Tacx Flow Assembly with wider road tires

I guess this is obvious to most of you knowledgeable riders but I have some observations (rather than a question) regarding Tacx Flow set-up with wider road tires.

My road bike does lots of non-urban kilometres on less than smooth (but still sealed) surfaces and therefore has 32mm wide Continental GP5000 tires (and therefore also about 32mm high).

The Tacx Flow assembly instructions say to mount the resistance unit in the upper set of frame holes for 700C wheels and the lower holes for 26" (which seems counter intuitive unless they assume that 26" wheels will have larger tires so that the overall wheel & tire diameter is greater than same for 700C)

With my wheel on the trainer the fit using the upper mounting holes was very tight and the pedalling effort very high, had trouble getting up to 32kph to complete the calibration but it did calibrate. The tightness gave great high effort training but not very realistic feel.So I thought I would try the lower set of holes and this worked very well. Effort much less allowing a higher, more realistic feeling speed, calibrated ok .

Given the increasing popularity of wider road tires especially on "gravel" bikes this must be a fairly common situation and maybe Tacx/Garmin should amend their assembly instructions.

All good now, the on trainer ride speed is pretty close to my outside experience for flat riding although the trainer is a bit optimistic about my climbing hills ability compared to following known and previously done climbs Hopefully my training will move me closer to what the Flow reckons I am doing.

  • As a followup on this there was a new update to the TACX Trainer (& utility) app in the last week and it would no longer calibrate for me, too loose, too loose even when it was screwed up as tight as it would go !

    So I pulled it apart and reset the resistance unit into the top holes again and it calibrated first go ? Still feels good, maybe even better but have to give it a fuller test.

    Given the comment by @8331069 I am still pretty happy with the Flow, the 6% max gradient simulation is a bit of a limitation especially as I now know it is speced for a 65kg user and anything heavier will not even get to the 6% level and therefore the Flow reckons I am much faster uphill than I really am on the same climbs in real life. The next higher spec TACX (Flux I think) is more than twice the price giving 10% and I am not going to buy a trainer which costs more than my bike!

    A suggested workaround is to increase my weight setting in the Garmin so that all hills are harder at lower grades even though it will still max out for the higher ones?

  • Hello, i just came across this community as I started facing problems with my tacx flow. I bought it 3 yrs ago and its been working perfectly well. I travel a lot and take it with me anywhere I go. I started having a problem with calibration. It would say its calibrated, a minute later it would say its too loose and this goes one. Every time i try to tighten it to the maximum the screw gets out of the hole and i have to adjust it again. The resistence machine is screwed on the upper holes based on my road bike wheels dimensions. My main issue is that pedaling has become so much harder. I would struggle to reach my power target however, speed seems to be perfect? How is that so?

    Thank you!

  • Hello, i just came across this community as I started facing problems with my tacx flow. I bought it 3 yrs ago and its been working perfectly well. I travel a lot and take it with me anywhere I go. I started having a problem with calibration. It would say its calibrated, a minute later it would say its too loose and this goes one. Every time i try to tighten it to the maximum the screw gets out of the hole and i have to adjust it again. The resistence machine is screwed on the upper holes based on my road bike wheels dimensions. My main issue is that pedaling has become so much harder. I would struggle to reach my power target however, speed seems to be perfect? How is that so?

    Thank you!