• Disc brake technical note

    From AMuzi@am@yellowjersey.org to rec.bicycles.tech on Tue Jul 14 13:29:33 2026
    From Newsgroup: rec.bicycles.tech

    Disc systems get hot, and are ruined by contamination with
    wax, brake fluid or oil products.

    This, apparently, is a secret.


    http://www.yellowjersey.org/photosfromthepast/discuser.jpg
    --
    Andrew Muzi
    am@yellowjersey.org
    Open every day since 1 April, 1971

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  • From =?UTF-8?B?Y3ljbGludG9t?=@cyclintom@yahoo.com to rec.bicycles.tech on Tue Jul 14 20:45:24 2026
    From Newsgroup: rec.bicycles.tech

    On Tue Jul 14 13:29:33 2026 AMuzi wrote:
    Disc systems get hot, and are ruined by contamination with
    wax, brake fluid or oil products.

    This, apparently, is a secret.


    http://www.yellowjersey.org/photosfromthepast/discuser.jpg
    Rim brakes do not have these problems. The idea that disks are more powerful is demonstrably wrong. i have locked rim brakes often and even rotated the entire bike around the front wheel and struck my head on the trunk of a parked car that I had failed to notice until nearly to late I hit my helmet before the front wheel hit the rear bumper of the car and this with Gatorskins of the bike.
    While there might be some use for disks on MTB's since the are purposely exposed to water and mud, you don't have that problem with road bikes
    t
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  • From Roger Merriman@roger@sarlet.com to rec.bicycles.tech on Tue Jul 14 21:10:22 2026
    From Newsgroup: rec.bicycles.tech

    cyclintom <cyclintom@yahoo.com> wrote:
    On Tue Jul 14 13:29:33 2026 AMuzi wrote:
    Disc systems get hot, and are ruined by contamination with
    wax, brake fluid or oil products.

    This, apparently, is a secret.


    http://www.yellowjersey.org/photosfromthepast/discuser.jpg




    Rim brakes do not have these problems. The idea that disks are more
    powerful is demonstrably wrong. i have locked rim brakes often and even rotated the entire bike around the front wheel and struck my head on the trunk of a parked car that I had failed to notice until nearly to late I
    hit my helmet before the front wheel hit the rear bumper of the car and
    this with Gatorskins of the bike.

    While there might be some use for disks on MTB's since the are purposely exposed to water and mud, you don't have that problem with road bikes


    ItrCOs certainly true that for myself I was more bothered by the gearing on
    the roadie which considering its price point, ie likely to be a commuter or similar, than an aspiring roadie, the rim brakes have been fine did require
    new pads as the originals where fairly poor!

    My commute to be fair is a flat route, fair amount of no interaction with others, no stop start traffic vs for example riding into central where you
    use the brakes much more so, and indeed at the time they where where
    becoming available the guys who do this day in day out, said they expected
    to save money on new wheels as rotors and pads are rather less expensive!

    The Gravel bike with its 160mm rotors can if one wants to, brake very hard,
    the MTB with larger rotors you can push even harder, and can absolutely
    apply rather more force than a rim brake.

    Locking a wheel let alone doing a endo is lack of control indicator than
    how powerful the brakes are, brakes like rim brakes that have less
    modulation ie rather on/off braking need greater care to avoid locking up.

    To AndrewrCOs point IrCOve certainly seen bikes that have been sprayed with WD40 and having to be taken in to be sorted!

    Rather surprising the roadie requires more maintenance to its brakes than
    the other commuter that has disks as the dual pivots get gummed up and then become sticky and more on/off vs the disks which maybe collect some oils
    but bar being noisy itrCOs relatively benign, this being the commute IrCOm not pushing hard so minor reductions in performance are just not something I
    worry about! The Gravel or MTB sure yes IrCOd get it sorted but the commute itrCOs not an issue.

