Author Topic: Stroke Rate for Distance  (Read 28046 times)

Quickbeam

  • Teahupoo Status
  • ******
  • Posts: 1128
    • View Profile
Re: Stroke Rate for Distance
« Reply #90 on: May 18, 2018, 06:32:22 PM »
Sometime soon I am going to do a thorough analysis of my latest board acquisition...a 14 Imagine Rocket.
I will be using my latest formula which I call SS.
(Smiles per stroke) for those that aren't familiar with the system. ):...........

This is what it should come down to. Now in my world, “Smiles per Stroke” takes in things like speed, stability, how the board handles in different conditions, how the board looks, etc., etc. And then there is just the intangible of “how does this board feel to me”?

But at the end of the day, I think you’ve nailed it Connector14. Smiles per Stroke. I love it  :)
Infinity Blackfish 12’ 6” x 23”
ONE SUP Evo 12’ 6” x 24”
Infinity Whiplash 12' 6" x 24 1/2"
ONE SUP Evo 12’ 6” x 26”
Bark Competitor 12’ 6” x 29”
Red Paddle Explorer (Inflatable) 13' 2" x 30
Starboard Airline (Inflatable) 12’ 6” x 27

ukgm

  • Teahupoo Status
  • ******
  • Posts: 1255
    • View Profile
    • Email
Re: Stroke Rate for Distance
« Reply #91 on: May 19, 2018, 01:59:31 PM »
By the way, I’m also currently piloting the use of an iPhone and its accelerometers as a means to test equipment. Early days on validating that one but I’m using it as part of my tests of the Allison fin system.

PonoBill

  • Cortez Bank Status
  • *****
  • Posts: 25864
    • View Profile
Re: Stroke Rate for Distance
« Reply #92 on: May 19, 2018, 02:04:48 PM »
The iPhone accelerometer is sensitive, but a bit noisy. How do you plan to use it?
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

ukgm

  • Teahupoo Status
  • ******
  • Posts: 1255
    • View Profile
    • Email
Re: Stroke Rate for Distance
« Reply #93 on: May 20, 2018, 01:53:08 AM »
The iPhone accelerometer is sensitive, but a bit noisy. How do you plan to use it?

There some after market apps but the raw data output is enormous. I’ll use stroke rate as the dependant and then look at the acceleration data as a variable when comparing equipment changes over a fixed distance.

Area 10

  • Cortez Bank Status
  • *****
  • Posts: 4057
    • View Profile
Re: Stroke Rate for Distance
« Reply #94 on: May 20, 2018, 03:43:06 AM »
The iPhone accelerometer is sensitive, but a bit noisy. How do you plan to use it?

There some after market apps but the raw data output is enormous. I’ll use stroke rate as the dependant and then look at the acceleration data as a variable when comparing equipment changes over a fixed distance.
Surely, Acceleration and stroke rate are only going to be useful when assessing fins if you were going in a perfect straight line somehow? If I put a tiny fin in, my acceleration might be high because they’d be no drag, and my stroke rate could be high or low depending on how I deal with the yaw. But I could be wavering all over the ship like a drunk grandma on a bouncy castle, and therefore be dead slow.

burchas

  • Custom Built
  • Cortez Bank Status
  • *****
  • Posts: 2508
    • View Profile
    • Email
Re: Stroke Rate for Distance
« Reply #95 on: May 20, 2018, 05:11:34 AM »
If I put a tiny fin in, my acceleration might be high because they’d be no drag...

More likely you're going to drift your tail like a dog longing for attention. Not sure that's a helpful metric ;)
in progress...

Area 10

  • Cortez Bank Status
  • *****
  • Posts: 4057
    • View Profile
Re: Stroke Rate for Distance
« Reply #96 on: May 20, 2018, 07:45:26 AM »
If I put a tiny fin in, my acceleration might be high because they’d be no drag...

More likely you're going to drift your tail like a dog longing for attention. Not sure that's a helpful metric ;)
THAT was my point, Burchas. Acceleration only mean something if you are accelerating in the right direction!

ukgm

  • Teahupoo Status
  • ******
  • Posts: 1255
    • View Profile
    • Email
Re: Stroke Rate for Distance
« Reply #97 on: May 20, 2018, 10:33:07 AM »
The iPhone accelerometer is sensitive, but a bit noisy. How do you plan to use it?

