Turbo Vado 2 4.0 or 5.0 or 6.0?

[mschwett]

A little more context.

Here's the individual chart for 40/100 with all records where Cadence and Pm and Pr are >0
View attachment 205986

And here's the chart with records where cadence > 59.
View attachment 205987

These charts were done in LibreCalc. It did the best fit linear trend lines. For the combined chart above I estimated the Pmax to be 380 since it’s a good assumption that Pmax does not change with Pr.

nice

the 1.6x is a bit higher than you’d expect 40% ease to deliver on an SL2, and it’s quite linear. “2.7x you” at 100% ought to be more like 1.1x you at 40%, but you’re seeing 1.6x. if the numbers are electrical, that’s really 1.3 and not so far off.

 

[mschwett]

Boost ratio and Pm as a function of Pr
View attachment 205988

ok, this starts to explain things. toss all the values where Pr is < 50 or > 200, they’re likely not steady state values in this sample set and there is enough delay in the motor starting and stopping that the values on the edges of transitions are just noise.

i’m betting it’s much closer to the predicted 1.4 ish electrical….

 

[Jeremy McCreary]

It's with some concern that I post this chart as it refutes my whole understanding of how the xx/xx and xx/100 tunes work.

Ditto.

I rode up and down the same street in approximately 1 mile laps in 20/20, 20/100, 40/40, 40/100, 70/70, 70/100 and 100/100. The chart shows Pm as a function of Pr for each segment. The resulting .fit file had 1880 records after I removed each record with cadence < 60. Admittedly these are still very limited rides and I'm not strong enough to pedal at much more than 200 watts for more than a few seconds at a time so there's not any data at higher Pr values. The chart lines end at the highest Pr I achieved at each tune setting.

Nice work. Thanks!

This chart was created using the slope and Y intercept from the linear trend line up to the clear inflection point when Pmax was reached.


View attachment 205980

I had expected XX/XX and XX/100 to have the same slope but the XX/XX curve to go flat at a lower Pm value (the saturation point we've bee talking about). Not so in any of the tunes. In each case XX/100 has a significantly steeper slope than XX/XX.

Tested the four X/X runs by visually estimating the Pm values at Pr = 50, 100, 150, and 200W. As you stated, the slopes of the ramps up to saturation are NOT proportional to X. Above X = 40, slope growth with X is significantly faster than linear at every Pr.

At least it's nice to see that the ramps are straight lines.

I expected the inflection points where Pm=Pmax to occur at the Pr values given the Specialized table showing Pr to get Pmax in each tune.
Tune____________Pr to get Pmax._____
_____________Spec table_____my data____comment
100/100_________85___________70_______pretty close
70/100__________268__________170______way off
70/70___________185__________200______pretty close
40/100__________436__________250______way way off

My simple Pm model based on earlier Spec documents predicts that SL 2 saturation should always occur at 139W in any X/X mode. Nothing like in either your data or Spec's recent SL 2 saturation tables.

Don't see any way to salvage that simple Pm model at this point. Hence, the underlying Spec documentation was pretty misleading. Will have to put up retractions on the old posts where my model was introduced.

I'd love for someone else try a similar exercise and see how your results compare.

Happy to help but have to get my !@#$^&*! bilateral plantar fasciitis under control first. Still riding in moderation with permission from doc and physical therapist, but high pedal forces definitely stir things up.

 

[mcdenny]

ok, this starts to explain things. toss all the values where Pr is < 50 or > 200, they’re likely not steady state values in this sample set and there is enough delay in the motor starting and stopping that the values on the edges of transitions are just noise.

i’m betting it’s much closer to the predicted 1.4 ish electrical….

By eliminating all the cadence < 60 records most of the low Pr records are gone too.

For 100/100 slope is 5.5, cutting 20% to get mechanical power would make it 4.4. Seems unlikely though it would be "4.4 times you."