Beneficial Ear

What an eye opening experience, not going to win many races at 3.6 w/kg average for an hour. I'm not sure of the accuracy of my new Elite Crono in/out trainer, but the wattage ratings are in-line with the estimates from my actual rides plugged into bikecalculator.com.

On that note, this is @ 190lbs.. I'm down from 207 earlier this month, and am far from "leaned out" (6'/6'1")... with diligence I think by May I can hit ~170 and be producing more power, 4.5 w/kg is very within reach - at least in my mind . I've only been... err.. commuting quickly? for about 6 months. The trainer should ensure I get a bit more structured, there is only so much that can be done in traffic (be it cars or a packed trail).

An excellent feature of this trainer is the computer can be used as a regular bike computer as well! No Ant+, but it has speed and cadence - cadence being something I didn't have before. This reading VERY MUCH helped me to maintain power, I could feel the struggle starting below ~70rpm, and the maximum efficiency ~90... having a number to stare at helped keep me in line for sure. What a joy to work on these things and not worry about freezing to death or getting run over!

I was hoping to be magically farther ahead than I thought, but this is a great baseline to establish - I hope to post in this thread in a few months having realized my goals.

RedVVing19

Right......

simonaway427

310 watts for an hour? Pretty darn good for a "commuter"

pdedes

My one way commute used to be 40km. You can get fast putting 400 km a week commuting.

rbart4506

The Elite Crono numbers are way out...It's all based on speed and your weight factored in...

My wife had one and then got a Powertap. Hate to burst your bubble, but you aren't putting out 3.6w/kg. Once she started riding with the Powertap she discovered that she had either quickly developed a case of the suckage, or her Elite Crono trainer had been lying...I voted for the latter

The only way to get reliable power numbers is with a tried and true power meter....

gadabout007

Exactly! I just signed up for Trainerroad a few weeks ago and am loving it. I use a powertap with my ftp set to 238 2.9W/k and struggle with some of the longer 3+ minutes at 115% intervals. My buddy who got me interested in trainerroad uses an elite mag trainer and virtual power has his ftp set to 210 and is able to complete the workouts. Out on the road I'd guess his ftp is somewhere between 175 - 190 watts... and I think I'm being generous with those numbers. He's also bragged to me that he's been able to complete 32 kilometers in one hour on the trainer. When I rode with him this past summer we completed 80 kilometers in about 4 hours and he was a complete mess at the end. His fitness has improved quite a bit and he's lost some weight since then, but not that much.

This is entirely my opinion, but all these estimated power tools aren't all that bad provided the threshold number that they give you is static and can be replicated over and over in a training environment. Even if the number is grossly exaggerated you have a number that you can train with instead of just spinning your wheels and not improving.

Beneficial Ear if you're serious about training/racing, you should probably look into a real powermeter. Powertaps can be found for less than $1,000 on ebay. You can also do a 20 minute ftp test on a computrainer with these folks in Chicago https://ffc.com/computrainer/ for $25. I'm sure it will be a humbling experience given the numbers your trainer is giving you.

jsutkeepspining

power number's given from trainers are generally junk. There are too many variables that can affect the number (tire pressure, how hard the thingy is clamped, ect). I rode a tacx genius one time. I was putting out 300 watts while rolling at 250 from my quarq. Using a power number from a trainer to plan training isnt good, but it isnt terrrible at the same time, but trying to say my ftp is x because my trainer said it is is complete junk.


I think i could be a pro cyclist by using the ftp number's from all these softwares that make up your power numbers.

Bah Humbug

They're better if you are consistent with setup. I always inflate the rear to 120psi and use five full turns of the knob on my KKRM, and that takes away much or most of the variability.

hhnngg1

Gotta take the TrainerRoad numbers with a grain of salt, often a big one for accuracy, but they're great for reproducibility. As long as you want to improve and not compare who's is bigger than who's, you can't go wrong with TR, even with a trainer that has numbers really off from a real powertap. You make that number bigger for longer, you're getting stronger and adding more stimulus.

