Smart trainer % grade ratings and rider weight/power, questions: Triathlon Forum: Slowtwitch Forums

Smart trainer % grade ratings and rider weight/power, questions

Mar 9, 20 6:54

I'm in the market to buy a smart trainer, finally. I'm tired of gearing myself to "pretend" in Zwift on my fluid trainer.

One rating that seems a combo of some math and actual mechanical ability of the trainer, is the % grade rating.

But, this depends on what kind of gear a bike attached to the trainer has and also how heavy the rider is.

I don't think a trainer can simulate 16% grade for a 100kg rider with an easier than 1:1 ratio on a bike. Same that a lighter, stronger rider spinning something different.

So, when I'm reading "10%", "16%", "25%"........can I cheat it down a little since I weigh less and am a bit stronger to not use a huge gear advantage OR does it still matter?

I'm between a couple of units and this could make my decision. I like to climb in Zwift. Our mountains are 4 hours drive from here, so it's what I've got.

Other unrelated questions:

-For Tacx/Garmin products (Neo or Flux), what's the support like? I'd hate to lose half my purchase on shipping costs if I get a bum unit in the warranty period. I see decent deals on the Neo 2 online, but REI only has the 2T and the Flux 2. I'd rather have the Neo 2 for the same price as a Flux 2. For me, this "shipping a trainer back" and losing money thing would be a deal breaker for an expensive unit. I confirmed via REI that within the 1 year I can dump it off at the local store OR they'd reimburse shipping.

I'm between a Neo 2, Flux 2, and Kickr Core post 2019 issued serial numbers.

The Neo 2 has a much bigger % grade rating and a lot of great reviews. But, not sold through REI any longer. I missed a huge deal on one by a day.

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Re: Smart trainer % grade ratings and rider weight/power, questions [burnthesheep] [ In reply to ]

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Sean H

Mar 9, 20 7:06

Post #2 of 14 (2346 views)

In zwift you can set trainer difficulty from 0%-100% (100% being what you'd experience in real life on that grade climb). So you can completely flatten climbs at 0% or make Alpe du Zwift just as hard as it is in person with 100%.

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Re: Smart trainer % grade ratings and rider weight/power, questions [burnthesheep] [ In reply to ]

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Ai_1

Mar 9, 20 7:28

Post #3 of 14 (2334 views)

The gear you are using is not relevant to this.
If you use your gears out on the road, why wouldn't you use them on the trainer too?

I bought a Tacx Neo2T in December so I've got a bit of experience on it now. I came from a Kurt Kinetic Road Machine. I really like the Neo and have no regrets about getting it. I use Zwift with the trainer difficulty set to 100%. I think a lot of people leave it at the default which is 50%. That means the trainer only simulates half the indicated gradient on an uphill and quarter on a descent. 100% is full gradient and half gradient respectively as you may have guessed!

On the steeper 12%+ gradients on Zwift I'm in my easiest gear (36x11) at low cadence churning out 300W to keep my ~85kg moving at a semi-respectable pace.

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Re: Smart trainer % grade ratings and rider weight/power, questions [burnthesheep] [ In reply to ]

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jfranci3

Mar 9, 20 8:15

Post #4 of 14 (2315 views)

These are overall power limitations and the devices torque limit. You can either hit the torque limit or power draw limit. The % is based on some rider weight and the flywheel spinning at some speed. I'd only pay attention to the watts number and you want some overhead above what you'd sprint at, but otherwise more isn't better. Same with flywheel weight - you need the weight and diameter (MoI) and gearing of that flywheel to know if its better, so just get one of the heavier ones but don't worry if its the heaviest.

I'd test ride all of them with Zwift (or similar) with a workout going and get the one that feels the smoothest.
Smoothness and quietness are more important than power.

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Re: Smart trainer % grade ratings and rider weight/power, questions [burnthesheep] [ In reply to ]

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exxxviii

Mar 9, 20 8:16

Post #5 of 14 (2315 views)

burnthesheep wrote:

One rating that seems a combo of some math and actual mechanical ability of the trainer, is the % grade rating.

% Grade is just a abstract way to say that it can deliver high resistance at low (virtual) wheel speed. So, if you want to simulate high power and low cadence drills, you need a trainer capable of managing high resistance. This is where the Tier-1 trainers (Neo, KICKR, Hammer, etc.) rule. Also, there really is no standard for how the vendors calculate this grade number.

