Virtual gear indicator with upshift-red-zone for budget trainers in RGT

SYSTM Software Feature Requests
1

In many sims, I’ve always thought there’s a big problem with hill sims. Basically, the only required effect (clarified) is that your avatar goes slower in a claimed-weight dependent way. For pros with 450 watts of sustained power on a rest day, that’s probably close to realistic on most hills.

For normal humans, when we hit a 15% hill, on whatever real bike we likely own, we cannot continue to spin along at 95 rpm doing 70% of FTP. First, power has to go up or you end up at 3.5kph which becomes counterproductive at best. Second even if you ramp up power so you’re at say 8 kph or whatever, you likely can’t do that at 95 rpm on that hill with realistic gearing in the real world. Of course this depends on what gearing you want to pretend the virtual bike has.

The most expensive, high-torque smart trainers can deal with this in slope mode, because even when you put your bike in the lowest gearing, they can generate enough torque to simulate a 25% hill for a 130kg rider (well…). But, those with more modest trainers can still generate plenty of torque; they’ll just have to gear up to do it, jus as is done on targeted workouts. So software prompts could alert when gearing is out of bounds. That’s not useful for racing, but it is useful for testing oneself on a climb on magic roads. Of course it doesn’t help sell expensive trainers.

On-screen you could have maybe a red warning “CADENCE TOO HIGH FOR SLOPE. GEAR UP.” Or maybe have a virtual-gear indicator bar that goes up and down, and goes into a red zone when you’re in too low of a virtual gear. Less importantly, If speed goes below something you could also have the sim stall entirely and flash “STALL”. This way you could hold yourself to realistic limits for the hill even on modest trainers.

TL;DR Budget trainers can produce enough torque to simulate big hills, but require manual shifting to do it. In-app effective-gear indication with warnings/prompts could keep riders in bounds for accurate (non-race) simulation of Magic Road climbs.

2

That hasn’t been my experience. Slope goes up and resistance goes up so that I have to downshift to be able to keep turning the cranks. If the slope isn’t too steep, I can downshift enough to maintain normal cadence, but if it’s steep, I run out of gears and have to slow cadence and even stand. It’s generally pretty realistic.

I do understand that some trainers can’t produce enough resistance at low rpm so you need to upshift to get the pedal resistance where it should be.

4

(posted now as a reply)

Yes, expensive trainers can do slope control, if turned on. The point is that by providing a virtual gear indicator and green and red zones, it becomes possible not only upshift when you “should” but also to know when that should be. Most people cannot calculate in their mind what the maximum cadence should be for a 12% climb at 230 watts in at minimum a 50-28 gearing while they’re putting out 230 watts. Shifting is the easy part.

So it’s possible to simulate climbs like this on lesser equipment, but it just requires the right information onscreen, which is sadly never available.

Of course if you’re racing, you probably don’t want to turn on slope mode anyway :s)

5

When you think about it, automatic slope control isn’t really better here. It’s actually kind of silly, and requires just as much or more pointless shifting. Basically the auto slope control increase the power to cadence ratio (lower cadence for same power), and you put it back where you want it by downshifting. The end result is you still pedal at the same power and cadence that you preferred and that you were at before the hill control kicked it anyway, but you got to pretend “feel” like you’re in the world because you got to flick your levers. It’s like motorcycle twisties with a vroom vroom sound effect.

It’s only when you run out of gears that it matters at all. At that point an expensive machine can simulate that with no further shifting, while a cheaper machine can also simulate it just fine, but then the cheaper machine requires shifting (previously it didn’t). The only thing missing is the indicators letting you know that. Somehow it’s more satisfying when the indicator is that you’re pushing harder than you want rather than the screen telling you you’re pushing easier than you should. But the net result is the same, and the amount of shifting is actually less most of the time.

7

I might have misunderstood your post completely then put my comment to a trash. Otherwise, it is not my experience at all. The end result for me is that cadence may remain the same but output power is lower. The speed is lower too. Quite realistic.

1 Like
8

Well, yeah, you’re not following me. There’s some psychology to the sims and possibly solutions people haven’t had that make them unaware of what could be. The first to realize is that that the trainer does not react to your choice of gears. For a fixed simulated slope every wheel speed will have a particular resistance. It doesn’t matter if you get that wheel speed at 2:1 gearing and 50 rpm or 1:1 gearing and 100 rpm. The wheel speed is the same, the resistance at the wheel is the same, and the power is the same. The trainer isn’t going to try to out-game your gear choice.

With that said, for any particular virtual slope, if you could choose any gearing you wanted, you could put out any power you wanted and, at the same time, any cadence you wanted. The choice is completely down to your abilities and preference. Changing the slope doesn’t change that. It just means that to reach that same combination of power and cadence you have to choose a different gear. So let’s say you are intent on riding at 80 rpm and 200 watts and you’re doing that on virtual zero slope. Now the trainer goes to virtual 5% slope. Yes, you feel that either you have to drop cadence or increase power, or you down-shift and keep can keep exactly the same cadence and power. Nothing changed. There is always a theoretical gear where 80rpm will produce 200 watts. So no matter what the trainer does, with enough gearing you can always get back to exactly where you were. The only simulated experience you’re getting is to feel like you’re on the road changing gears.

