I just have to ask: Which Trainer?
#1
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I just have to ask: Which Trainer?
It’s that time of year and there is usually one thread started where someone will ask “which trainer should I get?” Well, I haven’t read one that helps with the questions I have concerning turbo trainers. I currently have a set of Sprotscrafter rollers and a Minoura Mag trainer with handlebar mounted resistance control. I still plan to use the rollers in my indoor training but would like to upgrade the trainer. I have looked at some smart and not-so-smart trainers from Elite and Tacx. The not-so-smart trainers are ones with a digital handlebar mounted readout connected to the brake system that reads speed/watts/cadence/etc.. while the smart trainer uses a smart phone with applied app. I would like to pair my Garmin Edge 500 with it and use that for the information instead of my phone. I’m not into the Zwift or any computer based functions, just mainly interested in the power and slope with typical speed/distance etc… Any suggestions would be gratefully appreciated.
Here are a few that interest me:
Tacx Flow Ergotrainer with Skyliner Wheel Support - T2200 | TotalCycling.com
Qubo Digital Wired Turbo Trainer - | Decathlon
Elite Qubo Power Smart B+ Trainer
Here are a few that interest me:
Tacx Flow Ergotrainer with Skyliner Wheel Support - T2200 | TotalCycling.com
Qubo Digital Wired Turbo Trainer - | Decathlon
Elite Qubo Power Smart B+ Trainer
#5
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In theory, a fluid trainer should provide you with a more accurate and consistent power reading than any meter measuring strain/acceleration.
#6
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In theory, but the reality is the viscosity of the resistance fluid changes with temperature. This generally is a problem when the trainer is cold up until the fluid warms and then can be a problem again after a certain duration and speed. Many of the mainstream fluid manufacturers attempt to compensate for this with various different design and cooling mechanisms, but I'd take a strain gauge any day over a prescribed resistance curve.
#7
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In theory, but the reality is the viscosity of the resistance fluid changes with temperature. This generally is a problem when the trainer is cold up until the fluid warms and then can be a problem again after a certain duration and speed. Many of the mainstream fluid manufacturers attempt to compensate for this with various different design and cooling mechanisms, but I'd take a strain gauge any day over a prescribed resistance curve.
The Kurt fluid trainer I use, is filled with a "thermodynamically neutral liquid silicone", so power estimates are consistent across changes in the liquid’s temperature.
I did a lot of reading before buying the "InRide" power meter for my Rock and Roll trainer.
For $50, I added on a "power meter" that has been shown to be very accurate.
I don't think in any way I would be "much better off" with a $600 Stages unit for my indoor winter riding.
#8
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From: Lexington, SC
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Over time using the trainer will mean the chemical composition in the fluid solution will break down, and will be less "thermodynamically neutral". Temperature stability will only be within an upper and lower range of temperatures, and speeds. Outside those ranges the fluid is not "thermodynamically neutral", and those ranges will become narrower due to use.
That said, the trainer will be consistent day-to-day, and workout-to-workout. However, if you were to plot the in-ride power against a strain-gauge-based power measurement, you'd find that the in-power is less accurate season to season.
#9
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I should have been more specific.
The Kurt fluid trainer I use, is filled with a "thermodynamically neutral liquid silicone", so power estimates are consistent across changes in the liquid’s temperature.
I did a lot of reading before buying the "InRide" power meter for my Rock and Roll trainer.
For $50, I added on a "power meter" that has been shown to be very accurate.
I don't think in any way I would be "much better off" with a $600 Stages unit for my indoor winter riding.
The Kurt fluid trainer I use, is filled with a "thermodynamically neutral liquid silicone", so power estimates are consistent across changes in the liquid’s temperature.
I did a lot of reading before buying the "InRide" power meter for my Rock and Roll trainer.
For $50, I added on a "power meter" that has been shown to be very accurate.
I don't think in any way I would be "much better off" with a $600 Stages unit for my indoor winter riding.
Fluid resistance is nice, but if you want to use things like zwift you need feedback that the electronically controlled trainers provide you .
What's this $50 power meter you've added?
#10
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No such thing... that's what happens when you let marketing into engineering.
Over time using the trainer will mean the chemical composition in the fluid solution will break down, and will be less "thermodynamically neutral". Temperature stability will only be within an upper and lower range of temperatures, and speeds. Outside those ranges the fluid is not "thermodynamically neutral", and those ranges will become narrower due to use.
That said, the trainer will be consistent day-to-day, and workout-to-workout. However, if you were to plot the in-ride power against a strain-gauge-based power measurement, you'd find that the in-power is less accurate season to season.
Over time using the trainer will mean the chemical composition in the fluid solution will break down, and will be less "thermodynamically neutral". Temperature stability will only be within an upper and lower range of temperatures, and speeds. Outside those ranges the fluid is not "thermodynamically neutral", and those ranges will become narrower due to use.
