Hi!
I recently treated myself to a new smart trainer a cycleops 2018 hammer I really like the feel of it, its much quieter and smoother and the resistance changes are great.
makes Zwift a lot more realistic and enjoyable.
(what I used to use which was a elite Muin just a dumb one paired with a power meter)
anyway Ive done a couple Zwift races on it and it seemed to read a lot lower power than my Garmin vectors and Shimano 9100P.
after the first race I made sure everything was up to date…
hammer software,
Garmin vectors firmware
Shimano power meter firmware
calibrated the trainer using the rouvy app
even chucked a brand new dura-ace chain on (as I read that you can loose a bit through old chain, it was due a change anyway)
the trainer came with a brand new Ultegra cassette.
so the second race I dual recorded with the vectors running in the background as well as the Shimano.
the power averages was like this for the 1hr long race
cycleops hammer: avg power : 261.8watts
Normalised Power: 330.4watts
Max watts: 1105watts
Garmin Vector: avg power: 310.4watts
Normalised:379.9watts
max watts:1191watts
Shimano 9100P: avg power: 306.4watts
normalised power:373.7watts
Max power: 1144watts
as you can see the hammer is around 15% lower than the vectors, I feel like I’m missing something I have read other places the smart trainers can read lower than power meters but it seems quite a lot.
I have a SRM sitting on another bike which I might have a look at the difference tomorrow but the SRM always felt very similar to the Shimano 9100P its not going to be 50watts different.
has anyone else had anything similar with a Hammer or any other trainer.
I have a H3 and somilar to my 4iiii left crank over a hour ride. I cannot remember the loss you will see from pedals to a trainer but I think 10% is about normal. They never will match.
With that though try to calibrate hammer with the Saris app and see if there are any firmware updates. Worst case if you trust the garmins more then use that as the power source and the hammer as the controllable for the elevation part.
Hi Mike - I am having a very similar issues to yours. Comparing Hammer to my BePro duo power meter. Understand there is a loss of power inteh transmission, but as you found, it feels much more than I would expect, especially if i add the heart rate trend.
Was wondering if you had tried the suggestion from the other zwifters (saris for controllable and garmin for power) with any luck.
Tks a lot and happy zwifting…from a real novice of this virtual world!!
I was curious about the accuracy of my now 10-month-old H3. Been comparing it to my first-gen Vector pedals over the past few rides, and I have to say, it’s almost exactly what I’d predict if both were operating properly: a 3% lower value on average for the H3. Well within error and drivetrain-loss range. Very easy to compare the two using the “analysis” feature in Zwiftpower if you’re set up there.
tks a lot - will do a similiar test with Zwiftpower. Based on a ride i did at similar intensity the power difference was about 5-6% but i suppose I should do a more accurate test as you suggest. tks a lot.
I think people with more knowledge of this than I have would suggest that even 5-6% is totally reasonable. Most power meters spec a +/- 2% error, and drivetrain losses can be anywhere from negligible to 5% or more. My un-expert opinion would be that your stuff is working well even with a 5-6% discrepancy (assuming the smart trainer is the lower number).
