Fin Measurement Guide
Since the innovation of the adjustable fin block, skiers have reaped the benefits and the consequences of fin placement. Just as important as fin placement is your diligence in tracking your measurements. If you choose to adjust your fin, it's imperative to know where you've been. Keeping excellent records of your fin settings will help you restore previous settings that worked well for you, and help you determine future adjustments. This is especially important when setting up a new ski. This is the purpose behind myskilog.com which will help you track your ski settings -- and performances -- over time, and it's free for you to use!
While everyone's optimal fin settings are unique to your height, weight, skiing style and personal preference, manufacturer and professional recommendations for fin settings can go a long way to getting you into "the realm" of the proper settings. Most pros can detect an adjustment of less than 0.005 inches, which is thinner than a blade of hair. It's a sad scene when I check someone's fin and see that it's pushed all the way forward and all the way into the adjustable block -- unfortunately there isn't a way as of yet to produce accurate fin settings without a dial caliper.
Proper fin measurement is essential to dialing in your slalom ski. Unfortunately, many different variety of calipers exist and even more styles of measurement are out there. All calipers are not created equal - so you'll need to use specific techniques to make sure that your fin measurements come out the consistent with other skiers' measurements. The standardization of measurements is extremely important to keep your fin settings accurate.
You'll need an 8-inch dial caliper to perform fin measurements.
- Distance from tail.
Open the caliper and hold the caliper flat against the bottom of the ski with your thumb. Place the nose directly against the back of the fin. How flat you hold the caliper against the ski will directly affect your measurement. Carefully close the caliper until the moving jaw touches the very back of the ski. It's wise to do this measurement at least 3 times, or until you can find a consistent measurement. Completely remove the caliper from the ski and reset the nose against the fin between attempts. This takes a little bit of practice to perfect.
Distance from Tail typically will range 0.675 - 0.85
- Length of fin.
The two different styles are with "the tips" and with "the jaws". Using the tips is the only way that you can compare your measurements with someone with a different ski or different caliper. Place the tips of the caliper on the leading and tail edges of the fin. Make sure the caliper is a) flat against the ski and b) the tips are even (not crooked) where they are measuring the fin.
Length measured with the tips should range from about 6.7 - 6.95
- Depth
Fin depth is the easiest measurement to take. Open the caliper and place the nose flat against the bottom of the ski. Close the caliper so the moving jaw touches the bottom of the fin. The only trick here is to make sure you measure the deepest part of the fin.
Depth will typically range from 2.44 - 2.53
- Leading Edge
The Leading Edge of the fin is a slightly more technical measurement which isn't required for less advanced skiers. This distance is the measurement from the front of the fin to the very tail of the ski. While you could come up with this by simply adding the length of the fin plus the distanc from the tail, if you have a large dial caliper, you'll find that measuring this distance yields a different number than the simple addition of length versus distance from tail.
Definitive Fin Measurement
For the March/April WaterSkier Magazine, Rossi put together this complete guide to fin tuning. Read it through and you'll know how to measure within a few thousandths of the pros, using tips for length and the apporpriate style to use when taking your distance from tail (DFT).
Available in this PDF Download. Discuss this in the Forum
