Need low cadence & high resitance

dickyseville

Hi all,
A bit of advice please. I'm closely following an Ironman coaching plan. One of the weekly sessions is a high resistance & low cadence set (60 seconds on, 90 seconds off). The coaches say the resistance needs to be really high and cadence down as low as 50. If I had a dumb turbo I think it would be easy to achieve because I could manually turn the resistance right up which would force my cadence down. However, I use the Tacx Flow smart trainer and have created a custom workout on the Tacx app with 60 seconds at 400 watts followed by 90 seconds at 150 watts. The problem is with the smart trainer just doesn't seem to be able to get the resistance high enough. I get to 350 watts at 60/65 RPM in highest gear. It feels hard but just not hard enough and I'm struggling to get a session where my legs are screaming for me to stop at the end of it.
Does anyone have any ideas what I can do?
Many thanks,
Richard.

fenix

I was always taught not to go lower than 60 rpm so as to not overstress the knees.

My dumb trainer could let you do that - I've not used your smart one. Can you make it dumb and just use the gears ?

supermurph09

The Tacx flow smart should be able to handle that no problem.

Are you using the trainer to automatically adjust the resistance? If so, do you change gear as well?

dickyseville

Hi,
Yes I'm allowing the trainer to go to 400 watts then I change to the hardest gear. I try to drop my cadence right down but when I do that the turbo doesn't seem to keep the resistance high enough.

kingstongraham

Have you tried it when using it as a dumb trainer without erg mode just via the Bluetooth app?

I'm not surprised it has struggled, I've found had to change to a pretty high gear to get a minute at 500W at 110rpm. 50rpm is a cadence I can't imagine ever wanting to use in anger - wouldn't you be better doing some squats?

N0bodyOfTheGoat

If it's like the Direto, different gear ratios will have different ERG power ranges according to cadence. There's a table on the Facebook Direto Group that shows chainring/sprocket combos at differing cadences and what the power range is, for example IIRC, 34-18 gives ~84-480W @ 80rpm.

cld531c

Have you tried setting the turbo so its in the red (too hard) on the app when setting up to increase the resistance?

ronnierocket

Changing gear is the problem. Let the trainer do the adjustment, just pedal slower, the trainer will adjust itself to keep at it at 400. I do this sort of thing all the time on the Sufferfest apps, they go from 90 to 60 cadence often, I worry about the cadence and the trainer does the rest. My trainer is a Tack Neo

barongreenback

No, the Flow is the problem, not changing gears. As it’s cheap and cheerful the range of power is not great ie you have to change down into an easy gear for very low power and the opposite for the highest. The sweet spot for this turbo seems to be in the range of 150-400 watts. It struggles with low cadence/high power. Can’t remember the YouTube guy’s name (an Aussie?) but his review covers it.

I’m afraid you’ll need to upgrade - I’m also considering doing so as my training gets more sophisticated. It’s a great trainer to see if indoor training is for you though.

stevie63

barongreenback wrote:

No, the Flow is the problem, not changing gears. As it’s cheap and cheerful the range of power is not great ie you have to change down into an easy gear for very low power and the opposite for the highest. The sweet spot for this turbo seems to be in the range of 150-400 watts. It struggles with low cadence/high power. Can’t remember the YouTube guy’s name (an Aussie?) but his review covers it.

I’m afraid you’ll need to upgrade - I’m also considering doing so as my training gets more sophisticated. It’s a great trainer to see if indoor training is for you though.

Yeah it's Shane Miller that did a review on this recently. All low end wheel-on trainers suffer from this sort of problem.

EBEB

Some manufacturers who make Trainers provide graphs of max power vs wheel speed, Tacx did - hopefully they still do?

The essential point is that max power requires a high wheel speed in cheaper trainers. Even with the hardest gears you have (eg. 53x11) the maths says you need to maintain a cadence above X to get that wheel speed and power. This is why for my second trainer I went for a middle grade one (Tacx Bushido).

For now, put the bike always in the highest gear and let it try using just F-EC. If you find the official graph you can figure out roughly what the lowest cadence you can use is. I did Ironman Wales after using just an old dumb Tacx Flow and Golden Cheetah (and for an Ironman course the cycle is quite bumpy).