Watts seem really low

(J im Hubbard (D)) #21

Jeff , just checking , your bike you use on your trainer is it 700 x 23

(Tony Otero) #22

I will check the group on facebook and join. My wheels-tires are 700x23. The reason I contacted CycleOps wass to see if they have changed the formula for the trainer over the years and/or to see if my special edition (it is blue and  it was advertised on the TdF showings) has a harder power curve than current Fluid2. Maybe they marketed one for Pros (which I am not). But, could not get any info from CycleOps Support or truly the Fluid2 is the Fluid2 (but even though the head unit looks exactly the same I am wondering if they always used the same viscosity fluid and quantity, etc). I definitely find it hard to pedal. It is very difficult to get to the lower gears (small rings in back or larger ring in front) as the trainer effort will literally destroy my otherwise healthy knees. I am trying to avoid buying another trainer since this one SHOULD work…it does as long as I ride my own slow pace, as you know.

(Tony Otero) #23

I checked out the Zwift Sub 2  Group but it does not come out as a separate group. So, I assume since I am in the Zwift Rider’s Group I am on it.

(Jeff Shafer) #24

yes it is

(Tony Otero) #25

Did find Shoemith’s group and asked to join…

(Tony Otero) #26



I got a thoughtful response from Zwift Community Support. Without copying  the whole email let me share the specific part:

"we suspect that the Fluid 2 may have changed since 2004 which is why you’re seeing inaccurate readings. While we don’t have a way to confirm this since we don’t have that older model, everything you’ve shown us points to that, as does that forum thread with another user reporting the same issue.

As that is an older model without high demand, we don’t have plans to support it at this time, so our advice at this point (I know you wanted to avoid this, but…) would be to either look into a power meter or another, supported zPower trainer"

 I guess I understand. It is frustrating as I will be moving to the paid Zwift service soon (mainly for the winter) and really don’t want to buy another trainer. I guess a power meter (assuming ant+) is mentioned because that would provide the measured power and then adjust the speed in the program. I would assume that things in Zwift would right themselves and I would be able to go faster for the power exerted and reported.  Frankly, I want to avoid a new $300-400 trainer (and then end up with two) or buying what seems to be a more expensive more accurate option, an expensive $400-800 power meter. Thoughts guys?

(Maurizio Gigliotti) #27

TrainerRoad have option TrainerRelay to transmit as a power meter to zwift.
requires 2 ANT+ dongles

(Jeff Shafer) #28

My Fluid2 is not that old…I’ve had it for 2-3yrs and I believe the previous owner said they had it for 2yrs (and I am pretty sure what I have was the current model when I got it).  Had not heard about TrainerRelay on TR, I used TR exclusively before getting into the Zwift Beta, so I’ll have to see if I can find more info on that.   Means I’d have to keep both subscriptions, but seems like somerthing worth checking out.

(J im Hubbard (D)) #29

Jeff , when using TrainerRoad did you find it more accurate of your rides IRL . If so rebroadcasting TrainerRoad data to Zwift will work . You will need two ant + dongles and most likely two usb extensions . First open TrainerRoad and have connect with one usb + dongle . Then Start Zwift . which will use the other usb + dongle .  It will show on Zwift as if you were using a power meter . https://www.youtube.com/watch?v=08R8RM8BRG0

(Jeff Shafer) #30

Thanks Jim, I will have to try that.  I did some side by side comps in the beginning when I first noticed the issue.  At 120w TR it show about 80w on zwift / 140w TR showed about 100w Zwift.  The delta did seem to lessen some as watts increased…not sure but I think I was seeing 150-155 on Zwift when TR was 180w, but it’s been awhile.  During my group rides the stats I was getting from strava seemed to indicate that TR’s curve was fairly consistent, and if anything TR was probably slightly lower then IRL

(Tony Otero) #31

A couple of updates:

  1. I looked into a power meter. With my setup which uses Ant+ for Zwift and Bluetooth 4 with the Strada Padrone Smart Plus Computer I found two options ‘least’ expensive: PowerTap G3 Hub - but requires new dual Ant+/BT cap which is not out yet (assume $75) plus I would have to have  to have the rear Easton wheel rebuilt for total of $800-$1000, and the Stages left crank Power Meter for my FSA SL-K Hollow Carbon Crank-Set - just change out the left crack…about $623 (assuming it fits my 2008 version of the crankset - I need to double check that it does). Otherwise I have to buy a whole new crankset too (extra $200 for Ultegra 6850 compact).

  2. I tried a friend’s Cycle Ops Jet Fluid Pro and I could immediately feel the lesser resistance lower power curve. Just felt a lot smoother lower increasing effort as I got up to speed. Did not kill my knees the same way. On Zwift I was able to speed around 20 mph at 130 watts on the flats. Where I was previously climbing 7%-10% gradients and 2-4 mph it now seemed like I could do at 5-7 mph and higher power 180 watts (I am not a high power guy claimed on age)…seems more realistic That’s probably about right for me (if not giving me a slight boost.LOL).

During the test I was able to ride and draft at normal speeds although the fast riders were still much faster. It just seemed like I was able to find more riders to draft and ride with and, actually, the whole experience felt much more fun (dare I say social?). 