When that changes is when you can’t downshift any longer, because you are out of gears. That’s when the simulated hill “matters,” and this is more relevant for people with less power. Now you’re going to be forced to drop down to 60 rpm if you want to keep it down at 200 watts. If the hill goes steeper yet, you may be uncomfortable doing less than 60rpm so you will be forced to do 230 watts; now things get hard. These are the only times when the virtual hills actually matter.

But you don’t need a trainer that can deliver 100Nm of torque to the wheel hub to get that experience. If your trainer can’t increase resistance, you can do the opposite. You can shift up instead of down, and of course, you’ll find you’re mashing hard at low cadence to get that 200watts!

So the only thing that matters aside from “shifting experience” is making sure the rider is “in bounds” ie their cadence vs power is within physically allowed limits for the virtual hill and some pretend choice of gears available (and now you do get to pretend and choose whatever pretend gears you want).

So all this requires is a bar on screen that indicates what virtual gear-inch you’re in. That power determines virtual speed on the virtual slope, and the ratio of cadence to virtual speed gives you virtual gearing, so that can be displayed.
When your virtual gear gets too low (you’re pedalling faster/lighter than you should be for the hill) it goes into the red, and you should shift up to a harder gear to not “cheat.”

This may sound “no fun” like you’re having to do the simulating yourself, but the physical experience is exactly the same give or take minor “in-between” gear effects. And importantly, if you want to challenge yourself to simulate Mount Washington on RGT to see if you can get up it up without going below 5kph (and falling over) … you can do that, with a wimpy trainer. It’s very possible.

9

The short version of the proposal though… real power and virtual slope determines virtual speed and ratio of virtual speed and real cadence determine virtual gear. This can be displayed on screen and when it goes below a 36-28 (about 35 gear inches) or whatever, it can be in the red zone, indicating to gear up.

1 Like
10

Yes it is. Isn’t it a real life experience too?

That part I don’t follow for sure. Yes, having infinite gear combinations you could always find one that allows your preferable cadence & power. But that would be one match per resistance value. And it would be different gear ratios for different resistance values. Meaning wheel speed would be different too.
Bigger resistance → lower speed while keeping constant power & cadence. Still quite realistic.

11

It doesn’t matter if you get that wheel speed at 2:1 gearing and 50 rpm or 1:1 gearing and 100 rpm. The wheel speed is the same, the resistance at the wheel is the same, and the power is the same.

Yes, but that has nothing to do with the smart trainer. That’s just always true, and that was point. It’s true regardless of what the smart trainer does, so long as it’s not in some active feedback mode like erg mode, and for just simulating slopes, it’s not.

Bigger resistance → lower speed while keeping constant power & cadence. Still quite realistic.

We’re getting there… but the bigger resistance has nothing to do with it except that you had to achieve that in a different gear. Like you said, the end result is constant power and cadence, if you wish to keep constant power and cadence, and you can. The speed change is realistic, but that is just calculated from power and virtual slope and has nothing to do with the resistance change or the gear change. Speed comes from power and and slope.

So again, when it matters is when you run out of gears, regardless of the realism of a high torque smart trainer, a low torque smart trainer can still get you there, if you have a virtual gear indicator.

It’s a “paradigm shift” because we never had it. But it would work perfectly and is simple to apply.

12

I think where a smart trainer adds to a perceived sense of realism… is at the begining of the hill you feel that resistance change, and get to feel “whoah… real hills” but then you shift and you’re sitting back at the same power and cadence anyway. I mean yes, the real world is that way too. For small hills all that changes is speed until we get into pedaling dynamics that no trainers properly simulate anyway (not even the kickr, in fact the Neo has the right tech for it, but it isn’t applied). The fact is, on small to moderate hills, speed is all that changes significantly after shifting, and you don’t need a 100Nm of torque to change the speed of a guy on a screen. You just need a calculator. But breaking this illusion doesn’t sell kickers and neos. Onscreen virtual gearing to deal with times it does matter, doesn’t either.

13

I think I realized where we’re passing each other here. In case it wasn’t clear from my last responses, simulation speed has nothing to do with trainer wheel speed. It’s calculated from power and slope alone. Whether you achieve the needed power at low cadence via high trainer resistance and low wheel speed or the same power and cadence via low trainer resistance, high gearing, and high wheel speed, makes no difference. Your workout is exactly the same, and thus the speed on screen is also the same. The only serious lack of realism is that your shifting patterns are not realistic, and that you need a virtual gear indicator on screen so you know when your virtual gearing is too low.