Cycling Weekly e-Interview - part 1

A few months ago, I was sent a series of questions from Oliver Roberts of Cycling Weekly over in the UK.

I spent a wee-bit of time answering all of the questions he sent my way, and some of those answers made it into the final publication (which was cool to see!) - although, I had to purchase a digital copy of it to check out if I was quoted well! ;0)

http://www.zinio.com/cover?is=228905657&img=l

Anyway, since I took the time to answer the questions for him - I reckon my answers would make for some good fodder here on kdublog - I've added some additional nuggets where I felt like it, FWIW!

here goes - question #1:

[cycling weekly] "The received wisdom is 'as low as possible is better' is this in fact the case?"

[kraig] I don’t think so.

I’m living proof that lower is not necessarily better. For the better part of 15 years of bike racing my TT setup was such that I made the bars as low as possible. Then, I went to the Wind Tunnel here in San Diego (http://www.lswt.com/) and explored what I call the "design space".

I quantified how much my axial force changed as a function of reach, drop, elbow width, forearm angle, saddle position, etc… over several different tunnel sessions. What I found out was that I had been riding below my potential in flat TT’s, largely in pursuit of becoming as "aerodynamic" as possible.

Last year (2006), I set lifetime personal bests at the 20k distance with a bar position that was 10+cm higher than previous positions - simply because I intelligently used the tools at my disposal to measure both axial force (I used a wind tunnel) and power production (I used an SRM Pro Power Meter). I also re-learned how to surf the pain curve during the actual time trials - that's worth quite a bit of time, I reckon!

Here's a photo comparison of my position in 2004 vs 2006:



Sure, going lower will generally make you more aerodynamic (that’s why folks tuck on descents!), but at what cost to the other parameter - power production? Going fast is a balance of one’s axial force, power production, and most importantly, putting it all together and executing via the supercomputer on race day.

Here’s an article I wrote that tries to send the message that using tools to help guide the positioning process is often times helpful:

http://www.biketechreview.com/performance/faster.htm

Multi-tasking=ADD=Evil

Some think that multi-tasking is a talent to be admired and pursued.

Personally, I think it's evil:

I should really be working/focusing on something more important than this - but damn, the Eagles just might pull this one off!

;-)

Turkey Weekend Project

I've had this Cannondale frame/fork and build kit laying around since around March or so - just haven't had the motivation or drive to finally build it up.

I know, I know... Pretty crazy, huh?!

Well, my employer was nice enough to give us a few hours off on Wednesday prior to this long turkey day weekend - so, I took advantage of this early departure...

...and went for a ride!

hah! - but when I got back to "villa de Willett", I set out to get this bike built up!

It's been a long process, ya see, I'm kinda addicted to SRM based power and all, and this bike has/is making that a difficult thing to accomplish! Cannondale loves to do things "their way" so, that made the SRM Pro crank I've been using since '02/'03 obsolete - that Campy square taper crank compatible SRM doesn't work with the proprietary Cannondale BB/Hollowgram crank arms.

So, the quest began - and I've had lots of help along the way. First, Jason Yanota of the bikeage helped me out by selling me a barely used Cdale SRM spider/chainrings that I'd eventually be needing. Then, I picked up an SI crankarm from Craig over at wiredbike.com. I thought I was set at this point back in the April-ish time period...

Well, much to my dismay, it turns out that in order to fit an SRM on a Cdale, you need a slightly wider BB spindle. I could have made some modifications to the crank that came with the frame/fork (that I bought throug the team I raced for this year - JambaJuice/TaylorMade http://www.sd-fogracing.com ). So, it was April/May and the season was in top gear - I didn't really want to dork around with the position/bike I'd been riding for the last 15,000 km's...

Plus, I'm pretty lazy! :-)

Around comes last week, and I was figgerin' I needed to build this sucker up pretty soon in order to not be shamed on the next team ride I showed up for. So, I shot an email over to Craig @ wiredbike.com (make sure that if you are in the power meter market you give him a shot at the sale - he'll give you $50 off with a special BTR code, BTW) and it looks like he'll eventually be helping me buy an SRM compatible Cannondale spindle. Nice!

Also, a couple months ago, I saw an opportunity to pick up used SI Cannondale crank arms/BB spindle while perusing the obra.org mailing list (oooohhh, my disdain at the time for the obra officials was overridden by the need for cheap, used bike parts - LOL! :-) ).

Then, a few months passed...

With all the parts in hand to get this sucker together (albeit sans SRM power capability), I busted out the hacksaw, star nut setter, and some elbow grease/patience and finally built up the cdale on Wednesday afternoon. It went together really easily - the Campy Record 10spd parts are pretty sweet. Total pie to assemble.