I'm in the process of comparing a brand new Powertap wheel numbers to my TrainerRoad numbers on a Cycleops Fluid2, and at least for me, they're very similar, like 10 watts off, but I haven't done a full 2 x 20 min power test yet. Either way, I was surprised that I could hold 300 watts on the Powertap pretty readily - tried it on some short intervals so far (literally got the wheel on Friday) and it feels identical to the Trainerroad number. I have to fix a cassette issue but will chime in again later with some real tests.

Either way, Trainerroad is legit. I did a test outdoor ride with my Powertap yesterday with 6500 feet of climbing over 50 miles and I was fine for the entire ride, no bonking, and even still going strong at the end. I have done only ONE outdoor ride since mid-November, and it was a flat 30 mile ride with 400 feet of climbing. ALL of my bike ability since then has been Trainerroad (ok, I do a fair amount of running as well, but we know how that doesn't overlap much once you're going the elevataion/distances I'm going) so you can def perform well just by TrainerRoading it.

But yeah, forget about your absolute W/kg to compare to the charts unless you're on a true powermeter device.

jsutkeepspining

now the real question is what was your np we got to either laugh or congratulate you on ur weak or killer w/kg

Beneficial Ear

Power is really easy to calculate, dunno why it would be so far off? I could see perhaps if I used the standard wheel size given in the manual, but I used the Sheldon Brown formula - which has proven dead accurate on my Sigma... this number is lower/gives lower speeds than what is in the manual (humbling when I figured this out a month or so ago!).

In questioning the accuracy I realized that my scale shouldn't start at 4lbs, so I zero'd it out and viola now I'm actually 186, which is a wonderful thing, this makes my 180 goal so close! But, it means the weight I inputted of 214 (accounts for bike) was probably too high.. but it may not have been as I have a steel bike with lightweight nothing + a heavy lock/chain attached to it. I changed it to 210 and will have to redo the baseline tests again today.

I've definitely heard of inaccurate readings from trainers... but its also a consensus that if tire pressure stays consistent the readings will at least be consistent amongst the trainer itself. If it can A: stay consistent, and B: I can alter the variables (calibrate)... I should be able to get it accurate if I can get some sort of a reference, correct? I'm in a city full of computrainers, would it be safe to say if I can hold ~300 watts for an hour on one of those thats about where I'm at? I plan on renting an hour next week when I head to northside (one of the commutes that puts me in the ~50 mile range).

With that said, I just want to use this as an accurate training tool... bragging rights come from races, and I haven't entered one yet so there is nothing I can say

Beneficial Ear

What is np?

I thought this number was kinda low, which in my eyes made it reasonable... but maybe I'm finally finding good use for my disproportionately large legs? Or I'm actually making 200 watts, lol...

Btw my "commute" routinely takes me in the 50 mile per day range, and I treat stoplights as intervals whenever I'm not dead tired... this typically is with 15lbs (drill/batts/handtools/shoes/groceries) of stuff strapped to my back in a bookbag that becomes almost like a parachute in a crosswind. Also I was ~205 earlier this month so perhaps this plays into things as well?

Dunno, I just wanna ride with someone who's fast... cuz obviously everything else is just speculation

Beaker

There are a lot of variables that make comparisons between trainers and between trainer rides and road rides difficult. I used trainer road extensively last spring/summer while getting over an injury. I quickly realized that based on numbers from my PT that my indoor FTP was 5-10% off what I could achieve outdoors due to a bunch of reasons (such as temperature control, lack of momentum etc.) - this is quite a normal phenomenon from what I have heard and read. The other big intrinsic variable is how much load you put on the rear wheel for each workout, do you crank down the rear wheel the exact same number of turns each time, or go by feel?

