Just to be certain, you know crank length has to be correct in your bike computer, right? Every app or device you use has to have the correct crank length for them to read power correctly.
Also, it’s possible that you have a larger than typical power imbalance. I have about a 55% left to 45% right power imbalance. If I use a left only power meter, my readings are 55x2=110% of the actual power. Though now that I think of it, your Kickr is reading total power so I guess we can rule that out in your case.
numbers…power, etc…relate only to you and trying to compare them to others in a group ride doesn’t work.
riding position, cadence, fitness, etc. all go into the pot as it pertains to the metrics of power and heart rate.
aero is nearly everything…maintaining an efficient position is the biggest followed by clothing…baggy, floppy clothing is a watts thief and you will work harder than someone is more aero…not baggy…kit.
if you’re riding with more gravel oriented tires this is also a watts thief and you will work harder than the rider with ‘road’ tires.
cadence is also a mark of efficiency…the higher the cadence the less muscular effort and overall lower power numbers so perhaps if your cadence is under 85rpms compared to those at 90+rpms your watts will be higher.
well done for keeping up with the fast group on your first group ride…
I don’t want to fat shame you, but you claim to be a “lean 170lb”, at 5’7. I’m 168lb at 6’ and feel I could stand to lose 5-10lb. I’m certainly not fat, and I’m not saying you are, but I wouldn’t describe myself as lean.
I’m guessing you have a lot more muscle than me maybe. But anyway, I’m not saying “you need to lose some weight”, just that for a roadie 170lb isn’t very light.
I obviously can’t see any of the other riders you rode with, and if you said how hilly it was I missed it, but if they’re (say) 150lb, that could go a long way to explaining away a lot of the discrepancy in watts you’re seeing. In the fast group on the rides I go on some of the guys are as little as 130lb… I’m envious of their W/kg, but at the end of the day I’d rather be all-round strong than look like the next MTB crash will snap my body into smithereens!
You definitely are lean even if you don’t describe yourself as! I’m 6’1, 172 lbs and I have veins in my abdomen and my quads at rest . I’m probably around 10% body fat.I get the idea you’re trying to make with the OP, but let’s be realistic as amateurs.
You can’t just judge what a body will look like based on height and weight. There’s a reason BMI is widely considered to be very inaccurate for similar purposes.
If you want to get a better idea on the why, I found this YouTube video very helpful to visualize the issue
For for fun . Today I took out my road bike. Tarmac SL7. Road the same pavement route I was riding on my gravel bike. Road bike is 1.4lbs. Lighter with 28mm instead of 45 tires. I was about 6 mph faster at about the same watts.
That is really extreme! No way would I see that big of a difference - there must be more going on there other than tires. Your cda must be dramatically lower on your road bike. Weight wouldn’t account for much of the difference
It sounds like your doing everything right in terms of equipment. I still dont think it all completely adds up though. While all the aero items mentioned by this group are important and matter, id be very surprised if your wearing baggy clothes, etc enough to make a 35 - 40 watts difference.
My group spends a lot of time talking about power and trying to normalize things between ourselves. We find the 2 biggest factors to watts differences are rider weight and size, and who does the most pulling vs drafting. Assuming your with an average amateur group, your weight / height is probably about average. The other major factor that could be playing a role here is how you pause your computer (auto) vs others who may manually turn it off (or not and forget).
Id also expect a gravel bike to need more power for same speed, but i doubt it makes 35 - 40 watts difference, especially in a group.
I suggest going out with that group a few more times, and pay closer attention to what others are doing in terms of riders weight / size, clothing, power meters, pausing computers, etc and normalize as much as you can to ensure there is truly this big of a difference.
No way would I see that big of a difference - there must be more going on there other than tires.
I have road wheels for my gravel bike. When i ride it with the road wheels its about 5-7 mph slower than with the road bike on the same route at the same power.
that said, group riding is a distinct skill. I have been working hard to learn it, and i can stay respectably in the b groups. when i join the A groups all my inefficiencies are glaringly obvious. a semi truck might put out more torque but a sports car will get more speed.
That’s wild to me! I’m about 2 mph difference between my MTB and road bike at the same watts. I think I’m pretty slow relative to power output on my road bike because it’s a pretty relaxed position, but still…
Add the Evade helmet to the list . I forgot about Q factor. Then there is the difference in power meters. Shimano road, SRAM gravel. Even calibrated they can be a percentage off. I think all things add up .
I wish. Back in the day…More like 13 gravel bike 19 road bike. The gravel bike even feels slower on the road. It’s more of a mash fest vs easy spin on the road bike . On gravel it’s fine.
My old PowerTap wheel based power meter often had to be re-calibrated after 10-15 minutes of riding. This was the case especially during cold months because I keep the bike inside the house. Some power meters have temperature compensation.
I’m also thinking that your aero position on a gravel bike is different to one on a road bike.
From what you said about your hoods with flat forearms position being hard to hold for long, I think you’d benefit from a good bike fit. Speak to your riding mates. There’s always a few that had it done by a professional fitter. IMO best bike related spend ever
