Carbon fiber vs. fiberglass/plastic shoe sole

Hi all- I am buying my first pair of road shoes because a) I plan to start riding longer distance/multi-day tours, and b) I just found out that I have arthritis in one of the joints in my foot (kind of a bummer for someone in her 20s), so I need more support in the soles.

I see that higher end shoes are made with a carbon fiber sole, versus the lower end plastic or fiberglass soles. First of all, is carbon fiber significantly better than both of the alternatives? I know it is stiffer, which equals more support, but is it that noticeable? Also, is fiberglass significantly better than plastic?

I have tried Shimano R099, which fit pretty well, and Shimano R085 which also fit well. I have a somewhat wide foot, so Sidi was way too narrow. Pearl Izumi Vagabond R4 also felt good.

Any response/ suggestion on shoes would be much appreciated!

I'm probably not the best person to ask on this subject, as I keep buying nylon-soled Sidis and never try anything else. They fit me well, and if it ain't broke, don't fix it, right? ;)

But one thought did occur to me: if you're looking for more support, perhaps you might consider aftermarket insoles? I have high arches and one is higher than the other (enough that I can feel the difference). I use Superfeet in all of my cycling shoes- blue for mountain, gray for road- and they make a huge difference with arch cramping, hot spots and toe numbness.

Carbon soles are stiffer. This is different than being more supportive. If you seriously need more support than you currently have, carbon soles are not going to be an improvement -- you would probably be better served by insoles. Stiffness aids power transfer. I have a pair of carbon sole Sidis (though not the most expensive model) and a pair of standard sole Sidis (nylon probably?). The carbon soles are a bit stiffer. It IS *slightly* noticeable to me. If I were 190 lbs and putting out 500 watts on a regular basis, it might be a bigger deal, but I would say for the purposes of most primarily recreational riders (and maybe I am making an assumption about you here that I shouldn't, so say so if I am) once you are looking at a dedicated road shoe, the sole material is not hugely important, it's more gravy. It's not a revelatory difference for me.

But, that said, fit is pretty important, and all of my Sidis are much better fitting than my old, low-end Shimano road shoes. (Haven't tried the higher-end Shimanos though...).

If you have $$$ burning a hole in your pocket, by all means buy the most expensive, lightest, stiffest shoes you can justify. But I am of the opinion that the bling road shoe thing is more about style and having expensive gear than it is about power -- not to say that more expensive shoes don't have some nice features (I really like the BOA closure that Specialized puts on its top of the line shoes, for instance), but the performance difference gets smaller and smaller the higher you go up the line.

Thanks- that's what I needed to know. I think I'm gonna go with a less expensive shoe for now. If I find that I want something more I can always upgrade, but for now I think a lower end shoe should be sufficient.
Getting insoles is also a great idea. I will look into that.

I've had Specialized shoes with Carbon Fiber soles. I now have Sidis (with nylon soles, I hear) and I don't see a noticeable difference. I haven't taken them on 20+km climbs though, but even at the end of long rides (over 100 km with hard hills) they're doing well.

I have Sidis non-carbon soles but I use Aline Insoles in my shoes. These insoles are stiff and really helped me with foot pain. They work to correct alignment issues which I had due to really high arches.

I use Superfeet insoles. They have a website which will help you determine which one to use. I also use Superfeet in my hiking shoes.

Got them at REI about 4 yrs ago and it solved most of my foot issues.

You might want to check with a podiatrist about what kind of sole you need. I know this is different than arthritis, but a friend of mine has been having some nerve problems in one of her feet. They removed the nerve, but she's still having a lot of pain months later. Her doctor said she needs to give up her carbon soles, because they are too stiff and aggravating her problems. She's also getting custom orthotics.

So, for efficient power transfer, stability, and comfort the lightest, stiffest shoe is best. For specific medical problems, though, it could depend. A stiff sole may support your painful joints better, but you may just need the right insert.

Thanks for all the info! I think I'm going to go with the Pearl Izumi Vagabonds, they were the most comfortable that I tried (and conveniently the least expensive). I went to the podiatrist a few weeks ago, and he didnt say specifically whether carbon was preferable over nylon or not, but rather that I just need cycling specific shoes that have (relatively) firm soles. I am also getting custom orthotics from him, but he said they wont fit in cycling shoes. I will look into the other insole options for sure, and I'll see how my feet feel once I start riding with the right shoes.

See if you can get one made by some physician / physical therapist for your cycling shoes, too. That's what my friend is doing. I've been doing OK with the Specialized BG insoles (highest arch one), because my orthotics don't fit in cycling shoes either, but I don't have foot issues that cause major problems on the bike--just having the right shoes and cleat placement helps a lot. My issues manifest themselves more when running and walking (mostly running).

My LBS has a board for checking your arches, and they have special isoles for biking shoes. The soles come with various shims that allow you to adjust the fit of your shoes to you. A complete bike fit ($100 at me LBS) includes looking at how your shoes fit and helping you adjust your inserts and shims as needed to make sure that you are fitted properly.

Whatever you decide on, I can't recommend tri shoes enough. I love being able to ride my shoes without socks if I'm just doing a short evening ride or after I've been caught in a downpour and had my socks soaked through.