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.
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.
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.
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…
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.
@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).
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).
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.
Yup.
Speed = wheel circumference x wheel RPM x unit conversion factor
Wheel circumference for 700c/20mm wheel is 2.086m
More
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
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!!!
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.
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
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
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
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 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.
Are you on blue blocks post injury/ illness? Or just part of your training plan(s)?
Post surgery I had 4 weeks off the bike (started core/ strength at 2 weeks) then:
2 weeks recovery rides (or very low Z2)
4 weeks Base Block - 3:1 moderate volume (manually adjusted FTP down 10%)
1 week Half Monty + a few others
4 weeks Base Block - 3:1 High volume (new FTP)
(so I’ll correct my arithmetic - 11 weeks )
By the last 2 weeks of the second Base Block I knew fitness was returning (the Tempo efforts keep you honest ). I also knew I was feeling better because I was getting so bored - I was hanging out for the little “blips” in Recharger, let alone the slightly bigger ones in Tapers and Primers.
Whether injury, illness or planned, hang in there with the blue blocks - I have no doubt they’ll fare me well for our longer (100km+) group rides, even if I’m not yet back to form on the climbs (I’m a lightweight so look to these not to be lost by the group ).
5 minute power down 1 watt from March and 20 minute power down 13 watts from March.
Back in March I was ramping up for the racing season at the Velodrome and had come off the Winter training for the hour record at my Velodrome. Since the beginning of September (rotator cuff injury) I was “J.R.A.” and not doing too many structured high intensity workouts (or racing, season ran until mid-October).
The 7 second power is always off about 10-15% since I have a dumb trainer (wheel on, fluid trainer) and you just can’t generate 1000 watts on that setup.
So my FTP is higher than I was expecting.
The cortisone injection worked great for the pain and my physical therapy has gone very well. I am probably back to about 90% strength on the shoulder.
Thank you for asking!
This one is so difficult… After the first surge my power dropped below MAP and it took everything to bring it back up.
). I also knew I was feeling better because I was getting so bored - I was hanging out for the little “blips” in Recharger, let alone the slightly bigger ones in Tapers and Primers.
).