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Braking on carbon rims

topcattimtopcattim Posts: 766
edited May 2018 in Road general
I've must moved to a set of second hand Mavic Cosmics, lovely wheels, really smooth, great performance. I'm still getting used to braking on carbon rims, though - not as responsive as I was used to on my previous alloy wheels despite using Swissstop pads. Any advice on appropriate braking technique, e.g. later but sharper? don't worry about the squealing? In particular, I'm doing a few long rides at the Tour of Wessex next weekend where there are some long very fast descents and I want to make sure I'm safe but effective on that type of descent....

Posts

  • imposter2.0imposter2.0 Posts: 11,385
    topcattim wrote:
    and I want to make sure I'm safe but effective on that type of descent....

    In which case, it might be an idea to put your old 'familiar' wheels back on. Braking on carbon is always going to feel different, but there is no new 'technique' to learn, as such.
  • riekorieko Posts: 121
    Did you change your rim brake pads to carbon specific pads?
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  • topcattimtopcattim Posts: 766
    edited May 2018
    rieko wrote:
    Did you change your rim brake pads to carbon specific pads?
    Yes. And they're pretty good - braking on the Cosmics with Swissstops is much better than on my TT bike (which also has carbon rims but the pads are Aztec pads) just not as responsive as it was on my old alloy wheels. It's not a massive problem, but I'm just not yet as confident as I could be.
  • sungodsungod Posts: 13,778
    you just need to practice to get a feel for how they work

    don't drag the brakes, if you need to shave off speed pulse/alternate them
    to really slow down/stop, late and hard, same as for alloy

    make sure brake callipers are set up correctly, pads not too close/too far from the rims etc.

    'squealing' can be normal or might indicate contaminated rims/pads, try wiping with acetone
    my bike - faster than god's and twice as shiny
  • joey54321joey54321 Posts: 1,297
    Yeah, ime having ridden a variety of difference carbon wheel/pad combination it's just not as good at stopping. There isn't much you can do other than learn to anticipate it (scary in the wet too!)

    I'm looking forward to the day I can justify a new hydro disc bike with zipp 404 discs (or similar).
  • dannbodgedannbodge Posts: 994
    As above.
    I tend to alternate them and only brake for a couple of seconds on each one, even if controlling speed down a long hill.

    To stop the squeal make sure they are clean, and toe-in the pads slightly. Mine on squeal if i brake very hard quickly, on normal braking they are silent.
  • vpnikolovvpnikolov Posts: 568
    sungod wrote:
    you just need to practice to get a feel for how they work

    don't drag the brakes, if you need to shave off speed pulse/alternate them
    to really slow down/stop, late and hard, same as for alloy

    make sure brake callipers are set up correctly, pads not too close/too far from the rims etc.

    'squealing' can be normal or might indicate contaminated rims/pads, try wiping with acetone
    This.

    If you want to shave off speed, just pump/pulse the brakes (I like to see it as an ABS system, but not entirely!). This way you give the rims the opportunity to cool a bit. When cornering, standard way is pretty much applicable (as above).
  • First.AspectFirst.Aspect Posts: 7,426
    My mavics make a racket. Don't worry about it.

    Don't use acetone. Might dull the finish or at the very least start the labels peeling.
  • imafatmanimafatman Posts: 351
    Sounds like carbon rims are great at going uphill with the reduced weight and also great and going downhill because you can't bloody slow down enough. Sounds like a win: win.
  • norvernrobnorvernrob Posts: 1,431
    imafatman wrote:
    Sounds like carbon rims are great at going uphill with the reduced weight and also great and going downhill because you can't bloody slow down enough. Sounds like a win: win.

    Of course you can slow down enough, or thousands of people would fall off every week. I used to have Zipp 202’s with SRAM Red calipers and Swisstop Black Prince pads, and the braking was excellent in both the dry and wet. I never had an issue using them all over the Peak District where the descents can be as sketchy as they come.

    Disc brakes are great, I’ve got them on my CX bike, but let’s not pretend you need them to stop properly.
  • AndymaxyAndymaxy Posts: 197
    Dude, those mavic braking surface(if you are using 2018 model) are the best in the business, very close to discs in dry. I don't know what you can complain about.
  • thegreatdividethegreatdivide Posts: 5,138
    Andymaxy wrote:
    Dude, those mavic braking surface(if you are using 2018 model) are the best in the business, very close to discs in dry. I don't know what you can complain about.