Having said all that, I agree with your thinking - using your trainer power as an internal benchmark for training is solid. It is different than an outdoor FTP determined with a power meter, but that shouldn't affect your ability to train/retest on the trainer.

Beneficial Ear

My trainer uses gravity to hold the rear wheel down, hopefully this isn't a dealbreaker? I do make it a point to stay seated and consistent as much as possible, just standing momentarily for butt relief.

I suppose I can't get too emotional about these readings, beyond some sort of measurable gain - however accurate it may be.

On that note, I'm gonna hop back on and mess around with it some more right now . Its amazing to not have to stop after X time due to outside forces, regardless of numbers I'm sure this is good for overall fitness and will help me keep up with the fast group rides/races in the upcoming season

jsutkeepspining

in terms of accuracy compared to a real power meter its any where between 100 watts high or a 100 watts low. It will be consistent (so if you keep everything the same you will be able to train using power from that trainer). Where does it put you: idk too many things to take into consideration. there are guys with 200 watt ftps that could beat u in a race and guys with 400 watt ftps that could as well.

jrobe

If you want to "train with power," you need a tool that accurately measures power. End of story.

hhnngg1

The accuracy of calculating virtualpower depends largely on how reproducible your trainer's resistance is from unit to unit so it can be computed. For most trainers, that's actually a very big, variable range.

Tire speed alone on a trainer means squat without a power curve to match. Think about it - take of ALL the resistance from your rear wheel on rollers/trainers, and you'd be able to spin it at ridiculous rpms with minimal watts. The Sheldon Brown formula is ONLY accurate provided that your trainer exactly matches the exponential acceleration curve of a real-world flat road, which in the vast majority of cases, is false. (THe KK and Cycleops Fluid attempt to do this, the KK apparently does it pretty well.)

If you can borrow someone's powertap, you can in effect make your own power curve as long as your trainer provide the same resistance from session to session. Other than that though, it's a crapshoot at best.

And lastly, if your trainer says you can hold 300+watts for an hour+, but you haven't raced yet, there's a 100% chance that your numbers are total crap. Some state TT champions who average 27+mph on a 40k TT, do it on a steady 300 watts/per hour of effort. I somehow doubt you're that strong unless you're a competitive racer.

jsutkeepspining

now i've also heard of people who said the KK was reading 40 watts high compared ot a well calibrated ptap.... *innocent whistle*

Beneficial Ear

The Sheldon Brown formula I was referring to is only referencing the wheel size, not sure what formula you are referencing?

Today tire pressure is within 5 psi of yesterday. I lowered the weight to 210, which should *lower* the readings maybe 2% if my understanding of weight/power calculation is right?

@ yesteday's "optimum" cadence of 90 i was in a good "i can do this for an hour" zone @ around 300 watts. After upping the cadence to 100 and cutting out the bouncing I hit 417 average watts for 20 minutes after a ~20 min warmup. I doubt I could pull this for an hour - confidently 30 mins, 45 if I went total noodle legs at the end, but in the last 60 seconds I went to the smaller cogs and ended up with a max of about 600 watts, averaging about ~525 for that last minute.

After a cooldown I did some "all out" tests and got it up to 878 watts which I held for maybe 10 seconds (I wish I had a vid of myself I was makin male porn actor faces the whole time lol)... and I hit a max cadence of 172 rpm, which I held momentarily after setting at 150 for a few seconds... and with the resistance set at 1 (which reports a -1% "grade) I put it in the 50/11 and spun the rear wheel up to "50 mph".... and could have gone faster but if this bike fell off the trainer at that point I would have gone flying through a wall.

I know the only "legit" thing is the cadence, thats obviously easy to measure and probably 1% accurate... with that I'm kinda amazed I can hit 172 at all!

