New at Zwift Questions

OK folks just got to zwifting to improve trail riding in non winter months. I have a wahoo snap I established my ftp 108 now i started the ftp builder workout. the issue i am having is a fail various parts of the workout for instance the part where it wants short intervals of 180watts i have no problem reaching the goal my issue is when it wants you to back down to like 60 watts in between i have no feel in my pedals they are freewheeling back tire is really spinning i slow down my pedaling but almost have to let wheel slow down then start pedaling again which sometimes causes me to fail that section. any advice ? am i training in the wrong gear also i tend to overshoot likewhere it wants me at say 65 for 5 min is that ok ?? any advice or insite would be great thanks

Wheel on smart trainers and smart trainers in general have a minimum power resistance. 60 watts would be below that resistance so the trainer would be applying zero braking.

Are you sure your trainer is calibrated correctly. 108 for an FTP is really low. Have you done an advanced spin down and do you do a spin down after warming the trainer up for 10 minutes?

I would suggest putting your bike in the easiest gear possible. i.e. small chainring on the front and largest cog on the back.

advanced spin down! you’ll need the wahoo app on your phone to do this. you’re probably getting tire slip without knowing it. i thought my160w FTP was correct in the beginning, but after the spin down, it was more like 200w!

the key is to get that spindown time to be between 12 and 15 seconds (or so). you’ll have to tighten it down A LOT. they say two full turns, but i do 2.25 to get the right spindown time.

i even put a little mark on the knob where the tire just touches so that i can physically see it turn enough.

ok a little background on me i am 43 180lbs fairly good shape fairly active we trail ride a few times a year ususaly do a novice race once a year. wanted the trainer to make the first trail rides of the year less of a struggle and just get in better riding shape and lose a few lbs before spring. thanks for the info guys yes Nigel you seem correct its like there is no resistance from the trainer when it calls for those lower watts. Just got setup last sat i have done spindown but i usually just do on the main screen in zwift app. also i did not warm trainer up for the 10 min just did spindown and started riding. I do not see advanced spindown in wahoo app just spindown. the and thanks also Dan i will readjust the back wheel i will make mark on knob at tire touch and turn 2.25. now for the big question should i do the thing that about killed me FTP test again? Can i Do short Version???
my corrections will be
1.loosen and re tighten wheel and mark knob
2. Warm up trainer for 10 min then perform wahoo calibration test
3. redo my FTP TEST oooh GOD

you probably don’t have to redo the FTP test right away. as you ride on zwift, it will auto-update your FTP if you start posting higher. if i were you, i’d do the other things you listed, go for a ride and see if it feels better.

really, the FTP doesn’t matter that much; it’s more about getting wattage that “feels” right. you can go crazy and get a real power meter to really dial it in, but i believe the various folks that say the power is accurate to within 2ish percent.

also, heart rate monitor is even more useful – you and i are similar age/weight, and i find the most useful number is heart rate. for me, i have a pretty good feel for how long i can ride at 160BPM, 170BPM, and i know that if i tag 180BPM i’m very close to max heart rate and i have to be careful about blowing up.

rode about 7 miles last night after retightening wheel and warm up trainer then spin down test. did not ride super hard just enough to work up sweat and get hear rate up after i was done my ftp updated to 122.

sounds like it’s heading in the right direction. did it feel better? did you ride flats?

also, make sure you inflate that back tire each ride. i usually go 110-120psi.

A few suggestions…

I also have a Wahoo SNAP. With the tire at 110 psi and 2.25 turns on the tension knob the minimum watts is about 100. If you pedal really slowly, you might get down to 60 W.

Workout segments seem to be scored only on maintaining the prescribed watts. Cadence is only a suggestion.

Use the Wahoo App for spindown. I’ve had problems with spindown calibration through the Zwift App.

The Advanced Spindown is not an option for newer Snaps. Wahoo says it is no longer necessary.

You don’t have to re-do the FTP test. Just adjust your FTP until the workouts are appropriately challenging. As you progress you’ll probably want to increase your entered FTP value anyway.