I completed a 600km brevet.
It was a sightseeing brevet with some detours,
and I finished with about an hour and a half to spare
against the 40-hour time limit.
I used a SRAM Karoo (cycle computer) for the main recording,
and also recorded data separately with a Polar VANTAGE V3 (heart rate monitor),
but the recorded distance came out to less than 600km
because the measurement is based solely on GPS positioning,
and doesn't include the distance lost when GPS signal
was dropped inside tunnels.
Since I did take some detours though,
I actually rode about 606km.
I keep buying the flagship model heart rate monitors from Polar,
and the main reason I replace them
is the obvious decline in battery life
as the battery ages.
So I don't replace them every time a new flagship model comes out—
I usually skip a model or two.
After the VANTAGE V, I skipped the V2
and bought the V3.
The VANTAGE V had a quirk where it would draw a straight line
between the point where GPS signal was lost and the point where it was reacquired after a tunnel,
and add that distance all at once.
So after passing through a tunnel,
the display would jump by about 200 meters at the timing of the refresh,
and this would repeat until the numbers made sense—
but with the VANTAGE V3,
after GPS signal is reacquired,
it just operates normally.
Or maybe I just didn't know about it,
but this could be a spec change from a firmware update,
and perhaps with the latest firmware
the VANTAGE V would also stop
doing this distance reconciliation through tunnels.
If the spec doesn't include tunnel distance,
it should be the same as the SRAM Karoo,
but in reality the Polar tends to read
about 0.6km shorter per 100km.
I ran the SRAM Karoo with auto start/stop
(the feature that automatically stops recording at traffic lights)
turned off, never stopping the recording at all,
and recharged occasionally while riding.
The VANTAGE V3 barely makes it on a full charge,
but I recharged it at the accommodation near the turnaround point.
With the VANTAGE V3, I stopped recording for about
five and a half hours, including a 5-hour sleep.
This was because I wanted a pure record of actual riding time.
If someone asked whether I could do it in about 33 hours
(the time shown in the photo above) without sleeping,
the answer is definitely no—
my concentration and leg recovery wouldn't handle it.
When I parked the bike at the accommodation,
the Karoo showed an average speed of 18.7km/h,
but when I looked at it again after leaving after sleep recovery,
it had dropped to 13.8km/h.
I needed to bring this back up to the 15km/h average speed
required for finisher status during the return leg.
In older brevets, there was something called a "cutoff"—
if you reached a checkpoint with an average speed
converted to less than 15km/h for the distance covered so far,
you wouldn't get finisher status.
But the brevet I entered didn't have this cutoff system at all.
If it did, I would have been in trouble.
It took about 100km of distance on the return leg
to bring my average speed from 13.8km/h back up to 15.0km/h,
but after riding 400km already,
even if my speed drops below average on climbs,
the average doesn't fall right away.
Also, regarding the outbound leg finishing at 18.7km/h
and return leg starting at 13.8km/h—
these figures are calculated from the distance that doesn't include tunnel distance,
so in reality it's closer to 19km/h and 14km/h.
When my average speed recovered to 15.0km/h,
theoretically the people riding behind me at that point
hadn't yet recovered to the finisher requirement line.
When the Karoo's display actually showed
an average of 15.0km/h (actually higher),
I did a rough mental calculation of remaining time
if I finished at that exact pace,
and I had more than 40 minutes of buffer.
From there I kept pushing to build more margin,
and in the end I stretched it to over 90 minutes remaining.
It was a sightseeing brevet with some detours,
and I finished with about an hour and a half to spare
against the 40-hour time limit.
I used a SRAM Karoo (cycle computer) for the main recording,
and also recorded data separately with a Polar VANTAGE V3 (heart rate monitor),
but the recorded distance came out to less than 600km
because the measurement is based solely on GPS positioning,
and doesn't include the distance lost when GPS signal
was dropped inside tunnels.
Since I did take some detours though,
I actually rode about 606km.
I keep buying the flagship model heart rate monitors from Polar,
and the main reason I replace them
is the obvious decline in battery life
as the battery ages.
So I don't replace them every time a new flagship model comes out—
I usually skip a model or two.
After the VANTAGE V, I skipped the V2
and bought the V3.
The VANTAGE V had a quirk where it would draw a straight line
between the point where GPS signal was lost and the point where it was reacquired after a tunnel,
and add that distance all at once.
So after passing through a tunnel,
the display would jump by about 200 meters at the timing of the refresh,
and this would repeat until the numbers made sense—
but with the VANTAGE V3,
after GPS signal is reacquired,
it just operates normally.
Or maybe I just didn't know about it,
but this could be a spec change from a firmware update,
and perhaps with the latest firmware
the VANTAGE V would also stop
doing this distance reconciliation through tunnels.
If the spec doesn't include tunnel distance,
it should be the same as the SRAM Karoo,
but in reality the Polar tends to read
about 0.6km shorter per 100km.
I ran the SRAM Karoo with auto start/stop
(the feature that automatically stops recording at traffic lights)
turned off, never stopping the recording at all,
and recharged occasionally while riding.
The VANTAGE V3 barely makes it on a full charge,
but I recharged it at the accommodation near the turnaround point.
With the VANTAGE V3, I stopped recording for about
five and a half hours, including a 5-hour sleep.
This was because I wanted a pure record of actual riding time.
If someone asked whether I could do it in about 33 hours
(the time shown in the photo above) without sleeping,
the answer is definitely no—
my concentration and leg recovery wouldn't handle it.
When I parked the bike at the accommodation,
the Karoo showed an average speed of 18.7km/h,
but when I looked at it again after leaving after sleep recovery,
it had dropped to 13.8km/h.
I needed to bring this back up to the 15km/h average speed
required for finisher status during the return leg.
In older brevets, there was something called a "cutoff"—
if you reached a checkpoint with an average speed
converted to less than 15km/h for the distance covered so far,
you wouldn't get finisher status.
But the brevet I entered didn't have this cutoff system at all.
If it did, I would have been in trouble.
It took about 100km of distance on the return leg
to bring my average speed from 13.8km/h back up to 15.0km/h,
but after riding 400km already,
even if my speed drops below average on climbs,
the average doesn't fall right away.
Also, regarding the outbound leg finishing at 18.7km/h
and return leg starting at 13.8km/h—
these figures are calculated from the distance that doesn't include tunnel distance,
so in reality it's closer to 19km/h and 14km/h.
When my average speed recovered to 15.0km/h,
theoretically the people riding behind me at that point
hadn't yet recovered to the finisher requirement line.
When the Karoo's display actually showed
an average of 15.0km/h (actually higher),
I did a rough mental calculation of remaining time
if I finished at that exact pace,
and I had more than 40 minutes of buffer.
From there I kept pushing to build more margin,
and in the end I stretched it to over 90 minutes remaining.