How I wish I could ...Ahmmm..."make love to" you guys at your own game Let's see; I just might, at the end of this season.

But seriously guys, I am really extremely thankful to you for all your posts in these years; all the info was quite educative and motivating. Today I pushed myself to 2 hrs 36 mins, not counting some 5-6 mins when I was off saddle to tank up. Btw, Can one of you tell me if wind was a significant factor today, and did it assist me or push me back? by looking at the weather sites you are familiar with? I started clokwise route around 3:30 pm and ended around 6:15 pm. (I had a stopwatch, so didn't record start and end times)

I don't think 2:36 was that bad considering that I had just touring equipment: an upright bike that weighed atleast in the late teens, and normal running shoes. One doesn't realize in city commuting, but today I actually felt cleats would have made a difference...

And some pep talk for other newbies: I wanted to share my personal progress. The first time I did Lake Zurich (cycling after 10 years)in Jan 2009, it snowed and rained and became dark before I reached mid-way...I took me over 5 hours to complete the route. I later realized the bike I had from a budget stores was fit for a 9-year old to go to the neighborhood school...the leg pain lasted full 3 days.

My second trip was on a touring bike, in Feb; again a sub-zero day and frozen toes and fingers...I managed 3 hrs sharp.

Today, just my third attempt, I managed 2:36 (just over 25 kph average)... So I think there is no reason to get disheartened; with better equipment and technique one can improve drastically. That's what I learnt today. Hope that motivates more people to sign up.

And lastly, there is one thing that gives me immense satisfaction that no one can steal from me: while Salsa and Dakman were writing these expert posts from their home/office, I was basking in the lovely sun in my biking shorts and T-shirts

Hope to see you soon guys

That is a pretty good time....wind can be difficult to judge as in theory in a circular route you should have it behind you as much as in front of you. But crosswinds, as you may have can make it more difficutl.

my fastest around the lake was maybe 2h 20 about, but I only used the route in the early season so I am sure my mid season time would have been much quicker last year, after riding with the bike nuts on here to get myself into prime form (by my standards)

Just keeeping riding, and don't worry so much about your time, I ride for enjoyment, of course pushing yourself above and beyond what you think you can do is part of the enjoyment along with the comradery of fellow cyclists, especially those post ride beers. Have a great season.

Great post, totally agree, I was new to cycling in only 2006 and now I am a total nut. Don't be discouraged, ever, just keep at it and enjoy it, that is the key...being outside is the best, though I am huge advocate that one should force themselves to go up the hills in Zurich as that really is the best place to cycle. Uphill gets easier every time, as long as you aren't trying to keep up with hillseeker.

Btw along the way, today I saw atleast 30 serious cyclists on their racing bikes and professional attire. Was sheer beauty to watch them. I now believe some people can actually manage that route in under 1.5 hours...

I'm not so sure. The lake is 40.3 miles around. To do it in 1.5 hour would require 26.9 mph (43.4 kph). The power required by the cyclist to maintain this speed is dominated by the air drag, which is proportional to the speed squared. What this means is it takes about 77% more power to increase your speed by 33%!

For comparison (here we go again ), Lance Armstrong won a 55km (34 mile) time trial at an average speed of 46.4 kph (28.8 mph). I would guess Lance could do Zurichsee in 1:28 (with his 3kg time trial bike, streamlined helmet, and maybe even some fresh blood)... so I doubt anybody has done Zurichsee in 1:30, ever.

Great analysis but a pack of professionals could most certainly

Or someone motor pacing. Fair point though Patrick.

The other thing is the traffic lights which you are not always going to get green if you happen to be doing it on an open road!

I was referring to Lance when I said "some people" can do it .

Nice analysis, patrick, but I think (and you know better) the physics here is more complicated than you make it seem. Consider this situation: Suppose Lance can maintain 50 kph in perfectly still air. Which means, he has enough power in his legs to overcome resistance of 50 kph relative velocity (of course resistance is proportional to the square of velocity).

Now suppose suddenly we have a tailwind of 75 kph. What happens then?

(a) He no longer has to cut thru' the air which he was earlier cutting thru @50 kph, so he now has abundant spare power (as we all know, mechanical friction and tire rolling resistance add up to just 10-20% of total resistance for elite cyclists. Fortunately, unlike air resistance, these two only increase linearly).

(b) the 75 kph wind is actually pushing him till he attains 75 kph. This is in addition to the effect of (a). Only after he exceeds 75 kph does he start cutting into air, and have relative velocity and wind resistance.

So, with the combined effects of (a) and (b), he ought to now achieve 125 kph? Of course my analysis is wrong, but where? Should we have another thread dedicated to this? I don't think this part has been convered in earlier threads...

3 kg time trial bike
No wonder they could steal it and drop it back just like that

But while 3 kg sounds damn impressive, for reasons discussed above, (that wind resistance starts becoming disproportionally more significant for elite cyclists), reduction of each successive kilo off a bike makes progressively miniscule contribution to speed. On perfect flats.

When the road changes in altitude, of course each gram matters, becuase you now have the fourth resistance: gravity (which is why the bulkier people have advantage on flats, but lose out on uphills). If you thought it evens out on the way down, that's not correct: Unfortunately, the energy you spent in hauling yourself up a hill is not returned to you fully, because downwhill you are way too fast...So wind resistance eats up much of it on the way back

Coming back to lance' bike:
For perfect flats/velodromes, it is mostly aerodynamics. Period. Theoretically the weight should not matter at all !!! Practically it does, indirectly, thru' its effect on rolling frictions/bearing friction, but may be in decimal point percentages. Weight reduction is more of a marketing pitch in the competitive bike selling business, because customers find it easier to compare weights than aerodynamics forces of competing products. I am not saying a 3 kg bike is not faster than a 7 kg bike, but the actual effect is not as dramatic as it appears.

