Turbo Uncertainty

Hi All

We recently bought a new turbo (Saris H3) for when we need to train and can’t get outside or to the local gym’s Watt Bike.

Today I did a 2 hour fasted session keeping Z2 heart rate.
I switched erg mode off so I could change my intensity to keep heart rate in my zones.

In the easiest gear at 85rpm I sat at 150w. The only way to drop watts was to cycle about 65rpm which doesn’t seem right.
In the upper chain ring I can barely turn the pedals…it’s like cycling up a 22% hill.

At the end of 2 hours it told me I had cycled 15 miles (so 7.5mph throughout) which also seems odd.

I know every bike is different but indoors I usually cover 18+ miles per hour.

In erg mode it’s still tougher than 4 different Watt Bikes and 6 different Stages bikes I’ve used over the years.

Does anyone with more experience know if this sounds off and if it does, what it could be?

The LBS put the cassette onto the turbo and I don’t have the tools or knowledge to change the cassette at the mo.

Thanks in advance

You mention a host of issues. I’ll try to cover each one separately.

  • Assuming you are using the TrainerRoad app, when you switch to Resistance mode, you have a setting that controls the baseline Resistance level.

  • Here is a link to a post with the way to adjust Resistance Percentage on Mobile or Win/Mac.

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  • https://support.trainerroad.com/hc/en-us/articles/203103294-Speed-Distance-on-an-Indoor-Trainer

  • When using ERG mode, its effectively possible to use a range of gearing, from your lowest to your highest gear. You will be applying the same power in Watts, but the wheel speed at the trainer can be wildly different.

  • A workout in the lowest gear (which sounds like what you did) will report a low distance and speed for a workout at a given wattage (say 150w average).

  • A workout in the higher gearing will report a higher speed and distance for the same 150w workout and time.

  • This is why speed and distance on a trainer, especially on ERG mode is not a reliable metric. If you use the same gearing, you can at least compare from session to session.

  • It is also not appropriate to compare those speeds and distances to anything done outside. Way to many other variables even beyond what is mentioned above (wind, road roughness, etc.).

  • A mentioned above, its possible to ride an ERG workout in a wide range of gearing. One notable factor in the gearing is flywheel speed.

  • Low gearing leads to low flywheel speed. This tends to change the feel of the trainer to one more like low speed riding on a hill or rougher dirt surface.

  • High gearing leads to high flywheel speed. This tends to feel more like flat and fast road riding.

  • All of the above is VERY subjective, and not every person had the same experience or feeling. That said, I feel it is VERY important for each rider to experiment and find what suits their preferences and training needs.

  • My gut says that you “hurt” yourself more on this trainer because you were in lower gearing in ERG, and even in Resistance, while turning lower cadence too. A bad mix if you are not used to it. So dial in the settings and gearing and I expect that you will have a different (hopefully better) experience.

  • If you want to burn a few hours (and some associated beverages), here is a massive thread that covers this from every angle possible.

  • Big vs Small Chainring - Same Power (ERG Mode Gearing)

  • Assuming you picked a cassette similar to your actual bike, there’s no need to change it.

Did you perform a calibration on the trainer?

  • This should be done at least once a month for the H3, and done after about 10 minutes of riding to make sure the entire system is at operational temps.

You don’t mention a power meter, so if you are relying on the trainer for power reporting, you should do a new Ramp or FTP test on the trainer.

  • Your FTP from any other source is not likely to match on this trainer.

Finally, if you are new to ERG mode, this is very worth your time. I consider it essential viewing, because ERG is often misunderstood, and is very different from regular Resistance training.

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Thanks for all your input. I hadn’t seen the resistance level. It was set at 5/10. I lowered it to 1/10 and it felt more like the other Watt Bikes/Stages Indoor Bikes I have used before. I only tried this for 30 seconds in Resistance Mode so would need to see what it’s like on a proper workout but this looks promising.

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Cool. That answers my question about why I appeared to be doing 7.5mph.
On resistance mode, I can’t get anywhere near the top chain ring though so I had to use my lowest gear to get through the session…even though it was low level.
On the Watt Bikes I tend to sit for 220w at sweet spot and do 4x15 mins with 8 mins recovery.
On my outside bike I have a left sided power meter and tend to hold around 220watts for an hour-90 mins.

I know these aren’t directly compatible but I have no issues cycling in my upper chain ring outside for a 90 min undulating ride so should be able to get out of my easiest gear indoors surely?

I’ll see how it goes with the resistance level changed next time.

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When in Erg mode, on my Saris I push hard to get to 85rpm but would naturally sit at around 80rpm. It feels from the outset that I am cycling through treacle. I have tried a bigger gear and although the watts remain the same, it just feels too hard to be able to do for more than a couple of minutes.
On the Watt Bike I sit pretty comfortably at 90-95rpm which is closer to my outdoor riding cadence and neither feel like I am cycling through treacle…unless I’m exhausted but that’s me and not the bike.

I guess what I was getting at is that my home turbo feels harder and unlike any indoor bike I have used before…so much tougher. I may see if I can get some friends to have a go and see if they feel it feels ok.
Either I am expecting rides to be too comparable (my peak watts on a ramp test on a Watt Bike is 340 watts and 270 on my Saris) so I just need to accept it’s me, or they bike is actually significantly tougher and I will have to get stronger before I can consider trying to get to the big chain ring.
An issue is I cannot recover on intervals at 90-100 watts as you can’t do that low a wattage on the Saris. Even on the easiest gearing on Resistance mode at 70 rpm you are pushing 120 watts so it means on intervals I will have to stop peeling completely to recover.

Different trainer here (Kickr direct-drive) but yeah, if you set resistance = 0 in the TR app you should be spinning 85rpm at ridiculously low watts (maybe 20W or 30W).

The first time I did an FTP test in TR it was an 8-min test I think (Dec 2017). When the TR app switched from Erg to resistance there wasn’t enough to push against and I was silly spinning at 150 ish watts when I needed to be at 230 ish. It was t obvious in the TR mobile app where to change it, but I figured it out and did well on the second 8-min interval in resistance mode.