How important is boot flex?

Its more personal preference than anything. I think you'll be fine with a 90 flex if you notice you are over flexing your boots then you might want to look into stiffer boots.

I'd say the question of flex mostly comes down to personal preference. I skied a 90-flex boot for my first two years and it worked fine, but as I got better and started skiing with a more traditional (forward, driving the shovels of my skis) stance, I found myself wanting a stiffer boot. Now I typically ski 120-130 flex boots, and couldn't go back to a softer boot and still ski like I want to. But then I know some really good skiers with park backgrounds how can rage on 90-110-flex boots.

What skis do you use and would you say you tend to ski more centered / neutral, or with more of a forward, traditional stance? If it's the latter, it might be worth looking into stiffer boots as they can help you drive skis more powerfully (particularly longer, stiffer, and / or heavier skis) and they can provide more support when skiing really fast (since softer boots can "fold up" at speed and buck you forward). Some of the main potential downsides with a stiffer boot that I've noticed are that you might find it too "harsh" (since the boot isn't absorbing impacts as easily) or you might not be able to drive your skis because you can't flex the boot enough. Those are the things I notice, but I'm sure other people have other things that they notice with stiffer / softer boots.

And if you are interested in stiffer boots but don't want to buy a whole new pair, Pulse's ProFlex attachment is worth a look. I've had good experiences with it so far — the ramp up in stiffness is noticeable, without notably negatively affecting the boot so far.

While there is an element of personal preference in the "right" flex, there are factors that outweigh your personal preference, namely ankle flexibility. If you have limited ankle flexibility, it doesn't matter if you think you like soft boots- a soft boot in this scenario is going to cause you lots of discomfort. If you have limited ankle flexibility and you overflex a boot, your heel will left and your foot will shift laterally inside the boot. No one's personal preference will like that for very long.

Things are important when selecting your boot flex:
1. Strength/weight
2. Height
3. Ankle flexibility
4. Personal preference

When a boot is too soft for you, you will move but the boot will not react and you will need to exaggerate movements in order to get the same thing done vs. being in a stiffer boot. You're simply going to be working harder.

When a boot is too soft for you, your shin will glide more up and down the tongue of the liner. That friction will build up and become uncomfortable. Soft boots do not solve shinbang- they quite often cause it.

Ideally, you should be in the stiffest boot that you can still properly flex. That might mean a 130, that might mean a 100. But the ideal boot flex is dependent on those 4 factors I listed above. Get a boot that is supportive enough that it does more of the work for you, but it is forgiving enough that you are able to get your knees over your toes so you can balance properly.

tbh pretty important. I've started to really notice how my skis are less responsive because my boots are so soft. I have FT drop kicks 6 flex and i'm really thinking about getting 8 tongues & booster straps this season. My feet have to move a few inches with my boots before my skis respond to that input. Its really frustrating and I know I can ski a lot better with stiffer boots.

patagonialukeI'd say the question of flex mostly comes down to personal preference. I skied a 90-flex boot for my first two years and it worked fine, but as I got better and started skiing with a more traditional (forward, driving the shovels of my skis) stance, I found myself wanting a stiffer boot. Now I typically ski 120-130 flex boots, and couldn't go back to a softer boot and still ski like I want to. But then I know some really good skiers with park backgrounds how can rage on 90-110-flex boots.

What skis do you use and would you say you tend to ski more centered / neutral, or with more of a forward, traditional stance? If it's the latter, it might be worth looking into stiffer boots as they can help you drive skis more powerfully (particularly longer, stiffer, and / or heavier skis) and they can provide more support when skiing really fast (since softer boots can "fold up" at speed and buck you forward). Some of the main potential downsides with a stiffer boot that I've noticed are that you might find it too "harsh" (since the boot isn't absorbing impacts as easily) or you might not be able to drive your skis because you can't flex the boot enough. Those are the things I notice, but I'm sure other people have other things that they notice with stiffer / softer boots.

And if you are interested in stiffer boots but don't want to buy a whole new pair, Pulse's ProFlex attachment is worth a look. I've had good experiences with it so far — the ramp up in stiffness is noticeable, without notably negatively affecting the boot so far.

Think I'm gonna get out on the mountain and see how it feels and if anything I'll look into purchasing the item you recommended to get me through the season. Worst case I'll see a bootfitter. Thanks for all the help!

onenerdykidWhile there is an element of personal preference in the "right" flex, there are factors that outweigh your personal preference, namely ankle flexibility. If you have limited ankle flexibility, it doesn't matter if you think you like soft boots- a soft boot in this scenario is going to cause you lots of discomfort. If you have limited ankle flexibility and you overflex a boot, your heel will left and your foot will shift laterally inside the boot. No one's personal preference will like that for very long.

Things are important when selecting your boot flex:
1. Strength/weight
2. Height
3. Ankle flexibility
4. Personal preference

When a boot is too soft for you, you will move but the boot will not react and you will need to exaggerate movements in order to get the same thing done vs. being in a stiffer boot. You're simply going to be working harder.

When a boot is too soft for you, your shin will glide more up and down the tongue of the liner. That friction will build up and become uncomfortable. Soft boots do not solve shinbang- they quite often cause it.

Ideally, you should be in the stiffest boot that you can still properly flex. That might mean a 130, that might mean a 100. But the ideal boot flex is dependent on those 4 factors I listed above. Get a boot that is supportive enough that it does more of the work for you, but it is forgiving enough that you are able to get your knees over your toes so you can balance properly.

Listen to this man. ^^

A couple years back i switched from a 90 flex 3 piece, to a 130 flex traditional. Haven’t been happier. The control is amazing. I can testify that softer boots than you need absolutely reks you