  1. I then went back to the CycleOps2 because I had an idea to take off the bladed flywheel (jam a screwdriver in the hole to stop it from spinning and then use a ratchet wrench to take off the bolt pull off the flywheel and then out the bolt back on). That gave me about a 15% boost but still not enough. The bigger issue was that without the flywheel the unit just felt dead with no momentum. Not too much fun to ride. So, back to the drawing board.

  2. Given that varying the resistance seems like a good idea, I looked at some Magnetic Trainers. Howver, I read that they get easier as they go up in speed (makes sense it works that way) not gradually harder like fluid trainers and riding outdoors. Although looking at a power curve from one particular JetBlack M5 Pro (5 resistance levels) it makes it hard for me to understand this behavior since the curve does gradually increase. These are about $300. 

So,  the question is I a) do nothing save my money and ride slowly, b)  buy a new or used CycleOps Jet Fluid Pro - about $350 but it does not have variable resistance, also has to be used in the Zwift general ‘virtual power curve’ (not Zpower) and not as accurate c) Buy a Mag trainer like the M5 with its variable resistance, or d) bite the bullet and buy the darn power meter, Stages likely, assuming it fits my crank…otherwise I have to buy a new cranckset too (would probably go back to Ultegra 6850 compact crankset so another $200).

So, I know I should buy a power meter that I can use in and outside, but, honestly, it bugs me that a device that uses mainly strain gauges as  sensors, a dual transmitter, a battery, and minor electronics to process and do some calculations, balloons the price up to us to $1000. This is probably on $30 worth of parts…just bugs me. Makes no sense to me having played around with strain gauges and electronics in college.

Aaaagghhh  All this for enjoying winter riding here in New Jersey. Thoughts?

(Maurizio Gigliotti) #32

fluid 2 power curve ( vpower = trainerroad )

20km = zwift 79  watts  vpower 122 watts
25km = zwift 133 watts vpower 171 watts
30km = zwift 210 watts vpower 233 watts

tacx blue motion powercurve
20km = zwift 132 watts
25km = zwift 182 watts
30km = zwift 238 watts

(Tony Otero) #33

Maurizio those differences are not surprising. The differences are consistent with my general observations of low power numbers on Fluid2 (my number indicate 150 watts normal ride turns into 100-110 watts) and why Zpower then takes the power output and drops the effective speed in the game.

(C) #34

Hey Tony - well, I have to admit, I’ve done some online window shopping for power meters etc, but then I come back to reality and realize that I can’t throw any more money at my Zwift setup.

You know how the Fluid2 manual says to tighten the knob 2 to 21/2 turns… are there any calculations that can be done to figure out a better resistance setting for the flywheel? For example, instead of 2 1/2 turns… only 1 turn or something?


(Tony Otero) #35

Chris, I am with you on the power meters. So, on the Fluid2, while I have not done tests on this, it seems that varying the turns and tire pressure only gives you a very slight difference in the power curve…let’s put it this way, I can’t feel or measure it (without doing extensive tests). The only caveat is if the tire slips against the roller. Of course the problem with that is that it wears down the tire leaving a rubber strip on the roller (found this out by accident).

If I am to do something I should do it soon and get it in as a holiday present. That would pass the WAF.

(Jeff Shafer) #36

Jim, thanks for the insight on using TrainerRoad to relay the data to Zwift.  I tried that Friday, and for once I was actually riding with people.  It was like a whole different riding experience.  Much appreciated!

(Tony Otero) #37

Okay, here is my greatest stupid idea: what if I drill a small home on the top of the fluid unit and use an aquarium hose to suck out some of the fluid until the resistance curve matches the proper output (but where exactly to drill and how deep)? Cover with duct tape during the testing period until its where it needs to be then user a tap to thread the hole and a short screw with silicon to seal it.

(Maurizio Gigliotti) #38

tony try choose trainer tacx blue motion in zwift .

20km = zwift 132 watts
25km = zwift 182 watts
30km = zwift 238 watts

vs clyleop fluid 2 vpower trainer road

20km = vpower 122 watts
25km = vpower 171 watts
30km = vpower 233 watts


(Tony Otero) #39

Maurizio that  power curve seems better for me. I will try it. By the way, I have been looking at the lower priced tracx trainers to purchase.

(Jeremy Belcher) #40

I’ve got an older Fluid2 and get my butt handed to me in Zwift. I’m not in shape at all, but I’m generally in the bottom 2% of Strava segments while using Zwift. 

I finally purchased a Powertap wheel and compared it with the Zwift Fluid2 output today. Did a simple 20 minute ride at a fixed speed/cadence for the entire time. 

The Fluid2 increased in resistance over the 20 minutes due to heat. The trainer was in a heated room (~70 deg). 

Per the Powertap, I started at 115W and gradually increased to 150W by the 20 minute mark. 

Zwift reported 83W for the duration. 

Starting error of 40% increasing to 80%, explaining my horribad performance in the Zwift world and Strava segments. 

I’m going to experiment with wheel-to-trainer tension a bit and see how much that affects things. 

My tire was inflated to 100psi and trainer tightened to 2.5 turns per Cyclops instructions. 

So, if you’ve got an older Fluid2 trainer, it’s not just you :wink: