil. But someone could make just as good a brake and that was designed for DOT fluid.

I'm an environmentally minded person so, all things equal, I prefer mineral oil, but I prefer SRAM shifting to Shimano shifting so never say never. :beerchug:

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Lewn777
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by Lewn777

3Pio wrote:
Sat May 18, 2019 5:25 am
fxx wrote:
Thu May 16, 2019 10:24 am
dastott wrote:In my area of Japan I don't know any serious cyclists (regular racers or Strava KOM hunters or big mileage guys) that have discs on their road bike. Almost all ride carbon wheels though.
Asian cyclists seldom want disc because the riders are light around 60 kgs so they feel that disc brakes are unnecessary.

Sent from my SM-G965F using Tapatalk
Im not Asian, not that light (74 kg at a moment), riding plenty of hills on carbon tubulars... And feel that disc brakes are unnecessary, and just marketing gimmick for road bike.. And no, really dont feel that need stronger brakes even in wet and even im surrounded with mountains (grades from 5% to 20%)
I ride hills all day (cat 2, 3 and 4) and I weigh 76kg and have coated alloy rim brakes and I don't feel I need disk brakes either. But I'm sure you already knew that! I ride disk brake bikes every day, they're on my commuting bikes, so it's not as if I don't know what I'm missing. :thumbup:

fxx
Posts: 129
Joined: Fri Sep 17, 2010 2:10 pm

by fxx

Speaking of disc brake tech, MTB Shimano's XTR brake calipers are more technologically advanced than it's road cousins, with better pads and 4 pot calipers and they look very sleek too, why did Shimano decide to adopt flat mount line for road bikes? Both road and MTB lines should have been post mount so that roadies need not wait for trickle down tech.

After all many other road bike tech have adopted MTB features such as head set, sloping top tubes and now disc brakes.

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3Pio
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by 3Pio

Lewn777 wrote:
Sat May 18, 2019 11:41 am
3Pio wrote:
Sat May 18, 2019 5:25 am
fxx wrote:
Thu May 16, 2019 10:24 am
dastott wrote:In my area of Japan I don't know any serious cyclists (regular racers or Strava KOM hunters or big mileage guys) that have discs on their road bike. Almost all ride carbon wheels though.
Asian cyclists seldom want disc because the riders are light around 60 kgs so they feel that disc brakes are unnecessary.

Sent from my SM-G965F using Tapatalk
Im not Asian, not that light (74 kg at a moment), riding plenty of hills on carbon tubulars... And feel that disc brakes are unnecessary, and just marketing gimmick for road bike.. And no, really dont feel that need stronger brakes even in wet and even im surrounded with mountains (grades from 5% to 20%)
I ride hills all day (cat 2, 3 and 4) and I weigh 76kg and have coated alloy rim brakes and I don't feel I need disk brakes either. But I'm sure you already knew that! I ride disk brake bikes every day, they're on my commuting bikes, so it's not as if I don't know what I'm missing. :thumbup:
I just get back from XC MTB Ride (i havent riden MTB for maybe2 years), 92 km, and 2500 climb 90% off road.... And i have disk on my MTB (Magura Marta SL), which i have it since 2008 (Specialized Epic Marathon Carbon..)

If i told u that even on MTB i really liked XTR V-Brakes i had on bike before this (i was using Kool Stop brake pads then), but ok.. Let's say that on MTB Disk's are ok.. But on road.. Definetely not need them at all... BTW, guess what MTB wheelset size im riding? :)

ND4SPD
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by ND4SPD

Lewn777 wrote:
Sat May 18, 2019 11:23 am
DOT fluid often needs degassing
DOT fluid does not need degassing. Neither in cars, neither in bicycles. If you don't believe me, ask Sram:

https://www.sram.com/contact
Lewn777 wrote:DOT fluid absorbs moisture
Yes, and mineral oil doesn't. If any water enters the system which is using mineral oil, and sooner or later it will, the boiling point is instantly reduced to the standard boiling point of water (at sea level or if you want at 1013.25 mbar, or approximately 1 atm), ergo - 100°C.
Lewn777 wrote:DOT fluid can't be left in a can to be used later without going bad from moisture absorbtion.
It can be used later, and yes, with time it absorbs moisture. But DOT fluid is cheap, and beside that you have cheap testers for moisture content in the brake fluid. I had DOT fluid which was opened (and of course closed after using) for one or two years, and after testing it was still good, and used again...
Lewn777 wrote:The advantage of DOT fluid is it's heat dissapating performance gains, but those aren't needed in the application for bicycles.
That's debatable :)

