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Slowtwitch Forums: Triathlon Forum:
Estimated Bike Speed for IM

ktm520

Aug 25, 08 14:52

Post #1 of 12 (872 views)

Estimated Bike Speed for IM	Can't Post

I am trying to get a guestimate of bike speed for upcoming HIM (2 weeks) and then IM in November. I am a runner and I have no history of other tri races to fall back on, just my current training (begin bashing!). I am relatively new to biking but have an strong aerobic base, although not specific, to work off of.

I have gone 100+ twice (as part of weekly training) now in last month and held 18mph on a mix of hills and flats. I was not spent and tried to stay comfortable, I was certainly fatigued and ran ~ 4miles after each long bike with moderate effort. Today, I finished a 56 miler (18 average) with the final 30 minutes (10+miles) averaging 22mph on flat. This is after the 100+ on Saturday.

I am not going to buy a power meter at this time as I am new to the sport and do want to invest in it until I am hooked. I do use a HRM and will use it for racing to keep things in check. I would like to try and average 20 mph for the HIM and assess the IM pace from this effort and subsequent training.

My question is other than PM calculation or HR time trail what are some benchmarks in bike training that you can use to somewhat predict bike race pace. I understand all the uncontrolled variables that need to be factored, but let's assume they are even.

I know I am asking a lot for averaging 20 mph as a over-the-hill novice, but want to try and give the HIM an honest go but not blow up as I will not learn for the big day.

No offense, but save the speech for taking super easy for my first event as this is not in my make-up.

Cheers!

SCOTTinNJ

Aug 25, 08 14:56

Post #2 of 12 (858 views)

Re: Estimated Bike Speed for IM [ktm520] [In reply to]	Can't Post

I'll probably get flamed worse than you for this, but you can try to give this website a shot. I've found it to be fairly reasonable.

http://triathloncalculator.com/

-------------------------
Trek Madone 5.9SL
Felt B12

Spiridon Louis

Aug 25, 08 15:14

Post #3 of 12 (804 views)

Re: Estimated Bike Speed for IM [ktm520] [In reply to]	Can't Post

Well it depends a lot on the courses.

I averaged 20 in a very flat 1/2IM last year and 17 in a very hilly IM this year in much better condition.

Without looking it up, I believe 6 1/2 hours (17 mph) is a fairly MOP bike split for IMLP and most everyone is off the IMFL course by then.

Enjoy your races!

MuffinTop

Aug 25, 08 15:24

Post #4 of 12 (776 views)

Re: Estimated Bike Speed for IM [SCOTTinNJ] [In reply to]	Can't Post

I love that website. 8:24 IM, here I come!!
--
"Oh no, it's the dreaded Muffin Top!" --Mythbusters
http://willronco.com

Diesel

Aug 25, 08 15:59

Post #5 of 12 (704 views)

Re: Estimated Bike Speed for IM [ktm520] [In reply to]	Can't Post

Just go gonzo at your 1/2 and see how you run...

The general problem is that you are focusing on AVERAGE pace/speed. Big no-no, esp on the bike. Remember, it's a average and you'ld be surprised how much the turns, hills, aid stations, etc effect overall pace. Then, you have the whole "course accuracy" issue. The other problem is that you claim you weren't spent after your rides. Why else train..isn't that the point?

So..I think you have two questions.

1) Output. What is your fitness? Only some sort of test would yield that answer. I'm sure the scientists would love this, but perhaps do the SAME FTP test using the general course conditions, road surface, weather, temp, etc that you race...figure out your one hour speed and take 70-75% of that. LOL...that would certainly be a hack test at best. But..as you mention, you don't wanna know the truth...can't handle the truth (kidding). If nothing else, this would give you heart rate zone (albiet shabby ones).

2) Benchmark. How do you want to finish? Upper 50%? Upper 20%? Upper 5%? Then..simply take last year's results, figure out where you wanna finish and then hang that pace on your hat. Easy enough...but once again, isn't a very good strategy, esp for Ironman.

Good luck

jaretj

Aug 26, 08 4:49

Post #6 of 12 (543 views)

Re: Estimated Bike Speed for IM [ktm520] [In reply to]	Can't Post

Have you given any thought to using HR as a guide for your races?

jaretj

http://jaretj.blogspot.com

tajsss

Aug 26, 08 5:26

Post #7 of 12 (495 views)

Re: Estimated Bike Speed for IM [SCOTTinNJ] [In reply to]	Can't Post

Interesting calculator. I put in honest times for what I've been doing lately and for an Oly distance race it's estimates were pretty close to what I can actually do. Not sure I would trust it for selecting race paces, especially for long distance where pacing is so much more critical.

Murphy'sLaw

Aug 26, 08 5:43

Post #8 of 12 (457 views)

Re: Estimated Bike Speed for IM [MuffinTop] [In reply to]	Can't Post

Yeah, that website is swell.

Based on my training volumes (or lack thereof), it predicts I'd go 4:53 on an 'extremely flat' HIM.
So much for trying to break 4:20 at Demi Esprit, huh?

I guess the last three 4:3x's I did on rolling HIMs (Tupper Lake x2, Timberman) were just lucky?

It did predict my usual craptacular HIM swim split pretty accurately, so I'll give it that.
:-p

float , hammer , and jog

On ST hiatus from 11/1/08 until Spring '09

Roughster

Aug 26, 08 7:29

Post #9 of 12 (316 views)

Re: Estimated Bike Speed for IM [tajsss] [In reply to]	Can't Post

In Reply To

I input my data from my Vineman training logs and it came out with 10:40, I did a 10:35. So for me at least it was pretty close.

fred_h

Aug 26, 08 7:40

Post #10 of 12 (288 views)

Re: Estimated Bike Speed for IM [ktm520] [In reply to]	Can't Post

This year, I started to go "old school" and I did not wear a watch (and therefore no HRM) and I taped my bike computer. I have done it so far for one HIM and one "long course" tri (2K swim, 56K bike, 15K run) and I will do it again for my next HIM and the American Zofingen Long Course.

I actually felt great on the bike and the best thing is I was "free", I was no longer a "prisoner" of current speed/average speed, but instead I was paying a lot more attention to my body, the terrain and the wind.

Fred.

jaretj

Aug 26, 08 9:04

Post #11 of 12 (217 views)

Re: Estimated Bike Speed for IM [SCOTTinNJ] [In reply to]	Can't Post

I like that calculator. There's more to it than just race times, there is some insight to training intensities and that's allways welcome.

Thanks for the link.

jaretj

http://jaretj.blogspot.com

SCOTTinNJ

Aug 26, 08 9:39

Post #12 of 12 (182 views)

Re: Estimated Bike Speed for IM [jaretj] [In reply to]	Can't Post

No problem. I knew it would be controversial, but it has its uses. You probably know about this one too, but for running you can look at the McMillian web site.

http://www.mcmillanrunning.com/...unningcalculator.htm

-------------------------
Trek Madone 5.9SL
Felt B12

(This post was edited by SCOTTinNJ on Aug 26, 08 9:39)