DI2 Shifting Analuysis from IMMOO
Very cool stuff. DI2 is a game changer on technical courses like this, primarily because you can shift from the hoods. This sort of analysis will further let you maximize the speed from every watt you push. Can't wait to start analyzing this on my rides...
http://www.onetriguy.com/2015/10/29/ironman-shift-data-analysis/
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Question: Do you think it's necessary to 'compete' on race day? I ask b/c I'm starting to shop for a new bike in the near future. Bike prices have become so crazy over the last few years. I'm wondering if I'm leaving too much on the table if I stay old school with cables.
No doubt DI2 offers an advantage but only makes a difference on the margin. It's not going to make up for you being 20 watts short of your goal on race day. It also depends on the nature of the course you are racing as well. It won't be as advantageous at IMFL or IMAZ as it is at IMMOO or IMLP.
Ultimately it gets down to how much you want to spend. I personally like to buy my toys (cars, bikes, etc) slightly used as the prices drop precipitously after about a year. Case in point I bought my 11 speed DI2 Dura Ace P5 (MSRP of about $10,500) for $5,200 and it was less than a year old and visually almost perfect. You need to be patient and wait for the right bike at the right time, but it's worked for me many times.
Depending on how much you are looking to spend I'd certainly consider buying an older frame with DI2 vs. a brand new off-the-showroom-floor bike with mechanical. Case in point...Coach R road the IMMOO course with me three days in a row in July. He was riding his old P3 and had installed DI2, but it wasn't set up for internal cable routing so he had a Sanford and Son setup with wires handing all over the place with zip ties. Despite that, and 8+ year old frame technology he blistered the course...ultimately riding faster than he did on race day with Dino's borrowed P5.
What's your budget? I'm happy to help keep an eye out for you. A lot of folks are nervous about buying a high end bike on eBay....but I have done it many times and would do it again in a heartbeat. The buyer protections are strong enough in the unlikely event of an issue (I've probably bought a cumulative $15K+ in my lifetime without a single issue)
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And, as Jeremy notes, upgrading an "older" bike is always an option. In 2013, I put Di2 on my TT bike, originally purchased in 2000. Dont think I went any faster, or become more competitive, but I stopped thinking so much about shifting while riding. Kinda like the diff between stick and automatic.
As far as what to do with the data...I hear you. It's really cool stuff. I don't think there's as much practical application during a race, but more of a retrospective look that call allow you to evolve your race execution over time. For example if you see that you spend a lot of time in your big ring at low cadence and high watts, you may realize that you need to focus on this to lower your VI, for example. Just scratching the surface on this so hope we can learn from others as this data starts to be utilized more often. I view this as similar to swimming heart rate, which I know you have used Matt. Since you aren't going to be looking at HR during a swim there's basically no on-course application but by looking at trends over different swims in different conditions there may be application to adjust how you swim in the race.
What DI2 are you moving to? Ultegra it Dura Ace ? 10 or 11 speed?
The number could be anywhere in your range or even more.
"Even more". Yes.
For me, once I went to DI2 I can't go back. I rode it on my 10spd until 11spd became an option. I am not savvy enough to say 11 vs 10 speed; real speed comes from just getting F-ING stronger on the bike. But on a course where you are making countless shifting decisions, across 112 miles, to have them executed instantly vs waiting, say a second, is huge.
I can literally push my biggest gear in to a 10% hill and at the last second hold the buttons and I am flying. Contrast that with the person who has to shift, incrementally, over the course of the 1/4 mile build up, to get to the right space without dropping a chain, etc.
My personal bias is that triathlon race day speed is all about conserved momentum -- and DI2 facilitates that significantly (for me).
I don't have the Dfly so I can't really add anything else.
Thanks – I’m happy to share. Will try to keep my geek in check
A couple things needed to put my thoughts into perspective I am not a very experienced cyclist. I bought my first bike about 4 years ago. This means that I am still learning a lot of skills that more experienced people take for granted and this affects how I use and think about equipment. Also, If I am carrying it, I want to use it. No point in having 22 gears if I spend 80% of the time in 3 of them. Currently, my FTP is ≈255 down from 260+ in August (this according to WKO4 - I have not tested recently, just using the mFTP number) and I weigh ≈69-70kg... depending on how much beer I drink this week
Heading to CHOO, I had my bike setup with 50/34 up front and 11-25 in the back. I have an 11-speed Dura Ace with Di2 and D-Fly. There are not many hills at CHOO, it is a lollipop course design with two loops. Each loop is a net climb on the way out and a net descent on the way back with nothing that is very steep or long. Somewhat technical.
I rode a recon loop with the 11-25 and saw the following:
CHOO Recon Ride Stats
Summarizing, I was spending half as much time descending in the 50-11 that I spent climbing in the 34-25, and while descending, I was only hitting 50% of my wattage target and averaging a speed I could easily hit with a 50-12 setup. While climbing in 34-25, I had to crater my cadence to hit target watts. I wasn’t really using the 11t and thought that if I went to a gear above the 25t I would be able stay in the big chain to get over some of the rollers.
Based on all of this – I changed my setup from the 11-25 cassette to the 12-28 cassette for the race.
For what it is worth, I chose between those particular cassettes because I need a 16t gear with the compact crank. It is a 21 mph gear for me and with out it there is a 3mph gap between the 50/15 and the 50/17. This limits my selection of standard Shimano cassettes.
Overall ride stats below – the power data below (Pavg 170w / Pnorm 180w) does not match what came from the Garmin (Pavg 177w / Pnorm 180w) – I think that there was a tail on the ride file, after I got off the bike, that I cut off for for power analysis that is still included here. Race time was 5:31:25 (https://www.strava.com/activities/401802459):
IM CHOO Ride Stats
I'm Headed to IMFL right now... here is the how I used d-fly data for the setup.
I tried to put the 11-25t back on my bike for the flat course. I don’t have the bike skill and pushing a big gear with low rpm doesn't work yet. I burn too many matches with the mashing (knee gets sore too). Even on a flat course, d-fly was telling me that I do not ever benefit from the 11t so I am back to the 12-28 and that anything over 2% grade resulted in a chain ring shift. I switched back to the 12-28
At my current skill level – I believe that I will always better off with one extra climbing gear than with one extra fast gear, just because one any course that ends where it starts, more time will be spent climbing (low speed) than descending (high speed). I clearly need more horsepower
It is on my list of skills to build next year to learn to comfortably push a big gear at low cadence. I don’t have an opinion on it other that a lot of really good riders have this skill and I would like to work on it to see how it changes my approach to flat courses.
I have been considering how I can use it during training to identify skill gaps and drive improvement in these weaknesses. I don’t have a good answer for how to do this yet… it seems best suited for matching the equipment, the rider’s abilities and the course in order to optimize bike setup for race day. It is objective data to help make decisions.
The Di2 has helped me ride above my skill set. As a relatively new rider, I find myself shifting late. I find it hard to keep the VI super low with any hills. With Di2, I lock in a cadence and RPE, then shift to make power adjustments. The Di2 is so solid and so certain when it shifts that it is very forgiving of my novice riding skills. Similar to driving an automatic vs a manual transmission.
I love it. Anna didn’t see the need – but I put it on her bike anyway. Now she loves it. It makes riding steady easier (my opinion).
This is a lot longer than I intended - apologies for that!