Currently riding with SPD pedals and specialized MTB shoes on my Supersix. I am considering getting SPD-SL's and carbon road shoes. Am I likely to notice/experience any difference with new pedals/shoes?

I did do a search and I know that the SPD-SL provides a bigger platform that SPD's and theoretically a more efficient power transfer. Are carbon shoes that much stiffer than non-carbon so as to make any difference?

the stiffer the better

You probably won't notice a huge difference tbh. There is one, but unless you're racing, the difference is probably minuscule.

Unless you are the type who would notice a pea under your mattress, I highly doubt you will notice much difference.

The advantage of MTB shoes is that you can walk in them. I took a pair to Rome last Spring for when I rented a bicycle. Worked great! On my bike here, I went from an ancient pair of Diadora shoes, (but new unused - just hung onto them because my old pair never wore out). I had Look Keo on the Diadoras. Then went with SPD-SL, first with a pair of Shimano mid-range shoes and about a month later, a pair of Carbon sole Bontrager shoes. I have not noticed any difference between the three, (other than how well or poorly the shoe fit my foot shape and size).

As said by others, you probably won't notice a difference. Especially if you have good MTB shoes now. I went from bottom end MTB shoes and SPD's to SIDI Pro 5's and SPD-SL pedals and notice some difference, mostly in comfort and weight of the shoe.

I use Specialized non carbon road shoes (~$100) and they are great.

Yes, but equally as important, lighter and most probably better vented. The less weight you are spinning, the better.

That's what she said...

But seriously, we all know the difference is that the OP will look more pro. Might as well p pick up some white bartape while you're at it...

No.

On very long rides (>100 miles), I get hot spots on the balls of both feet with SPD pedals and shoes with flexible soles. With SPD-SL pedals and shoes with stiff carbon soles I don't get hot spots, presumably because the pedal pressure is spread out over a larger area of my foot instead on being concentrated.

I was using a topline Shimano MTB shoe with eggbeaters... for quite few years

after some research I compared these shoes to a pair of Sidi Carbon Zephyrs (mid-line road carbon) and found that the Shimanos were 1lb heavier for the pair.
I changed to the Zephyrs and used Quattro cleats w the eggbeaters... saving a pound of weight on the feet.

The change feels quite dramatic at 90 + rpms...

I also have and use same Zephyrs with Shimano SPD-SLs on my Tarmac. Definitely has a more 'locked in' feel over the eggbeaters, but how much actual, if any, improvement in power transfer is a guess.

This.

incorrect

When I changed from MTB shoes to road shoes back in the 90's, I saw a noticable difference. Now, my MTB shoes had a decent amount of flex in them, so it's most likely going to depend on stiffness in the MTB shoe vs. stiffness in the road shoe you pick. Today's MTB shoe might not be as flexible as mine were back when, so you might not notice the increased efficiency that I did.

I made the exact same switch in shoes and pedals, for comfort reasons, and haven't been disappointed. Nice carbon soles and a wider point of attachment also feel more secure and powerful. it may not make you faster, but you'll feel like a beast.

What kind of difference? You'll notice your bank account balance shrink a bit, and you'll have more shoes in your closet. That's something.

I ride SPD pedals, because I ride out to some incredibly scenic places, and occasionally like to get off the bike, walk to a different vantage point, fill my water bottle out of a mountain stream ( I have a purifier ) and the like. I used to get painful hot spots on parts of my feet, because my shoes flexed too much. I got a pair of carbon shoes, but kept the SPD pedals, and the discomfort went away completely.

The noticeable difference will not be due to the carbon but that you are going from MTB to road shoes. The difference between decent carbon and non-carbon road shoes is negligible. How well the shoes fit you will make a much bigger difference.

I recently bought a pair of Specialized Elite road shoes. They fit SPD pedals as well as 3-bolt cleats. The soles are very stiff, and definitely an improvement over any MTB shoe I've tried. They run slightly small - I normally wear a U.S. 13 (47 Europe), but had to opt for the 13.75 (48 Europe). These are great shoes if you want to stick w/ SPD's:

https://www.specialized.com/us/en/bc/...jsp?spid=56683

I made this switch from SPD to SPD-SL a month ago and have not noticed much of a difference in efficiency or comfort. SPD shoes are fine unless they are not stiff...in which case you may want to upgrade the shoes. I use and love my Sidi Dominator 5's for SPD. I am having a hard time getting used to the single-sided entry of the SPD-SLs... the SPDs are much easier to use. If it weren't for the fact that my SPD pedals and cleats were squeaking badly, I'd go back to using those.

Using a shoe that is comfortable, fits, is stiff/supportive, and has a reputation for lasting a long time is the most important. It's like a saddle....there is no "1" that will be the best for everyone. You have to find what works for you.

As for pedals - You can ride anything with any pedals that match up. It doesn't really matter, but.......


......there's a reason why there are so many different pedal designs out there and why there is a road vs mtb style design.

Incorrect.

I almost wound up in that club. My local REI had a 20 % off sale on cycling shoes, right when I needed another pair. Unfortunately they didn't have them in my size, which is a shame because they seemed like great shoes and I kind of wanted a pair.

Stiff carbon shoes will matter. If you have stiff carbon shoes, then the pedal will not matter.

For example. I ride eggbeaters with a stiff carbon road shoe. There are no hotspots because the shoe is stiff enough that the small platform is irrelevant.

It will also depend on the shoes. If you have a stiff higher end MTB shoe...the difference will be less noticeable.

I started with MTB shoes and Eggbeaters and the difference for me was dramatic. My 661 MTB shoes felt like slippers compared to the Specialized Comp road shoes. As other mentioned, weight plays a part in it too. I recently picked up a pair of Specialized Pro shoes with a full carbon sole. Not only is it stiffer, its noticeably lighter.

Walking is a non issue for me. Only time I'm off the bike is walking to the restroom or getting a drink at a market.

What is considered stiff? I have the Specialized Sport MTB shoes and they don't bend.