That said, the trainer will be consistent day-to-day, and workout-to-workout. However, if you were to plot the in-ride power against a strain-gauge-based power measurement, you'd find that the in-power is less accurate season to season.
Liquid silicone has exceptionally high heat resistance, exceptionally low thermal conductivity, high viscosity stability (through large temperature changes), and "extremely high" shear stress resistance.
What do all of these properties mean?
Over the life of a fluid trainer, used within it's normal trainer duties, the fluid will not break down, and it's viscosity over the course of a workout will not affect power readings.
#11
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From: Lexington, SC
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#12
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It's a known fact and has been proven many times with people that have done extensive tests that the "virtual curve" power meters aren't accurate, that was my point about the B+ meter as that it's not a real power meter.
Fluid resistance is nice, but if you want to use things like zwift you need feedback that the electronically controlled trainers provide you .
What's this $50 power meter you've added?
Fluid resistance is nice, but if you want to use things like zwift you need feedback that the electronically controlled trainers provide you .
What's this $50 power meter you've added?
I assure you, I don't need the feedback of a smart trainer to enjoy Zwift.
When the grade changes and my speed drops, I shift gears to raise resistance, and the extra power makes me climb faster.
#14
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From: Lexington, SC
Bikes: Lynskey R240, 2013 CAAD10
Having worked with silicone-based fluids when I was in a research lab, I can say that they do break down. Noticeable? No. Measurable? Yes. The point I was trying to make is that strain gauges offer a more consistent measure over time.
I have a CycleOps Fluid2 that's about 11 years old, with roughly 800 hours on it. No leaks, but its silicone-based fluid has broken down to the point where operating viscosity requires a longer and longer warm-up period. I used to track the data when I had my PowerTap wheel, and not only is it measurable, but it's noticeable. About 10 minutes of wheel speed approx. 20 mph and initial temp of 70°F and then there's a dramatic increase in resistance. That's kinda contradictory to the previous statement, but what I mean by noticeable is that day to day, week to week and month to month you won't notice the changes.
I don't plot that trainer any more since getting a Kickr.
Last edited by silversx80; 11-16-16 at 09:48 AM.
#15
I started using the Kinetic Rock and Roll Trainer. Ive only put about 70 miles on it thus far, and I can say that if I sat stationary, I would be bored out of my mind. Don't get me wrong, doing 20 miles on this trainer is mentally exhausting as is, but it would be worse on a regular stationary trainer. I follow one video where all you do is grind up a hill, and rocking back and fourth makes it that much more fun as you see the guys in the video do it. About 50 minutes into it, you get to the top of the mountain and afterwards you have a long descent. It is so pleasurable to actually lean in on the corners and watch the camera tilt as well, giving you a realistic feel as you still have to engage your core to get back to level state.
On a side note, I think trainers are boring in general, I wish I could ride out but drivers here are crazy and lacking patience, that I don't want to risk getting hit at night. Its bad enough battling them during daylight.
On a side note, I think trainers are boring in general, I wish I could ride out but drivers here are crazy and lacking patience, that I don't want to risk getting hit at night. Its bad enough battling them during daylight.
#16
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Well, there we go. 
Having worked with silicone-based fluids when I was in a research lab, I can say that they do break down. Noticeable? No. Measurable? Yes. The point I was trying to make is that strain gauges offer a more consistent measure over time.
I have a CycleOps Fluid2 that's about 11 years old, with roughly 800 hours on it. No leaks, but its silicone-based fluid has broken down to the point where operating viscosity requires a longer and longer warm-up period. I used to track the data when I had my PowerTap wheel, and not only is it measurable, but it's noticeable. About 10 minutes of wheel speed approx. 20 mph and initial temp of 70°F and then there's a dramatic increase in resistance. That's kinda contradictory to the previous statement, but what I mean by noticeable is that day to day, week to week and month to month you won't notice the changes.
I don't plot that trainer any more since getting a Kickr.
Having worked with silicone-based fluids when I was in a research lab, I can say that they do break down. Noticeable? No. Measurable? Yes. The point I was trying to make is that strain gauges offer a more consistent measure over time.
I have a CycleOps Fluid2 that's about 11 years old, with roughly 800 hours on it. No leaks, but its silicone-based fluid has broken down to the point where operating viscosity requires a longer and longer warm-up period. I used to track the data when I had my PowerTap wheel, and not only is it measurable, but it's noticeable. About 10 minutes of wheel speed approx. 20 mph and initial temp of 70°F and then there's a dramatic increase in resistance. That's kinda contradictory to the previous statement, but what I mean by noticeable is that day to day, week to week and month to month you won't notice the changes.
I don't plot that trainer any more since getting a Kickr.