    Roger Merriman

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  • From Joerg@news@analogconsultants.com to rec.bicycles.tech on Tue Jul 14 14:17:31 2026
    From Newsgroup: rec.bicycles.tech

    On 7/14/26 1:45 PM, cyclintom wrote:
    On Tue Jul 14 13:29:33 2026 AMuzi wrote:
    Disc systems get hot, and are ruined by contamination with
    wax, brake fluid or oil products.

    This, apparently, is a secret.


    http://www.yellowjersey.org/photosfromthepast/discuser.jpg


    But it did make the noise go away :-)


    Rim brakes do not have these problems.


    If someone greases them up like in Andrew's example, they do.


    The idea that disks are more powerful is demonstrably wrong. i have
    locked rim brakes often and even rotated the entire bike around the
    front wheel and struck my head on the trunk of a parked car that I had
    failed to notice until nearly to late I hit my helmet before the front
    wheel hit the rear bumper of the car and this with Gatorskins of the bike.

    While there might be some use for disks on MTB's since the are purposely exposed to water and mud, you don't have that problem with road bikes


    That's probably because you don't ride much in foul weather or on
    unpaved roads. I do, and sometimes have to. Disc brakes have a huge
    advantage over rim brakes when things are wet or muddy. Like here, right
    in town where I live:

    https://maps.app.goo.gl/8CuL5kBopXmm1scW9

    The other downside of rim brakes is when road dirt gets sprayed onto the
    bike by passing cars. That can result in an awful grinding noise when
    you have to reach in. You literally hear the rims being eaten up but
    can't release the levers because a red traffic light or something is
    coming up or you are on a steep descent. That ages a rim quickly, within seconds.
    --
    Regards, Joerg

    http://www.analogconsultants.com/
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  • From zen cycle@funkmasterxx@hotmail.com to rec.bicycles.tech on Thu Jul 16 06:51:04 2026
    From Newsgroup: rec.bicycles.tech


    cyclintom <cyclintom@yahoo.com> wrote:
    On Tue Jul 14 13:29:33 2026 AMuzi wrote:
    Disc systems get hot, and are ruined by contamination with
    wax, brake fluid or oil products.

    This, apparently, is a secret.

    http://www.yellowjersey.org/photosfromthepast/discuser.jpg

    Rim brakes do not have these problems. The idea that disks are more
    powerful is demonstrably wrong.

    Well, demonstrate it then....Besides, you've claimed repeatedly in this
    forum that disc brakes are bad for bikes because they have too much
    power. Here's one example: https://groups.google.com/g/rec.bicycles.tech/c/pfsO-q6qYaY/m/kJr0MdrDAQAJ
    "I consider them extraneous on road bike. Far too powerful for a 16 lb
    bike."

    Here's another: https://groups.google.com/g/rec.bicycles.tech/c/uREthtpJ8BY/m/I--V52JsBQAJ
    "I ride on the flats with gravel bikes and disks are WAYYY too strong
    for me"

    and another: https://groups.google.com/g/rec.bicycles.tech/c/uREthtpJ8BY/m/fhDwboHFBQAJ "Disks are simply too powerful and too easy to lock up"

    and another: https://groups.google.com/g/rec.bicycles.tech/c/ffqs2o-wiyQ/m/hKFs3pkzAwAJ "They work well but are FAR too powerful for a gravel bike"

    i have locked rim brakes often and even
    rotated the entire bike around the front wheel and struck my head on the
    trunk of a parked car that I had failed to notice until nearly to late I
    hit my helmet before the front wheel hit the rear bumper of the car and
    this with Gatorskins of the bike.

    Yes, you can lock up a wheel with rim brakes, no one has ever argued
    that you can't. The point is that it takes less power applied to the
    lever with a disc brake, IOW you get more braking power with less grip
    force. Whether you need more braking power on a road bike or not is
    another matter.

    It's physics tommy, the laws are the same for you as they are for the
    rest of us, whether you like it or not.

    While there might be some use for disks on MTB's since the are purposely
    exposed to water and mud, you don't have that problem with road bikes

    You do if you ride where is wet and muddy....