I'm no pro when it comes to building bikes, so I'm sure you'll give me plenty of grief if you see me out on the road, but here it is after the first ride I took it on this morning:



Here's a close-up of a saddle I took a chance on - it's a Selle-San Marco Aspide - no padding, just the carbon shell:



I was surprised at how comfortable it appeared to be after the 70 minute jaunt I took it out for today. We'll see how it works out long-term.

You'll notice that I have a PowerTap power meter on the bike whilst I'm waiting to get the SRM on-line.

The trials I've had with that thing will have to wait for another post! ;-)

The PowerTap seems to work OK, but damn, trying to download that sucker (it's an older model with a serial port connector) proved to be quite a challenge!

As for the Cannondale, it didn't seem to make me break any of my previous records I have thrown down while going up Couser Canyon Road near where I live, but dang - new bikes always feel pretty cool!!!

I am having a bit of a hard time getting where I'd like to be position-wise - I reckon I'll need a shorter stem (120mm currently on it) and a seat post with a wee-bit more setback. Hard to get italian seat tube angles these days for us "old skoolers"... ;-)

Hope you all had a great holday weekend here in the U.S., and if you are elsewhere in the world - I hope you just had a great weekend! :-)

peace,
-kraig

The Fiber Profile Column

Whoa, big "whoop-de-doo" over on the BTR forum for the past few weeks where lots of undies got up in a bundle. Ahhh, geeeeeezzzzz, it's just a web forum about bike crap - glad I got the chance to open the johari window for myself a bit in that thread.

Refreshing, in fact, to state some of my values, my ideas on changing behaviors, and having the opportunity to represent what I believe (ya know, bike racing isn't a math problem!) despite being continually attacked by a select few.

Anyway, during the sharing of ideas, I linked to a great thread that took place a long time ago, where Kirk made some good observations back in January of 2006. Here's a particularly relevant post in that thread:

http://biketechreview.com/phpBB2/viewtopic.php?t=504&postdays=0&postorder=asc&highlight=fiber+column&start=48

Here's the relevant bits of that post for those averse to clinking on links and whatnot:

"For a given cadence, changes in power (force) are the result of changes in the motor-units recruited. More force, more power, more motor-units. Fatigue can also result in the recruitment of additional motor-units. When motor-units normally recruited at a certain power begin to fatigue (produce less force when they fire), additional motor-units are recruited to take up the slack in order to maintain the power (force). Because of the progressive, sequential nature of motor-unit recruitment with the needed force, increasing power (force) generally requires additional recruitment.

I look at an entire muscle as a column, a column roughly divided up into power levels I call fiber-profiles. At max power (say a 5s sprint), most of the column fires. At low power, only the bottom section associated with that power is used. As fatigue at a given power sets in, the fiber-profile "creeps up” the column, as additional motor-units are recruited to maintain force (added to the top). So, the fiber profile associated with a given power as fatigue sets in includes more motor-units than when fresh.

So, take the example of cruising along at 250w (let’s say that’s a tempo intensity), a certain fiber-profile (composed of individual motor-units) is used to generate the force required to produce 250w. Over time, fatigue will set in within that fiber profile. That fatigue manifests as reduced force. In order to maintain that 250w (force), additional motor-units, ones normally recruited at higher powers, are then brought into that power’s fiber-profile.

So, it terms of recruitment associated with 20MP (or any power), as long as the power is at that level or higher, I know that AT LEAST the smallest potential fiber-profile associated with that power is recruited…and as fatigue sets in…that fiber-profile only grows larger (more motor-units recruited…added to the top) to make up for the drop in force production in the fatigued motor-units. The fatigued motor-units are still recruited, their force production just drops. So, that 250w *may* eventually recruit some of the motor-units normally within the >95% of 20MP profile with sufficient fatigue, but it is unknown to me exactly when this happens. When I train at intensities > a given power, say 95% of 20MP, I know that a given fiber-profile is recruited, and as fatigue sets in, this profile creeps up the column.

So, I think that at least a minimal level of recruitment can be associated with a given power, and that by acknowleding this minimal profile, I can quantify the amount of stimulus seen by that minimal profile (although it may grow to include more motor-units) via my choice of 60s chunks which include that profile (bins or time in zone are similar). I’d love to hear of ways that recruitment order and force production can commonly get tossed out of whack so that limitations to this way of thinking can be identified. If these issues do exist, it may also influence the use of powermeter data in general, because if non-sequential recruitment of motor-units occurs, a given power number has less meaning (at least to me). There is always more to be learned!

Kirk"

Yeah, visualizing things in terms of a column of fiber recruitment makes sense to this caveman, especially considering that when one uses gears, cadence is confined to a relatively small range (outside of the transition to/from coasting).

Good stuff to think about, anyway.

Oh yeah, I've disabled comments on this entry, so, if you'd like to engage others on the topic, feel free to sign up and post your thoughts on the BTR forum:

http://biketechreview.com/phpBB2/index.php

keep it real out there, folks.