#17
<---- Staff Systems Engineer
As I teach junior engineers -- perfect is the enemy of good. There will always be sources of noise (uncertainty) in the system that you can't afford to design out. So you design in enough margin that you don't care. The same is true for power measurement and training. Your legs don't need extreme accuracy. For example, if your workout calls for 3 minute VO2Max intervals you need to be somewhere between 105% and 120% of FTP. Target the middle of the range and even a 10% difference between power readings on your FTP test and your current workout won't take you out of the zone.
Back in the day, riders got plenty strong training with RPE and occasional heart rate measurements with a stopwatch. Virtual power, when used wisely, is a useful tool for amateur riders. There's nothing wrong with using something better if you can afford it, but if you are talented enough to actually need it, your sponsors will hook you up.
As I teach junior engineers -- perfect is the enemy of good. There will always be sources of noise (uncertainty) in the system that you can't afford to design out. So you design in enough margin that you don't care. The same is true for power measurement and training. Your legs don't need extreme accuracy. For example, if your workout calls for 3 minute VO2Max intervals you need to be somewhere between 105% and 120% of FTP. Target the middle of the range and even a 10% difference between power readings on your FTP test and your current workout won't take you out of the zone.
Back in the day, riders got plenty strong training with RPE and occasional heart rate measurements with a stopwatch. Virtual power, when used wisely, is a useful tool for amateur riders. There's nothing wrong with using something better if you can afford it, but if you are talented enough to actually need it, your sponsors will hook you up.
#18
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From: Lexington, SC
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When I bought mine in 2005 I remember the included literature stating it was a silicone-based fluid... or that may have been an email conversation with the company. I can't remember which one it was. Also, if my memory is serving me correctly, pretty much all major fluid trainers use similar silicone-based fluid compounds.
#19
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I was worried with the increasing engineering participation that validated assumptions would creep in and logic would begin to make it's way into the forum.
Then you relieved me by making a very BF statement, and putting these worries to rest.
#20
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From: Lexington, SC
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<---- Staff Systems Engineer
As I teach junior engineers -- perfect is the enemy of good. There will always be sources of noise (uncertainty) in the system that you can't afford to design out. So you design in enough margin that you don't care. The same is true for power measurement and training. Your legs don't need extreme accuracy. For example, if your workout calls for 3 minute VO2Max intervals you need to be somewhere between 105% and 120% of FTP. Target the middle of the range and even a 10% difference between power readings on your FTP test and your current workout won't take you out of the zone.
Back in the day, riders got plenty strong training with RPE and occasional heart rate measurements with a stopwatch. Virtual power, when used wisely, is a useful tool for amateur riders. There's nothing wrong with using something better if you can afford it, but if you are talented enough to actually need it, your sponsors will hook you up.
As I teach junior engineers -- perfect is the enemy of good. There will always be sources of noise (uncertainty) in the system that you can't afford to design out. So you design in enough margin that you don't care. The same is true for power measurement and training. Your legs don't need extreme accuracy. For example, if your workout calls for 3 minute VO2Max intervals you need to be somewhere between 105% and 120% of FTP. Target the middle of the range and even a 10% difference between power readings on your FTP test and your current workout won't take you out of the zone.
Back in the day, riders got plenty strong training with RPE and occasional heart rate measurements with a stopwatch. Virtual power, when used wisely, is a useful tool for amateur riders. There's nothing wrong with using something better if you can afford it, but if you are talented enough to actually need it, your sponsors will hook you up.
As an engineer, I agree. As a cyclist, I don't. The higher your FTP, the bigger the jumps with those ranges. My FTP right now is about 340W (using the 95% method), so my VO2 range is 357W to 408W. 50W, no matter who you are, is a big jump. I can carry 357W for a little over 20 min on fresh legs, while 408W is only good for about 5 min tops on those same legs. So the power difference is not a linear comparison to time in zone (400% time in zone does not require a 25% drop in power). Caveat: persons, conditions, training loads will all add variability to performance.
Can the amateur benefit from more accuracy and precision in their training data? Yes, if used properly. And, precision is more important than accuracy anyway. You don't need to be a pro to reap the benefits.
#21
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From: Lexington, SC
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Engineers agreeing in the same forum, using logic for arguments? Witchcraft, I say!
#22
It's the Kurt "InRide" module.
#25
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An "amateur" cyclist may get some use out of virtual power if he/she uses it wisely... That made me laugh.
If speed and resistance are known, "virtual power" is at least as accurate as measured power.
Road cyclists use meters to measure power because resistance is unknown.
Resistance and speed are both variables in a measured power calculation (power meter on the road), yet speed is the only unknown variable in a "virtual" power calculation.
How could you argue a calculation with more variables is more accurate?
Because it's cycling..




