Full Frontal - The Thread

I’m in!

Congrats - also try standing starts to get an NM number. However, note the video doesn’t have the bagpipe music.

Noted, thank you. On both counts…

Just had that one laying around in the memory banks for such an occasion, @Sir_Brian_M?

:wink:

I’ve been binge watching the original series, when I’m not suffering correctly. Glutton for punishment I suppose.

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I just finished my first Full Frontal. Heart rate is back down and I can see straight. All the advice in this and other threads was super helpful as was The Knowledge podcast (especially the part about using a smaller gear for the NM intervals). I was most worried about getting the gearing right, but my nerdy calculations worked. Even though I woke up with a headache and had to wait until later in the day to SufferTest, it was a success: each time I finished an interval still turning the pedals, it seemed like a miracle. SYSTM types me a Rouleur—which I interpret as: game to ride, but broadly mediocre with no outstanding strengths.

Here are my results. Compared to my mid-plan Half Monty 5 weeks ago: FTP+13 and MAP+5. I don’t have as good benchmarks for the other metrics, but NM was better than any previous sprint effort–probably because I did those in too big a gear and couldn’t get my cadence high enough.
image

I’m a happy Sufferlandrian.

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Really detest FF but for the first time last weekend it felt like I got the pacing right. After a long season and 6 weeks of occasional riding I was expecting a fairly big drop from my last one. Not so. Slight drop in FTP and MAP but increases in the other 2.

Now on to the Criterium plan…

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Yep, I’m a member of that club too :rofl:

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Story of my life, @AkaPete :wink:

NM aside, that’s a solid performance - especially first time out the gate. I’m a “sprinter”, and still find NM to be the finickiest metric to get right.

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I had a look at your ‘nerdy calculations’ and it highlights the issue I had during my 20min effort.

My cadence was 90-92 for most of it. Ideally, I’d ride it a little higher at 95rpm. I geared down to reach a higher cadence, the cadence shot up to 98-100 with the power dropping about 15W. So that wasn’t ideal and I reverted back to the 90-92rpm.

So now you’ve triggered me in doing my own nerdy calculations… :thinking:

You may want to skip this bit

Using this graph: link as a starting point.

First I translated the x-axis to real world speed, i.e. km/h.

With that done, I found a cubic relation between power and speed in the form of:

P(v)=a * v^3 + b * v^2 + c * v
with P being the power in Watts
and v being the velocity in km/h
(there’s no ‘d’ as the power curve goes through (0,0)

For the different level modes I found for a,b and c:

Level 0 Level 1 Level 2 Level 3
a 0.0057 0.0073 0.0075 0.0078
b 0.0507 -0.0383 -0.0521 -0.0681
c 0.3332 2.6255 3.9924 5.3626

Then assuming that the speed is derived from a 622 x 23c wheel/tyre combo I calculated the power at 93 - 96 rpm per level:

Level 0

Gear: 34 50
11 349 - 381 1021 - 1117
12 275 - 300 799 - 874
13 222 - 241 639 - 698
14 182 - 198 520 - 567
15 151 - 164 429 - 469
17 109 - 118 304 - 332
19 82 - 89 225 - 245
22 56 - 61 152 - 166
25 41 - 45 109 - 118
28 31 - 34 81 - 88
32 23 - 25 58 - 63

Level 1

Gear: 34 50
11 391 - 425 1132 - 1240
12 312 - 338 885 - 968
13 254 - 275 707 - 773
14 212 - 229 577 - 629
15 179 - 193 478 - 521
17 134 - 144 343 - 373
19 105 - 113 258 - 280
22 78 - 83 180 - 195
25 62 - 65 134 - 144
28 51 - 53 105 - 112
32 41 - 43 80 - 85

Level 2

Gear: 34 50
11 432 - 468 1196 - 1306
12 349 - 377 942 - 1027
13 289 - 311 759 - 827
14 244 - 262 624 - 679
15 210 - 225 523 - 567
17 161 - 172 382 - 413
19 130 - 138 293 - 316
22 100 - 105 211 - 226
25 81 - 85 161 - 172
28 68 - 71 129 - 137
32 56 - 59 102 - 107

