Monday, January 25, 2016

Proposed update to the 1-second gap rule: 3-second gap

It's been a long time since I've done a post here, mainly because I've been working from home a lot, and the loss of my mind-numbing Caltrain commute means loss of blogging time.

But I'm compelled to break the silence, at least briefly, to propose a change to the UCI cycling rules... Here's a video of the final km of stage 4 of the Tour Down Under this year. It was a twisty-curvy run to the finish, riders strung out in a single line, the sprinters and "puncheurs" at the front, the climbers drifting further back. Results are on CyclingNews. You can't directly see it from the video but Richie Port (BMC) let a gap open in front of him, that gap according to the finish line timing exceeding the 1 second threshold of the UCI rules (general regulations):

1.2.107 When several riders finish in a group, all riders in the same groupe shall be credited with the same time. If there is a difference of one second or more between the back of the back wheel of the last rider in a group and the front of the front wheel of the first rider of the following group, the timekeeper-commissaires shall give a new time taken on the first rider of this group. Any difference of one second or more (back wheel – front wheel) between riders implies a new time. (text modified on 1.01.05; 1.01.09).

A side effect of this gap was Cannondale's Michael Woods, who was behind Port, also lost 8 seconds, a time loss which would eventually cost him third place in the overall standings.

The big problem here is (as seen in the video) it takes a good number of seconds for a full pack to cross the line with a technical finish. Those more than a second from the front are at the mercy of riders. This creates an anomalous situation. In racing in general, not just cycling, if your competitors go faster that doesn't help you. Here it can -- the rider in front of Port went faster, opening a gap, and that helped Gerrans increase his lead over Port. Gerrans eventually won by 9 seconds, so it would have been 1 second without the gap (all other things the same), but still that was a substantial time difference in a race like this one.

You might say "well then riders should stay near the front". But the whole point of this rule is to reduce the pressure on riders being at the front. This is a safety thing. Without the 1-second rule you'd have riders trying to force their way through dense packs ahead in order to minimize the time gap to the leaders. This would be disaster. But with random gaps potentially opening in a large finish, that pressure may be attenuated but it still exists.

A solution is to reduce the penalty for gaps opening. I would write the rule as follows:

1.2.107 When several riders finish in a group, all riders in the same groupe shall be credited with the same time. If there is a difference of one second or more between the back of the back wheel of the last rider in a group and the front of the front wheel of the first rider of the following group, the timekeeper-commissaires shall give a new time taken on the first rider of this group. Any difference of at least one second but less than three seconds (back wheel – front wheel) implies a time equal to the time of the group ahead plus the time of the gap (one to three seconds). Any difference of three seconds or more (back wheel – front wheel) between riders implies a new time. (text modified on 1.01.05; 1.01.09; 1.01.17).

The new text is in boldface. So if the gap is one or two seconds to the rider ahead, instead of getting a fresh new time with a gap relative to the leader of that group, you get a time with a gap relative to the trailing rider of the group. So if the leaders cross the line from time 0:00:00 to 0:00:07, taking 7 seconds to cross, then there is a 1-second gap, then the next rider under the present rules would get a time 0:00:08, while under the proposed rule change, he would get a time of 0:00:01. This seems a more appropriate penalty: a 1-second gap caused a 1-second penalty on overall time, not an 8-second penalty.

At some point, though, a gap means you weren't able to keep up, and a fresh time is appropriate. I set that at 3 seconds because it seems to me 3-seconds really does imply a serious split. 1.0 seconds, though, can readily happen, as was shown in this finish video at the Tour Down Under.

Monday, October 5, 2015

Levi's Grand Fondo: neutralize technical descents

A rider died in this past Satuday's Levi's Grand Fondo when he missed a corner on the Hauser Bridge descent and went off the road. Here's the story in the Santa Rosa Press Democrat.

Michael Muhney, 40, said the rider was just ahead of him and was “just barreling” down the hill despite numerous course marshals cautioning riders to be careful on the descent. “He was hauling,” he said.

The Fondo is a "timed ride" and not "a race" according to the story. Here's how Oxford English Dictionary defines race:

race (noun) 1A competition between runners, horses, vehicles, boats, etc., to see which is the fastest in covering a set course.

I don't know -- seems to apply here.

So the problem is you have a race over a technical, dangerous course and that means people are going to take risks, and when people take risks by definition sometimes things go wrong and people get hurt or die. Fine -- if you want zero risk of death stay in bed in the morning but then your house may burn down and you'll die anyway. So we need to accept risk. But the key here is that the obvious hotspots for risks are these technical Sonoma descents.

