Yup, was updated the day before … it’s just not mathematically possible for a smoothing algorithm to make 30s @ 50w over target completely vanish. The only way that happens is if you’re then under target afterwards for a significant time (I wasn’t) or if the Kickr is just not bothering to record actual power in ERG mode.
We really won’t know until you try a test with the “ERG Mode Power Smoothing” turned off. A retest in that condition may be more useful in seeing what is really happening here.
1 Like
It’s a known issue that in erg mode wahoo defaults to transmitting target power. Not actual. Dcrainmaker has pointed this out in reviews expressing his displeasure about being “lied to” by the trainer. Sounds like wahoo has continued this practice as a default for the kickr bike.
That difference in feeling is to be expected between big vs small ring - at least in concept. Maybe it’s exaggerated on the kickr bike - but small ring/low inertia riding having a feeling like the resistance drops as you progress through the pedal stroke is “normal”.
So the ‘power smoothing’ option is in fact just a ‘lie to me’ toggle. Awesome.
Maybe, I think the way I had the (really big/little) gears set up is helping expose whatever is going on as well. Maybe Wahoo are just doing a surprisingly amazing job of emulating really low/high gearing?
I’ll probably retest this tomorrow with power smoothing now off (couldn’t find this in the android app, had to install the iOS one, grr) … If anyone has other ideas for ways to tweak the test I’m open to ideas!
1 Like
Check my post about this “issue” : Tacx Flux S - Gearing / accuracy
1 Like
I did a very similar experiment, switching back and forth between the big and little rings, and got very similar data. Big ring was more spiky, bigger power variability, while the small ring looked smoother. Though I am the complete opposite when it comes to feel. For me, riding in the small ring gave smoother power numbers, AND felt way better. My cadence in both was consistent, but the small ring felt better in every way; more stable, easier to stay on target, smaller fluctuations. Whereas the big ring felt horrible to me. I could feel every one of the power fluctuations, and the entire interval felt like a back and forth between too easy/too hard. I felt the overs and unders in power, and made the interval a lot harder to finish. I do all my trainer rides in the small ring, much higher quality workouts for me.
1 Like
Would be really interesting to see your power vs. cadence lines if you have the files still … and was this on a Kickr trainer?
Agree. The problem is the higher fly wheel speed on the trainers. Pick a gear that the output seems the same and stick to that in erg. Specially if you are training outside so the data is more consistent.
1 Like
Yepp. Check the topic I’ve posted on this matter. Although the tacx is reporting the same power output, the 4iiii says differently. Could be that more people having this issue and that’s why the big vs small ring feels different in rpe/real power.
1 Like
Agree.
There are enough posts here on the forum where people say there is a “big” difference in RPE between big and small ring for the same power. My take is that in many cases, its more than just pedaling mechanics driving the difference, it’s also because the power meter measures power differently between the two.
1 Like
Does someone know in which of the podcasts this specific topic is discussed? You all have great input but just curious to hear what the TR team has to say.
They don’t hit it as a specific topic. It is mentioned at least 2 separate times (maybe 3) and it has more to do with specificity than anything. Not sure on the episodes unfortunately, since it’s not a stated topic.
1 Like
After reading the whole thread, I understand that the choice of small vs big ring is quite subjective and comes down to personal preference and goals.
But in regard to the muscles used (flat vs climbing) and performance outcome, I’m sure it’s not that black and white? If I were to train in the small ring and hit all my targets indoors, but ride in the big ring outside on mainly flat roads, there is still plenty of carryover from my indoor training to my outdoor rides in the big ring. Maybe not an optimal carryover but still more than enough.
Obviously, I will have to test this myself by trying it out. Did my first erg ride this morning and will discover what I prefer in the following weeks/months.
1 Like
Re-did a smaller version of my hi-lo gear selection test (on Wahoo Kickr Bike, now with power smoothing turned off). Gears were changed to a more normal 36/52 11-27 range. This was the previous test: Big vs Small Chainring - Same Power (ERG Mode Gearing) - #368 by aurigan
The screenshot shows one interval, first half at 52x11, second half at 36x27. The dip in the middle is the shift in gears across the entire range.
The differences observed are smaller as the gear range is more narrow but, as before, the power in the high gear appears to be more variable while the cadence is smoother. The reverse is true in the low gear - power generation is more smooth, cadence less smooth.
Interestingly, subjectively, it felt somewhat easier in the low gear this time - none of the ‘slipping’ I was previously experiencing @ 30x36, cadence naturally floated into 95-100 range whereas @ 52x11 it felt like I was having to focus to stay >90rpm.