Level 3

Gear: 34 50
11 475 - 512 1269 - 1383
12 388 - 417 1006 - 1094
13 324 - 348 816 - 886
14 277 - 296 676 - 732
15 240 - 256 569 - 616
17 188 - 200 423 - 455
19 154 - 163 329 - 353
22 121 - 127 242 - 258
25 100 - 104 188 - 200
28 85 - 89 154 - 162
32 71 - 74 123 - 130

I was running the test on Level 3, as I was afraid of spinning out on the sprints. It was fine for the sprint. In honesty: Level 0 would have been sufficient for my strength: 50x11 at 110rpm is 1600W (still > 500W above my current sprint power)

The 20 min effort was done at 50x19 @ 90-91rpm. When I wanted to run a slightly higher cadence, I shifted to 50x22 and dropped in watts whilst increasing way too much in cadence. Looking at it now, I should run it in Level 0 and at 50x17. That should give me a good range around my expected 20min capability whilst in ideal cadence.

So long story short, I was running the entire FF on Level 3 in order to have sufficient resistance for the sprints. Turns out, I should definitely have run the steady state in Level 0.

L3? Ewww. That line goes up fast…:cold_sweat:

Yeah, it wasn’t very smart - flatter curve is much better I’d wager.

@TrapMeSuf Excellent. Love your analysis. Two comments (most people will want to skip the super nerdy second one where I refine your analysis and almost perfectly reproduce the published level mode power curves).

  1. Because the 5 second sprints aren’t steady state and start at pretty low power (recommendation is to go into them at 85-90 RPM near FTP), the actual power over the few seconds you have will be massively higher than steady state because of the acceleration. So you may be able to start in an even lower gear. While I’m a weak sprinter, starting my sprint in a gear where I do FTP at 85 or so RPM hugely improved my performance. Neal Henderson talks about gearing for FF in this Breakfast with Boz podcast. The sprint discussion starts around 10:53. The one minute effort would have different considerations since you’re supposed to surge and fade (while hanging on for dear life).
Summary

I appreciated that you used a multiple regression with up to the cubic term. That got me thinking. I know that that the power needed to hold steady speed with wind resistance (including wind created by the bike’s motion through the air) is proportional to the cube of wind-speed. So that’s the cubic term. They also accounted for grade and maybe rolling resistance which I suspect are directly proportional to speed. That would mean there’s no square term. Your square term is probably compensating in a weird way for error in reading points off the chart or just making the regression fit worse. You might get a more accurate reproduction of the power curves if you leave the square term out. But the bigger implication is that if the Level Mode Power Curves are calculated from a formula (which they probably are) and the formula deals with grade and air resistance, then the formula has just two unknowns (the coefficients for speed and speed cubed). That means we can solve the equation for each level by reading off just two points from the chart for each level. The challenge is reading the points accurately enough.

So: I got as close as I could for levels 0 to 4. Then I got graphical and overlaid the Wahoo chart on top of my chart and fine tuned my point readings until the charts perfectly overlapped. I think that’s pretty close to proof that the function just has third and first degree terms. Here are the overlaid charts. The bottom five (which are slightly darker because they are sitting directly underneath the Wahoo curves) are the ones I calculated. I got the grid to line up just about perfectly, but you can see evidence of the overlay in axis titles, the chart title, and the two legends.

I think that proves that the formula has the form: P = av^3 + cv (where v is speed) with the coefficients shown below. I just calculated levels 0 to 4 on a KICKR (using mph because that’s what the chart has and because I’m an American).
image

Notice that my estimate for “a” (coefficient for the cubic term) is essentially the same for each level. “c” increase with level because grade increases.

So now all that’s left is calculating power for each gear. You obviously have enough to do that yourself. Happily (and not surprisingly), the answers are close to yours, generally a little lower.
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Doesn’t sound so bad when you describe it like that!!