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Lewn777
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by Lewn777

ND4SPD wrote:
Sat May 18, 2019 8:16 pm
Lewn777 wrote:
Sat May 18, 2019 11:23 am
DOT fluid often needs degassing
DOT fluid does not need degassing. Neither in cars, neither in bicycles. If you don't believe me, ask Sram:

https://www.sram.com/contact
Lewn777 wrote:DOT fluid absorbs moisture
Yes, and mineral oil doesn't. If any water enters the system which is using mineral oil, and sooner or later it will, the boiling point is instantly reduced to the standard boiling point of water (at sea level or if you want at 1013.25 mbar, or approximately 1 atm), ergo - 100°C.
Lewn777 wrote:DOT fluid can't be left in a can to be used later without going bad from moisture absorbtion.
It can be used later, and yes, with time it absorbs moisture. But DOT fluid is cheap, and beside that you have cheap testers for moisture content in the brake fluid. I had DOT fluid which was opened (and of course closed after using) for one or two years, and after testing it was still good, and used again...
Lewn777 wrote:The advantage of DOT fluid is it's heat dissapating performance gains, but those aren't needed in the application for bicycles.
That's debatable :)
I've got three mountain bikes in two countries with Shimano mountain bike brakes (XT, SLX and Deore) that I've had for years and probably lazily only bled about twice each bike over the last five years. I have seen dirt speks (probably be from the system itself rather than from oustide) and discoloration in the fluid, but I have never seen moisture. Even if there was some moisture oil and water don't mix so the moisture would condense and end up a small film above the oil in the reservior and not effect braking as it would not be between the lever and the caliper. So honestly I can't see your worry about water entering the system as any kind of problem.

mattr
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by mattr

Water is denser than mineral oil. So it sits at the lowest point of the system. Which is a problem. Especially with bigger, heavier, harder braking riders. Hit that magic 100 degrees C (plus a little bit due to pressure in the system) and poof, you're braking on a steam spring.

Water in DoT is only really a problem if you leave on open bottle in a damp garage or workshop, or on the shelf immediately above the kettle for several years. In a dry workshop, or with the lid on, it's a complete non issue for a handful of years (open bottle) or a decade or so (bottle gets closed after every use.)
Degas is also a waste of time, unless you like shaking the bottle to make sure "all the goodness" is mixed in. I did actually see a youtube video of a guy degassing DoT, nothing happened. Nothing came out.

Vacuum fill of a brake system would have been more useful though!

TobinHatesYou
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by TobinHatesYou

Crying about degassing again Lewn777? We’ve already discussed this. The only reason why SRAM includes the degassing procedure is because they can.

You can’t degas water “bubbles” in mineral oil though.

ND4SPD
Posts: 78
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by ND4SPD

Lewn777 wrote:
Sat May 18, 2019 11:27 pm
I've got three mountain bikes in two countries with Shimano mountain bike brakes (XT, SLX and Deore) that I've had for years and probably lazily only bled about twice each bike over the last five years. I have seen dirt speks (probably be from the system itself rather than from oustide) and discoloration in the fluid, but I have never seen moisture.
Shimano recommend oil replacement when oil becomes severely discolored:

https://si.shimano.com/pdfs/dm/DM-BR0005-12-ENG.pdf

Park Tool once a year if the bicycle is extensively used:

https://www.parktool.com/blog/repair-he ... adjustment

Sram also once a year:

https://www.sram.com/sites/default/file ... _rev_c.pdf
Lewn777 wrote:Even if there was some moisture oil and water don't mix so the moisture would condense and end up a small film above the oil in the reservior and not effect braking as it would not be between the lever and the caliper. So honestly I can't see your worry about water entering the system as any kind of problem.
Wrong. Like I already said at least twice earlier, if any water enters the system which is using mineral oil, and sooner or later it will, the boiling point is instantly reduced to the standard boiling point of water (at sea level or if you want at 1013.25 mbar, or approximately 1 atm), ergo - 100°C.

