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  1. #201
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    Quote Originally Posted by voss View Post
    Literally broke my heart. I lost the bike within 20 seconds at Mace store in Clnbrasill street, video and all, the Dogma was a road warrior. You pour your heart into a bike and then some scumbag steals it
    /
    Just smile remembering that the crappy carbon wheels will eventually fail and the guy will likely end up with a broken face. Karma will work out in the end.

  2. #202
    dcb
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    It seems from what I've read that newer generation carbon clinchers are more capable of staying structurally sound during heat build up from braking. Since this probably makes the weak link the tire or tube blowing out during heat build up, I was wondering if tubeless road tires would be better or worse in this regard than conventional clincher tires. I ask because I recently bought a bike that came stock with tubeless ready carbon rims. Thanks in advance for any thoughts on this subject.

  3. #203
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    Few cents and short story from my side regarding carbon clinchers and safety in the mountainsÖ

    As a wheel builder I have couple of wheels in my garage for my disposal. From all of them I mostly love and use the carbon clinchers. I wonít explain why as this is not the right post for it.

    Iím using 38mm HTG rims from Yishunbike bike. Living in Swiss Alps so far I was mostly focusing to find the most temperature resistance carbon molds possible to make sure that during long descends rim will not fall apart due to overheating.
    I must say that the choice I made with those rims was very correct. This year only I did over 5k km on those wheels with very long climbs and crazy descends in hot & rainy days. No issues with braking at all. Road trips with 200km and over 5k meters climb were pure pleasure. Braking surface is very solid, braking power is acceptable, no issue with the carbon mold at all.

    The setup I used was:

    - Yishun 38mm HTG rims
    - Black prince braking pads
    - Velox rim tape
    - Light Conti race inner tubes
    - Veloflex 25mm tires

    I got full confidence with this setup until one particular day when front inner tube exploded on steep descend catapulting me over the handlebars
    I was going on very hilly road with the 16% descend which last for 4-5km. The road is very narrow, technical with many sharp curves so I had to exceptionally drag on both brakes constantly for few minutes which normally I never do. Almost at the end of the descent the front tube suddenly explodedÖ

    Spending few days on recovery and rebuilding the bike I did some analysis:

    - First of all, looking at the broken tube Iím 100% sure that it exploded due to heat. The tube went under the tire bead which caused the damage
    - Partially it could be caused by tires. Veloflex are brilliant but they are very easy to mount with bare hands without any levers. I think that if the tire would be tighter, the inner tube pressure wouldnít lift the tire so easily and potentially tube would stay on in right place
    - Velox tape is not the best choice for high pressure. Although it was mounted properly during the usage the tape moves and some rim holes may be uncovered
    - I remember putting 110 PSI on front which I believe now it was too much. Maybe having 100 PSI would leave enough room for potential tube expand due to heat
    - Iím thinking that itís actually better when rim is hot (like aluminum) as it means that the heat is transferred more easily. Carbon is barely warm after descends but it can mean that inside the temperature is much higher and it canít get out causing tube expansionÖ just a thought and observation

    So the conclusion is that I will still try & use carbon clincher setup but with some modifications:

    - Same rims and pads
    - Rim tape will be from Schwalbe 16mm
    - Inner tubes will be standard this time, thicker = more rubber = safer?
    - Tires will be with tighter bead, like conti 4000
    - Lower tube pressure at start, max 100 PSI

    Happy to hear your thoughts and observations which could limit the risk of accident like mine

    Cheers
    Tomas
    Custom wheels handcrafted in Switzerland
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    https://blackcatwheels.blogspot.ch/

  4. #204
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    My quick two cents on your explosion:

    Black Prince pads. Not the rim tape or high pressure or tires.

    Black Prince and other such pads like Enve grey are a rubber based compound. Rubbery if you will. They work by applying mass friction due to the rubbery type material. This material heats up like crazy, even melts the pads, that's why they leave streaks on the rim surface.

    I am strongly against anyone using Black Prince pads on carbon rims based on experience. I don't care what kind of rims they are or who made them.

    I am strongly in favor of the Yellow King type of pads instead. Also Farsports/Tokyowheel/Origin 8/etc. use a Ceramic Fiber pad. Both of these types are dusting pads. They have no rubbery texture and leave no streaks or material behind on the rim, they dust away instead. Like a brake pad on a disc brake.

    These dusting away pads dramatically reduce heat build up. So much so that I can't recommend Black Prince or anything like it anymore to anyone. I've seen them ruin far too many rims and almost kill far too many people.