I think this all conceptually makes sense … somewhat easier gears are more ‘tolerant’ of your pedal stroke not being smooth as they allow your foot speed to slow/accelerate without creating big power spikes (because the erg resistance is lower). But, if you go too easy, then your imperfectly smooth stroke gets sorta amplified by the very low resistance and ends up creating such nasty cadence spikes that it feels a bit out of control.
So … really high gear = higher RPE, really low gear = also higher RPE, somewhere in between juuuuuust right.
Presumably exactly which gear would lead to the lowest RPE would be down to how smooth your pedal stroke was - the smoother it got the higher the gear that would work best for you. I guess it’s also possible that the lowest RPE gear for some might be outside of a standard road cassette range.
2 Likes
I have an odd scenario.
I climb outside at a much higher level than I can do in a flat TT. This is probably similar to most people.
BUT
I find big ring efforts in TR much easier than small ring efforts.
So i don’t think that using the big ring on the trainer is the answer to better flat / TT speed. I think there is something else happening.
Which camp is everyone?
Prefer
small ring trainer outside climbing?
small ring trainer outside flat / TT?
big ring trainer outside climbing? - This is my preference.
big ring trainer outside flat / TT?
Can someone do a poll to see if it gives us some direction?
I could, but I think it would be lacking.
- Additional variables like the specific trainer in use (in combination with the gearing), and the rider weight (which matters in terms of their sense of inertia/momentum in riding outside) are likely to impact a person’s choice.
With all the debate, range of experiences, and pure personal preferences… I don’t think there is a singular answer or recommendation that can be given.
-
There are some possible recommendations for a starting point, but I have landed on my preferred recommendation of telling people to experiment and choose what they feel is “best” for them.
-
I know what I like and seems to work for me. I’ve done a lot of experimentation since before this topic started, and even more based on the discussion since then, and think there is no single “right” answer.
-
The additional guess I have is that we are well into “marginal gains” territory (about where it even “matters” towards training impact) with the limited info we have right now.
-
Ideally, it would be great to see some good studies to look into the flywheel situation and see what if anything really hide in it. Until then, all we really have are anecdotes and lots of guessing
1 Like
Thanks.
My approach is to do warm up, rest interval and cool down in the small ring and alternate small / big each interval set starting with the small.
I will ‘fine tune’ with the gear if i fail an effort.
Hopefully that addresses as many limiters as possible.
3 Likes
Just read this whole thread and have flipped on deciding big vs small ring about 150 times. Did down 3 coffees whilst reading this novel though!
In the notes that I have made, I have somewhat formulated a sketch - albeit very rough one - to gather some comments on. I have also summarized as best as I can all of the above:
- SCHOOLS OF THOUGHT + STATEMENTS
Small ring simulates hill riding through lower angular momentum (low inertia is commonly used to describe this in this thread)
BUT WHY?
- Small ring equates to the flywheel spinning slower than the big ring = low angular velocity = Indoor trainer produces more torque to achieve a certain power number
- Small ring has less flywheel speed than the big ring, thus, allowing the unit to adjust closer to the target speed (Video)
- Small ring result in a more smoother and consistent pedal stroke which utilities different muscles than the big ring (Video)
Big ring simulates flat riding through higher angular momentum (high inertia is commonly used to describe this in this thread / flywheel spinning fast = high angular velocity)
BUT WHY
- Big ring equates to the flywheel spinning faster than the small ring = high angular velocity = Indoor trainer produces less torque to achieve a certain power number
- Big ring has more flywheel speed than the small ring, thus, the unit doesn’t track the target speed as closely as the small ring. (Video)
- Big ring result in a wider range and less consistent pedal stroke which utilities different muscles than the small ring (Video)
- WHY DOES ONE FEEL HARDER/EASIER BUT FOR OTHER PEOPLE IT IS THE OPPOSITE?
From what I can gather, the consensus seems to be that riding one way or the other, and finding it harder or easier, is largely dependent upon the type of riding you have done in the past. Predominantly a hill climber = more than likely going to find bigger chain ring harder. Predominantly a flat rider = more than likely going to find the smaller chain ring harder. Riding on the small ring and big ring recruits different muscles in different ratios, thus, depending upon your strengths, weaknesses and prior riding history, one of them seems to be more difficult in the TR sessions.
