Small watts and speed when climbing, smells like tire is burning

Hello fellow Zwifters, I’m new to Zwift, and I have a problem.
When I climb uphills with >7% gradients, Zwift shows very small watts count, like 60-70 watts, and 4 km/h speed, even if I’m pedaling like crazy. Also, it starts to smell like something is burning.
On flat sections, it’s feels ok, and it shows like 200 watts when riding at 30-35 km/h speed. My trainer is Tacx Vortex Smart. The rolling part of the trainer is now covered with two blue stripes from Tacx trainer tire that I use.

The trainer is calibrated in the Tacx Android app. Firmware is up to date.
What should I do?

It sound like your wheel is spinning on the trainer. You can reduce the Trainer difficulty slider .

The more your wheel spin the less power you will be able to produce.

I had the same issue a couple of years ago on the Tacx Bushido, eventually it became to hot and it blows up my inner tube :angry:

What I did is replacing the “blue” trainer tire with some old “real/outside” tire. Perhaps it have better grip on the roller than the blue trainer tires.

Oh and clean the roller, otherwise you get the burning smell again :wink:

I had this exact same issue on Wednesday with my Tacx Vortex also!!

Mine was doing it when atempting workouts using ERG mode.
Riding up to 200w was fine, but as soon as intervals went to 300+ the resistance would ramp up as usual until at the correct power for the interval, but then the resistance would dramatically increase but the wattage reading would rapidly drop… even though i was pedaling much harder to try to maintain it

Never had this problem before and have been using Zwift with this trainer for nearly 1 year now. I rode on Monday and on Tuesday too with no issue. My tyre is always inflated to the correct pressure, AND Tacx Utility showed it was correctly calibrated as well.
I also tested my trainer on the Tacx utility app and was able to cycle to 500w with no problems at all (i mean no technical problems… i was pretty worn out!), so it’s definitely a Zwift related issue.

Has yours done the same thing since?
I’ve been away past 2 days so unable to test, but was thinking of uninstalling Zwift and reinstalling to see if that fixes it.

You can see all the blue tyre compound that got sprayed over the trainer

My problem was that when trainer added resistance on climbs, the tire started to slip, it was overheating and destroying itself. The solution is to tighten the resistance unit so it has more contact. I tightened it as much as the calibration utility in the Tacx app allows, and now I can climb without any problems.

Ah, that’s an easy fix then :+1:t2:
Different to my problem

Hi Steve - i have exactly the same issue plus my rpm displays in excess of 120 when I’m barely doing 60 - did you ever mange to resolve the issue?

Hi Phil

I’m not sure what the cadence issue would be for you, but I did solve my problem.
I talked to Zwift and worked out that I had recently moved my fan closer to the laptop, as well as buying a wifi booster… and we determined that they were both potentially interfering with my ant+ signal, so I moved them a bit further away.
Plus I increased tyre pressure to 110psi, and tightened the resistance on my Tacx to closer to the maximum limit of resistance in the Tacx app, before being “too tight”.

Hi Steve

Thanks for the response. I use both an ipdad with bluetooth and laptop with ant+ so will try your suggestions with both devices!


1 Like

Hi Steve,
Thanks for this. Same issue here last night above 7% gradient also. HR in zone 3, cadence round 100 and on big ring on bike, watts down around 90 though and speed c4kph. When you say calibrate to too tight do you mean the right hand side of the optimal zone or all the way out to the right?

I made sure it was closer to the right limit of the optimal zone, but not out of it.
Hope that helps Luke…

Perfect thanks Steve, I recalibrated this morning will test out this evening again. I was dead last on the KOM last night :sleepy::sleepy: but roughly in the middle in the placings on the sprint sections and I’m an ok climber so something amiss!!

Fingers crossed!

Worked a treat!! Unlocked the 700 & 800 watts and better output on climbs, very happy thanks!

good stuff :+1:Ride On :smile:

Hi Guys - been having the same problem getting this calibrated…knocking my pan in for past few weeks on climbs when my speed drops to approx -7kmph on 10% gradient while pushing 250watt at 85-90 rpm cadence - ■■■■, runners are passing me. Will try all above fixes and I also think it is time to replace tyre as there is blue dust everywhere…will see how I go with this.