Tuesday, January 28, 2020

Gravel Power Analysis: Texas Chainring Massacre

Here's what it took for Mat Stephens to win his fourth Texas Chainring Massacre, just ahead of teammate Spencer Seggebruch.



 Gravel Power Analysis is a new column by coach Zach Nehr, who last year did a Power Analysis column on pro road racing. This year, as he is racing gravel with Panaracer/Factor p/b Bicycle X-Change, he’ll regularly check in with power analysis from gravel races.

Over 600 riders toed the start line of Spinstry’s 2020 Panaracer Texas Chainring Massacre, a traditional gravel season opener held about 50 miles outside of Dallas, Texas.

This would be my first time competing in a ‘real’ gravel race. I had done a few local events in Kansas and Wisconsin, but you could number those participants in tens, not hundreds. By the time I line up at The Mid South in March, it will be thousands.

I have a lot to learn in the world of gravel racing, so I absorbed as much as I could from my Panaracer/Factor p/b Bicycle X-Change teammates in the few days before the race. Food, tire pressure, tools, nutrition, strategy, and pacing are all going to be keys to your success – or failure. I studied as much as I could, but I also realized that I would never fully understand ‘gravel’ until I jumped into the deep end.

On a cool Saturday morning in Valley View, Texas, I lined up for the Texas Chainring Massacre, prepared for 100 km of dirt, gravel, pain, and (hopefully) some fun.


As it turned out, my teammates had quite a bit of fun, as Mat Stephens and Spencer Seggebruch went 1-2 at the finish.

Mat Stephens’s Texas Chainring Massacre, by the numbers:

Height: 5 ft 11 in (1.81 m)
Weight: 65.3 kg (144 lbs.)
Age: 37
Distance: 103.7 km (64.43 miles)
Time: 2:47:37
Avg Power: 216 W
Normalized Power: 264 W (4.04 W/kg)
Work: 2247 kJ



Spencer Seggebruch’s Texas Chainring Massacre, by the numbers:
Spencer Seggebruch
Height: 5 ft 8 in (1.73 m)
Weight: 72 kg (158.7 lbs.
Age: 28
Distance: 103.1 km (64.09 miles)
Time: 2:46:16
Elevation Gain: 802 meters (2631 feet)
Avg Power: 262 W
Weighted Average Power: 295 W (4.1 W/kg)
Work: 2639 kJ


How Texas Chainring Massacre was won
The peloton existed in some sort of ebb-and-flow state for the first 10 miles of the race. Apparently, this first section was supposed to be “neutral,” but judging by the fact that we were lined out in the crosswinds going 20+ mph on gravel, I would venture to say it was not.

After we rolled out of town, we turned left onto a frontage road. The group stayed compact as we pedaled along the pavement, the majority of riders trying to save as much energy as they could by utilizing the draft.

Mat Stephens (Panaracer/Factor p/b Bicycle X-Change) rode at the front during this section, sometimes on the front, with an emphasis on positioning over energy-saving. I soon realized he was right.

After 10 miles, the peloton turned right onto the first serious gravel sector, and the race was on. We hit the first hill at over 500 W, and the once-compact peloton soon turned into a long, bouncing line of straggling riders.

Stephens “Neutral Start” (Mile 0-10.4):
Time: 28:25
Avg Power: 169 W
Avg Speed: 35.7 kph (22.2 mph)


Stephens Start of first gravel sector (Mile 11.2-11.7):
Time: 1:33
Avg Power: 427 W (6.54 W/kg)
Max Power: 671 W
Avg Speed: 35.8 kph (22.3 mph)

Over the course of the next 20 miles, a field that was once 300-strong whittled down to 50, then 40, and then 20. Attacks kept flying, some on gravel and some on pavement. Each acceleration dispatched a few more riders, because on gravel, the race never really slows down. At the front, riders just keep going and going and going – in some races, such as Dirty Kanza, it will eventually be every man or woman for themselves.

Stephens’ teammate, Spencer Seggebruch, put in a big attack with one other rider around Mile 16, building up a 30-second lead in a matter of minutes. The chase behind became frantic as the group hit a wildly exposed section punctuated by a steep gravel climb that turned straight into the headwind. Riders came over the top of the climb in ones and twos, with Stephens in the front group of just five or six.