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  • From Mark J cleary@mcleary08@comcast.net to rec.bicycles.tech on Thu Jul 16 11:18:10 2026
    From Newsgroup: rec.bicycles.tech

    On 7/16/2026 5:51 AM, zen cycle wrote:

    cyclintom <cyclintom@yahoo.com> wrote:
    On Tue Jul 14 13:29:33 2026 AMuzi-a wrote:
    Disc systems get hot, and are ruined by contamination with
    wax, brake fluid or oil products.

    This, apparently, is a secret.

    http://www.yellowjersey.org/photosfromthepast/discuser.jpg

    Rim brakes do not have these problems. The idea that disks are more
    powerful is demonstrably wrong.

    Well, demonstrate it then....Besides, you've claimed repeatedly in this forum that disc brakes are bad for bikes because they have too much
    power. Here's one example: https://groups.google.com/g/rec.bicycles.tech/c/pfsO-q6qYaY/m/kJr0MdrDAQAJ
    "I consider them extraneous on road bike. Far too powerful for a 16 lb bike."

    Here's another: https://groups.google.com/g/rec.bicycles.tech/c/uREthtpJ8BY/m/I--V52JsBQAJ
    "I ride on the flats with gravel bikes and disks are WAYYY too strong
    for me"

    and another: https://groups.google.com/g/rec.bicycles.tech/c/uREthtpJ8BY/m/fhDwboHFBQAJ "Disks are simply too powerful and too easy to lock up"

    and another: https://groups.google.com/g/rec.bicycles.tech/c/ffqs2o-wiyQ/m/hKFs3pkzAwAJ "They work well but are FAR too powerful for a gravel bike"

    i have locked rim brakes often and even
    rotated the entire bike around the front wheel and struck my head on the >>> trunk of a parked car that I had failed to notice until nearly to late I >>> hit my helmet before the front wheel hit the rear bumper of the car and
    this with Gatorskins of the bike.

    Yes, you can lock up a wheel with rim brakes, no one has ever argued , but that you can't. The point is that it takes less power applied to the
    lever with a disc brake, IOW you get more braking power with less grip force. Whether you need more braking power on a road bike or not is
    another matter.

    It's physics tommy, the laws are the same for you as they are for the
    rest of us, whether you like it or not.

    While there might be some use for disks on MTB's since the are purposely >>> exposed to water and mud, you don't have that problem with road bikes

    You do if you ride where is wet and muddy....


    I was not one to embrace disc brakes but frankly there is no doubt they
    are better in the rain and going down fast descents. Rim brakes go much
    worse in wet and they can over heat in a big downhill. It is hard to me
    to imagine they can heat a rim enough to blowa tire but they say it is possible. The pads though can definitely melt. Disc brakes far superior
    but the question is do you really need them?
    --
    Deacon Mark
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  • From Roger Merriman@roger@sarlet.com to rec.bicycles.tech on Thu Jul 16 18:01:17 2026
    From Newsgroup: rec.bicycles.tech

    Mark J cleary <mcleary08@comcast.net> wrote:
    On 7/16/2026 5:51 AM, zen cycle wrote:

    cyclintom <cyclintom@yahoo.com> wrote:
    On Tue Jul 14 13:29:33 2026 AMuzi-a wrote:
    Disc systems get hot, and are ruined by contamination with
    wax, brake fluid or oil products.

    This, apparently, is a secret.

    http://www.yellowjersey.org/photosfromthepast/discuser.jpg

    Rim brakes do not have these problems. The idea that disks are more
    powerful is demonstrably wrong.

    Well, demonstrate it then....Besides, you've claimed repeatedly in this
    forum that disc brakes are bad for bikes because they have too much
    power. Here's one example:
    https://groups.google.com/g/rec.bicycles.tech/c/pfsO-q6qYaY/m/kJr0MdrDAQAJ >> "I consider them extraneous on road bike. Far too powerful for a 16 lb
    bike."