    "But it's the industry standard MMs".... I don't care. I don't care what anyone has to say really, I only care about what I've experienced over the years.

    Avoid Black Prince pads and any such rubbery ones if you value your safety. Switch to pads that dust away.
    use a torque wrench

  5. #205
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    Thanks!

    Very surprised hearing your opinion about black prince pads. This is the last item on my list I would change
    SwissStop claims that those generate 30% less heat than other pads. I also observed that they do leave streaks on the rim. It doesnít damage the rim itself, at least not mine so I didnít worry about that too much

    What I read about yellow king pads is that they are also rubber based but harder compound comparing to black prince. So far all pads Iíve seen were rubber basedÖ
    Would you be able to put couple of links to the pads you recommend? Iíd be happy to try them

    Cheers
    Tomas
    Custom wheels handcrafted in Switzerland
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    https://blackcatwheels.blogspot.ch/

  6. #206
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    Quote Originally Posted by blackcat_wheels View Post
    SwissStop claims that those generate 30% less heat than other pads.
    Bingo! Definitely listen to the manufacturer not "some dude" spouting off generalizations and stuff.

  7. #207
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    I understand my position is controversial.

    I don't advocate for Yellow King as a pad, I think they suck balls. What yellow pads are Mavic using now on their carbon rims that dust away? Those. I advocate for pads that dust away. Sintered construction I think it is? I'm no expert. The pads I use are "ceramic fiber" construction that just dusts away. Doesn't leave any streaks or material behind on the rim besides dust.

    My personal experience with Black Prince has not been good. I can say the same with Enve grey, the old ones they used. I can't say that any pad that leaves streaks is any good for that matter. I think the Reynolds blue are in this category as well. I don't like that method of braking.

    I don't agree that Black Prince pads generate the least heat. Or even that they run cool at all. I consider them to run quite hot and keep getting hotter as the descent runs over half an hour or more.

    I use these:

    https://www.niagaracycle.com/categor...bon-rims-black

    use a torque wrench

  8. #208
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    I remember reading that Veloflex specifically recommends against using the open clincher tire on carbon rims due to the possibility of the sharp edge of of the carbon rim cutting into the sidewall or bead of the tire.


    Sent from my iPhone using Tapatalk

  9. #209
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    Quote Originally Posted by blackcat_wheels View Post
    SwissStop claims that those generate 30% less heat than other pads.
    I don't quite see how this claim works. If you are slowing yourself and your bike down, the same amount of kinetic energy has to be dissipated, no matter what pad you are using. The heat either goes into the rim or into the brake pad/holder and is then dissipated through convection (mostly) or radiation.

    Brake pads would seem to be a lousy conductor (since they are largely a rubber-type compound) and you are unlikely to have good heat transfer directly from the pad to the air due to the small surface area. A cooler pad just means more heat is being put into the rim and then it is up to the rim to get rid of the heat.

  10. #210
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    Carbon clincher being safe for descend on hills or mountains...

    Quote Originally Posted by typ993 View Post
    I don't quite see how this claim works. If you are slowing yourself and your bike down, the same amount of kinetic energy has to be dissipated, no matter what pad you are using. The heat either goes into the rim or into the brake pad/holder and is then dissipated through convection (mostly) or radiation.

    Brake pads would seem to be a lousy conductor (since they are largely a rubber-type compound) and you are unlikely to have good heat transfer directly from the pad to the air due to the small surface area. A cooler pad just means more heat is being put into the rim and then it is up to the rim to get rid of the heat.
    I agree with you on the energy generated being the same, but if the pad were more thermally conductive, it would conduct heat away from the braking surface and into the pad, pad holder, and brake arm, then connective cooling can work as well.
    Last edited by mfdemicco; 3 Weeks Ago at 01:15 PM.

  11. #211
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    Do the sidewalls of carbon rims wear a lot faster than aluminum (rim brakes)?

  12. #212
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    Quote Originally Posted by mfdemicco View Post
    Do the sidewalls of carbon rims wear a lot faster than aluminum (rim brakes)?
    no, much less so.
    With alloy you will pick up little slivers of aluminum in the brake pads, and eventually the aluminum will wear away. This leaves a concave section in the brake track.

    With carbon you are not losing any material in the brake pad. The brake pads will wear a bit faster than alloy pads on alloy rims, but the rims do not become concave over time. Eventually the carbon can wear, but usually after a much longer time than alloy.
    www.boydcycling.com Handcrafted Revolution

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