Mattr in the post lower also explained it.

And beside overheating, I forgot about vapor lock. Vapor lock occurs when the oil inside the brake system becomes heated, which causes the water or air bubbles inside the brake system to expand. This can then result in a sudden increase in the brake lever stroke. DOT fluid is here also better, because it is hygroscopic.
mattr wrote:
Sat May 18, 2019 11:40 pm
Water is denser than mineral oil. So it sits at the lowest point of the system. Which is a problem. Especially with bigger, heavier, harder braking riders. Hit that magic 100 degrees C (plus a little bit due to pressure in the system) and poof, you're braking on a steam spring.

Water in DoT is only really a problem if you leave on open bottle in a damp garage or workshop, or on the shelf immediately above the kettle for several years. In a dry workshop, or with the lid on, it's a complete non issue for a handful of years (open bottle) or a decade or so (bottle gets closed after every use.)
Degas is also a waste of time, unless you like shaking the bottle to make sure "all the goodness" is mixed in. I did actually see a youtube video of a guy degassing DoT, nothing happened. Nothing came out.

Vacuum fill of a brake system would have been more useful though!
Nice metaphor with steam spring :mrgreen: :mrgreen: :mrgreen:

I don't know about a decade or so, I have not tried it, but it can be tested with the testers for moisture content in the brake fluid...

Like I said, DOT fluid does not need degassing. Neither in cars, neither in bicycles.
TobinHatesYou wrote:
Sun May 19, 2019 12:49 am
Crying about degassing again Lewn777? We’ve already discussed this. The only reason why SRAM includes the degassing procedure is because they can.

You can’t degas water “bubbles” in mineral oil though.
Again, like I said, DOT fluid does not need degassing. Neither in cars, neither in bicycles.

Also, Sram does not include degassing procedure in their products. Maybe someone mistook bleeding for degassing.

You can't find degassing anywere here:

https://www.sram.com/service

You and everyone else can also contact Sram and ask them about degassing:

https://www.sram.com/contact

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Lewn777
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by Lewn777

TobinHatesYou wrote:
Sun May 19, 2019 12:49 am
Crying about degassing again Lewn777? We’ve already discussed this. The only reason why SRAM includes the degassing procedure is because they can.

You can’t degas water “bubbles” in mineral oil though.
Oh god still going on about your purchases. Some cronic post purchase rationalization via crowd proxy again. OK SRAM are best ever, like better than Campagnolo, Shimano, FSA and everyone else. Trek make the best bikes like, ever especially the Madone and Emonda. All bikes must be setup tubless and have disk brake because newer must be betterer.

We got it already. :beerchug:

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Lewn777
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by Lewn777

ND4SPD wrote:
Sun May 19, 2019 2:44 am
Lewn777 wrote:
Sat May 18, 2019 11:27 pm
I've got three mountain bikes in two countries with Shimano mountain bike brakes (XT, SLX and Deore) that I've had for years and probably lazily only bled about twice each bike over the last five years. I have seen dirt speks (probably be from the system itself rather than from oustide) and discoloration in the fluid, but I have never seen moisture.
Shimano recommend oil replacement when oil becomes severely discolored:

https://si.shimano.com/pdfs/dm/DM-BR0005-12-ENG.pdf

Park Tool once a year if the bicycle is extensively used:

https://www.parktool.com/blog/repair-he ... adjustment

Sram also once a year:

https://www.sram.com/sites/default/file ... _rev_c.pdf
Lewn777 wrote:Even if there was some moisture oil and water don't mix so the moisture would condense and end up a small film above the oil in the reservior and not effect braking as it would not be between the lever and the caliper. So honestly I can't see your worry about water entering the system as any kind of problem.
Wrong. Like I already said at least twice earlier, if any water enters the system which is using mineral oil, and sooner or later it will, the boiling point is instantly reduced to the standard boiling point of water (at sea level or if you want at 1013.25 mbar, or approximately 1 atm), ergo - 100°C.