Seggebruch’s long break (Mile 15.5-32.8):
Time: 45:52
Avg Power: 320 W (4.4 W/kg)
Max Power: 1070 W
Avg Speed: 36.2 kph (22.5 mph)


Stephens had multiple teammates up in the front group with him, but a highly-motivated chase chased them down in the next few miles. When John Borstelmann – Stephens’ teammate and defending Texas Chainring Massacre champion – flatted about halfway through the race, the lead group slowed down for the first time in well over an hour. Riders took a break to stretch, eat, and evaluate the situation – they were in a lead group of 10, with no one in sight behind, and about 25 miles to go.

(Stephens) Pace eases up (Mile 31.1-39.7):
Time: 21:13
Avg Power: 197 W
Avg Speed: 39.4 kph (24.5 mph)

Stephens was incredibly efficient here, utilizing his aero bars in the crosswinds, and bike handling skills in the corners. He did not put out the most raw power, but Stephens was often the fastest rider out there.

A few miles after this point, I missed a turn – gravel races don’t usually have corner marshals, barricades, or orange cones. Having a solid head unit with GPS navigation and 12+ battery life is crucial for gravel racing, which can sometimes turn into a 12+ solo affair.

Stephens didn’t make the same mistake – he had done a full course recon a few days before, even marking down this corner as one that was easy to miss.

Because of my navigation kerfuffle, the front group split in two. Stephens and his teammates had three out of five in the front group as the race approached its steepest climb. The gravel road wound right, then left, before pitching up to over 12 percent as the riders climbed up into the trees. Stephens held over 400 W on this pitch just to maintain traction at a measly 6 mph.

(Stephens) Effort up the steepest pitch of the race (Mile ~42):
Time: 1:36
Avg Power: 330 W (5.05 W/kg)
Max Power: 543 W
Avg Speed: 23.2 kph (14.4 mph)


After a furious chase in the crosswinds, the chase group regained contact, and again there were eight riders at the front of the race. As the course turned left onto a section of highway, Stephens launched a massive attack. His power peaked at 890 W before Stephens quickly moved down into his aero bars. At 35 mph, no one could put a dent into his gap on this section of road.

(Stephens) Race-splitting attack (Mile 48.5-49.2):
Time: 0:28
Avg Power: 570 W (8.7 W/kg)
Max Power: 1176 W
Avg Speed: 50.9 kph (31.6 mph)

Moments after a duo bridged across to Stephens, Seggebruch launched to do the same. In less than 30 seconds, Seggebruch made contact with the front group, now four-strong with Stephens, Seggebruch, their teammate Scott Moniger, and Dillon Caldwell. The ability to bridge between groups – riding across a gap from one group to another – is another key to success in gravel. Races often split from the gun, and the ability to do short, sharp efforts will see riders leap-frogging their way to the front of the race, rather than time trialing behind for hours.

Seggebruch’s bridge to the front group (Mile 48.5-49.2):
Time: 1:16
Avg Power: 325 W (4.5 W/kg)
Max Power: 890 W
Avg Speed: 48.9 kph (30.4 mph)
Max Speed: 56.8 kph (35.3 mph)

With less than ten miles to go, Seggebruch launched another big attack in an attempt to break up the front group. Hitting 1278 W, Seggebruch gained an advantage in almost an instant. Stephens waited patiently before launching across himself, making his effort in the crosswind just a mile after Seggebruch’s.

Seggebruch’s big attack (Mile 53.4-53.8):
Time: 0:47
Avg Power: 525 W (7.3 W/kg)
Max Power: 1278 W
Avg Speed: 46.7 kph (29.0 mph)

(Stephens) Bridge to Seggebruch (Mile 54.4-54.8):
Time: 0:50
Avg Power: 481 W (7.4 W/kg)
Max Power: 886 W
Avg Speed: 39.8 kph (24.7 mph)

For the last 15.4 km (9.6 miles), the Panaracer/Factor p/b Bicycle X-Change duo averaged nearly 24 mph on a heavy mix of gravel, pavement, and crosswinds. While one pulled at 300-400 W, the other enjoyed the draft at 200-250 W.

(Stephens) Final 15 km (Mile 54.7-64.3):
Time: 24:24
Avg Power: 248 W (3.8 W/kg)
Max Power: 594 W
Avg Speed: 38.3 kph (23.8 mph)

By the time they reached the final few hundred meters, the chase group was nowhere to be seen. Stephens and Seggebruch rolled across the line 1-2, taking the team’s first win of the season, and Stephen’s fourth win at the Texas Chainring Massacre.




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