And now for something totally different: Jens Westergren is researching BMX power requirements and has some data to share as well. Below is a chart of his data and some of his comments/questions:
The new UCI Supercross format (Olympic format) consists of two time
trial runs as qualification then a number of finals, in all around 5-10
heats of 30-45 s duration. Because of the jumps and turns it´s rater
different from for example 400 running.
I’m currently working on a “performance criteria analysis” of BMX racing
for the Swedish Olympic Committee. My only problem is that the amount of
published research done on the subject is to put it nicely,
A pubMed search gives maybe seven relevant hits, of which all of the are
about injuries in BMX racing (must be a very dangerous sport…)
This is what I´ve found:
Politi, S.; Heazlewood, I. Exercise physiological, biomechanical and
predictors of bicycle motor cross in young adults : a preliminary
study.Mathematics and computers in sports : 3rd conference held at
Bond University, Queensland, Australia, 30th September to 2nd October,
1996, Queensland, Bond University, 1996, p. 123-153.
Attached is the power output graph of a 74 kg top level Swedish rider,
measured by a SRM pro system fitted to his race bike. To avoid any
interference from other riders (and crashes…) it was done as a time trial.
This is especially relevant now since the UCI Supercross
use time trial runs to qualify. I would be very grateful if you could post
this on the forum!
If you have any insight for Jens, contact him at email@example.com.
Sometimes I get on a kick with one particular workout. At the moment it is this one:
Watts are yellow and heart rate is in red.
This is four sets of 5 X 1 minute repeats. Today the goal was to keep my watts over 300 for every rep until I either made it to the end or blew up. Today was a good day as I made it right to the 20th rep before I faded below 300 watts. This is the first time I have made it this far so a good day out.
One of my major goals this winter is to make my legs stronger and this workout certainly taxes them. They are pretty tired right now, but a good tired.
If you don’t ride & race a 29er this post will make abolutely no sense to you. You’ve been warned.
Tire selection for 29er race tires is limited at best. Switching over to tubeless 6 years ago was a big performance improvement. As far as cycling equipment innovations go, tubeless tires are on the level of suspension forks and clipless pedals. 29ers are a blast – but one of the tougher nuts to crack is tire selection. At this time there is not a single tubeless 29er tire available. The only tubeless option is some sort of conversion using non-tubeless tires. This involves a rim strip to seal the spoke holes and putting some sort of latex (or other chemical) sealant in the tire. Stans makes is a popular commercially available conversion kit for 26ers and 29ers.
This is not without significant risk, however. There seems to be no standard for producing 29er tires. As opposed to their little 26″ cousins, 29er tires almost always fit loose. You can mount a 29er tire by tossing it across the room, it’ll land on the rim just fine :) Also, the beads have been breaking or simply blowing off the rim when converted to tubeless. Not good!
Last time I checked Stans recommends only one type of tire for 29er conversions: wire beaded WTB. That’s what I’ve been using all season. The race setup is a Nanorapter rear, Motoraptor front. They weigh in at about 760-780 g each. Ouch.
The big red S comes to the rescue. They’ve previously announced that they’ll never make 29ers…but their defunct WC star was at one point interested in 29ers, so they set about designing a decent race tire for 29ers. The Fast Track is the end result of their work, and after one ride I’m jumping for joy.
Finally their is a viable 29er race tire. They are light. Compared to the wire bead WTBs, 300ishg lighter, and that’s rolling weight. The weight difference is immediately apparent in moderate to high speed turns. The bike loses some of its longboat handling qualities. They are grippy, much more so than the nano/moto combo. The comparison ride was a snowpacked dirt road, and in those conditions the tires felt like velcro. They are supple. I ran them at 32R30F and at those pressures found them to be very compliant in the rough. They are not as high volume as the nano. On the Dos, rear tire clearance is an issue. With a nano on my Mavic Open Pro there is only about 3mm room between the top of the tire and the bottom of the wishbone. There is more than twice that now with the Fast Tracks. They come with an aramid bead, which as I understand it is considerably stronger than typical kevlar beads. I’ve taken the leap and mounted them tubeless. They aired up much more easily than any other tire I’ve mounted tubeless on 29ers, probably because they actually fit snugly on the rim. So far so good.
I’m thinking this tire outperforms anything I’ve used to date on 29ers…but I’ll hold on that call until I abuse them on trails. But putting my bike in the 23 lb range by changing tires? How could that not be exciting! So long as that bead holds…
Getting psyched now…my 24 lb Dos niner just lost half a pound. The big S just released their new Fast Track 29er tire. Can you say excited? Can’t wait to try these rippers out down in the warm desert southwest…
Durango’s got it.