There some after market apps but the raw data output is enormous. I’ll use stroke rate as the dependant and then look at the acceleration data as a variable when comparing equipment changes over a fixed distance.
Surely, Acceleration and stroke rate are only going to be useful when assessing fins if you were going in a perfect straight line somehow? If I put a tiny fin in, my acceleration might be high because they’d be no drag, and my stroke rate could be high or low depending on how I deal with the yaw. But I could be wavering all over the ship like a drunk grandma on a bouncy castle, and therefore be dead slow.

It’s an important point you raise. It only reiterates why most testing needs to be for an individual paddler, not for a group. That way, tests like this are not specifically saying whether technology A is better than technology B but how efficiently a paddler uses technology A or technology B. A straight line when paddling is an indicator of paddling efficiency. With something as dynamic as SUP with so many factors involved, having tests which are relative is essential in my view.

To give you an example, I’ve done some tests whereby a fin works well with a given board but change a paddle and a different combination was actually better.
« Last Edit: May 20, 2018, 10:35:14 AM by ukgm »

Area 10

  • Cortez Bank Status
  • *****
  • Posts: 4057
    • View Profile
Re: Stroke Rate for Distance
« Reply #98 on: May 20, 2018, 11:39:10 AM »
Yeah, you’ll get the same for boards.

The board that *you* will be fastest on can quite easily not be the board *I’m* fastest on.

It’s funny, because if you say that to someone they will generally accept it. Especially if they have ever tried a board that was truly too tippy for them, or too low volume.

But then when it come to spending their money, they still think that if they buy the board that Connor Baxter is paddling, they will be as close to him in performance as they can get.

I guess that’s the power of marketing. It somehow allows us to hold happily two contradictory beliefs in mind at once.

It happens with fins too. You just have to try a bunch and note very carefully how they perform for you and your board, and get to know what works for you. You’ll drive yourself nuts trying to work out all the dynamics (don’t ask me how I know this) and then at the end you’ll realise that all you’ve learned is only true of *you* so is of next to no use for passing on as information to others.

ukgm

  • Teahupoo Status
  • ******
  • Posts: 1255
    • View Profile
    • Email
Re: Stroke Rate for Distance
« Reply #99 on: May 21, 2018, 12:10:52 AM »
Yeah, you’ll get the same for boards.

The board that *you* will be fastest on can quite easily not be the board *I’m* fastest on.

It’s funny, because if you say that to someone they will generally accept it. Especially if they have ever tried a board that was truly too tippy for them, or too low volume.

But then when it come to spending their money, they still think that if they buy the board that Connor Baxter is paddling, they will be as close to him in performance as they can get.

I guess that’s the power of marketing. It somehow allows us to hold happily two contradictory beliefs in mind at once.

It happens with fins too. You just have to try a bunch and note very carefully how they perform for you and your board, and get to know what works for you. You’ll drive yourself nuts trying to work out all the dynamics (don’t ask me how I know this) and then at the end you’ll realise that all you’ve learned is only true of *you* so is of next to no use for passing on as information to others.

When I tested the Black project Tiger vs the Maliko my coast down tests showed the tiger was lower in drag as the deceleration was less. You'd expect this due to its smaller size so no surprises there. However, in actual time trials, it was within the noise of the test when compared to the Maliko. The reality was that with the board it was in (coupled with the nuances of my stroke), it produced a fractionally lower stroke index. When I rechecked the GPS coordinates, it became obvious that I was having to put less strokes on each side to maintain the right straight line course. As a result, this created extra time delays due to the paddle changing sides and this negatively affected the Stroke Index. As a result, on that board, I use the Maliko instead. However, my stroke is still improving year on year so this is something I'd recheck at some stage.

