How important is a carbon sole on a cycling shoe? I just picked up a set of Lake CX170 shoes from Bonktown. I just ordered the Lake Tri shoe (forget the model #) a few weeks ago. The tri shoe has a carbon sole. The CX170 is not carbon, but damn are the comfy so far (BOA lacing system). My thought is to use the tri shoes for shorter races and use the road shoes for longer rides/races. I am not putting out tons of power (MOP cyclist at best).
Is the lack of a carbon sole a big deal?
Not sure the answer, others may be able to help…but as a primarily long distance guy, I would say comfort is very important over the long haul and can influence performance, particularly if that comfort translates to more time in aero position.
Carbon isn’t important, but stiffness is. The stiffer the sole, the more power goes into the pedal instead of being wasted on bending the sole. Carbon is very stiff for its weight, so it’s a good material for the sole.
Completely unimportant. I will agree that stiffness is relatively important, mostly for comfort reasons, but you can make equally stiff soles in carbon and plastic. One will weigh more than the other though.
Not a big deal at all. I’m not above shelling out $$ for stuff, but in this case the stiffness gain is negligible and the weight savings is miniscule. I’d rate it very near the bottom of the upgrade value spectrum, both in absolute gain and bang-per-buck terms.
For comparison, rather than replace my old ~$150 Sidis with a new ~$300 pair, I splurged instead on a pair of insulated winter MTB boots so I can ride in greater comfort throughout more of the year.
Carbon is a big deal precisely because it provides such significant stiffness. I have a pair of old Sidi’s with the nylon (?) sole that I ride on the trainer. They feel like flip flops compared to my carbon-soled shoes, so there is no question power transfer is diminished by less stiff soles, particularly when it matters most (sprinting and climbing). If all you do are flat tris, then not as big a deal. But regardless, beware of a bad fit. A stiff sole in a shoe that fits poorly will give you hot spots that can be unbearable. I almost could not walk after long rides in one ill-fitting (for me) pair.
the power transfer argument is fairly bogus. If you assume that the shoe sole deflects 1/2" (which is quite a lot–probably beyond realistic), a cadence of 90 rpm and a pedaling force of 70 lb you get about 5 watts lost. Certainly not detectable by feel, and would probably be hard to measure.
For energy to be lost by sole deflection it has to go somewhere. That somewhere would be heat and I doubt that even the flexiest shoe sole heats up at all. Shoe soles flex like a spring, the energy is absorbed when it flexes on the downstroke and released when it relaxes on the upstroke.
So you’re cool with tossing 5 watts. Good for you. What’s your age group?
I felt a difference going from a carbon soled Nike Pogio to Bont A1’s. In the Nike’s I could feel the shoe flex around the pedal. If you don’t think its possible you’ve never ridden a good carbon soled shoe.
All my cycling shoes are carbon.
As many have mentioned, it has great stiffness to weight. Then again, so does nylon. So why carbon over nylon? One of the selling points for me is longevity. A nylon sole will break down and become more flexy much quicker. For a roadie who is killing it every day and racing every weekend, this might be six months. For someone who rides just a few times every week, nylon may last a few seasons.
My first set of cycling shoes was a cheap pair of Forte Tri shoes from Performance. They had a very cheap, plastic, flexible sole. I didn’t really know the difference until I got my carbon soled shoes.
But the Lake’s that I referred to in my OP seem pretty rigid. They are said to have a “Fibre Reinforced Nylon Sole”. The reviews that I have read online say that for this type of sole, Lake did good job and they seem plent stiff for most people.
All my cycling shoes are carbon.
As many have mentioned, it has great stiffness to weight. Then again, so does nylon. So why carbon over nylon? One of the selling points for me is longevity. A nylon sole will break down and become more flexy much quicker. For a roadie who is killing it every day and racing every weekend, this might be six months. For someone who rides just a few times every week, nylon may last a few seasons.*and carbon starts out stiffer; it has a better stiffness to weight ratio than nylon
I think you feel a difference in stiffness, but I don’t think there is any loss of power due to the sole flexing
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I think you feel a difference in stiffness, but I don’t think there is any loss of power due to the sole flexingcan you think of any benefit to having a flexible sole?
Sidi claims that soles with a bit of flex are more comfortable. With most soles today I think they tend to be all stiff enough
Maybe, but I’d disagree. Just curious what shoes do you use and have you tried a good carbon soled shoe? I know good carbon sole is vague but basically saying there is a difference, obviously my Nike v Bont was proof of that.
I think carbon soles are only there because they can charge more to put them in there. I have both carbon and noncarbon shoes, and the noncarbon one is so friggin’ stiff that you’d break your foot before you bent it significantly. I notice no difference whatsoever in them, and am convinced they make them just because they can, and charge more for the theoretical advantages and weight savings. If it’s bike related, if you can make it out of carbon, you can charge a lot more for it.
your also forgetting stack height
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With bonk town it’s sort of an academic argument though. Carbon soled t2.6 shoes only like $35 more than the nylon ones…problem solved.