# Braking with carbon versus aluminum rims, myth or reality?



## gordy748 (Feb 11, 2007)

Hi all. On a mad whim I picked up a set of Easton EC90 slx wheels on eBay over the summer. I decided to give them a try over Christmas, and I've now firmly moved over to the tubular side of the Force.

When I switched them over I put on a set of Swiss Stop pads. Before I was using Mavic Open Pro ceramic rims with Campy pads, so I was expecting a significant decline in braking performance. I was surprised to find braking in the dry was nearly as good with the carbon rims, and while the wet was certainly a lot worse, it wasn't nearly the disaster I was expecting and was pretty manageable as long as I was mindful of the conditions.

Bear in mind I live in Seattle. It's steep. It's wet. Braking in damp conditions is a huge concern.

So I'm now looking at training wheels... I was initially thinking of aluminum tubulars before I found how hard it is to find alloy tubular Campy wheels (_why oh why?_), or how plentiful and cheap Chinese carbon wheels are. For me it seems a no-brainer to get some Chinese carbon wheels to train on. I don't have to change pads, just the wheels.

Thoughts? Am I mad or just some sort of genius? Or somewhere in between?


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## Jay Strongbow (May 8, 2010)

Do I have this straight? your new Easton carbon wheels suck in wet conditions so you want to get a rain set and you're thinking another carbon set because your carbon set doesnt brake well in the rain?


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## gordy748 (Feb 11, 2007)

Sorry, let me get this straight...

My old brake set-up used ceramic rims, which were phenomenally good, and much better than my old alloy rims. When I went to try the carbon rims, I found them not _as_ good, but not nearly as bad as I thought they'd be. Wet weather performance was much more sh!tty at initial bite compared to the ceramics, which changed dramatically as I applied pressure. At full load it was still worse, but never a shorts wetting moment.

So yes, they didn't slow me down so much, and the performance gap was exaggerated in the wet, and the progressive feel wasn't nearly so good, but it's not to say they really sucked. Which was what I was expecting...


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## steve90068 (Jul 29, 2009)

here ya go! 25mm Alloy Tubular - Boyd Cycling


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## forge55b (Jan 30, 2011)

You are kind of all over the place. You want wheels that brake better then what you currently have in the wet or are comparable in the wet?


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## emartin (Mar 11, 2009)

I raced with rims with alloy and carbon braking surface. I feel much more confident with the alloy braking surface in any condition. Carbon rims wear pads very quickly, make a insane sound, have no initial bite wet wet, no modulation...for racing application alloy surface anytime. As a matter of fact, right now, I only use full carbon wheels on my TT bike.


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## gordy748 (Feb 11, 2007)

Ok, I'll try this again.

I was expecting wet braking performanceto be a lot worse than it actually was. Mediocre, yes. But not Nearlythe nightmare I keep hearing about. And not much worse than my commuter bike, which uses straight alloy rims. Hence my initial question: are carbon rims really that bad in the wet?

If so then I'll source aluminum rims for training. If not them I'll get some cheap Chinese carbon ones ones instead.


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## cycocross (Dec 11, 2011)

You need special break pads for the carbon wheels? Do they wear faster on AL rims? that would be my concern. but then if you can coin the carbon rims I guess replacing pads more often won't break you.


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## stevesbike (Jun 3, 2002)

*here you go (at about 17 seconds in)*

here you go (at about 17 seconds in)


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## gordy748 (Feb 11, 2007)

Ay caramba! Just as well the organizers provided spectators to prevent him hitting that car!


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## 2silent (Dec 26, 2009)

he is saying that all sorts of people complain about them and therefore he was surprised that they didn't suck nearly as much as he had anticipated... he therefore is considering using them always.

a couple thoughts-

1. different carbon rims/pad combos etc. make huge differences

2. who doesn't race CX on full carbon wheels? They obviously aren't THAT bad. 

I like my DV46s and the only place I'd question using them always would be if I were in the big mountains.


