Category Archives: Power Meters

Early adopter woes

Oct 1 I ordered the ANT+ updater for my PowerTap MTB hub.  This gizmo upgrades the firmware in the hub such that it transmits on 2 channels:  1 to the power tap computer head, the other channel on ANT+ sport.  The ANT+ channel is a semi-open protocol and several devices speak the language.  Among them in Garmin's Edge 705.

 I picked up a 705 after this years Canadian affair in which I left behind another GPS unit - doh!  The 705 had already caught my eye though because it is ANT+ and would eventually be able to communicate with power transmitting hubs/cranks.

 The ANT+ updater arrived last weekend - the update was fast and easy, with a few other wrinkles though - I'll have those details up on lwcoaching.com eventually.  Once updated, the 705 picked up the PT signal immediately - bingo!

Yet...it is not as simple as it seems.  The 705 uses an (unknown to me) algorithm to smooth the raw recorded data and in the process the integrity of that data is gone.  It baffles me why they take a quality raw data stream and alter it!  It essentially takes the good stuff and turns it into less good stuff.  It's really a bigger issue with variable efforts such as occur in road racing and single speed MTBing.  Steady endurance rides would probably come out similar.  It scrubs about 30% of L6 power from every one of my SS files when compared to the PT CPU.

So heads up y'all.  Gizmo integration is just around the corner but ain't here yet.  If you want a 705 to go with your PM it's best to hold off for now.  If you've spent $1,500 on your sweet power meter you probably want it to record good data and for now that means stick with the PT CPU in the powertap system.

Payson Plums

Payson, AZ is smack dab in the middle of my old stomping grounds.  Way back when - before I rode bicycles in earnest (think disco and polyester) - I lived on the NE side of the Phoenix metro blob and escaped to the Tonto national forest on a weekly basis, sometimes to the 4 Peaks area, sometimes The Rim, sometimes places in between.  Payson was always the watering/feeding hole amidst it all.  So when I learned the Payson course was to become the 24 hour natz in '09/'10 I just had to go check it out.  There's mojo in them thar hills.

 After Moab last year I'm pretty sure I swore off lappers for life but never say never.  I was fried from attempting to regain a season's fitness in 6 weeks and still injured to boot.  It was one of the dumber things I've done to do that race last year.  This time around I'm healthy, rested, and excited for some laps on a new course!

As much fun as it is to do big epics, traveling cross country or state without hitting the same trail twice, lappers have strong appeal still - so long as I am rested, strong, and hungry.  It's a good feeling to work the course over, learning it's flow, getting smoother by the lap.  It's more internal than external. 

We had an awesome pit crew.  Sarah absolutely nailed the pit boss routine on the first try, and Kong kept us rolling smoothly.  We've been so preoccupied with SS riding this year that our geared stable had gotten really tired, so Kong had his work cut out for him.  I rode my 5 year old Trek Fuel for the entire race.  I had a backup bike but he wouldn't let me ride it, said something about it not being safe??  Lynda's fork blew on her FS in the first half of the race so she got to ride a hardtail for most of the race. 

The course is short but has distinct sections.  The first little bit flows nicely up a gradual climb with a kicker at the end - that takes you to rocky bitch.  RB is exactly that, steep, rubbly, embedded rocks shaped like spears...good stuff.  A rolling section takes you to the base of the climbing where there are a series of steep climbs.  In the middle of the course there are big views over to the Mazatzal mountains and wilderness areas - awesome sunrise over there!

The race.  I came with an analytical approach (big surprise, eh?) and a power meter.  I was pretty happy Nat Ross was there as he always schools me in 24s...kind of like Tinker, he'd be a good yardstick to see if I could still do this thing - and if the new ideas were working.  One big surprise was the heat.  The forecast I saw said mid 80s which is warm, but I swear it was 95+ on those steep climbs with the ever so slight tailwind.  Maybe it was the heat, maybe I ate some bad stuff in Payson...but I had gut issues galore.  It was hard to manage, and no solids would go down, period.  At one point Sarah, who had been trying to get things I'd eat, put some plums in a dixie cup and I went nutz over them.  The next pit there were about 6 dixie cups full of plums ;)  That is a cool magic trick Sarah!

Nat lapped me not long after nightfall.  I expected this and it didn't bother me at all.  What I didn't expect - and what did bother me - is when he passed me again about 4 hours later.  OMG he must be an alien!  But no, Kong told me we'd been playing leapfrog in the pits.  Whew, now I felt better. 