    They pinched the idea from Campagnolo. I've got Bora Ultra 35s and Ksyrium Pro Carbon SLs and yip, they stop like a dream.

    I think the OP has older rims?
  • MatthewfalleMatthewfalle Posts: 17,380
    imafatman wrote:
    Sounds like carbon rims are great at going uphill with the reduced weight and also great and going downhill because you can't bloody slow down enough. Sounds like a win: win.


    Bizarrely MF and I have never had a problem stopping with carbon rims.

    Admittedly we don't do it often as brakes are for cowards but when we really, really have to it's never a problem.
    Postby team47b » Sun Jun 28, 2015 11:53 am

    De Sisti wrote:
    This is one of the silliest threads I've come across. :lol:

    Recognition at last Matthew, well done!, a justified honour :D
    smithy21 wrote:

    He's right you know.
  • Vino'sGhostVino'sGhost Posts: 4,129
    topcattim wrote:
    I've must moved to a set of second hand Mavic Cosmics, lovely wheels, really smooth, great performance. I'm still getting used to braking on carbon rims, though - not as responsive as I was used to on my previous alloy wheels despite using Swissstop pads. Any advice on appropriate braking technique, e.g. later but sharper? don't worry about the squealing? In particular, I'm doing a few long rides at the Tour of Wessex next weekend where there are some long very fast descents and I want to make sure I'm safe but effective on that type of descent....

    Youll be fine the only tricky descents are off Bullbarrow hill on the Sunday and the drop off the Quantok on Monday and then the descent of Porlock also on Monday and only a kamakaze would consider riding down there at 40mph into a sharp right hand bend on a 20% plus gradient off camber corner; you'll know its coming anyway by the smear of earlier cyclists lying over the road and ambulances picking the pieces up.

    As for squealing please set your brakes up properly, they work better then too.
  • First.AspectFirst.Aspect Posts: 7,426
    topcattim wrote:
    I've must moved to a set of second hand Mavic Cosmics, lovely wheels, really smooth, great performance. I'm still getting used to braking on carbon rims, though - not as responsive as I was used to on my previous alloy wheels despite using Swissstop pads. Any advice on appropriate braking technique, e.g. later but sharper? don't worry about the squealing? In particular, I'm doing a few long rides at the Tour of Wessex next weekend where there are some long very fast descents and I want to make sure I'm safe but effective on that type of descent....

    Youll be fine the only tricky descents are off Bullbarrow hill on the Sunday and the drop off the Quantok on Monday and then the descent of Porlock also on Monday and only a kamakaze would consider riding down there at 40mph into a sharp right hand bend on a 20% plus gradient off camber corner; you'll know its coming anyway by the smear of earlier cyclists lying over the road and ambulances picking the pieces up.

    As for squealing please set your brakes up properly, they work better then too.
    Once you have saved up and bought a set of such wheels, and deposited some brake pad material on the rims and they've started squealing, can you get back to us and let us know how to stop that, short of sanding the top layer of epoxy off? I'd love to know.
  • Bloody hell, have they moved the Tour of Wessex to the Alps or Pyrenees?
    I'm sorry you don't believe in miracles
  • AndymaxyAndymaxy Posts: 197
    Bloody hell, have they moved the Tour of Wessex to the Alps or Pyrenees?

    Get out!!!!
  • JTUKJTUK Posts: 67
    I have Mavic Cosmic Carbon C40 wheels. They are very nice and quick. I try not to use the brakes too much, they squeal when they heat up. Better to just let them run on, but when riding with others I often find I’m always gaining on the descents so it’s unavoidable to stop passing riders in front. If in doubt stop and let them cool down. Also wipe the rims clean with a tissue to get rid of any dirt and remember to check your pads are in good condition.
  • singletonsingleton Posts: 2,031
    I was a bit nervous of carbon wheels, but I bought some Reynolds at the end of last year and they've been just fine - no problems at all.
    I do avoid dragging my brakes - but that's probably a bad habit on all wheels anyway.
  • Vino'sGhostVino'sGhost Posts: 4,129
    topcattim wrote:
    I've must moved to a set of second hand Mavic Cosmics, lovely wheels, really smooth, great performance. I'm still getting used to braking on carbon rims, though - not as responsive as I was used to on my previous alloy wheels despite using Swissstop pads. Any advice on appropriate braking technique, e.g. later but sharper? don't worry about the squealing? In particular, I'm doing a few long rides at the Tour of Wessex next weekend where there are some long very fast descents and I want to make sure I'm safe but effective on that type of descent....