The software will control the resistance to simulate the climb. So, if you entered your total weight in the trainer software, it will tell the trainer to drive a resistance curve appropriate to the climb grade. Then, you just stand and grunt.

I have done a few real-life climbs in the 20% range. My cadence was around 60, speed was 7 MPH, and power was around 320W (IIRC). My Tacx New 2 trainer can deliver that exact feel with plenty of room to spare.

My one support encounter with my New 2 was fine. Its power reading was way off. I simply returned it to my merchant (Clever Training), and they swapped it.

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Re: Smart trainer % grade ratings and rider weight/power, questions [Ai_1] [ In reply to ]

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burnthesheep

Mar 9, 20 8:18

Post #6 of 14 (2313 views)

Ai_1 wrote:

Thanks!

For reference, I'm a size that it only took about 240w to do the Alpe in about 55min.

I now understand about the gear thing. If it is a simulation, the gear is the gear indoors or outdoors. Gotcha.

I'd probably leave it on 100% all the time, as the point is that I enjoy the climbing and variances in grade. We've only got like 2min to 4min hills here at a max of 12% for maybe 30 yards and averaging only normally like 4-8%. So, it's the fun/challenge.

I just don't see a reason to buy a trainer with above 16% grade if Zwift doesn't even have a climb "yet" with a grade that high. I'm sure a few of the real world video simulation climbs have bigger, but those aren't my thing really.

I'm just torn between what I see as an inferior product through REI in the Kickr Core or a Flux 2 versus buying off the internet for the Neo 2 that's on sale.

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Re: Smart trainer % grade ratings and rider weight/power, questions [burnthesheep] [ In reply to ]

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exxxviii

Mar 9, 20 8:35

Post #7 of 14 (2297 views)

burnthesheep wrote:

I'm just torn between what I see as an inferior product through REI in the Kickr Core or a Flux 2 versus buying off the internet for the Neo 2 that's on sale.

I would not hesitate to buy a Neo 2 from Clever Training while they have them on sale. That is a freakin' steal!

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Re: Smart trainer % grade ratings and rider weight/power, questions [burnthesheep] [ In reply to ]

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Ai_1

Mar 9, 20 8:54

Post #8 of 14 (2282 views)

The fastest I've done the Zwift Alpe is just a couple of minutes slower than you. Still well under the hour.
It took me a 268W average, but I was on the Tron bike which is a little heavy! ;)

Where the 100% hurts you is in races. The couple of weeks that I had the Neo, I hadn't changed the trainer difficulty, so it was still at 50%. I did several rides including a few races and I really liked it. Then I realised the difficulty was only at 50% and put it to full. the next race was a lot harder! On terrain with regular gradient changes, I found myself continuously late for gear changes. I wasn't used to changing gear on the trainer due to external factors (i.e. game terrain). Although it was necessary with 50%, the need was much less sudden, severe, and frequent. It suddenly became much more important to pay attention to the terrain! I've improved at this but still miss the visual cues unless I'm really concentrating. Outdoors I see and feel the gradient changes coming and my use of the gears is much more proactive and intuitive.

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Re: Smart trainer % grade ratings and rider weight/power, questions [Ai_1] [ In reply to ]

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burnthesheep

Mar 10, 20 5:38

Post #9 of 14 (2175 views)

Ai_1 wrote:

Where the 100% hurts you is in races.

I'd be doing some ITT's and maybe a TTT with my Zwift team. The pacing expenditure in ITT at 100% slope would be great for me.

Maybe not needing 16% for an ITT, as nothing around here is like that. But the 16% grade would just be for mental engagement on those 2 to 3 hour indoor rides.

I've decided on the Core from local at REI. They have one. They're going to let me open the box to check the serial number/build date and that it has the correct static electricity updated plug and has had the "bolt tightening" updates. So that maybe for birthday pair it with a climb unit.

I watched the most recent DC update video and sound video for it, and the wife was like "uhm, yeah, that's a lot quieter".

I would do the Neo 2 from Clever, but.....reading reviews the thing is beastly to move around and I'd be moving it enough to not want to move a 50lb unit. Also wasn't happy that their power over 25mph sucks. As in ITT on flatter stuff I'd certainly be spending a LOT of time over 25mph and in the 27+mph range. So, if that's off much at that range.........that's a deal breaker right there (I do have a meter, but it is a left-only crank meter that reads stupid low).