At some point Sologoat was in his pit not feeling so hot and I had a chat with him.  Just like Moab last year he was feeling the effects of hammering a dry climate with a touch of elevation.  Asthma sucks...it hounded me for the first few years of racing and I felt bad for him.  He was remarkably calm and unbothered by it though, at least outwardly.

The night was sweet.  The temps dropped, as did my HR finally (but not power ;) and I was getting the flow of the course down nicely.  The night actually seemed to help clarify some of the trickier sections of the course.  At Moab the dark seems to obscure them. 

As I started lap 16 Nat was right in front of me, so I slowed a bit as he got rolling out of his pit.  Stalking ;)  He was still riding damn strong, slowly pulling away in the first climb to rocky bitch.  I closed the gap on the descent, then fell back again in the fast rolling section.  He was cooking!  We finished that lap up together chatting a bit....in the pit I recall mentioning that when you ride the paved section with Nat you don't get to eat LOL.

I left the pit about 20 seconds before he did on lap 17 and he closed that gap by the top of the first climb.  I'd been working this descent over for awhile, and felt super confident so let it all hang out this time around.  By the bottom I was on my own so I kept on the gas for that lap.  It was time to race!  There was a lap to pull back ;)

After 2 hot laps I knew I had to back off, so did and kept it right at that manageable pace.  Could I do this for 6 more hours?  Could Nat?  I was slowly pulling that lap back on Nat, and we were both starting to suffer a lot from all accounts.  I know I was.  Trans Utah crept into the back of my head, then the front of my head.  The mental and physical cost of continuing on into the pre-noon heat was crushing my soul.  I flat out did not want this race badly enough.  I wanted to have fun in TU in 2 weeks time.  So I grabbed a chair in the pit.  When Nat came in he was most happy to see this "David Harris, how much longer do you want to ride?!!" was his booming voice.  He may have been suffering on the bike but was still full of swagger on his feet.  The elite men's field was 3 deep and we were all done for various reasons.  We walked over to Dan & John (promoters) and told them our intentions to make this a 19 hour race and they were completely fine with that.  We sat in the shade and chatted about things like Cross Vegas and twisting throttles.  Dan has a monster of a KTM I was drooling over.

24 hour Natz next year has strong appeal.  It will be hard.  Brutal.  I like the Eatough plan of old - do the stuff you really like most of the time, and one bitchin nut buster 24 hour race per year.  Payson will be my nut buster next year and I'll be bringing plums!

Payson Stampede 24 Hour Mountain Bike Challenge

...is the next destination. September 20-21.

I talked with an official at USA Cycling who confirmed this is going to be the venue for the 2009 and 2010 NORBA National 24 hour Mountain Bike Championships.

Well I haven't done a 24 hour solo since Worlds last year and am in just the right mood for one at the moment. So we are packing up the ship and sailing it over to Payson with gears, suspension and power meters on every bike!

Dave and I are racing the 24 hour solo with power meters and Danielle is racing the 12 hour solo with hers. We will have a plethora of data to get the 2009 and 2010 Nationals training plans nailed.

It is a climby one. From topofusion 1366 ft/ 8.8 mile lap. This chart of the course is from a GPS file provided courtesy of Dan Basinski the Payson race promoter. Thanks Dan.

The trickiest part of racing 24's is pacing. How do you pace a 24 to end up with the most laps? Go fast from the gun and hang on? Even split? Negative split? We are gonna be doing a little experimenting in Payson and if we get it all right we'll have the power data to back it up. Precise numbers from differently paced races over one course at the same time. Now that is data to keep us busy this winter and juice to use when cooking up the killer Nationals training plans in 2009 and 2010 - yummy :-)

Single Power

My Single Speed got a new rear wheel today. With a Power-Tap hub in it. It's gonna kick off some data and tells us all what all this one gear pedaling stuff actually looks like. I don't think the powers seen are as high as others do. Shortly we will know...

One of the fun things before Trans Rockies was working with power meters to figure out how to be faster as a team than two individuals. Dave and I rode together, looked at power files, figured out what speeds and powers were good for towing. Discovered above about 12 mph drafting was more efficient - and a lot safer than towing. We learned distributing weight makes a huge difference and crunched all the power numbers to come up with a strategy that won us that stage race. The whole discovery process was a lot of fun and made me a better coach along the way. I do love a learning curve.

Now it starts over again with power meters going on the single speeds and more single speed racing on the horizon. So far I have only raced cross country distances on my SS. Maybe we can go back to Trans Rockies next year and race it single speed?? How about that...