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## looigi (Nov 24, 2010)

stevesbike said:


> here you go (at about 17 seconds in)


That guy was locking up and skidding his rear wheel. Not a problem of insufficient braking as far as it looks.


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## mtnroadie (Jul 6, 2010)

Easton has perhaps the best carbon braking surface out there, they stop me great in the rain, unfortunatly their hubs can take the wet. So i am stuck riding them in the dry. 

Carbon will always suck compared to aluminum when it comes to braking, it will never catch up. That is why disc brakes are long over due. and not just a road make over i am talking light disc brakes with new materials carbon roters with aluminum brake tracks and carbon calipers perhaps. Super cars have carbon ceramic brakes why cant road bikes?

The bike industry needs to stop draging it feet and put some new technology thats actually worth paying for out there. Just like the auto industry there is more $ in less progress!


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## sneakyracer (Dec 1, 2007)

As you can see in the video a lot of times braking performance in the wet is limited by tire traction not by rim/pad friction. In the dry its a different story but still the most important thing then would be to deal with heat on long braking descents.


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## wetpaint (Oct 12, 2008)

With Swiss Stop yellows, my carbon wheels have better braking than my aluminum wheels. Sure they're not great in the rain, but they stop me just fine.

I've used Dura Ace, Koolstop Salmons, SS green on aluminum and none of them make the braking as good as my carbon wheels.


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## aclinjury (Sep 12, 2011)

mtnroadie said:


> Easton has perhaps the best carbon braking surface out there, they stop me great in the rain, unfortunatly their hubs can take the wet. So i am stuck riding them in the dry.
> 
> Carbon will always suck compared to aluminum when it comes to braking, it will never catch up. That is why disc brakes are long over due. and not just a road make over i am talking light disc brakes with new materials carbon roters with aluminum brake tracks and carbon calipers perhaps. Super cars have carbon ceramic brakes why cant road bikes?
> 
> The bike industry needs to stop draging it feet and put some new technology thats actually worth paying for out there. Just like the auto industry there is more $ in less progress!


Car racing have a budget that is out of this world, and even then, car race teams most of them are struggling with cost.

Disc brakes already exist in touring bikes, and soon, UCI will allow it to be in cx. Cx can definitely use disc brakes for the mud issue. But as far as light super road bikes go, I don't think we will ever see a reasonably priced disc brake system. The metal calipers and steel discs are just too heavy. Making them lighter using exotic material and fabrication will kill the price of the bike. This is not to mention that frame and fork will also have to be beefed up to handle the disc/caliper mounting. I don't think buyers are yet willing to pay $6000 for a 16/17 lbs bike that used to be 14/15 lbs.


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## arai_speed (Aug 19, 2003)

A pair of bricks for $270 that might give you what you want?

http://www.flyxii.com/products_1.asp?menuid=334&id=604


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## pbanders (Feb 20, 2012)

I recently have acquired carbon clinchers (Reynolds DV3K). I've been riding and racing since 1972, I'm 5'11" and 150 lbs. I'm also a former non-professional wheelbuilder, I've built about 30 wheels. My bike is a 2011 Scott Addict R1 with Dura-Ace 7900. Reynolds are supplied with proprietary brake pads, and have a texturized braking surface. Braking is good, but not as good as an Al surface. Somewhat more force is required, and braking action is not as linear as with Al. Under most conditions, such as flat/rolling fast recreational riding, the difference is easily managed. Even fairly significant descents (e.g. 1500' or so) are OK as long as you anticipate your braking zones, and the descent isn't so steep that constant braking is required. I have not ridden these in the rain, but I would conjecture they are much worse than Al. I rode the Levi's GranFondo last year, which had plenty of rain, and saw many people with carbon rims having a very difficult time on the 17+% wet descents - so much so, that carbon rims are essentially banned in the 2012 event. Just use some common sense and you shouldn't have any issues. The aero advantages of deep carbon combined with low weight are definitely attractive.


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