Tacx Flux Power vs. Road power

bl0k3

Hi guys (hopefully some of you have a Tacx Flux)

I am trying to gauge my real world power on the road as I have been told trainer power can be a bit off (I can't justify a PM at the moment, however, intending to buy one in the summer).

Please can everyone post their indoor/outdoor powers (FTP) and state what equipment they are using?!

Looking to start racing in the near future but my indoor figures leave a bit to be desired... :roll:

Cheers

jgsi

Just to ease your angst, real cycle racing has damn sight lot more to do with other stuff than FTP and w/Kg.
The latter only have real significance in Zwift.
I really would not worry about it.
You get licence, you enter race... and after that it is up to you if you actually enjoy the experience.
It is not for everyone but if you are having a good day it is addictive.

bl0k3

I understand that FTP isn't the full picture when it comes to racing... although surely the higher the FTP, the lower percentage of your maximum power will be required to stay in contact with a given group.

I am more interested in hearing the experiences of others when it comes to trainer power in comparison to road power. My Zwift FTP is ~215W, although I have been advised it is likely that I can expect approx. 15% higher on the road (247W). That is a huge difference and would put me around 3.5W/kg, where I would be fairly confident in having a go at entry level racing.

imposter2.0

Most people used to line up for their first race despite having no idea what their FTP was. If you want to race - 'just do it'. Worry about your FTP after.

gethinceri

Mine’s about 10% lower indoors on the Flux.

N0bodyOfTheGoat

From my experience over the last year of having a turbo with integrated power meter (Direto in my case) and then buying a 4iiii crank power meter around April, if you regularly (at least every other day if it's your only workout) train hard around your estimated FTP on the turbo for 20min+ sessions, your body will adapt within a few weeks and your estimated FTP values will become very similar indoors and outdoors (depending on how closely your turbo and bike power meters sync).

Most recent two outdoor efforts...
https://www.strava.com/activities/17812 ... /1793/2988
https://www.strava.com/activities/18821 ... /1648/2763 (drop after illness and less cycling)

Progression indoors since getting back on the turbo in early November...
https://www.strava.com/activities/19665 ... sis/0/1174
https://www.strava.com/activities/19824 ... sis/0/1179
https://www.strava.com/activities/2004978892/analysis (just under 20mins to do the same climb as above)

So I'm now working off a rough estimate ~290W FTP, when I was ~218W back in January (while getting used to the shock of trying to judge how much power I could sustain for ~20mins; up virtual hills bigger than I have climbed in the real world; with far less air movement to wick away heat).

However, my best sustained power for an hour to date outdoors is ~255W IIRC, not helped by the rolling terrain of the South Downs with nothing bigger than a ~3.2 mile cat3 just north of Petersfield, plus the odd junction to navigate safely.

cruff

Indoor - 315 (taken from a 1 hour test on an Elite Direto)
https://www.strava.com/activities/1430391416

Outdoor - 316 (taken from a road bike ten off 332NP with Garmin Vector 2)
https://www.strava.com/activities/1008431525


In general I find I can keep a steadier cadence and effort on the turbo (obviously) but my TT bike power is lower than my road bike power cos of my position (last 25 on TT bike I did was 282 NP for 57:48 - https://www.strava.com/activities/1668303133)

Don't worry too much about the accuracy of the power readings until you can afford or justify a PM. Just concentrate on doing an FTP test and making sure you give it everything you've got, then base your power zones on that and train to them. If you eventually buy a PM, use that as the power source on the turbo instead of the trainer, do another FTP test and adjust your zones accordingly

'Racing' is a bit of a broad term as well - depends what you want to do
If you're looking to race crits, rather than worrying about power, go out and time yourself doing a flat loop on your own on a reasonably calm day. If you can average 30-32k/h for an hour you'll be fine getting round power wise, provided you can sprint regularly and recover. Most crit racing at cat 4 is positioning and not getting chopped.
If you're looking to road race, you'll need positioning, a power curve that suits the races you're doing and the right weight (I'm a fat b@stard, for instance, so I don't do hilly races).
If you want to TT, then solid, consistent efforts like over-unders are better training - but don't neglect the intervals either cos you'll make gains there too.

Midlands Grimpeur

Please can everyone post their indoor/outdoor powers (FTP) and state what equipment they are using?!

There is lots of debate about indoor power vs outdoor power due to the fact, as you have highlghted, that some people experience a discrepancy between the two (lots of debate as to why this is on other threads). IMO there is not much point in getting other people's numbers as that won't tell you if you personally have a discrepancy between your numbers, you may or you may not, until you get some data from outdoor riding with a PM there really is no accurate way of knowing whether your indoor FTP is representative of what you can manage on the road unfortunately.


As others have said you may as well sign up for a race and see how you get on as lots of other factors, in addition to FTP, will determine your ability to compete in a road race.

joey54321

Unless you know the person regularly checks the calibration (and I don't mean zeroing it) then it will be meaningless for you.

Just enter the race.