Flex Comparison Between The Intuition Gold ID Liner and The Intuition Flexalon Liner
By Ken Arsenault
The intent of this comparison is to determine the increase in flex when using the Gold ID liners molded over the stock Trufit Comp & Team Pro Liner in the Dalbello Krypton Pros. I’ve posed this question to several folks including the epicski forum, Dalbello North America, and Intuition Sports. All answers have been something along the lines of “significantly stiffer”. When I posed the question to Intuition Sports, they told me that no one has ever done a comparison and sent me a brand new pair of Flexalon FX Full Custom Liners so I could figure it out for myself (Are those people cool or what!).
The answer to the comparison flex question is the Gold ID is 10% to 15% stiffer than the Flexalon. There is a whole bunch of data coming with charts and pictures so if you only want the answer, you don’t need to read further.
FX is the grey and orange one on the left, Gold ID on the right.
According to Intuitions Sports, the FX liners are very similar to the same ones you would get with the Kryptons as a stock liner; except the FX is heat moldable (Intuition said the FX liners will be online soon). As far as stiffness goes, though they are moldable, they are very similar in flex because it is a tongue design.
Lacking the tools or access to them to do this with high speed computer aided equipment, I decided to first go be feel, and then the one thing I could (or anyone else could) do to measure the difference in distance travel of the knee.
I thought of several different ways but most required special tooling so I wanted to come up with a simple way to measure that I could do consistently. I looked at using a weight scale to measure force but the scale I have isn’t very accurate and accurate digital scales calibrate each time used and that gets annoying real quick.
The final process was to tape a ruler to the top of my skis, turn my bindings up to “Fat Bastard”, hook a rod to the top of the front of my boot liner with the other end on the ruler and the leaned forward. The rod slides along the ruler and when you stop moving, you use that measurement. You also have to note the distance the rod is in when you are in a neutral position. From there it simple math to determine the distance traveled.
So I wouldn’t have to worry about muscle fatigue or anything of the sort, I kept my body upright and leaned forward without using ankle muscles to flex the boots. I wasn’t measuring how far I could flex the boots but the difference in the liners, so I had to use a process that wouldn’t permit me to max it out and each time I leaned forward, I weighed the same. As long as I leaned forward the same way each time, since I weighed the same each time, the force applied to the boot was the same. The only thing to stop me is the stiffness of the boot and by changing things around, the distance the rod traveled would change. So in effect, I became the tool that I thought I didn’t have.
The next step is to make a chart with this info and inserting the info I received from Dalbello North America. I talked to the person there that I was told knew tons about the boot. He walked me through a chart over the phone that I used as my base of information. I was then able to do the math to fill in the missing data (because I am smarter than a 5thGrader!).
This isn’t designed to figure out how to determine the flex you need. It works well with the Krypton Pros because there are so many settings. The chart provided is rough and will give you an idea of the ever so elusive flex of a boot. What Dabello states as 130 and another manufacturer does can be completely different, so you have to not be too anal about it. I measured to the eighth inch and would take the measurement several times to get out any variances.
My experiences using these boots for two seasons and what I’ve seen and read others do, support the data.
The rest of this is all data. Have fun.
Me – 50 y/o, 5’7”, 175#. 5+ years skiing. No (useful) ACL in Left leg. Aside from the ACL and limited dorsiflexion, no abnormalities. I could stand losing 15-20 # but other than that, I’m healthy.
Boots – 25.5 (296BSL) Krypton Pro, hard zeppa. Believe they are 2007 vintage. They have a Booster strap but it was NOT used during this experiment. These boots have a rated flex of 100-140 (range is based on stiffener and forward lean wedges). This flex rating is based on the stock liner and not the Gold ID liner. For the comparison I used the #4 forward lean wedge.
Boot modifications - heel lift (for limited dorsiflexion) and insta print custom foot beds. – 2 degree canting using provided insets. Boots were professionally fitted by Green Mountain Orthotics Lab. Other than being told I have a well balanced neutral stance, I also feel that way in these boots with the above set up.
Boot Tongues – Grey is 100 Flex and Black is 115 flex (info provided by Dalbello N/A)
Liners being compared:
-Molded Intuition Pro Gold ID (MGID). Have 94 ski days on them. I assure you, they are broken in.
-Un-Molded Intuition Flexalon FX with tongue (UFXT). Have not been skied. They aren’t the exact same that would come with the Krypton’s as stock liners but are a very close match and are a good substitute for this comparison.
The FX liner impressed me. I haven’t even molded it yet and it feels comfortable enough to ski in. Something in the back of my mind is telling me a boot with a tongue should have a liner with a tongue. Really like the big loops on the tongue and the back. Makes putting the boot on and adjusting the tongue a breeze.
Environment –All experiments were done in my basement on a cement floor. Average temp is about 72 F and humidity is approximately 55 %. It is understood that in the winter on a mountain, it will be much more difficult to flex these boots but for comparison purposes, climate doesn’t matter as long as all tests are conducted in the same environment.
