Iron Distance Bike Speed

Devo, My race is in September, so quite a ways out.  Are you thinking I'll get faster?

As far as thinking of running the marathon after, I keep that in mind.  I'm going at a very moderate pace when biking.  My age is 24, and my max heart rate is somewhere in the low 190's.  When I'm biking my heart rate averages around 130.  So I'm not hammering and spiking my heart rate.

Does that give any more insight?

He was probably wondering how you would progress from your current high water mark of 56 miles at 18.4 MPH to 112.  If your race is in September, you can probably expect to be able to maintain that same speed as you progress through long rides.  My speeds on long rides ranged from hi 17's on days when the wind was howling and I crashed nutrition-wise to hi 19's on my good days.  On race day, I averaged 19, but the wind was howling.

Just remember that the key to a good Ironman is a good run, and the key to a good run is not slowing down on the run, and the key to not slowing down on the run is not wasting your effort on the bike.

I have said this before, and I believe it is useful to mention it here.  Training and racing an Ironman is easy.  Yeah, I know it's freaking hard, but it's easy because you train yourself to go at an easy pace all day long, just like a golf cart.  You go out, flip the switch to "on" and just run, run, run or ride, ride, ride.  The hard part is doing it consistently and extending your endurance past your previous limit. 

So that's why I say that this 18.4 current average, which is easy for you, is what you should strive to maintain as you extend your endurance.  To say that correctly, you should determine the HR that corresponds to the 18.4, and maintain that HR zone for all your training and racing.  (Of course I don't own a HRM, so all of my training was based on feel and perception.  Real caveman here.)

I have finished reading an interesting article by Rich Strauss entitled " Important Information for IM Participants!".  It offers very good advice on pacing one's self for each segment of the IM.  The bike pacing section will be of particular interest to you; it is broken down into four parts.  Of particular interest is the author's contention  that the first 30 miles will "make or break your bike leg" and, therefore, suggests an easy pace, even holding back in order to allow the heart rate to settle back from the swim.    

site:  http://www.trinewbies.com/Article.asp?ArticleID=107

Sound advice there Mike!  Althought I've never correlated the 1 mile walking = 1 mph loss on the bike, but that seems close enough.  I think your idea of  just focusing on HR, PE, Cadence & Power on the bike is a good suggestion.  Very often,  many get too caught up in maintaining a certain speed and push way too hard for the bike.

There is no way of accurately estimating the eventual bike split in the IM.  Just pace right,  eat right, ride easy and get the time when you hop off the bike

For all of us thats not RACING an IM,  the bike leg should NEVER be hard work.

It's only natural to wonder and do the what if game, especially as you get closer to the race. Your build confidence in your fitness, we're competitive peeps, and you start to conjecture about how fast you can ride the bike leg or what your split will be. Perfectly natural. However, as Mike pointed out, this can be fatal on race day. Your much more important split is your bike/run brick. A 5:20 bike isn't much good if it results in a 5:20 run (walk). A 5:35/4:00 is much better.

Consider this: booger/cruise the swim and you'll only go about 5' "slower" than normal. Cruise/booger the bike (assuming no mechanicals) and you'll probably leave about 15' on the course, unless you completely implode yourself in the first half. But implode on the run and you're looking at walking 16-17' miles vs running 9-10'. Do the math on 20 miles like that and you'll see the IM is about not slowing down on the run.

The difficulty is that we have so few times to practice an IM in an actual race. We're lucky to do 1-2 per year. 3 is VERY tough to pull off. My best executed race was IMWI'02 on what I consider to be mediocre fitness. I'm much more fit now and am working hard to get back to the execution place I was 3 years ago. This is largely a function of:

1. Holding my IM bike fitness in reserve to use on the run. This past Sunday I cruised to a 4:56 for 112. Flat course and I had good winds, but I can ride all day at 22+. However, at CDA I'm prepared to sleep to a 5:15-20 to yield a sub 3:30 run.
2. Identifying my "One Thing" now, so I have absolute focus on race day. http://www.cruciblefitness.com/etips/IMMental.htm  For me, it's a 3:30 run, yielding about a 9:45 (52/5:15-20/3:30). Why? That's my potential. I want to do it, get it done, take off the IM hat until I turn 40 in '08 :-)

So, just train using HR, watts, speed, whatever. Lots of info and training plans on my site to help you. Ok to play the what if game but on race day be humble and conservative.

Great advice!   Definitely makes sense when you put it into that perspective.  Thanks Mike.  Thanks Rich!!