Alu VS Carbon braking performance

naavt

Hi all,

I didn't resist from sharing this and hear your thoughts about it.

Went to commute today and picked up my dusty "city" bike, an old 90's chromoly frame with a new Centaur group, Mavic Ksyrium wheels, and was really surprised and impressed by the braking, particularly on how much more bite it has compared to my all carbon bike with Record direct mount brakes and Campy pads (and I'm talking dry weather here).

I don't know if my Centaur bike really stops earlier (or if I'm being influenced by a different "feel" on the levers), but it certainly feels like.

Anyone sharing the same experience between Alu and Carbon rims?

Bottom briquettes

Carbon rims don’t function properly from the friction point of view, until the pads and rims are warm ( warmer than an alloy rim and matched brake has to be to function at its best efficiency) alloy rim and the brake pads on them work much better from cold.

naavt

Bottom briquettes wrote:

Carbon rims don’t function properly from the friction point of view, until the pads and rims are warm ( warmer than an alloy rim and matched brake has to be to function at its best efficiency) alloy rim and the brake pads on them work much better from cold.

If I understood it right, you're saying that both will perform equally in the dry if the carbon rim has had some braking?

I was thinking the exact opposite, since one of carbon's weakness is heat dissipation.

imposter2.0

Bottom briquettes wrote:

Carbon rims don’t function properly from the friction point of view, until the pads and rims are warm ( warmer than an alloy rim and matched brake has to be to function at its best efficiency) alloy rim and the brake pads on them work much better from cold.

This is just nonsense and should be ignored. Milemuncher has obviously watched a bit of F1 on the telly and extrapolated...

super_davo

I've heard for years the stories of inadequate carbon rim braking and stuck to alloy. I had a lightweight set on my road bike and carbon / alloy deep section wheels on my TT.

This year I got my first full carbon wheels and I've been surprised at how good the braking is. The absolute power is there, but they don't seem as "grabby" as my alloy rims, so the modulation is better. I'd say the dry weather performance mirrors that of my hydraulic disk braked bike. I haven't really used them in the wet a huge amount yet, when it could all fall apart, but in the dry they've been great.

Brakes are Ultegra, pads are Lifeline, wheels are Chinese with Basalt brake track.

MiddleRinger

In the dry, my carbon rims brake well (Swissstop carbon specific pads). They're nowhere near as good as my Mavic "Exalith" brake tracked alloy rims, but easily comparable to regular alloy braking and I have utmost confidence in their stopping power.

If it's raining though, they get a little bit dicey! The pads take far longer to "grab" and require more lever force to do so.

stueys

Alloy rims brake better than carbon, especially in the wet. Carbon has improved over the last few years but it still doesn't match alloy.

naavt

I have not yet done a brake test comparing both (which I can just making a charcoal marks and measuring stop distances - albeit not being a very scientific method).

Probably stop distances will be very alike, and if they are, we can then argue if a direct mount system really is better than a dual pivot one (and I'm talking about comparing a top tier with an entry level one).

The thing is that the lever feeling is very different. Today I went to work with my commuter again and I find the brake feel so much better on the aluminium wheels.

I have to do half the effort in the levers on some descents in my commuter by comparison, and braking from the hoods is just more easy on this bike.

cycleclinic

This stories of poor braking on carbon relate to some rim pad combinations but not all. Carbon rims can brake like good alloy rim and pad combinations in all conditions.

rickeverett

Yes, carbons aren't as good overall as alloy, but there are variables.
Personally I wouldn't and haven't worried. If you are using carbon, you are usually more experienced dealing with descents and braking. Instead of constantly rolling and breaking and burning your rims up. You break when you need to and the stopping power is there with carbon. It doesn't bite the same but stops you for sure. First time in the wet I was dressing it, but the breaking performed very well.

sloppyschleckonds

Don't be shy about grabbing a handful of brake

frzmln

As far as i’m concerned carbon braking surfaces are dangerous, i’ve seen it give up and cause a front wheel to imploed. Luckily it was at the end of a descent.


disc brake + carbon wheel = ok
calipers + carbon braking surface = not ok

To each his own. Stay safe.

thegreatdivide

frzmln wrote:

As far as i’m concerned carbon braking surfaces are dangerous, i’ve seen it give up and cause a front wheel to imploed. Luckily it was at the end of a descent.


disc brake + carbon wheel = ok
calipers + carbon braking surface = not ok

To each his own. Stay safe.

Agreed. The fatality rate in the peloton from dangerous carbon rims is astounding. I'm amazed the sport is allowed to continue and the wheel manufacturers are still in business. Ban this evil filth.

craigus89

frzmln wrote:

As far as i’m concerned carbon braking surfaces are dangerous, i’ve seen it give up and cause a front wheel to imploed. Luckily it was at the end of a descent.

disc brake + carbon wheel = ok
calipers + carbon braking surface = not ok

To each his own. Stay safe.

Oh look, another generalisation based upon a single experience of limited value.

Ever considered that it was user error rather than the wheel at fault?

joe2008

I actually prefer braking on my carbon rims, wet or dry, to braking on my alloys; they're smoother and less grabby.

I only use cheap (£5 for 4) Wiggle Lifeline blue carbon pads, they're great and last for ages.

shirley_basso

Agree those pads are ace and dirt cheap, usually offer superior braking to most factory supplied ones and as they are soft, work well in a range of conditions.

gingerflash1975

I use Zipp 303 NSWs with Swisstop pads (though will look up those Wiggle ones!).

Braking in the dry is excellent, as good as I had with Mavic Exalith (the machined surface). Better than normal alloy in my experience.
In moderate, normal rain, they're very good too. Not noticeably worse than aluminium.
Only in torrential rain are they any worse. There's a second or two delay until the pads bite. They're then fine.

In the rain, the pads don't disintegrate in the way pads for aluminium rims do.

Some of the comments in the posts above are simply out of date. Carbon rims used to have a problem with braking, both wet weather and heat management, but i think the reputable manufacturers have overcome them now.

shirley_basso

I have 303s too and run the Zipp Tangente pads on the rear and Wiggle Lifeline on front (fronts wore out so I replaced just that one).

I find it works great for me.

thegreatdivide

Zipps with Tangente Platinum Pro Evo pads are a great setup and they've been fantastic for me in all conditions, however the next step up has been mu Bora Ultra 35s with Campagnolo pads. The new Bora surface must be as good as it gets for carbon right now - they're just brilliant!

shirley_basso

I would love to trade in my Zipps for Boras.

Vino'sGhost

ive got 303s and find no problems with the tangentte pads. I prefer the smooth progressive nature of the braking too.

I also like the cylon noise they make