Zwifting - I think I need help!

[sizbut]

"For riding on the flat, it's better to be bigger." - In what way?

[LittleWheelsandBig]

Lower watts/kg needed for a given speed because more total watts produced. grams already explained it. Not many folk produce >5 W/kg for extended periods. Lots of people can do 3 W/kg.

[drossall]

Did anyone try TdZ stage 7?

I used a gravel bike - I bought the Cervelo Aspero specially for that kind of thing. I've never bothered with the mountain bike, and I'd forgotten that I'd got one. I'd seen it said that road bikes weren't ideal for the jungle - I did it on a TT bike once by mistake -  but it only looks slightly rough to me and something that a decent steel road bike would take in its stride. Certainly hadn't occurred to me that it would actually need an MTB. I am a road rider, but I do have a real MTB, so I've no particular objection to them - I just thought it was atom bomb and canary territory.

On the Fondo today, people were swapping bikes for the jungle section. I've never bothered with that either. I suppose I should, but really, swapping bikes in a sportive? So I just rode a road bike. Not sure how much difference it made really.

I've got to repeat the TdZ stage tomorrow - my connection failed and I lost the ride, after I got on-screen confirmation that I'd completed it, so maybe I should try a different bike.

[sizbut]

Lower watts/kg needed for a given speed because more total watts produced. grams already explained it. Not many folk produce >5 W/kg for extended periods. Lots of people can do 3 W/kg.

That's assuming that bigger automatically means more power - enough to neutralise the weight/aero disadvantage and then some to spare. Sadly that isn't true. I'll agree that a bigger frame on which to attach muscle and lever them provides the potential for more power - but it's not automatic. I'm the same size and weight as Andre Greipel but can't manage even half his peak power. I wish.

I know a superbly fit 100kg Zwifter, every inch of his body is finely honed muscle - and on anything beyond a 100 metre sprint my 85kg flab wins because all I have is leg muscle, not the extra 15kg of huge arms, abs and pecs.

Size a rider can't do much about apart from good aero, but weight they can. For any rider, reduce weight equals go faster. Yes, there are limits. In G's last book his discusses the difference between his track weight and road weight. He also mentions discovering his weight limit, the point at which lossing any more weight causes a power drop - presumably the point at which he's lost everything else that isn't muscle.

The working of size and weight can at least be modelled. Doing the same for the human body and power is much harder, much less predictable and absolutely not guaranteed.

ps. the average weight of the UCI pro peleton in 2017 was 70kg, but I guess they don't know anything.

[TimC]

The physics of Zwift is hugely simplified compared to real life, and makes several assumptions in its calculations of how fast you'll travel for a given power, weight, height and gradient. However the assumptions are consistent across all users and, knowing that, certain statements can be made. One is that a 100kg rider at 3w/kg on the flat will always outpace a 60kg rider at 3w/kg. there is a crossover to an advantage for the lighter rider on a hill, but you'd need to experiment to establish exactly where it is.

[LittleWheelsandBig]

When the Team Time Trial was country-based, rather than trade team, there were four-man teams over 100km dead-flat with a minimum of three finishers. After a few years, winning teams ended up almost always being >180cm and >80kg. Pure horsepower folded into an aero position. If being smaller and lighter was an advantage over extra power in that event, the team riders would have been <170cm and <65kg.

Given the amount of climbing in the Tour de France and the daily time limits, there is a strong selection pressure for lighter riders. That doesn’t apply to riding Dutch and Belgian kermesses and American criteriums, where big strong riders prosper.

You can point out instances where outliers confound the trend but the trend exists. Bigger is usually stronger and stronger is usually faster on flat ground.

[grams]

The physics of Zwift is hugely simplified compared to real life [...] One is that a 100kg rider at 3w/kg on the flat will always outpace a 60kg rider at 3w/kg.

Noooooooo..... this holds true in real life too!

Let's look at these numbers again:

• 100kg: 334W
• 85kg: 325W
• 70kg: 314W
• 60kg: 312W

Despite the huge variation in weight, they're barely any different. On a flat road, 300-ish watts gets you 40 km/h, no matter how much you weigh.

[DuncanM]

Or you could look at the worlds TT. https://en.wikipedia.org/wiki/UCI_Road_World_Championships_%E2%80%93_Men's_time_trial
Filippo Ganna = 82kg.
The only ones under 70kg were Wiggins, Dumoulin (both listed at 69) and Jaja way back when (and in San Sebastian when it was quite hilly).
Or Paris Roubaix - long and flat. The only rider in the last 30 years to list under 70kg was Philippe Gilbert at 69kg but he's clearly the outlier (both Boonen and Cancellara weighed >80kg and the heaviest is Backstedt at 94kg!).

In general, especially if it is hilly, a lighter rider is more likely to win, but on flat ground, absolute power matters more than weight. The link posted to the equations demonstrates that, on the flat, weight is only a factor in the drag caused by rolling resistance (assuming CdA stays the same). So if you are training a general cyclist, you might want them to lose weight up until the point where they lose power, but if you were training someone to ride on the flat, power is more important than weight and that's where the focus should be (which is why the track team didn't care about how much G weighed, only the amount of power he could generate).

[sizbut]

The physics of Zwift is hugely simplified compared to real life [...] One is that a 100kg rider at 3w/kg on the flat will always outpace a 60kg rider at 3w/kg.

Noooooooo..... this holds true in real life too!

Let's look at these numbers again:

• 100kg: 334W
• 85kg: 325W
• 70kg: 314W
• 60kg: 312W

Despite the huge variation in weight, they're barely any different. On a flat road, 300-ish watts gets you 40 km/h, no matter how much you weigh.

No. The figures show the heavier ride having to waste 6% of their power just to stay equal. Over an hour plus race, that's a lot of extra energy to find.

[sizbut]

I quoted average weight of the whole UCI pro peleton. If you want to selectively sample individual  examples from individual races that fit your argument that's poor science.

[DuncanM]

What relevance does the weight of a pure climber have to flat racing? On the flat, they spend all day hiding in the bunch and hoping to hell there are no cross winds because their relative lack of power will screw them over in echelons.

You don't think a 100kg rider has >6% more power than a 60kg rider (at the pro level)? If you are 100kg cyclist, you're not someone carrying a big upper body around, you are just a huge individual, with giant lungs and legs.

[citoyen]

I quoted average weight of the whole UCI pro peleton. If you want to selectively sample individual  examples from individual races that fit your argument that's poor science.

I don’t know about the science but I know I would never put money on Domenico Pozzovivo to win a flat time trial.

[morbihan]

I might be able to help solve the conundrum.
Im into a block of climbing at the moment as training for TCR.
Im currently doing steady rate climbs with my real weight plugged in.
I'll be switching the weight up in the coming days to simulate bike luggage and ride at the same steady/endurance rate.
I'll note the different times up Alpe Du Swift etc.

[TimC]

The physics of Zwift is hugely simplified compared to real life [...] One is that a 100kg rider at 3w/kg on the flat will always outpace a 60kg rider at 3w/kg.

Noooooooo..... this holds true in real life too!

Let's look at these numbers again:

• 100kg: 334W
• 85kg: 325W
• 70kg: 314W
• 60kg: 312W

Despite the huge variation in weight, they're barely any different. On a flat road, 300-ish watts gets you 40 km/h, no matter how much you weigh.

No. The figures show the heavier ride having to waste 6% of their power just to stay equal. Over an hour plus race, that's a lot of extra energy to find.

We seem to be talking at cross purposes. Remembering that it's Zwift, not RL, we're talking about, W/Kg is the de facto comparative measure used in-game. Race categories are divided by W/Kg, group rides are defined by the target W/Kg, and so on. Although imperfect, it's the most effective way of categorising riders in the game. An FTP of 3W/kg is probably a reasonable dividing line between the amateurs, like me, and the people who take it a bit more seriously. 3 W/kg for me is 285W right now, and that's well beyond my virtual FTP. Yet I can fairly comfortably (FACV of 'comfortably') put out 1000W for 5-10 secs or so on a sprint. So I ride in 'D' Cat rides, have no hope of winning any races whatsoever, but can place pretty high up in sprints whatever the category.

In real life, my FTP is a bit higher than it is on my Tacx Neo, and my peak sprinting power is much the same, but I wouldn't expect to get anywhere near the younger, lighter riders in any competitive aspect. Which is why I never race in any form, and rarely (even in normal times) ride with other people. There are basically a lot more factors at play than there are in the game - one being I don't care enough to push hard outside! And I'm ancient.

[L CC]

There isn't a conundrum to solve. It is a fact that it is a lot easier to find 100kg riders who can put out 3w/kg than 70kg riders who put out 4.2w/k and for women weighing 50kg (there are a lot of those in Zwift) putting out 6w/kg is dream time.

Up hills, being heavier is a disadvantage. No one is disputing that.

I regularly place higher in virtual races against women who put out more w/kg than me, because I put out more watts. As long as it's fairly flat.

Perhaps we should race - my 2w/kg will beat sizbut's 2w/kg on a Tempus Fugit TT because it is flat and my watts are higher. I also have an advantage being female and 160cm, Zwift knows I am built like a cannonball and makes me slippy.

[TimC]

I'll race you, fboab! For 100m, perhaps. Then I'll be back to 'hello sky, hello, sea, hello sloth (wtf is a sloth doing on a phone wire?)' and enjoying myself. Somewhat.

[Asterix, the former Gaul.]

Since I got my first HRM I have had a look at my fellow 'rode withs' just to make sure I am 'normal'!  (someone who passed me going up got 100km/h on the descent, must have tall gears!)

The HR variations are considerable and sometimes someone hits a high but the power output doesn't seem to match.  There can be quite a large variation between riders' average HR for much the same performance.  My average is between 146 and 150 over a longish ride with a peak of 169/170, over 220-age, but I feel ok with it.  I rarely race people, only myself!