One curious thing, the "grade" on the computer goes down as I keep up the power... and returns after I rest for a min. I *think* its accounting for heat generation. On that note, aside from a few "hill climbs" in the 20 minute test where I bumped it up to 4 and 5 resistance, the reported grade was around 1% @ level 3, tailoring off to about .7%... to me this feels more like fair day road riding on smooth pavement than any other setting. For the max power test I put it on level 6, which is TOUGH, but its the only resistance I could utilize my biggest gear on + put down some real power without having to spin at stupid high cadences.

And for at least 15% of all the above I was deep in the drops to make it a bit more realistic.

Even if this thing is off in lala land my FTP should still be at least 300 watts? Maybe the 100-200 miles a week all winter in a heavy jacket/layers and layers of pants (typically long johns, pajama pants, then khakis) + a puffy 15lb or so bookbag has paid off? Could it be the vegetarian diet, of which I've recently gone as organic as I possibly can and gotten into the Garden of Life Raw Meal stuff? My legs are disproportionate to the rest of me, and after many teenage years of focusing on dunking a basketball (which I was pretty good at!) and doing very little upper body workout, this has stuck with me (i'm 27 now, btw).

I know this is all "bench racing" and kinda moot until I'm in a race... but what is life without speculation????

But now that I've made these claims... and however uncomparable to the outside world they may be... where can I go and get official/repeatable/accurate numbers while its all snowy/freezing outside? Is a computrainer gonna have the same overall issues?

My "real world" goal is 25 miles in one hour... numerically speaking me + aero I'm pretty dam close, 2 more months of training and unless I'm at my peak I should definitely be able to do it?

DaveWC

It makes no sense to acknowledge that perhaps all of your power measurements are meaningless and then say that they could still indicate an FTP of X watts. If they're off, they're off and they indicate nothing. What difference does the FTP# mean in this case anyway? Unless you plan to train with power outdoors the method you're using to guesstimate FTP doesn't matter and won't be something you can do anything with when you return outside.

jsutkeepspining

yeah the 400+ watt for 20 min thing strikes me as a "this trainer's wattage readings are gibberish". Don't bother worring about wattages. Really too many people try to find out how strong they are without any real chance of figuring out how strong they truely are. It's just like how everyone before they owns a power meter beleives they have a 300 watt ftp, then they test witha powermeter and they are in the low to mid 200's. Just to put it into perspective. I'm fairly strong, ftp is 350 and my peak 20 minutes is 370. Now the trainer might be givign u good information, or it could be completly false. If you really want to see how strong you are either ride witha group of fast riders, go do a test on a computrainer (only one that is 1.5-2% accurate), or use a real powermeter. The elite is like 300 dollars, so im guess its complete crap in terms of power readings.

also for the goal, during my ftp test sitting on the tops and hoods i averaged 26 mph (read very un-aero), so you dont need that much power to go sub hour on a 40k tt with aero stuff. Not to crush your dreams, but your ftp is probably somewhere in the 100-300 watts (probably not on either of the extream sides).

Perp

Just curious on your weight. I rode with a local pro, who's at 5.2W/kg and it's humbling how much faster he can climb.

To be on topic, my FTP on a computrainer was 256W (3.8W/kg). FTP on cyclops Fluid 2 trainer seems to be 263 (Although I'm a bit heavier now and not in as fit as when I did the computrainer test.). The road race I peaked for last year, the winner had a higher W/kg for the entire race compared to my FTP! At least I lasted 3 hrs before getting dropped from that group lol

jsutkeepspining

155

Beneficial Ear

I'll schedule 1 hour of computrainer time for next week. By then I should have improved my form a bit, gotten closer to my ideal cadence, and should be fractionally more fit.

Dream crusher or eye opener it'll at least serve to get a good baseline I can compare accurately to in a month or 2.

186lbs, 417 watts @ 20 mins... 4.9 w/kg... I see why it sounds a bit outlandish

gsteinb

I thought you pushed two bills?

shrug. Maybe you need to calibrate your PM? If you're riding around at 270 watts for four hours you should probably suck less than you do.