    Here's another:
    https://groups.google.com/g/rec.bicycles.tech/c/uREthtpJ8BY/m/I--V52JsBQAJ >> "I ride on the flats with gravel bikes and disks are WAYYY too strong
    for me"

    and another:
    https://groups.google.com/g/rec.bicycles.tech/c/uREthtpJ8BY/m/fhDwboHFBQAJ >> "Disks are simply too powerful and too easy to lock up"

    and another:
    https://groups.google.com/g/rec.bicycles.tech/c/ffqs2o-wiyQ/m/hKFs3pkzAwAJ >> "They work well but are FAR too powerful for a gravel bike"

    i have locked rim brakes often and even
    rotated the entire bike around the front wheel and struck my head on the >>>> trunk of a parked car that I had failed to notice until nearly to late I >>>> hit my helmet before the front wheel hit the rear bumper of the car and >>>> this with Gatorskins of the bike.

    Yes, you can lock up a wheel with rim brakes, no one has ever argued , but >> that you can't. The point is that it takes less power applied to the
    lever with a disc brake, IOW you get more braking power with less grip
    force. Whether you need more braking power on a road bike or not is
    another matter.

    It's physics tommy, the laws are the same for you as they are for the
    rest of us, whether you like it or not.

    While there might be some use for disks on MTB's since the are purposely >>>> exposed to water and mud, you don't have that problem with road bikes

    You do if you ride where is wet and muddy....


    I was not one to embrace disc brakes but frankly there is no doubt they
    are better in the rain and going down fast descents. Rim brakes go much worse in wet and they can over heat in a big downhill. It is hard to me
    to imagine they can heat a rim enough to blowa tire but they say it is possible. The pads though can definitely melt. Disc brakes far superior
    but the question is do you really need them?

    Need no but consumer definitely want, my commute is so flat that as long as itrCOs not very wet itrCOs fine with rim brakes. Unlike into central London where Rims definitely require more caution and added risks if you do need
    to brake hard.

    Hence that sort of riders were one of the first roadies to adopt disks.

    In fairness you can cook both rotors and disk pads do need to get things
    really hot! IrCOve certainly done both over ten years though this is off road and thus much more demanding.

    Roger Merriman

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  • From AMuzi@am@yellowjersey.org to rec.bicycles.tech on Thu Jul 16 13:59:34 2026
    From Newsgroup: rec.bicycles.tech

    On 7/16/2026 11:18 AM, Mark J cleary wrote:
    On 7/16/2026 5:51 AM, zen cycle wrote:

    cyclintom <cyclintom@yahoo.com> wrote:
    On Tue Jul 14 13:29:33 2026 AMuzi-a wrote:
    Disc systems get hot, and are ruined by contamination with
    wax, brake fluid or oil products.

    This, apparently, is a secret.

    http://www.yellowjersey.org/photosfromthepast/discuser.jpg

    Rim brakes do not have these problems. The idea that
    disks are more
    powerful is demonstrably wrong.

    Well, demonstrate it then....Besides, you've claimed
    repeatedly in this forum that disc brakes are bad for
    bikes because they have too much power. Here's one example:
    https://groups.google.com/g/rec.bicycles.tech/c/pfsO-
    q6qYaY/m/kJr0MdrDAQAJ
    "I consider them extraneous on road bike. Far too powerful
    for a 16 lb bike."

    Here's another:
    https://groups.google.com/g/rec.bicycles.tech/c/
    uREthtpJ8BY/m/I--V52JsBQAJ
    "I ride on the flats with gravel bikes and disks are WAYYY
    too strong for me"

    and another:
    https://groups.google.com/g/rec.bicycles.tech/c/
    uREthtpJ8BY/m/fhDwboHFBQAJ
    "Disks are simply too powerful and too easy to lock up"

    and another:
    https://groups.google.com/g/rec.bicycles.tech/c/ffqs2o-
    wiyQ/m/hKFs3pkzAwAJ
    "They work well but are FAR too powerful for a gravel bike"

    i have locked rim brakes often and even
    rotated the entire bike around the front wheel and
    struck my head on the
    trunk of a parked car that I had failed to notice until
    nearly to late I
    hit my helmet before the front wheel hit the rear bumper
    of the car and
    this with Gatorskins of the bike.

