Wattage on flat vs. climbs

Anything about Power (watts)

Moderators: malfukt, Tacx support, mcorn, Tacx Moderator, Tacx Video Production

Post Reply
Posts: 5
Joined: Thu Mar 12, 2015 10:35 am

Wattage on flat vs. climbs

Post by Hauki » Thu Mar 17, 2016 1:54 pm

I have i Genius with latest software. I'm struggling to understand the wattage readings. I can maintain 260watts on flats for 30 mins. But when going for climbs (typical 4 - 6%) I have difficulties to maintain 200 watts even I'm feel working much harder. I dont have power meter to check what is the reality.

Can it be just me and the and I really can put much less power on climbs despite harder effort or can this be a problem with system/equipment and what to do?

My normal cadence in flats is 80-90 and on climbs maybe 10-15 less.

Appreciate all the help as this is frustrating.

User avatar
Posts: 1873
Joined: Sat Oct 07, 2006 9:06 pm
Location: USA, Houston, TX

Re: Wattage on flat vs. climbs

Post by ms6073 » Thu Mar 17, 2016 3:53 pm

It sounds like your roller pressure is a tad to high. My suggestion is to reduce the pressure on the roller by 1/2 turn, warmup the trainer, then perform a calibration, and then repeat the training with the climbs. Note it may also require you repeat the process in order to fine tune the calibration to get it where you want, but typically while the Genius is a very good trainer, the way inertia is simulated often makes rear wheel trainers a bit more difficult on climbs that in the real world. That is one of the reasons TTS offers the PowerMode setting to help riders in such situations during training.
TTS 4.19.1 | T2800 NEO Smart
MSI GS70 Laptop | Windows 10 x64 | Intel Core i7-4710HQ 2.40 GHz | 16 Gb DDR3 1600 MHz | GeForce GTX 870M
Samsung 32" LED TV

Posts: 5
Joined: Thu Mar 12, 2015 10:35 am

Re: Wattage on flat vs. climbs

Post by Hauki » Fri Mar 18, 2016 2:04 am

Here must be a lot of guys owning power meters. Could please share your observations. How does the power in your case compare if you pedal on flat slightly below yor ftp vs if go for climb pushing harder and hetting heart rate to increase. In what region are the power readings in your case in those two situations?

Other question, is here anybody who have been able to solve this kind od problem with your tacx?

Appreciating all comments.

Posts: 8
Joined: Wed Mar 04, 2015 4:15 pm

Re: Wattage on flat vs. climbs

Post by roarmo1972 » Mon Apr 04, 2016 3:21 pm

When climbing the wattage is much more correct. With slope 0 % and below it shows way too much.

Testruns - Genius vs Power Meter

Date Duration avgSpeed Avg HR Avg Watt
2016.01.25 01:03:56 37,76 152 255W - With Power Meter
2015.12.14 01:04:22 37,51 128 303W - Genius Watt

With power meter I couldnt keep the wattage, even with much more heartrate.

Posts: 43
Joined: Tue Dec 01, 2015 3:43 am

Re: Wattage on flat vs. climbs

Post by EHB » Fri Apr 08, 2016 5:40 pm

I have made many comparisons between a Tacx Bushido Smart and a Power2Max crank power meter

My conclusions are that
1) the Tacx takes a long time to warm up (12-14 minutes) after which it it's accurate. It also cools down quick
2) it is not specific wattage or gradients that are a problem. I regularly train at over 400W. I can't do much more than a minute at over 500, but that seems okay too. I have also tried high gradients and it is fine if you maintain a cadence greater than 80ish
3) what it doesn't like is slow cadences. It is much harder to maintain an endurance zone wattage at 50rpm than at 110. The increased hardness is not because of an increased power error as the real PM is still low. It is just RPE and HR hard. I personally think it is because of the inadequate handling of simulated inertia at low cadences.

It is obviously not good as you've paid for a trainer that can simulate certain gradients, although if you look at the Tacx graphs on their website you will see the simulated gradients are often necessary on maintaining an unfeasable speed. I'm hoping for a firmware update to sort this.

I would suggest try repeating the hills but switch to a lower gear in a high cadence. There may be a difference between how our trainers work, but I suspect you will be okay.

User avatar
Tacx Video Production
Posts: 3850
Joined: Sun May 09, 2004 11:49 pm
Location: Belgium

Re: Wattage on flat vs. climbs

Post by Tacx Video Production » Fri Apr 08, 2016 8:06 pm

Easy way is to simply use a Heart Rate monitor strap ride at the same watts on the flat & on a climb then see if there really is any significant difference...NORMALLY Heart rate will mirror your watts, there can be slight differences for riders that have specialised in types of cycling but for any typical road rider that does a bit of everything 300watts will be 300watts effort & have a heart rate that will reflect that effort...it should not change if your suddenly doing 300watts in big ring as opposed to 300watts in the small ring with less inertia

Post Reply

Return to “Wattage”

Who is online

Users browsing this forum: No registered users and 2 guests