Home General Training Discussions

My interesting n=1 Road Bike vs Tri Bike experiment

In the past 2 years, I have put thousands and thousands of miles/hours on my tri bike (Cervelo P3 and Cervelo P5) and I have put a couple of hundred miles on my Road Bikes.  I am so much more comfortable on my tri bike because that's simply what my body has adapted to.  

I recently got a brand new Road bike and it is very comfortable, I love it.  It's a Cannondale SuperSix with Ultegra Di2.  I spent the last 5-6 weeks or so on my road bike exclusively because I did the ~75 mile Hell of Hunterdon bike ride/race 3 weeks ago and then last week, I did a very hard 64 mile Tour of Battenkill CAT-5 bike race on it.  Both the HoH and Battenkill had lots of elevation change and many many dirt sections.  They were very cool and very hard and I had what I would define as "respectable" finishes in both. 

I also recently signed up for Strava and uploaded my last yr's worth of bike files.  One of the Strava "segments" near me is the local Sprint Triathlon "Doc 'n Sok" course which happens to be one of the things I throw into a lot of my local rides because it's a fun little ~10 mile loop with several hills and some fast rollers.  My PR time on the Doc 'n Sok loop from the files I uploaded from last yr was 35:10 ridden on my P3, but I didn't know I was racing anybody (or myself) at that time, and this was good for 6th on the leader board.  

The KOM for this loop is owned by my favorite mechanic at my LBS (and overall great guy).  He's a CAT-1 mountain biker, a cyclocross racer, and CAT-3 roadie.  He has logged into Strava an average of 7 rides per week so far this yr and has ~3,000 miles logged already this yr.  His PR on the course is 26:24 so I have a ways to go...  But I would love nothing more than to knock him off.  He's the best mechanic I know and likes to make fun of me for being a *gasp* Triathlete.

2 weeks ago (the week before my Battenkill race) I decided I was going to kill myself on that loop.  I needed a hard workout anyways and I was thinking that I could move up from 6th to maybe 2nd place.  So I went out and did just that.  Spiked my power, dropped the hammer and crushed the course on my Road bike.  I stayed in my drops almost the whole time and just rocked it.  I had a 3+ minute PR for a 31:54 which was only good enough to move up 1 spot to 5th place.  Doh!

Battenkill was last week, so I finally got onto my Cervelo P5 on my training ride this Wednesday on my rollers (I had been on my P3 all JOS).  Today was my first ride outside of the yr on my Tri Bike, so I figured I may as well do the Doc 'n Sok loop again.  I was wearing almost the exact same gear as 2 weeks ago (bib pants, rain jacket, road helmet).  But I had 3 full bottles on me today instead of 2 on my road bike and I think my P5 weighs several pounds more than my Supersix.  I do have Vittoria Rubino Slicks (reasonably slow training tires) on my P5 and I had (even slower) Gatorskins on my Road bike.  Today, I actually had to slow dramatically at one of the red lights on the course, then I had about a minute coming down one of the gradual hills where it wouldn't upshift to my big ring (still need to adjust it for the Osymetric Rings I put on).  But when I uploaded my file today, I had posted a 28:46 to move into 2nd place on the Leader board, only 2:20 behind mr fast guy!  I am so tempted to throw on my Zipps (with Race tires) and Aero helmet and see if I can knock him off!  

When I looked at my power files in WKO+ today I was shocked to find such a big discrepancy in my Power outputs.  I wish I had actually worn my HRM today, but I know my RPE was lower today.

4/6/13, Cannondale SuperSix Road Bike, Gatorskins, NP=291W, Top Speed = 35.5mph, Total Time = 31:54

4/20/13, Cervelo P5-six Triathlon Bike, Rubino Slicks, NP=253W, Top Speed = 40.7mph, Total Time = 28:46 

That's a ~10% faster in Total Time while using ~15% less Power!!!   That is absolutely REDONKULOUS in my opinion so I thought I'd share... 

 

Comments

  • Nicely done, Sir!

    Question - what was the VI for the two rides?
  • Why so surprised? Name one top triathlete or Pro Tour rider who uses a road bike in a timed draft-free situation. Aero position trumps weight, despite the loss of power in a bent over posture. 80% of the work to increase speed when going 40+ km/hour goes into fighting wind resistance.
  • I had to go back to my files to calculate the VI and I realized I got the range for the Power wrong on my tri bike ride. So the Power was actually 278W for that one, but the times were correct. But still less power and dramatically faster. (I will edit my original post)

    @Joe-- The VI for the road bike was 1.05 and the VI for the tri bike was 1.06, so essentially the same.
    @Al-- I knew the tri bike would be faster, but I thought I remember hearing something like ~1.5mins over a 40k TT was normal. ~3 mins on a ~10 mile TT blew me away with the magnitude of the increase on a lower power output. This would imply like ~30mins or so difference over an Ironman, on a hilly course! (if it's actually possible to extrapolate something like this)
  • Well then, can't edit the original post because the "edit" button doesn't seem to exist for me right now...
  • That's a pretty cool reminder.

    I took mph off of my screen at the beginning of last year. And, sometimes, it bugs me cuz of this power discrepancy, looking at lower watts while tucked. However, the bone that's thrown my direction is when we come to a regrouping point and the buddies (only a couple of us have power meters) want to know what kind of watts are driving that last Xminutes at ~25mph (or whatever) and we get to tell them that the watts are a good bit lower than what we were pushing back in Jan/Feb on the road bikes. They can't believe it!

    cool reminder.
  • John,

    A good reminder that aero trumps power.  I need to look at lowering my front end this year and really dialing in my position.  In any event I also don't need a road bike anytime soon, especially where I live with no hills. 

    Gordon

  • I really don't think some people realize just how much faster a good aero position is versus a road position or very slack aero position.
Sign In or Register to comment.