    Yes, you can lock up a wheel with rim brakes, no one has
    ever argued , but that you can't. The point is that it
    takes less power applied to the lever with a disc brake,
    IOW you get more braking power with less grip force.
    Whether you need more braking power on a road bike or not
    is another matter.

    It's physics tommy, the laws are the same for you as they
    are for the rest of us, whether you like it or not.

    While there might be some use for disks on MTB's since
    the are purposely
    exposed to water and mud, you don't have that problem
    with road bikes

    You do if you ride where is wet and muddy....


    I was not one to embrace disc brakes but frankly there is no
    doubt they are better in the rain and going down fast
    descents. Rim brakes go much worse in wet and they can over
    heat in a big downhill. It is hard to me to imagine they can
    heat a rim enough to blowa-a tire but they say it is
    possible. The pads though can definitely melt. Disc brakes
    far superior but the question is do you really need them?


    Both systems work. They're different. Neither is 'better'
    overall; they do different things differently.
    --
    Andrew Muzi
    am@yellowjersey.org
    Open every day since 1 April, 1971
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  • From =?UTF-8?B?Y3ljbGludG9t?=@cyclintom@yahoo.com to rec.bicycles.tech on Mon Jul 20 17:26:22 2026
    From Newsgroup: rec.bicycles.tech

    On Thu Jul 16 11:18:10 2026 Mark J cleary wrote:
    On 7/16/2026 5:51 AM, zen cycle wrote:

    cyclintom <cyclintom@yahoo.com> wrote:
    On Tue Jul 14 13:29:33 2026 AMuzi--- Synchronet 3.22a-Linux NewsLink 1.2
  • From =?UTF-8?B?Y3ljbGludG9t?=@cyclintom@yahoo.com to rec.bicycles.tech on Mon Jul 20 17:30:44 2026
    From Newsgroup: rec.bicycles.tech

    On Tue Jul 14 21:10:22 2026 Roger Merriman wrote:
    cyclintom <cyclintom@yahoo.com> wrote:
    On Tue Jul 14 13:29:33 2026 AMuzi wrote:
    Disc systems get hot, and are ruined by contamination with
    wax, brake fluid or oil products.

    This, apparently, is a secret.


    http://www.yellowjersey.org/photosfromthepast/discuser.jpg




    Rim brakes do not have these problems. The idea that disks are more powerful is demonstrably wrong. i have locked rim brakes often and even rotated the entire bike around the front wheel and struck my head on the trunk of a parked car that I had failed to notice until nearly to late I hit my helmet before the front wheel hit the rear bumper of the car and this with Gatorskins of the bike.

    While there might be some use for disks on MTB's since the are purposely exposed to water and mud, you don't have that problem with road bikes


    It?s certainly true that for myself I was more bothered by the gearing on
    the roadie which considering its price point, ie likely to be a commuter or similar, than an aspiring roadie, the rim brakes have been fine did require new pads as the originals where fairly poor!

    My commute to be fair is a flat route, fair amount of no interaction with others, no stop start traffic vs for example riding into central where you use the brakes much more so, and indeed at the time they where where
    becoming available the guys who do this day in day out, said they expected
    to save money on new wheels as rotors and pads are rather less expensive!

    The Gravel bike with its 160mm rotors can if one wants to, brake very hard, the MTB with larger rotors you can push even harder, and can absolutely
    apply rather more force than a rim brake.

    Locking a wheel let alone doing a endo is lack of control indicator than
    how powerful the brakes are, brakes like rim brakes that have less
    modulation ie rather on/off braking need greater care to avoid locking up.

    To Andrew?s point I?ve certainly seen bikes that have been sprayed with
    WD40 and having to be taken in to be sorted!

