Aidoneus

I just got a Wahoo Kickr Snap-on trainer for winter riding. While free rides seem okay, I do not understand others. In particular, if I try shifting down to my small ring to bring cadence up, it frequently gets much, much harder. In contrast, for free rides I can stay in my biggest ring and highest gear almost constantly...something I could never do in reality on my Ogre loaded with racks and bags.

Eric F 

I'm not clear on what you mean by "free rides"? Also, what are the "other" rides?

If you're using a smart trainer with Zwift (and they are properly connected to each other) the resistance you feel in the pedals will be dictated by the gradient of the course you're on in Zwift, or by the wattage demand from a programmed workout (ERG mode).

kcjc

Assume you are inquiring about "erg" mode, then you need to learn how it works. Technically, the trainer is using an "mrc" script to provide you with a set resistance for a specified period of time (erg rolls off the tough much easier). If you are not meeting the targeted power output, the trainer will increase or decrease the resistance depending on your output. Your ability to sustain that resistance is measured based on the torque you apply to the pedals multiplied by the angular velocity or your cadence. Except for abrupt changes, your gearing has limited impact on the application so long as you can sustain the power output, i.e., the same pressure on the pedal at the same cadence. If there is an abrupt power drop, typically if you change gears and your cadence drops, the trainer responds by pilling the resistance. Think of it as a cadence game. Keep it steady. You don't need to change gears. You either can do the interval at the prescript resistance or you can't.

Also, use the wahoo app and turn off the power smoothing. It's a lie to make one feel better. No one can generate power as smoothly as depicted in the wahoo's report when the power smoothing is on. It's wahoo's sad attempt to keep one focus on maintaining steady power output by lying about how one produces power.

Aidoneus

Some rides specifically say free ride on the start icon. I think erg is what I am talking about.

Trying 2x2 map, gearing had little to no effect. When my cadence went down, and I tried changing gears, it just got harder.

I should have said thanks! So, it is a feature and not a bug, lol.

Eric F 

In ERG-mode, that is the "spiral of death". It doesn't react the same way as the real world.

PeteHski

It is normal for gearing to have little effect in ERG mode. The trainer resistance should automatically adjust to match the workout power target at whatever cadence you are pedalling . ERG mode is usually best on the small chainring in the middle of the cassette, but it doesn’t matter that much what gear you choose. If you let your cadence drop then the resistance will ramp up to maintain the power, which is probably what you felt.

In free ride mode the resistance should match the road gradient. So hills should feel harder and descents easier like they do in real life. It sounds like this isn’t working correctly if you can ride the whole course in your highest gear.

spelger

it is hard to stumble upon an erg mode ride by mistake. all of the workout rides are erg mode. pretty mcuh everythign else is what you are clalign a free ride.

Aidoneus

Yes, I experienced the cycle of death. Note that I said I could stay on my big ring and max gear _almost_ constantly. Riding the rolling Scotish hills I did a bit of changing gears, lol.

Anyhow, guess this thread can be closed. Thanks to everyone who responded!

PeteHski

You might want to check out the “Trainer Difficuty” setting in Zwift. Default is 50% which effectively flattens all the hills by half their true gradient. But also your Snap is limited on the slope gradient it can replicate.

rm -rf

The reason I lower the Trainer Difficulty setting is to let me use higher cadences on the climbs. That works better for me, especially on the longer climbs.

The climbs still require the same amount of power to climb at the same speed. Just allowing spinning instead of mashing a low gear.
(Or a low Trainer Difficulty allows for very slow climbing at easy pedaling force without bogging down.)

This Zwift Insider article covers all the Trainer Difficult details. Flat routes vs climbing, rider weight considerations, etc.

rm -rf

ERG mode workouts on Zwift
In ERG mode, a steady pedaling effort will allow the trainer to stay at the workout's current watts target, no matter what gear I'm using. (So I use a middle gear on the cassette for less chain noise.)

For example, the workout is at 200 watts for 2 minutes: I pedal steadily, and it stays right around 200w. I see 205, 201, 197, 204...

To adjust my cadence in the workout:
If I start pushing harder on the pedals, the watts briefly increase, and now I can let off the increased power, and start pedaling at a faster cadence, back at the 200w range. Note that I didn't shift gears on the bike!
Easing off the pedaling effort, the watts drop, then I can continue at a lower cadence, with the watts back at the 200w range again.

The workout screen prompts are actually not helpful:
For a 200 watt target,
I pedal at a moderate cadence at 150 watts, and it says "More Power!". But if I keep the same steady cadence, it will quickly ramp up the resistance to 200 watts, requiring some more pedal force to maintain the cadence. If I push hard at the More Power prompt, that increases my cadence, too, which I didn't want.

So, a steady cadence is the key to doing workouts at a target power number. The trainer will adapt to me.

Aidoneus

Thanks for the link and the tips! I've only been using my trainer for a week, so all of the info is helpful. Especially concerning erg mode, which I will try again...some day, lol.

choddo

Kind of agree but workouts don’t always use ERG mode and when they don’t those prompts are fine.