BestBikeSplit and Zwift

John Katsoudas

I just upgraded to a Premium membership on BestBikeSplit using the Team EN discount (Yay!) and I've been playing around with the different models.  I see that there's an option to export a BBS race plan to a .zwo file that can be used as a custom workout in Zwift. Does anyone here do this? If so, What things are you looking to validate when you ride one of these race simulations?  I could see doing a few of these to try out different IF, max power settings, and overall TSS, and see how running off the bike feels with the different plans.  Do you do these throughout the season or save them for when you're getting closer to race day?  I'd love to hear how folks are using this capability.

Al Truscott

Using BBS to test-drive potential race-day strategies is a good idea. And Zwift is a great training tool. But I would argue that mixing them together would not be as helpful as doing the BBS test-ride in the Real World. Things like managing nutrition when not sweating in a pain cave, dealing with wind, holding aero position for hours at a time, learning about the effects of clothing & bike gear, being able to do a real T2, etc, etc provides much more actionable data for a race. All this grows in importance the longer the race is. So playing around for an Olympic - might work.
It's hard enough to fully simulate and thus fully prepare for what happens over the course of a 5 hour day on the road in an HIM. Adding the artificiality and potential disconnects from riding in Zwift just makes the issue that much more complex.

John Katsoudas

Thanks @Al Truscott .  I totally agree that all of those things are important to test and practice.  However, I'm wondering specifically about validating one BBS power plan vs. another, i.e., different IF, different capped max power, how running off different TSS feels, etc.  I honestly can't see myself riding all the various segments of a BBS race plan outdoors accurately enough to be able to validate one plan vs. another.

For example, here are two plans I'm looking at for 70.3 Coeur D'Alene:

Plan 1:  0.80 IF, max power 90% FTP (256),  NP 226, VI 1.02, TSS 163, Time 2:33:37

Plan 2:  0.82 IF, max power 85% FTP (241),  NP 233, VI 1.01, TSS 171, Time 2:32:33

These two plans are within 1 min of each other, but plan 2 is a flatter power profile where I "burn fewer matches" on the climbs but higher overall NP and TSS.  I have no idea which one I'll be able to run better after.  This is the sort of stuff that I was hoping to be able to validate by riding these two scenarios in Zwift, followed by a brick run.  Am I way overthinking this?

Al Truscott

Hopefully someone with actual experience using BBS to fine tune an HIM bike leg will answer your question - all I have is opinion and bias. And my bias is that the lowest possible VI at the proper IF will result in the best chance for a successful run.

The Coeur d'Alene bike course does not contain any steep climbs - they are long, but "highway grade", meaning 4-6%, completely doable in aero position. Likewise, the downhills are gentle enough that I was able to pedal the entire way down, hitting 42-5 mph. I can't imagine that Option 1 is better than 2, as far as ability to run off the bike is concerned. And I also doubt that in the real world, you'll end up doing the VI shown in either.

Gabe Peterson

I used BBS with TrainerRoad in the past.  I plan to use it with Zwift this season for Oceanside 70.3.  For IMSR, I will probably break it into two parts just because I don't know that I can do 5-6 hours on the trainer.  For Oceanside I already created the power profile in BBS, exported the .ZWO file, and loaded it into my customer workouts.  It appeared correct when I looked at it in the workout builder.  I'll try it in the next couple weeks.

When I did it with TrainerRoad, I found it was a good way to get used to the power output for the course.  Naturally, race day will be a bit different.  Even better, you can take the BBS power out of the race course using Garmin Power Course.  I found that very helpful to avoid overcooking the bike, especially on hills where other racers mystifyingly drop the hammer.  You can read an account from my Boulder 70.3 race report.

Rich Stanbaugh

I used BBS to model Cabo and I downloaded the BBS course to Zwift. I had a couple goals: 1.) to get a feel for how tired I would be after riding the BBS course, and 2.) just to have a model of the Cabo hills that I could ride.

Initially, I created the BBS file by setting a target TSS. I did not like the ride file this generated because there were (my opinion) some unreasonable power spikes. My goal with BBS was to push the hills a little, ride the downhills and flats a little easier and end up with a TSS around 240. When I planned the ride for 240 TSS, BBS had me pushing VO2 powers up some of the hills.

So I changed my approach. First I used BBS to plan the ride using the BBS mode for target TSS. I then took the resultant normalized IF from that plan and set the BBS planning mode to be the Normalized Power Mode and, in this mode, used the IF from the TSS mode capped my max watts at 80% of FTP. I generated a new course file using these settings.

The result was a race file that had nearly the same TSS as my target, but the ride file did not contain any surges above 80% ftp (and these were on high grades for short times).

I found this approach to generating the file to give me something that matched my goals of slightly pushing the hills in strategic places in order to optimize the time for the effort while, at the same time, not including any unreasonable (my opinion) power spikes.

Riding this course in Zwift was helpful for me. Zwift showed me the unreasonable climbs in the original files and led  me to the above process of choosing the power cap (80%).

Hope this helps!

Chris Oubre

I used a BBS file on Zwift for IM New Orleans. That course is totally flat and doesn’t really benefit for a BBS plan. 

That at said I ride a dumb trainer and was unable to make it out doors for my RR ride. The BBS workout file enabled me to estimate how long I needed to ride on Zwift to get the tss in my legs for the run. Not a true RR but the best I could get. 

For what it’s worth, other than all the issues A pointed out regarding food, sweat, etc...  it will be a good simulator of the effort on race day if you rode the course alone. Much closer than if you just did 56 miles at some local course.