    Rather surprising the roadie requires more maintenance to its brakes than
    the other commuter that has disks as the dual pivots get gummed up and then become sticky and more on/off vs the disks which maybe collect some oils
    but bar being noisy it?s relatively benign, this being the commute I?m not pushing hard so minor reductions in performance are just not something I worry about! The Gravel or MTB sure yes I?d get it sorted but the commute it?s not an issue.
    I did a lot of riding in wet weather though nothing like Brtaish weather. So I didn't have much problem with rim brakes though I can easily imagine that disks are much better for MTB tires and deep mud.
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  • From Roger Merriman@roger@sarlet.com to rec.bicycles.tech on Mon Jul 20 19:07:24 2026
    From Newsgroup: rec.bicycles.tech

    cyclintom <cyclintom@yahoo.com> wrote:
    On Thu Jul 16 11:18:10 2026 Mark J cleary wrote:
    On 7/16/2026 5:51 AM, zen cycle wrote:

    cyclintom <cyclintom@yahoo.com> wrote:
    On Tue Jul 14 13:29:33 2026 AMuzi wrote:
    Disc systems get hot, and are ruined by contamination with
    wax, brake fluid or oil products.

    This, apparently, is a secret.

    http://www.yellowjersey.org/photosfromthepast/discuser.jpg

    Rim brakes do not have these problems. The idea that disks are more
    powerful is demonstrably wrong.

    Well, demonstrate it then....Besides, you've claimed repeatedly in this >>> forum that disc brakes are bad for bikes because they have too much
    power. Here's one example:
    https://groups.google.com/g/rec.bicycles.tech/c/pfsO-q6qYaY/m/kJr0MdrDAQAJ >>> "I consider them extraneous on road bike. Far too powerful for a 16 lb
    bike."

    Here's another:
    https://groups.google.com/g/rec.bicycles.tech/c/uREthtpJ8BY/m/I--V52JsBQAJ >>> "I ride on the flats with gravel bikes and disks are WAYYY too strong
    for me"

    and another:
    https://groups.google.com/g/rec.bicycles.tech/c/uREthtpJ8BY/m/fhDwboHFBQAJ >>> "Disks are simply too powerful and too easy to lock up"

    and another:
    https://groups.google.com/g/rec.bicycles.tech/c/ffqs2o-wiyQ/m/hKFs3pkzAwAJ >>> "They work well but are FAR too powerful for a gravel bike"

    i have locked rim brakes often and even
    rotated the entire bike around the front wheel and struck my head on the >>>>> trunk of a parked car that I had failed to notice until nearly to late I >>>>> hit my helmet before the front wheel hit the rear bumper of the car and >>>>> this with Gatorskins of the bike.

    Yes, you can lock up a wheel with rim brakes, no one has ever argued , but >>> that you can't. The point is that it takes less power applied to the
    lever with a disc brake, IOW you get more braking power with less grip
    force. Whether you need more braking power on a road bike or not is
    another matter.

    It's physics tommy, the laws are the same for you as they are for the
    rest of us, whether you like it or not.

    While there might be some use for disks on MTB's since the are purposely >>>>> exposed to water and mud, you don't have that problem with road bikes

    You do if you ride where is wet and muddy....


    I was not one to embrace disc brakes but frankly there is no doubt they
    are better in the rain and going down fast descents. Rim brakes go much
    worse in wet and they can over heat in a big downhill. It is hard to me
    to imagine they can heat a rim enough to blowa tire but they say it is
    possible. The pads though can definitely melt. Disc brakes far superior
    but the question is do you really need them?




    I disagree Mark - disk brakes with their smaller diameter clear the water
    off of the disks faster than rim brakes but both do it. And disks make
    one heck of a lot of noise clearing the water.

    If your disks are making a heck of noise they almost certainly have some
    sort of contamination, my old MTB commuter often does though generally once itrCOs been used itrCOs fine, and rain absolutely does reduce the effectiveness of rim brakes, if itrCOs just wet roads or drizzle on my
    commute itrCOs fine means I have reduced braking, but my commute though slow ish route has no points that thatrCOs a problem, if though itrCOs a downpour thatrCOs another level and can get iffy ie onerCOs ability to stop quickly goes. Unlike the old MTB which braking is largely unchanged.

    But my commute is very easy on brakes hence IrCOm unbothered by the rim
    brakes, folks with more stop start and or faster routes the lack of braking
    is absolutely an issue.

    Roger Merriman

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