Area 10

  • Cortez Bank Status
  • *****
  • Posts: 4057
    • View Profile
Re: Stroke Rate for Distance
« Reply #100 on: May 21, 2018, 02:49:38 AM »
Well, there ya go. But the question will be whether the data you gather will actually give you more accuracy in your decision-making than just ones general impressions when paddling. Because if it’s the case that you can just try two fins and pick the best one for you by feel alone on let’s say 80% of the time, and with all your fancy data you can only achieve a similar level of accuracy, then what’s the point of all the fancy stuff in practice? I guess it’s similar to comparing the utility of using heart rate vs, a subjective “effort index” when exercising: if the effort index can account for about 90% of either the expected training effect, or the HR values, then you might as well throw away the HR monitor, really. Not that I do, because I’m a data junky. But you get my point.

ukgm

  • Teahupoo Status
  • ******
  • Posts: 1255
    • View Profile
    • Email
Re: Stroke Rate for Distance
« Reply #101 on: May 21, 2018, 03:23:11 AM »
Well, there ya go. But the question will be whether the data you gather will actually give you more accuracy in your decision-making than just ones general impressions when paddling. Because if it’s the case that you can just try two fins and pick the best one for you by feel alone on let’s say 80% of the time, and with all your fancy data you can only achieve a similar level of accuracy, then what’s the point of all the fancy stuff in practice? I guess it’s similar to comparing the utility of using heart rate vs, a subjective “effort index” when exercising: if the effort index can account for about 90% of either the expected training effect, or the HR values, then you might as well throw away the HR monitor, really. Not that I do, because I’m a data junky. But you get my point.

As far cycling goes, I threw my Heart rate monitor away around 10 years ago  ;D

To pick up your point, the question is whether someone's intuition is as sensitive as proper data collection. Now I know I can get field testing with a data coefficient of variation of 3% across multiple flatwater runs. That's a big ask of someone's intuition and sensitivity. I personally think that's unlikely and not helped with the chaos of the conditions and any placebo's that may be in play. If you're a rough water racer, formalised testing probably won't help until an appropriate test is designed to suit its needs.

Either way, a lot of this is irrelevant unless people race because if you don't, you're better off just picking something you like the feel of. It's all about enjoyment. For those that do race, the next question is whether you believe a fin choice has an impact on your outcome. At smaller events (whereby draft trains are few in number), my own testing shows that fin choice is crucial. In a more packed and tactical affair, I'd defer to sensations and feelings as the needs are different. Put simply, it boils down to the main rules I lay out when I work with people. These are:

1) Know the events specific needs and characterisics.
2) Identify the athletes assistive/resistive factors.
2) Quantify the athletes assistive/resistive factors.
4) Implement the training and investment to maximise the needs and assistive factors whilst doing likewise to reduce the resistive factors.
« Last Edit: May 21, 2018, 03:39:21 AM by ukgm »

Area 10

  • Cortez Bank Status
  • *****
  • Posts: 4057
    • View Profile
Re: Stroke Rate for Distance
« Reply #102 on: May 21, 2018, 05:49:23 AM »
Interesting. What characteristics of fins do you think assist/resist drafting?

ukgm

  • Teahupoo Status
  • ******
  • Posts: 1255
    • View Profile
    • Email
Re: Stroke Rate for Distance
« Reply #103 on: May 21, 2018, 05:54:50 AM »
Interesting. What characteristics of fins do you think assist/resist drafting?

It's no so much that but if you're going to be paddling alone in a race, the water will be calmer so you could go for a less stable and faster fin. In a bunch race it might be different and you might want a little more stability (coupled with the ability for the race to see more drafting so therefore be shielded more often therefore making your hydrodynamic optimisation less important).

I know there has been some discussion about the Allison fin concepts* resisting drafting. I've only got anecdotal feedback of some friends trying to draft me on my board in training when I use that set up but I personally think this effect has been exaggerated. Paddlers of a similar ability to me be seem to be able to cope with it but granted, it does create a quirky wake.

*(by the way, I'm still waiting to test that set up but the usual prevailing westerlies haven't been in evidence so far this year with our current warm weather)
« Last Edit: May 21, 2018, 05:57:28 AM by ukgm »

yugi

  • Cortez Bank Status
  • *****
  • Posts: 2228
    • View Profile
Re: Stroke Rate for Distance
« Reply #104 on: May 21, 2018, 05:58:04 AM »
So. What characteristics of fins do you think assist/resist drafting?

 


SimplePortal 2.3.7 © 2008-2024, SimplePortal