Process for Second Comparison – After putting on my boots and making sure they were both fitting identical, I stepped into the bindings of my race skis with the heel binding on the highest setting. I would then take several steps in place to make sure my bones were stacked (feet under knees and knees under hips). The motion was done by only flexing the ankle until stopped by the stiffness of the boot. The skis were on my padded cement basement floor. The tails of the skis did not come off the ground flexing in this manner.
The rod is a support rod from a shelf. Though the liners being compared aren’t exactly the same height as you can see in the photo, the neutral measurement was taken in each liner and the distance traveled was based on each liner’s measurement.
The flat edge of the rod made it easier to take a measurement as shown in the below photo.
Left boot MGID & Right boot UFXT then RB MGID & LB UFXT -
Standing doing single leg flex (not in bindings) of each leg after adjusting buckles to make boots fit evenly (UFXT seems thicker in toe box since it isn’t molded) and wearing boots for 5 minutes. Fit was based on heel position in heel pocket and ability to lift it and uniform fit around calf.
The boot with UFXT requires significantly less effort to flex. I felt as though I was crushing the boot with the UFXT liner in it compared to the one with the MGID. UFXT tongue height is about as high as MGID wrap at the shin. UFXT is approximately 1-1.5 inches shorter on each side of calf. UFXT and MGID are approximately the same height at rear of boot. When liners were changed in boots (LB MGID & RB UFXT – LB UFXT & RB MGID) the results were the same. When trying to flex both legs at the same time, the side with the UFXT would flex so much more that I was always stopped by the side with the MGID.
Noticed that when using the UFXT liner, the cabrio tongue would sometimes get caught on the liner edge and not fully seat. You just have to flick it over so it’s no big deal but it was an observation. Could probably be negated by putting the booster strap directly over the tongue but you usually don’t do that with the Cabrio design.
Both boots were worn and both boots were set up with the same liner. When changing liners only one boot was changed at a time and re-buckled to insure a similar fit.
Double leg flex - Measured distance rod traveled on right side as described above.
Similar results to first comparison. All tests were repeated multiple times to verify measurements. Made it a point to not let my heel lift. Noticed that when using the wedges the heel of the liner can get caught on it during removal of the liner (long handled shoe horn fixed that). I also had to make sure to project me hips forward to make it easier to do the motion the same way each time.
I didn’t notice as much of a change using the stiffness wedges without a forward lean wedge. Not even sure if they are meant to use without a forward lean wedge. I stuck with the #4 wedge and forward lean because when I sampled with the #8 set, the results were similar.
The Cross Reference Table:
The yellow and green blocks have the info I received from Dalbello. The “Add 10” isn’t 10% but “10”. When I completed all the measurements, I lined up my results on the FX liners with the info from Dalbello and it was then fairly easy to fill in the blanks for the Gold ID liners. The less distance traveled the higher the flex. This doesn’t mean if you do the same process and travel a certain distance you can use my cross reference; it only works for me.
The blue blocks are a sanity check to see if I’m close with the “Flex Guess” column using the info in the green blocks; pretty close. Nothing really seems out of whack and I would say it’s as accurate as any other basement experiment. The “Hi” position on the MGID for both tongues are the ones that are off the most but in distance the Black Tongue is only ¼” and the Grey Tongue is only 1/8”. Pick whichever one you are most comfortable with.
Without a doubt this was not the most scientific study to ever be conducted but when measuring something as variable and elusive as “ski boot flex”, close enough really is good enough. I’ve read that the Gold ID liner is about 25%-30% more stiff than the stock liner. That statement seems high based on my results. It would also mean with the Gold ID Liner, the flex would go to 180! The people that made those comments stated they were guessing and were only going by feel.
Over this past season I did ski the warmer months with the Gold ID and Black tongue (approximately a 130 flex). My observations from that were it was way too stiff for me and two different PSIA L2’s that I work with stated they thought my boots were too stiff. They based this on the fact they didn’t notice my ankle flexing enough. My findings support their statements.
I would say on average the flex increases 12 %. The chart shows that changing the FX liner for the Gold ID liner raised the flex 15% but when the stiffness wedges came into play, the flex change dropped to 10%-13%.
When using the cross reference table, it’s probably something like =/- 5. Round up or down as you see fit.
This coming season I’m going to ski using the FX liners for a couple of reasons. I really like the Gold ID but I want to try a little bit less flex. I’ll see how it goes and figure it out.
Once I mold the FX liner and ski it I’ll post a review. I have high expectations on it based on using it for this comparison across the last several days.
Feel free to try you own comparison and post your results. You could try the method I used and see if you get similar results.
Remember, the goal was to compare the stiffness of the liners and not necessarily determine the flex of the boot.
Hope you enjoyed it as much as I did getting out of mowing the grass, and yes I know I have too much time on my hands.