carleton

Just watched.

Wow. Great ride by Sahrom.

I bet Glaetzer wishes they had round-robin now, hahaha. Well, maybe he'll come in with fresh legs and a bit of anger and light up the kilo tomorrow.

(Before the Kilo)
[Glaetzer to mechanic] "Go up 3 teeth on the chainring."
[mechanic] "Huh? Wha?..."
[Glaetzer] "You heard me."
[mechanic] "But, boss?!..."
[Glaetzer glares]
[mechanic] "Yes, boss!!"

carleton

Sahrom qualified for Worlds with a 10.293 a month ago, which put him in 35th place of 36 riders. Seems like 10.013 is fast for him.

Poppit

I've somehow got it in my head that he's done a long 9 somewhere, could be wrong though

Poppit

They opened up a new velodrome last year, looks like it's having the required effect
https://360player.io/player/eDUco3/
https://baikbike.com/exclusive-interv...nal-velodrome/

SyntaxMonstr

9.977 at the Asian Champs in Feb.

carleton

I stand corrected. He continued to race well the remainder of the tournament, finishing 4th.

carleton

Gleatzer wins the Kilo with 59.340 which is 0.393" faster than his time at worlds 59.733".
Dawkins for 2nd with 59.928" (no kilo at Worlds)
Skinner for 3rd with 1.01.083 (slower than Worlds)

carleton

Track is done at the Commonwealth Games. At first glance it seems that every timed event saw a new Commonwealth Games record and even some Para world records.

Nice.

queerpunk

i saw a video of Glaetzer's kilo and it looked like he was in an ungodly massive gear.

zizou

If you can check out the mens points race. Exciting race and Mark Stewart was absolutely ruined by the end...the live feed camera followed him for a while track centre, you could hear Cameron Meyer congratulating him and full of praise and then Mark saying Cameron was a hero to him when he was growing up, he's best track rider he's ever seen but more importantly a great person...was quite a touching moment.

queerpunk

so a 58-13.
good god.

carleton

If someone can link me to a video of the ride, I can calculate the gear.

Anyone got a link?

queerpunk

https://www.facebook.com/groups/1716...4284713584384/

carleton

Thanks! I'm on it. Give me a sec.

carleton

After pouring over the video frame by frame and a bunch of basic math:
1/2 lap splits were as follows:

0125: 11.724"
0250: 06.748"
0375: 06.364" (fastest 1/2 lap, first half of lap 2)
0500: 06.408"
0625: 06.595"
0750: 06.848"
0875: 07.145"
1000: 07.508"

I thought it might be a 53/12. But, 58/13 seems to be the best fit. Good call.

carleton

Thanks!

Without giving out all of my secrets, first lap excused, the cadences were in the 110s to high 120s range.

pierrej

Might have been as big as a 62x13 are what I've heard.

A lot of the times except for that last day when the kilo was on were at very low air pressure as the was a cyclone off the coast, with the warm air and humidity where it was the track was lightening fast apparently

carleton

62/13 doesn’t check out, unless the line he rode was really bad (swerving above the red) which didn’t happen. The line wasn’t perfect, but it was good enough.

I gave him about +0.2” “imperfect line” penalty each 1/2 lap.

62/13 would have him much faster each lap given the same cadences for a gain of like -3.5” to -4.5” off of the ride.

I could be wrong, but I’m confident in my assessment.

carleton

63/14 would work. It’s only one gear-inch higher.

58/13 = 120.5”
63/14 = 121.5”

carleton

Had Glaetzer ridden the theoretical perfect line he would have clocked a 55.81”.

During this ride, I estimate that he rode 1,062M...62 extra.


EDIT:

No human can ride a perfect line...especially at 45mph / 70kph.

EDIT 2:
1,062M, not 1,065

Clythio

Didn't get the math.
If you ride wide DeltaR all the 4 laps, 8 turns, you'd ride extra 4 x 2pi x DeltaR.
If DeltaR was 1m wide, it would give only extra 25m.
If ave DeltaR = 0,50m (very bad line), the extra lenght would be 12,7m, or only 0,76 sec lost.

If ave DeltaR = 0,25m - regular line for a good rider, extra lenght would be 6,4m, or only 0,38 sec lost, a reasonable estimative for the damage on Glaetzer ride.

carleton

Assume: Glaetzer's gear is 58t/13t.

His published 125M splits are:

11.724s
6.748s
6.364s
6.408s
6.595s
6.848s
7.145s
7.508s

I counted actual pedal strokes on multiple splits throughout the ride. I counted 13.75 revolutions multiple times.

To calculate his average cadence for the 1st split:
(observed) revolutions per (electronically timed) second:
13.75 revolutions / 11.724s = 1.173 rev/s

(observed) revolutions per (electronically timed) minute
(13.75 revolutions / 11.72s) x (60s/1min) = 70.369 rev/min



So, that's how I calculated the avg cadence for the first 125m split. Here is the result for all:

70.37 rpm
122.26 rpm
129.64 rpm
128.75 rpm
125.09 rpm
120.47 rpm
115.47 rpm
109.88 rpm

Average: 115.24 rpm

If Glaetzer rode a 58t/13t at 115 rpm, his average speed would have been 64.5 kph or 17.9 m/s (assuming a tire rollout of 2095mm)

Glaetzer's recorded time was 59.340s.

s = vt

If Glaetzer rode 64.5 kph for 59.340s, he traveled 1,062 meters...62 meters further than necessary.


Notes:
- Redoing this helped me find a transcription error in my calculations. So, the overshoot was 62 meters, not 65 as I previously reported.
- I was counting pedal strokes from a shaky video with lots of camera cuts. I could have made an error here.
- I assume that his rear tire rollout is 2095mm. This is a fairly common number used in cyclocoputers. The actual value could be larger or smaller, but not vary by more than 1 or 2 percent and thus not affect things that much. Maybe +/- less than 1 meter in the total distance traveled.

carleton

Also, with your calculation, you are assuming that the rider simply rides x distance away from the optimal inner path of the oval or circle.

That didn't happen in Glaetzer's ride It doesn't happen on anyone's ride. This is why distances recorded on our bike computers don't match up with what we thought we rode.

Assume that this is a 250m velodrome:


If a rider rides the black line:
- They will ride 250m per lap.

If the rider rides the red line ("DeltaR", change in radius between black and red, in your post):
- They will ride 250m + (2pi x DeltaR).


NOW...

- What happens if they ride the black line but swerve only once up to the red? Small penalty in a 4-lap ride, right?
- What if they do it twice?
- 3 times?
- 4?
- 5?
- 10?

There will come a point when going up and coming back will cost more than simply staying up (2pi x DeltaR).

Don't believe me?

What if he rode back and forth like this?

(hyperbolic theoretical example to illustrate zig-zagging):


For a given net distance traveled down the cloth each row of thread is a different length depending on how wide AND how often the zig zags happen.

This may account for why my number is bigger than yours.

Obviously, riding the black line is best. But, I think there is a point where staying on the red line is faster than constantly fighting back and forth between black and red lines. Basically, fighting to stay laterally smooth may prove faster than fighting to stay close to the black line.

queerpunk

(obligatory mention of Lucy Lines)

Morelock

Trackies pretty well cleaned up the Road TT as well. Didn't expect the win from Meyer, really thought it was going to be (Hamish) Bond's day to shine.