Last night the FLC concert hall was the place of a cycling fundraiser multimedia show and auction hosted by none other than Bob Roll. The first part of the show highlighted several local cyclists and cycling related organizations. Notables to get their mug shots at theatre size projections included Robbie Robinette for winning the 40-44 road champs, our very own Ben Kraushaar for his his winning ride at mammoth, 7 year old Christopher Blevins, national BMX champion (I had no idea Dtown BMX was so big…but Neds kid is doing too), Martha Iverson for crushing every record in her path to numerous victories and national titles both on and off-road, Bill Manning and Trails 2000 for many years of trail advocacy and trail work/construction…then moved on to the big dogs. Todd and Troy wells (the brothers just snagged the Elite and U23 national cross titles), including a great video interview with Todd; Chris Wherry including a video of the final 10 minutes of his national championship ride (you gotta see this one – Pate and Wherry worked Horner over good), Bob Roll, and Tom D, including footage of his Brasstown Bald win in Georgia.
Afterwards, we got to hear from some of the starz.
From left to right: Ned, Roll, Michael Barry, Liam and Dede Barry, TD, and Chris W. Bob Roll is always entertaining – if ever you have a chance to see this guy do his thing (aside from OLN) do it.
Take away points:
- Ned will race forever. “I have to stay in shape cause once I get out of shape I can’t get it back.” This shouldn’t come as a surprise.
- TD’s primary goals for ’06 look to be the Giro, taking in the California and Georgia tours along the way, but Michael Barry says TD’s got a good chance (it sounded like 4 riders are under consideration) of leading Disco in France. Tom was more relaxed, mature and generally strong and confident that ever before.
- Dede’s greatest triumph is motherhood. #2 was the silver in Athens. Liam is one happy little guy and really likes microphones & TD!
- Bob Roll’s single professional victory was the result of the peloton getting stopped by a train when he was off the front.
Looking around in the packed concert hall, there were dozens if not hundreds of cyclists that could have also been featured – there is just that many talented cyclists in Durango. Must be something in the water here.
So if you’re looking for a cycling hotspot to call home…Durango is darn tough to top.
The presents under our Christmas tree are a constant and taunting presence to the kids at the moment and I’m taking full advantage of the “be good or Santa will know” tactic. They were gone for a few hours today to pre-school and kindergarten – my time to get out for a wee ride without the bike trailer in tow. It was very chilly down here in the desert again today and I knew Santa had a nice new warm cycling jacket wrapped up for me under the tree………
It’s back wrapped up under the tree again now!!
It did keep me nice and toasty warm on the descent :-)
Guitar Ted spent yesterday at the Trek university (?) in Iowa. He shared some exciting news for the 29er crowd, check it!.
It’s December 13 and Durango finally got some of the white stuff. It’s been the first year I recall that you could ride your MTB all the way to December. It’s been great, but oh man the Nordic and Alpine folks are jonesin.
According to my training plan, the build up for Old Pueblo begins today. It might sound odd, given that I’ve done 4 White Rim rides in 2 weeks, that I consider today as the beginning of the build…it’s more of a seasonal attitude thing. Growing up in Michigan, I was programmed at an early age to put on winter fat in the fall, and no matter where I live it happens every year. Late October to Jan 1 is typically a time of weight gain, regardless of training volume. Gimme some pie dammit! This year seems to be different. I’m super excited for what’s to come in ’06 and feeling fresh as a daisy at a CTL of 124.
The trainer is no way to start this build, so I opted for some interval work up Junction Creek road in the snow.
Riding MTB in general reduces power output. Combine that with snow and it becomes a judgement call whether to call it a skills ride or L5…it often required quite smooth form to avoid slippage, and going down was a real treat!
In between intervals 4 and 5 the shifting took a nap. I have no idea why :)
Riding in the snow turned out to be a ton of fun, and I think I just discovered another strong point of these 29er wheels. Hmmm….
Here’s how it all turned out:
If you’ve seen my rants on wattage, you know why I’m doing this kind of stuff in December…but for the benefit of everyone else: the short answer is that after a long season of long events (feb-oct), my power duration curve gets very, very flat. That means top end power declines while long term power rises. I view the winter as the time to rebuild top end power – a rather different take than most, but it works for me. For MTB ultras, the trick is to have plenty of top end, and great long term power. It’s a difficult balance to achieve…but hell, riding a lot can make up for a lot training mistakes;)