Photo below of muscle recruitment in the various sections of the pedal stroke. Riding up a hill and/or on the flat, as well as riding in the small ring with low angular momentum and in the big ring with high angular momentum, equates to different muscles being recruited in different ratios:
- WHERE TO NOW?
After going into a deep rabbit whole of threads and reading about prior TR experiences with the small vs big ring the consensus that I have drawn is …
In my own personal experience, I find the small ring easier because I have done a lot more short punchy climbing as part of training rather than the long efforts in the big ring. When I switch over to the big chain ring in intervals I find it more challenging. Some people are the opposite to me, and some are the same - I guess it comes down to the differences and similarities in how we have trained previously.
From what I have read, it seems that preferring one over the other in the TR training, is limiting a potential different training stimulus to add to your training tool bag. That said, I do understand that one of the training principles is ‘specificity’ and am completely onboard with that as a training principle, but unless you are targeting a specific climb or a specific flat TT circuit and need to specifically target the big or small ring for that ride/event, why wouldn’t you want to spice up the old training and jump over into the grey area and use both on the indoor trainer?!
So what is my plan moving forward …
Current TR plan and goals:
I am currently doing the General Build HV plan and am looking at doing the Rolling Road Race HV specialty plan leading into Summer. No races in the pipeline but have some killer group rides down the coast over Summer which involves mostly undulating terrain at high pace. My goal is to become a stronger cyclist in those bunches over the Summer period.*
Biggie Smalls or Smallie Bigs?!
I am thinking about mixing up whole and intra sessions each week on the big ring and small ring so that I can recruit different muscles in different sequences and ratios. I also have a front wheel choc that raises the front wheel to simulate climbing ‘up’ a gradient so I will use that in conjunction with the small ring sessions.
A super rough guide/indication below:
-
Shortoff + 6 (VO2 Max) = Big ring. NO FRONT WHEEL CHOC.
-
Pettit (endurance) = Small ring. FRONT WHEEL CHOC USED.
-
McAdie + 1 (threshold) = Big ring in sets 1 and 3 (12 min O/U’ers) + small ring for sets 2 + 4. NO FRONT WHEEL CHOC.
-
Cheaha (endurance) = Big Ring + will do 3 x 20s 180% FTP spikes in small ring. FRONT WHEEL CHOC USED.
-
Spruce Knob + 3 (tempo) = Small ring for sets 1 and 3 (30 min intervals) + big ring for set 2. FRONT WHEEL CHOC USED.
-
Budawang + 5 (threshold) = Set 1 + 2 small ring (5x9-minute intervals 102% FTP) + set 3, 4 and 5 big ring. NO FRONT WHEEL CHOC USED
NOTE:
By no means is what I am doing the bees knees or gospel! Definitely wouldn’t suite everyone and hey, nothing is ever perfect right?! Personally I just thought it would be interesting to share, and try, an ‘in the middle’ medium approach to the debate.
7 Likes
Good sum up, thanks! One of the big asset of the small ring for me, despite it gives me lower number, is the lower noise. I am using Wahoo Kickr’s (V1 & V2). Using the bing ring makes more noise than 2 big fans blowing air.
Regarding your thoughts, I wouldn’t recommend to use both. I would stick to the one you’ve used for the test. Workouts are doable like that, at least from my experience. That’s the only thing that matters.
-
As you allude to, I do recommend that people test in ERG in the gearing that they plan to use for most training. It will attempt to maintain consistency of data and “Relative FTP” for that gearing and the efforts performed in that gearing.
-
We have seen examples where results of RPE can vary between gearing extremes, as well as the fact that some trainers have more or less power data accuracy at certain gearing ranges. Both of these considerations are important.
-
I do think that considering use of different gearing is a reasonable thing to do. The Slow & Low vs Fast & High ranges make sense to me on one level. Choosing based on your goals, preferences and such are rational, and even mixing in some variety is worthwhile as well, IMO.
-
Some people are more limited with their FTP and trainer combo due to technical limits of the trainer. For those, they may have to use one extreme or the other that doesn’t align with the “common sense” approaches mentioned above. Some may even have to employ shifting to hit the highs and lows of their ranges. Those aren’t a real “problem” in my eyes, because I don’t think we are talking about huge impact to the final training of the rider in any case.
-
All that said, we still do not have concrete info about what, if any, difference that ERG gearing actually leads to for real training impact. It is all anecdotes and gut feeling at this point. It may well fall into the marginal gains territory, if there is any “real difference” in the first place.
-
So the considerations of noise and general preference may be find to place as the priorities and leave the whole flywheel speed as a very secondary consideration.