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I’m assuming you are calculating speed from the gear ratios and cadence. Can you supply that equation?

Yup.
Speed = wheel circumference x wheel RPM x unit conversion factor

Wheel circumference for 700c/20mm wheel is 2.086m

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I meant to use 23mm, which is 2.096, but had a typo. It makes little difference. I don’t actually know what Wahoo assumed when they created the power curve chart, so my gear to power calculations could be a little off. Probably not material.

Wheel RPM = cadence x gear ratio

Since the wheel circumference I’m using is in meters and cadence is RPM, I need to convert m/min to miles/h.
Meters x 3.28 / 5280 = miles. And minutes x 60 = hours. So the unit conversion factor is 60x3.28/5280 = .03727

In its full glory:
Speed = 2.086 (m/rot) x Cadence (rot/min) x Gear Ratio (unitless) x .03727 (mile-min/m-hour)

To illustrate. Assume a cadence of 85 RPM with a 50/17 gear. Then:
Speed = 2.086 x 85 x 50/17 x .03727 = 19.44mph

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10 weeks of Z1/Z2 riding (trainer only) following surgery were making me feel ummm … un-Sufferlandrian. My workouts had only blue blocks!

Well today sorted that - Full Frontal. I was determined to do it differently this time - not a big event, not a huge mash-up workout, no need to feel the Fear.Treat it as just another workout (good advice from this forum although can’t remember from who - Sorry.)

OK so I did the Prep week, made sure I got enough sleep and ate well, had my pre-event breakfast …. For just another workout.

But it wasn’t. Brutal!
Sprints OK
MAP I paced well with steady power start to finish and tasted my breakfast for a second time at the end of it (always confirms a good effort).
FTP section - same as usual: 2 minutes in I want it all to end.10 minutes in and I’m questioning why I haven’t eased off on the power. 7 minutes seems a miraculous turning point for me where I can see home. 20 minutes and I tasted my breakfast for the third time.
AC - could hardly get back on the bike let alone turn the pedals. But true Sufferlandrians do. So I did.

All but AC numbers back where they were pre-injury. FTP and MAP up from HM 4 weeks ago. Considering only blue block training/ riding for the last 10 weeks I’m pleasantly surprised. Now to work on repeated efforts! And, with recent surgeon clearance, get outside!!!

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Well done. Knock the FF beast down to size. And glad to hear your recovery is going well. Am also doing a lot of blue blocks @ present, so you give me some comfort.

“You have no power over me.” - Labyrinth

:wink:

To start the 12 week XC MTB plan with correct numbers I completed Full Frontal today.

Last April I did my first and in July I’ve completed Half Monty. So I know what kind of suffering is required, but this time I had some numbers to aim at. I even wrote them down on a post-it :blush:

I was excited about the test since July-October was focussed on running. I had 2 half marathon races in October. Somewhere I was hoping it would not negatively impact my cycling performance…

My experience per block:

NM: I need to practice this more… Still struggling with selecting the right gear. The increase of 104W is quite impressive :blush:

MAP: was able to keep a high cadence 105-110, but not reaching my Half Monty power (lost only 1%). More importantly, I turned my VO2 weakness into a strength :muscle:

FTP: a very long 20 minutes with nice cadence (90-100), but missing Half Monty power target by 4%. Here I was also missing my heart rate monitor, which was acting weird so I disconnected it

AC: my new weakness :sweat_smile: This one is so difficult… After the first surge my power dropped below MAP and it took everything to bring it back up.

At first I was a bit disappointed with FTP being a bit lower. But now I’m happy with these fresh numbers so I can work to make them better.

Question: anyone else struggling with selecting gears and level with a 1x12 MTB setup? The gaps between gears are quite big, so you really need to stick to a gear per block and play with cadence only.

@McKluit Use the same gear that you selected for the FTP. Spin at FTP at a normal 85 to 90rpm coming into the test and then accelerate to max cadence.

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