Corrections/improvements welcome. I must do less brainwork and more legwork now

Of course tailwind will help you go faster, but if you have tailwind on one side of the lake it will be headwind on the other. In fact such a situation will always hurt your overall time, because you spend more time facing the wind (you go slower) than with the wind (you go faster). The only time wind can help you on a circuit is when it changes directions dynamically to be behind you most of the time.

True, a fit rider could do it in such a time with favorable wind conditions.

I am by no means a good rider, but on Saturday I took my bike back for the first ride of the season.

I put a new battery on my computer, so it was all zeroed.

I just did a short ride Zurich-Horgen-Zürich to dust myself off, when I started I was feeling heavy and slow, and my back not fit enough to bend down. My speedometer showed ~22 Kmh at the beginning, but at some point I reached ~40kmh somewhere in Thalwil.

At the end the computer showed average speed of 28Kmh which is not bad for an old and cranky guy on his first ride after the winter

At that pace the short lake tour ( through the Rapperswil bridge ) can be done in around 2:30

The next day on sunday, I did my first mountain short ride Zürich-Horgenberg-Zürich.

I wanted to go to work by bike this week ( Zürich-Samstagern so 30Km one way with 900 mts elevation ), but I have been lazy and the temperature was somewhat low.

I'll wait until we are over 12°C before doing that. It takes me usually 1:20 so an average speed of ~24Kmh. ( coming down is faster so ~45 minutes )

I am quite happy with these times, and for sure I am by no means a fit rider on the dakman, hillseeker league, but this keeps me happy and fit.

Patrick, Salsa, I agree with you, but my query is a little more advanced than that. What you are talking about is "kinematics": the science of time and speed; it doesn't consider the actual forces. Yes, I am aware that when you go 4 kph one way and 6 kph on the other way, your average isn't 5 kph, but only 4.8 kph. If it were 1 and 6, the average is 1.7142...

What I was asking was in the domain of kinetics, which deals with time, speed and forces.

Can anyone explain what is happening when a guy is going 50 kph and then has a tailwind of 75 kph? In such cases is it better to have an upright bike than a racing bike becos you can then get more "push" from the back with a larger surface exposed?

I feel compelled to add my stats here as Lake Zurich is the only route I do with some regularity

I've cycled it many times with a not too bad regular bicycle but the tires and gears set limits. Usually it took me 2:23-2:41. I now have a road bicycle with regular pedals and it takes me roughly 2:18. The personal records of some friends of mine are 2:12, 2:05 and 2:00 but then it begins to become work I hope I can make it again a bit closer to the 2 hours mark this summer!

The very first time I cycled around the lake it took me a whopping 4:23 and I was a dehydrated picture of misery at the end. Nowadays I add Obersee and its hills to the route and stay comfortably under this time.

If you cycle clockwise around the lake you save some time because there are less crossroads.

Regarding the wind, doesn't it blow from the lake most of the time? (Subjective impression, physically not possible )

Anybody interested in an unhurried tour de lac this Saturday afternoon?


Protip: There's a ferry between Horgen and Meilen

I was also speaking in the domain of kinetics, just not considering a hurricane force dynamically changing wind that is always at your back. I was hoping to keep things simple enough that most people could understand.

The force on the rider is typically modeled as a sum of at least 4 things:
0. Human input: applied at the tire contact patch in direction of travel
1. Rolling resistance: proportional to the speed. applied at contact patch against the direction of travel
2. Air drag: proportional to the relative speed squared (my speed minus wind speed), always applied in the direction of the relative wind.
3. Friction: usually constant or affine; difficult to model and a minor contributor.

Now on air drag, it is proportional to the "frontal area" times the drag coefficient times the speed squared. Sitting up might increase your frontal area by an additional 20% (my guess), so if you sit up, it is possible to increase the air drag force from behind by 20%. But of course, the vector is only in this direction if you are traveling slower than the wind. The rest all depends on the situation: how hard the rider is pedaling or braking, what type of tires they are using, etc. In general this never happens if the rider is pedaling, since virtually any rider pedals hard enough to overcome the rolling resistance at any attainable safe speed. But if you aren't pedaling, than it can happen for sure and you'd want to sit up. After all this is how the boats move around the lake!

There are a lot more forces at play. As far as I know rolling resistance and rotational resistance at the bearings increases with speed too, so while not in the same league as wind resistance they play a role.

The other thing you have to consider is that a rider is not a machine, just because someone can develop 300W in one position it does not mean that they can develop it in the optimum aerodynamic position. This is why riders spend time in the wind tunnel, not to get the best aerodynamic position but to get the one that allows them to produce the best balance between power output at threshold and wind resistance.

A flat back actually helps cardiac output and therefore O2 uptake, so there may be a case for keeping a tucked position even if it was a pure tailwind course. Of course this has to be weighed up against keeping the chest open to let O2 in in the first place.

Also, if there really was a time trial with 75km/h winds I think all this would be academic. There would be cross winds somewhere on the course, and a time trial bike would be nearly impossible to ride in this kind of cross wind.

I think I'll not go skiing anymore this season, so I'm in, meteo says will be sunny but cool.

Where do you start ? we could setup an event and get out from Stadelhoffen for example and do the tour clockwise ?

Sunday

-2°/10°

I usually start in Zurich as well, Rentenanstalt. How's the Bellevue 912 bus stop at the lake for you, Saturday 14:00?

Rentenanstalt is perfect for me, I live in Zürich Enge.

So let's define a time and create an entry on the calendar

I need to do more flats this year, last year I was doing mostly hills and this makes you stronger but not thiner

I'd love to hear your rational for this!