    Youll be fine the only tricky descents are off Bullbarrow hill on the Sunday and the drop off the Quantok on Monday and then the descent of Porlock also on Monday and only a kamakaze would consider riding down there at 40mph into a sharp right hand bend on a 20% plus gradient off camber corner; you'll know its coming anyway by the smear of earlier cyclists lying over the road and ambulances picking the pieces up.

    As for squealing please set your brakes up properly, they work better then too.
    Once you have saved up and bought a set of such wheels, and deposited some brake pad material on the rims and they've started squealing, can you get back to us and let us know how to stop that, short of sanding the top layer of epoxy off? I'd love to know.

    Ive run 303s and 404's for years without squeeling. I wash my wheels, i use a bit of toe in. (or they squeel). I use the ridiculously expensive Zipp pads.

    15 years ago when i started using reynolds wheels they were juddery and squeeled. Apart from in the wet when they didnt work at all.

    When you've grown up and learned how to set up and maintain your bike come back to me, Id love to hear from you.
  • joe2008joe2008 Posts: 1,531
    My carbon rims don't squeal at all, and stop better in the wet than my alloys did.

    I never wash my rims; I use ridiculously cheap Lifeline (Wiggle) carbon pads £4.99 for 4 - they last forever.

    The braking surfaces are still sound after 3 years of riding 12 hours a week over Exmoor's extremely hilly terrain.

    https://www.tokyowheel.com/products/eli ... r-wheelset

    Built on DT240 hubs with Sapim CX-Ray spokes - at the time I had the option of returning them after 365 day trail with a 110% refund (this offer has since been reduced to 65 days, the 110% refund still stands).

    Obviously I had every intention of returning them, but they had preformed so well that I kept them, thinking I may not be as lucky with a replacement set.
  • topcattimtopcattim Posts: 766
    edited May 2018
    Bloody hell, have they moved the Tour of Wessex to the Alps or Pyrenees?
    :D:D:D
    As far as I'm aware, the ToW isn't yet being held in France. But it does have some steep sharp descents, with tight turns, and frankly, having ridden up and down the Stelvio, Izoard, Alpe, Mortirolo etc, I've found descending those a lot easier (open, straight, predictable road surface) than bombing down Bulbarrow Hill or the road from Lulworth Ranges into West Lulworth! Still, I'm looking forward to this weekend, and thanks for all the advice.
  • matt_n-2matt_n-2 Posts: 581
    I've just got some FFWD F6R tubular and use Swissstop Black Prince, braking is pretty good, spent last Sunday in the Welsh hills (Blwch, Rhigos etc) and didn't have any issues.

    The FFWD brake better than my old 303s with the same pads interestingly.

    One of the guys with us has Vision Metron 40 and had those Lifeine blue pads in, very squeally!
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  • ugo.santaluciaugo.santalucia Posts: 26,441
    This topic is like one of those large turds that one flushes repeatedly and they keep coming back up....
  • svettysvetty Posts: 1,904
    This topic is like one of those large turds that one flushes repeatedly and they keep coming back up....
    Not a phenomenon I am familiar with Ugo - perhaps you need to eat more fruit and veg? :wink:
    FFS! Harden up and grow a pair :D
  • First.AspectFirst.Aspect Posts: 7,426
    joe2008 wrote:
    My carbon rims don't squeal at all, and stop better in the wet than my alloys did.

    I never wash my rims; I use ridiculously cheap Lifeline (Wiggle) carbon pads £4.99 for 4 - they last forever.

    The braking surfaces are still sound after 3 years of riding 12 hours a week over Exmoor's extremely hilly terrain.

    https://www.tokyowheel.com/products/eli ... r-wheelset

    Built on DT240 hubs with Sapim CX-Ray spokes - at the time I had the option of returning them after 365 day trail with a 110% refund (this offer has since been reduced to 65 days, the 110% refund still stands).

    Obviously I had every intention of returning them, but they had preformed so well that I kept them, thinking I may not be as lucky with a replacement set.
    I think the Mavics I have are a bit basic. I have some Xentis wheels I use with the same pads and they make a carbon brake noise - the same you can hear on TV, boys - but they don't squeal. So its not a toe in/out thing.
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