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Re: Smart trainer % grade ratings and rider weight/power, questions [burnthesheep] [ In reply to ]

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Signal8

Mar 10, 20 16:51

Post #10 of 14 (2106 views)

I don't know what you are paying for the Core at REI (google shows $900). That seems like a lot for Wahoo's second tier product. Especially when you can get Saris' top tier Hammer for $499. Yeah, it's the H1 and not the more current H3. But, the only difference between the H1 and H3 is the paint job and the decibel level.

https://bikecloset.com/...y79x8HoaAvSAEALw_wcB

Last edited by: Signal8: Mar 10, 20 16:53

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Re: Smart trainer % grade ratings and rider weight/power, questions [Signal8] [ In reply to ]

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Titanflexr

Mar 10, 20 20:29

Post #11 of 14 (2057 views)

Signal8 wrote:

Love the H1, and at $500 it's the best value smart trainer out there by a mile. It is a bit loud at high rpms though compared to the current generations (my pain cave is in the garage so it's not a concern).

Zwift really needs better cues on the gradient (I keep searching for a drone angle that will help with this). This is why there are so few riders in Titan's Grove (lots of short rollers).

ECMGN Therapy Silicon Valley:
Depression, Neurocognitive problems, Dementias (Testing and Evaluation), Trauma and PTSD, Traumatic Brain Injury (TBI)

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Re: Smart trainer % grade ratings and rider weight/power, questions [Titanflexr] [ In reply to ]

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Signal8

Mar 10, 20 20:41

Post #12 of 14 (2051 views)

At $500 for the H1, there is no reason for someone who is budget constrained to look at any other trainer.

They say the H1 is louder than the current gen, so I have trust that. But, it's the only smart trainer I've ever used...so I have nothing to compare it to. I can still hear my fan and drive train noise above the trainer, so I don't find it loud at all.

The 2-second leg between the Zwift gradient being displayed on my monitor and when the trainer started changing resistance took a bit of getting used to. Early on, it seemed like I was always chasing the gradient changes with shifts too late. Titans' Grove accentuates this issue more than any other area (maybe parts of NYC too, but I don't spend much time there).

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Re: Smart trainer % grade ratings and rider weight/power, questions [burnthesheep] [ In reply to ]

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scott8888

Mar 11, 20 3:06

Post #13 of 14 (2005 views)

The % gradient thing is all a bit fuzzy because Zwift is adjusting speed. For a while a number of companies were listing the % as relative to a 75kg rider at ~10mph but I was never sure how that was calculated nor have I seen it listed that way frequently. My experience though as ~60kg rider with a strong preference for high cadence is that the gradients feel harder than outside. Even when climbing I like to spin but on Zwift (with a Tacx Flux) I quickly run out of gears when the difficulty is set to 100% and I *think* this is why many racers leave the difficulty at 50%. Basically the trainer seems to want to pile on the resistance as slope goes up rather than dial back the speed in a way which is unrealistic for lighter riders.

I never had to deal with Tacx customer service but all the info they sent with the trainer and paper work looked user friendly. I have dealt with Garmin over Vector issues and its been fine. A bit slow but I was never stuck with a bill. So I don't think the merger will have created a customer service nightmare.

In terms of selecting trainers I would expect steep discounts in the Flux 2 very very soon. A new Flux has released but it looks like the launch was timed to correspond with the Taipei Bike show which then got cancelled. I suspect other companies are in the same boat where they have new trainers but corona virus is killing the marketing launches. It is also going to wreck havoc on product shipping/production due to China's shut down. So keep an eye out for price changes as its going to be a very unusual year in terms of new product releases.

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Re: Smart trainer % grade ratings and rider weight/power, questions [scott8888] [ In reply to ]

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burnthesheep

Mar 11, 20 5:29

Post #14 of 14 (1981 views)

I went with the core. It was the revised one with the newest serial numbers (correct plug and tightened bits inside).

I watched the DCRainmaker videos for trainer noise and went with the Core over the H1. Honestly, nothing wrong with the H1 but I do also run a long cage RD on my road race bike and my cross bike. I read that the long cage would rub on the H1. Folks say not a big deal, but I just want something to work without anything like that.

Also, I am a member at REI and would get either $90 cash back at year end or credit to use.

So, really, it was $90 less if I accept the dividend check.

The % grade worked great with no lag. The 12% parts of Leith or Keith hill or whatever at 100% trainer setting was nuts on a 39t front! Too bad I was down a boatload power not using my fan.

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