Is there any way of extending my gearing capability on the flats?

Another gearing question - sorry if it has already been answered, but not sure if there is an answer.

First off: I understand how trainer difficulty works. This is NOT a trainer difficulty question.

On my bike the gearing is very deliberately set-up for making climbs in real life. My biggest gear is 49 (on the big chainring) and 13 (at the back), my set-up is biased towards smaller gearing that helps me get up and over the Alps every few years.

In the real world, I will rarely push that gear unless I’m going downhill; most of my time is spent in the small ring at the front at a reasonable cadence.

But in Zwift when racing/riding and not in erg/workout mode, the only gear I can get reasonable power numbers from is my biggest gear. I end up going up AdZ in the biggest gear I have; which is mad.

As an example, my FTP is 299. I will only be able to ride at 299 in the biggest gear I’ve got. If I drop down 1 gear then I’ll end up spinning like a washing machine to get anywhere near 299. IRL, if I rode in my biggest gear then my legs would snap after not much time!

In other words, when I’m in the real world, my maximum realistic gear is somewhere in the middle of my range, but on Zwift, I have to put it in the biggest gear and keep it there because anything else is too light and doesn’t give me the power output. In the real world, I’d go up AdZ in my granny ring, but on Zwift I can only go up in the polar opposite biggest gear I’ve got.

When going uphill, this is less of an issue, but for level or downhill sections it’s a bit annoying and means I’m effectively riding Zwift on a fixed-gear bike.

Is there any setting I’ve missed that can essentially offset my gearing to make it harder at lower gears, to give me the range? As I said at the start, trainer difficult is not going to help me here because TD only helps when going uphill.

What sort of trainer are you using, and is it set up properly? Are you in ERG mode, by chance? Is your trainer difficulty set to 100%? (You mention that you understand TD, but don’t say where you have it set.) To me, it certainly sounds like there is some issue, as climbing the Alpe in your 49x13 at 299 watts doesn’t sound right, unless you’re only doing about 25rpm. And while you certainly would spin out on a decent descent in a 49x13, just like you would IRL, I would think that you’d be OK with this gear for riding on the flats. You might be at a pretty high cadence, but nothing too unmanageable.

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Definitely not in erg mode. 5 month old Kickr Core, set-up correctly and frequently calibrated.

When in erg mode, it works perfectly and I ride in a mid gear because it doesn’t matter.

When I’m in non-erg mode (e.g. racing, or group rides, or free rides) my cadence is on the low side (I’m more of a grinder), but not THAT low (typically 80 rpm in most races, although today was as low as 69 when climbing the alpe).

Trainer difficulty is currently set quite low (30%) but have tried various combinations and it makes little difference, other than uphill obviously.

I calibrate my Kickr Core frequently - at least once a week and often a few times, whenever I take the bike off the trainer.

Up to now I haven’t really thought much about it - it’s not a huge problem, because I just pop it in the biggest gear 30s before the timer countdown, but it wasn’t until I did my first outside ride for 2 years last weekend that I wondered what had happened to my legs and why the big ring was so much harder to push in the real world than on zwift!

Moving the trainer difficulty to 100% would change this, but do nothing to change the resistance on the flats (sounds like you already know that).

The only thing I can think of is to make sure your weight and height are correct in Zwift. I have a core as well and don’t have any issues on the flats getting enough resistance. My gearing is 50/34 in the front and 11 speed cassette in the back.

Just to add, in case it helps, a real example. I have Campag 10 speed gears.

49 x 13 (my biggest gear*) at 82 RPM on the flat will give me roughly 280w, give or take (3.2 w/kg)

If I pop it into the next gear down (assume it’s 49 x 15, but I haven’t counted), then at 82 RPM I’ll get 240w roughly (2.7 w/kg)

If I pop it down another gear then at the same cadence I’ll be around 200w (2.2 w/kg).

If I keep it in the big ring at the front, but knock it down another gear or two at the back I’ll easily end up around 150w, which is recovery pace.

So, this means in reality I have one gear that I can race in; if I try and race in my second biggest gear then I just can’t maintain the cadence needed to pump out the power.

Or, other words, I can’t keep up with the other riders unless I’m in my biggest ring, based on my own natural cadence (which is slightly low, but not in any way unusual).

*I should add for thoroughness it’s actually my 2nd biggest gear, but I can’t seem to shift into the biggest gear reliably, so it’s my biggest usable gear.

Frustratingly, I’ve checked and these are all correct - everything is accurate. I recognise I could bump trainer difficulty up but I’ve tried various settings and found that 30 - 40% in races is the best to enable me to get the most power out; any higher and it becomes a serious grind.

And just to be clear; I don’t have a problem on the flats getting enough resistance overall, but it’s just that I have to be in the biggest gear to do it (e.g. I wouldn’t want a bigger gear, it’s more that I think I should be able to achieve the same resistance in a middle gear).

When I rode outside recently, it took a few seconds for my brain to reconcile the messages my legs were giving me. I had almost expected to be in the biggest gear like I am on zwift, but there’s no way I could do it - it was just way too big.

If I rode in the same gear on Zwift that I would on a flat road in real life then I’d be pushing out around 140w and spinning out.

I’m not doing a great job of explaining the problem, other than to say: I’ve ridden 51 events/races on Zwift and I haven’t yet changed gear once.

There is a big difference in speed between a 48 x 13 and a 53 x 11 that most racers use.

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Try another app (e.g. a free trial of Rouvy, RGT, SUF, etc) and see if you still have problems there.

I would guess that there’s something wrong with your trainer’s SIM mode (the other mode from ERG).

Strange! I used 50-60% TD and I never run out of gears on my bike though I have 46-33 and 10-28 in the back. Climbing AdZ at an average of 270 w at 86 kg I use the 33 up front and the 4-5 largest cogs in the back. Trainer is a Tacx NEO 2T.

One thing to look at is the wheel circumference used within the Wahoo App. It could well be setup for the incorrectly sized wheel. Mine is set to 700 x 32c which matches the smallest tire I use on my bike (diameter of 2.16m).

Either yours is set for a really small wheel, or if it is “normal” you could change your custom wheel diameter to say 2.75m - mountain bikers with 1x use this hack with good success to provide better range.