Mattr in the post lower also explained it.

And beside overheating, I forgot about vapor lock. Vapor lock occurs when the oil inside the brake system becomes heated, which causes the water or air bubbles inside the brake system to expand. This can then result in a sudden increase in the brake lever stroke. DOT fluid is here also better, because it is hygroscopic.
mattr wrote:
Sat May 18, 2019 11:40 pm
Water is denser than mineral oil. So it sits at the lowest point of the system. Which is a problem. Especially with bigger, heavier, harder braking riders. Hit that magic 100 degrees C (plus a little bit due to pressure in the system) and poof, you're braking on a steam spring.

Water in DoT is only really a problem if you leave on open bottle in a damp garage or workshop, or on the shelf immediately above the kettle for several years. In a dry workshop, or with the lid on, it's a complete non issue for a handful of years (open bottle) or a decade or so (bottle gets closed after every use.)
Degas is also a waste of time, unless you like shaking the bottle to make sure "all the goodness" is mixed in. I did actually see a youtube video of a guy degassing DoT, nothing happened. Nothing came out.

Vacuum fill of a brake system would have been more useful though!
Nice metaphor with steam spring :mrgreen: :mrgreen: :mrgreen:

I don't know about a decade or so, I have not tried it, but it can be tested with the testers for moisture content in the brake fluid...

Like I said, DOT fluid does not need degassing. Neither in cars, neither in bicycles.
TobinHatesYou wrote:
Sun May 19, 2019 12:49 am
Crying about degassing again Lewn777? We’ve already discussed this. The only reason why SRAM includes the degassing procedure is because they can.

You can’t degas water “bubbles” in mineral oil though.
Again, like I said, DOT fluid does not need degassing. Neither in cars, neither in bicycles.

Also, Sram does not include degassing procedure in their products. Maybe someone mistook bleeding for degassing.

You can't find degassing anywere here:

https://www.sram.com/service

You and everyone else can also contact Sram and ask them about degassing:

https://www.sram.com/contact
It could be a problem with mineral based systems if there was any moisture in the system. Only it's never really been reported and I've never seen it so you can go on and on about this being a 'problem' with mineral oil, but it's completely a non issue. I really don't see how moisture is ever going to enter a sealed system from below, more likely it would condense from the air in the reservoir and how the hell it would make it down to the caliper I have no clue. It's not a jam jar in an elementary school experiment.

These days SRAM have probably ironed out the deafening dry warbles, the even louder wet disk warbles, the gas bubbles trapped in the tiny reservoir causing the dead levers and needing to de-gas the fluid because of it, then leaving the levers strapped overnight to get rid of yet more bubbles trapped around pockets around the calipers and the need to spend hours tap-tatting on the cables and calipers. I came to the conclusion that DOT fluid was totally wrong for the application of bicycle brakes. That was what I had to do with Avid Juicy brakes ten years ago to make them work on my mates bike, they were garbage, but the newer generations of SRAM brakes are probably much better. :thumbup:

Why you need to go on the internet to attack mineral oil options that work perfectly well, are environmetally friendlier and in fact are the more trustworthy and more reliable market options is beyond me. Maybe you're yet another post purchase rationalization baby that's bought SRAM and needs to crybully over their choice being the cleverest choice to ensure that they've made the best choice.

Fact is SRAM shifting is excellent, their newer disk brakes are proabably very good. But also Shimano and Camapgnolo are excellent choices too. Why you feel the need to smear the 'oppostion', it just strikes me as incredibly childish. If you'd have actually used Shimano or Campagnolo and found some flaw, then you'd have a point, but you're simply putting down options you have no experience with.
Last edited by Lewn777 on Sun May 19, 2019 3:48 am, edited 1 time in total.

by Weenie


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