Using HR as a training aid is not something I have really grasped!

[gibbo]

I'll race you, fboab! For 100m, perhaps. Then I'll be back to 'hello sky, hello, sea, hello sloth (wtf is a sloth doing on a phone wire?)' and enjoying myself. Somewhat.

I'm concerned for the wellbeing of that sloth since I've ridden past it many times and it hasn't moved. I reckon it may have died and rigor mortis has set in leaving it hanging there.

Just a thought.

[Legs]

I thought I was being really clever when I tweaked the gearing on my 9spd hack bike to help my climb real-life Staffordshire hills with my son in the Hamax seat.  I mishmashed myself  a 13-14-15-17-19-21-23-25-28.  It was fine for riding on the road, but since I've moved that bike onto the Tacx I've realised that I keep really wanting 53x16!  Back to the shed, methinks - I can definitely ditch the 28T!

[L CC]

Since I got my first HRM I have had a look at my fellow 'rode withs' just to make sure I am 'normal'!  (someone who passed me going up got 100km/h on the descent, must have tall gears!)

The HR variations are considerable and sometimes someone hits a high but the power output doesn't seem to match.  There can be quite a large variation between riders' average HR for much the same performance.  My average is between 146 and 150 over a longish ride with a peak of 169/170, over 220-age, but I feel ok with it.  I rarely race people, only myself!

Using HR as a training aid is not something I have really grasped!

As I'm sure has been covered umpteen times before- 220- age only works on a population level; and what HR vs Power looks like is only worth comparing between your own performances not next to anyone else's. The other thing is cadence- that high cadence all the plans want cyclists to do 'for efficiency' raises your heart rate more than mashing.

(Generally anyone quoting the 220-age thing always comes out with "mine's much higher than that; I'm amazeballs". Just as balance; I think my HR makes me 70  )

[L CC]

I'll race you, fboab! For 100m, perhaps. Then I'll be back to 'hello sky, hello, sea, hello sloth (wtf is a sloth doing on a phone wire?)' and enjoying myself. Somewhat.

I'm concerned for the wellbeing of that sloth since I've ridden past it many times and it hasn't moved. I reckon it may have died and rigor mortis has set in leaving it hanging there.

Just a thought.

It probably died from all the riders whacking it trying to give a high 5 as they ride past..

[Asterix, the former Gaul.]

Since I got my first HRM I have had a look at my fellow 'rode withs' just to make sure I am 'normal'!  (someone who passed me going up got 100km/h on the descent, must have tall gears!)

The HR variations are considerable and sometimes someone hits a high but the power output doesn't seem to match.  There can be quite a large variation between riders' average HR for much the same performance.  My average is between 146 and 150 over a longish ride with a peak of 169/170, over 220-age, but I feel ok with it.  I rarely race people, only myself!

Using HR as a training aid is not something I have really grasped!

As I'm sure has been covered umpteen times before- 220- age only works on a population level; and what HR vs Power looks like is only worth comparing between your own performances not next to anyone else's. The other thing is cadence- that high cadence all the plans want cyclists to do 'for efficiency' raises your heart rate more than mashing.

(Generally anyone quoting the 220-age thing always comes out with "mine's much higher than that; I'm amazeballs". Just as balance; I think my HR makes me 70  )

Maybe, but really I have never taken much interest in such things before I started getting stats from Zwift.  I've never been a competitor in any kind of race since my schooldays, cycling or otherwise. 

Clearly the 220-age thing is quite useless.

As far as cadence goes, my average is invariably c.70 for some reason.  However I can't believe the figures when I do the steep climbs and get onto the lowest gear.  It says I am doing 30-33 when the whole point of shifting down was to keep to 60-70 which is what it feels like. My last ride at one point -a very steep incline - it says I am getting 191 watts with a cadence of 31. That rpm seems most unlikely.

[Asterix, the former Gaul.]

I'll race you, fboab! For 100m, perhaps. Then I'll be back to 'hello sky, hello, sea, hello sloth (wtf is a sloth doing on a phone wire?)' and enjoying myself. Somewhat.

I'm concerned for the wellbeing of that sloth since I've ridden past it many times and it hasn't moved. I reckon it may have died and rigor mortis has set in leaving it hanging there.

Just a thought.

I was pleased to spot the Pterodactyl recently and also the warning sign about the Yeti.  I never saw it though.

[drossall]

I've got to repeat the TdZ stage tomorrow - my connection failed and I lost the ride, after I got on-screen confirmation that I'd completed it, so maybe I should try a different bike.

I did repeat it, and was much faster on the stock Zwift MTB than on the posh Cervelo gravel bike. Not sure why, except that Zwift physics makes it that way

[chrisbainbridge]

Stage 8 was fun. Laps of London doing 35-40kph in the he bunches for 170W.
And a PB on the course seemed to get me 250xp as well.

I am strangely enjoying it.