Why can I hold a power wattage of 400 when I'm doing a climb, but when the gradient becomes zero, my power drops to 150?

Hi, I’m quite a heavy cycler who has been using zwift for a few months. I can climb for a decent period and hold over 400 for 30 minutes +. My current ftp is 302 but if a did a test I could probably increase this.

My problem is, when I am climbing in a group race I always increase my position dramatically, but when the gradient drops back down to 0, I battle to get a decent level resistance on the pedals to push consistently above 200w, and get taken over again by everyone I passed on the hill! I have my trainer (tacx neo2) difficulty set on max.

Is there something I’m doing wrong? It almost feels that if the gradient was consistently set at 3 i would be cycling at my natural race pace (if that makes sense) as that would at least ‘feel’ like I am on a track. Any advice or help would be massively appreciated!!

Are you changing gears as you ride along on your bike or do you always stay on the same one?

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I’m pretty much consistently in my lowest gear. I start the race in that gear to try and get a good powerful start. But when I drop down to a normal cadence (80-85 rpm) that’s when my power really drops and I feel no resistance on pedals to try increase this.

Hi @Scott_Yarham

Welcome to the forum.

Your FTP should be at least 380w going by the data given. FTP is 20 minute power X 95% .
400w x 0.95 = 380w .

You should change gears and pick up the cadence when you see it flatten out.

What gears di you have on your bike. A MTB have low gears and it is hard to generate high power on flat roads.

Thanks Gerrie. Very much appreciated. Is my issue then starting the race in the lowest gear and therefore on flats not being able to drop my gear down to get more power? I can try this in tomorrow’s tour of watopia stage 3.

Yes it’s a mtb, so that will be the key reason then. Okay that makes complete sense, so there’s nothing much I can do then to try improve power on flats unless I go absolutely flat out.

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Yes that’s the reason. Only option will be to see if you can change the biggest chainring to something bigger.

I would like to see zwift add a resistance toggle (a bit like in workout mode) which could help to artificially add bigger gears to a bike.

Or the ability to set a minimum gradient. so flats or downhills never went below a set limit (1% for example) but when the hills went higher than that the real world feel would kick back in.

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Yeh that would be awesome.
You setup your wheel size, your transmission and cassette setting.

Let’s say you run a 11-32 and you want to try out 11-28, zwift works their way through it with the resistance they put in the trainer. Pretty sure it’s doable

See Increase baseline resistance

You’re effectively racing against road bikes, on a smooth road with low rolling resistance, with an MTB gearing. The gear you start the race in is irrelevant - the only thing that counts is how fast you can get that rear wheel to spin.

My issue too on an MTB - smash the hills but have to work hard on the flats. I changed my rear cassette when we got the direct drive but need a bigger big ring too. It’s fine on trg in erg mode but more noticeable in rides/races. End up with a high cadence.

I have my trainer (tacx neo2) difficulty set on max.

That is the issue - you are just spinning out of gears. Put your trainer difficulty setting in Zwift to zero and you will be able to put out the same power downhill as you will be able to put in uphill.

Not much point paying for a Neo and effectively turn it into a dumb trainer.

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That wont accomplish anything as the simulated gradient will then be 0% all the time and the OP will then “spin out” all the time…TD isnt going to help if one just doesn’t have a big enough gear

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Just set up a custom workout for the amount of time you want to ride and change from erg mode to slope mode then ride the route you want.