Latest start to complete a 100km ride before midnight

[CrazyEnglishTriathlete]

Seriously JPO after a bad day at the office yesterday decided to do the planned 100km ride even if I had a late start.  Working in the Hague means no hills, so left at 7.39pm and was back at the late night store after a round trip to Mijdrecht to pick up supper at 11.43pm.  That made me wonder what the latest start to finish a 100km ride was.  (Not thinking about a PBP where the first 100km can be a mad dash, but the ride isn't finished until 2 or 3 days later).

[psyclist]

71 people have read this thread and nobody replied yet. Maybe it is not just me who is trying to get their head around the question.

From an audax perspective, the latest start would be just before midnight for the ride to be counted for the current day. But I'm sure you know that.

If it is from a desire to finish before midnight, then surely it would depend upon your speed potential, prevailing weather and terrain.

Could you expand on the question?

[jsabine]

The reductive answer is presumably 20:39:59, as if you start any later and still finish before midnight, you must have averaged more than 30km/h.

How much earlier do you need to be comfortable? In my case, probably about 1800 ...

[dim]

Just a general guideline ...

If you are cycling from a point, and ending at the same point, (i.e. in a loop), the elevation gain will be the same as the elevation downhill. If there is headwind for half the way, there will be tailwind for the other half, so it balances out

depending on your fitness, you should finish a 100km ride in under 4 hrs (25 Km/hr) if you dont stop to rest for a lengthy period, and assuming you have no mechanical issues / punctures etc ...

obviously, if you are fitter, you will finish much sooner, but when I plan a new ride, I estimate the time based on 25 Km/hr .... if I finish sooner, it's a bonus

[Greenbank]

If you are cycling from a point, and ending at the same point, (i.e. in a loop), the elevation gain will be the same as the elevation downhill. If there is headwind for half the way, there will be tailwind for the other half, so it balances out

Only sometimes.

Not all climbing is the same. A rollercoaster road that climbs/dips 5m at a time (so that you can maintain momentum) is much nicer than a series of big steep climbs followed by descents with a sharp turn at the bottom, etc. A strong sidewind for the entire ride is way more tiring than a still day. Wind direction and strength changes over time. etc.

Closest I've come is doing a 100km ride starting at just after 5pm, would have finished that in under 5h.

[Kim]

Only sometimes.

Not all climbing is the same. A rollercoaster road that climbs/dips 5m at a time (so that you can maintain momentum) is much nicer than a series of big steep climbs followed by descents with a sharp turn at the bottom, etc. A strong sidewind for the entire ride is way more tiring than a still day. Wind direction and strength changes over time. etc.

Also, you ideally want the headwind to happen while you're climbing, as you'll be travelling at a lower speed and less affected by it.

[Karla]

[revises loop integrals from first year maths lectures]

[Samuel D]

If you are cycling from a point, and ending at the same point, (i.e. in a loop), the elevation gain will be the same as the elevation downhill. If there is headwind for half the way, there will be tailwind for the other half, so it balances out

Even if the wind is steady in strength and direction (it rarely is over several hours of riding), it doesn’t “balance out” because aerodynamic drag varies with the square of the relative wind speed. This means you always pay a penalty if your airspeed varies during the ride, as it must with wind and hills.

For the same reason, time trialists ride harder on climbs despite the biological cost of that uneven power output.

[frankly frankie]

Everyone rides harder on climbs don't they?

[Ian H]

Everyone rides harder on climbs don't they?

Except elderly time-trialists using power-meters.

[Samuel D]

Everyone rides harder on climbs don't they?

Yes, but often for the wrong reasons (or just for fun). If what dim said was true, the fastest way around a course would be constant power.

[hillbilly]

71 people have read this thread and nobody replied yet. Maybe it is not just me who is trying to get their head around the question.

Tru dat. 

Perhaps CET's bike changes back into a pumpkin at the chimes of midnight? 

[Whitedown Man]

TBF to CET, his thread title is completely clear

[mattc]

TBF to CET, his thread title is completely clear

Unfortunately the detailed description made things rather unclear (as did posting it under "Audax", which as pointed out early on, brings max speed limits into the puzzle ... )

Still, it has created some entertaining debate on a range of topics, including a suggestion that flat rides are no easier than hilly ones. Or something ...

[Frank9755]

Also, you ideally want the headwind to happen while you're climbing, as you'll be travelling at a lower speed and less affected by it.

Are you sure?
Headwind on the climb means you'll be in it for more hours, going very slowly (relative to the ground, but quicker relative to the air), then you'd have tailwind on the descent when you don't need it!
If I had the choice I'd go for for tailwind on the climb / headwind on descent to even my speed out.  Would be faster overall

[Kim]

Also, you ideally want the headwind to happen while you're climbing, as you'll be travelling at a lower speed and less affected by it.

Are you sure?

No.

Headwind on the climb means you'll be in it for more hours, going very slowly (relative to the ground, but quicker relative to the air), then you'd have tailwind on the descent when you don't need it!
If I had the choice I'd go for for tailwind on the climb / headwind on descent to even my speed out.  Would be faster overall

I was saving the tailwind for the flatter part of the ride, when it's more useful. 

[postie]

What about crossing time zone's 

I.e. a straight out 100km

Only trying to help.

[frankly frankie]

Headwind on the climb means you'll be in it for more hours, ...

But to some extent sheltered from it (you're in the lee of the hill).

[grams]

What about crossing time zone's 

There's a *pause for Googling* three and a half hour time difference at the border between Afghanistan and China. I reckon that's enough to time for a fast rider to do a 100 km. Yes, it's quite hilly there, but as we've learnt on this thread, hilly rides are no slower than flat rides.

So the answer is midnight in China.

[grams]

If the ambition is to start and finish on the same day then you need to set off at 23:59:60 on the day of the leap second.

(Edit: I seem to be replying to a deleted comment)

[hillbilly]

I hope people are taking account of leap seconds when coming up with their answers.

https://en.wikipedia.org/wiki/Leap_second

Never mind helmet pictures.  This question highlights the weighty areas that could stimulate discussion and controversy in Arrivee.   

[hillbilly]

If the ambition is to start and finish on the same day then you need to set off at 23:59:60 on the day of the leap second.

(Edit: I seem to be replying to a deleted comment)

Re the edit.  I changed it because I wasn't sure of the maths!  Professional vanity.

[fuaran]

What if an audax crosses the international date line? Most of it is in the ocean, but you could use a pedalo...

[hillbilly]

Regulations state that AUK events are cycle rides.  So I suspect a pedalo might be ruled out as it is not a cycle. 

That said, I don't think its been tested and so I would suggest someone seeks clarification from the relevant AUK official.

Of course, a scuba mask and a cycle might be possible, but I suspect completing the ride within time limits might be challenging.

[Delph Cyclist]

TBF to CET, his thread title is completely clear

Well I for one didn't understand the question, or at least, felt that the question wasn't complete, but at least it gives the opportunity to answer lots of different questions instead.

The Plains 300 starts at 23:00, which is only a hour before midnight.  However, that's for a 300km and I don't know what adjustments you need for a 100km.  The event used to start it at 00:01 giving us a massive 23 hours 59 minutes before midnight (plus or minus any leap seconds you want to take into consideration and note that I am ignoring relativistic effects).  Don't tell anyone, we actually set off at 00:00.