One option is to do what we do with Low-Key Hillclimbs GPS-timed multi-climb routes: neutralize the worst descents (actually in Low-Key we neutralize everything but the climbs). These rides are likely using chip timing anyway. So put a mat at the top of the descent, another at the bottom, set a "reasonable safe and conservative speed" for the descent, and if the rider is faster than this then add time to his overall time equal to the difference between how long it would have taken at the conservative speed and his actual speed. Want to go further? Set an unsafe speed threshold and if he's going faster than this than penalize him the time difference between his speed and the unsafe speed.

Don't want to use timing mats? Then use GPS. When riders are paying in excess of $100 entry fees, it's really not much to require posting data to Strava. We do that in the Low-Key Hillclimbs.

This sort of solution would do little to change the nature of the competition. That's about pushing your body over a challenging course. It's not about railing dangerous descents where 50+ year old eyes can't adapt to the difference between shade and sun quite like they used to and riders go flying off the road. Descending skill is a wonderful asset and should be honored but we don't want to encourage riders to risk their lives in an event like this, essentially an unsanctioned race. Restrict the crazy descending to USAC races with their upgrade system and their field limits.

Wednesday, September 30, 2015

Low-Key Hillclimbs 2015

It's time once again for the Low-Key Hillclimbs, and this will be the 20th anniversary of the first edition, when Kevin Winterfield and I brashly organized a series of 12 consecutive weekly climbs extending from October through almost Christmas. And the amazing thing is we pulled it off. I'm less brash now but I don't need to be: I have fantastic support in putting the series on and so far we've had minimal interference. It's really been a wonderful thing.

I've got some decent fitness this year after having ridden SuperTour, organized by Sid and Linda Fuhrer, then raced the Mt. Tam Hill Climb and the Fremont Peak Hill Climb. For the first time in years I've actually been focusing on training instead of riding, and it's helped, starting with the fantastic dose of base I got from SuperTour. My time at Fremont Peak wasn't what I wanted, although I rode fairly well at Mt. Tam the week before. It was particularly hot at Fremont Peak so that took its toll.

But for Low-Keys, I'm coordinating week 1 so I don't get to see how I'm doing there until week 2, Page Mill Road. I really look forward to that one -- it's a classic time and makes for a great competition with its variable grade and fantastic views. Then week 3 is Alba Road, a climb we've done only once before in 2009. Then Mill Creek for week 4, a road I've never ridden but a short and intense climb which will be done as a time trial. Week 5 is a GPS-timed climb up Purisima Creek trail, a really fantastic off-road climb which is accessible to all bike types. Then week 6: Bohlman, but without On Orbit. The only year we tried that before was 1998 when it got canceled due to weather. Week 7 is OLH (wink, wink) which is the climb for which times matter. Week 8: Mountain Charlie, another Low-Key first. Then Mt. Hamilton and it's another Low-Key wrap.

The forecast has been for a wet fall so hopefully Low-Key luck with the weather and we squeeze them all in.

Saturday, July 4, 2015

Cannondale 2016 Evo: Damon Rinard leads switch to Stack-Reach design

Previously I blew it by posting that Cannondale had retained the old geometry for the new 2016 Evo. This had shocked me since I knew they'd hired Damon Rinard, formerly of Cervélo, the pioneer in stack-reach design, something the old Cannondale clearly did not follow with weird kinks and jogs in its stack-reach progression due to odd jumps in seat tube angle as sizes increased. I'd gotten the geometry chart by clicking links on the Cannondale website, but somehow I'd clicked a link for the 2015 geometry starting from the 2016 Evo page. So I'd been too hasty.

Well, I was finally pointed to the correct geometry chart. Here's a comparison of old Evo and new Evo:

2015 Evo:


And, finally, the 2016 Evo:


Here's the stack-reach progression:


Plotting stack versus reach shows the design has switched to a stack-reach focus, with continuous small increments in seat tube angle rather than descrete jumps, with a design transitioning from closer to the Trek H2 in small sizes to closer to the Trek H1 in larget sizes, but always between the two.

Bottom brackets are 2 mm lower in every size except the 52. Previously there was a jump from 52 to 54, and now there's a jump from 50 to 52. The jump at 58 remains. This is consistent with the trend to fatter tires.

Trails are slighly increased relative to the older Evo, and are significantly larger than on the CAAD-10 curiously, in the small sizes, mostly because the CAAD-10 uses a 5 cm (as opposed to 4.5 cm) rake fork in the smaller sizes. Here's CAAD10 geometry, which other than the trail is similar to the older Evo:


Sunday, June 28, 2015

2016 Cannondale Evo

[b]Comment:[/b] The following post is in error. The geometry chart on the Cannondale site is still the 2015 bikes. Bikerumor had an article where they described geometry changes for 2016, including adjustments to stack-reach in small and large sizes, and a general drop in bottom brackets consistent with the trend to wider, deeper tires. I'll post a follow-up post when I get the geometry chart for 2016.

Cannondale just announced it's 2016 Evo.

There's been a flurry of really attractive new bikes announced this year, including the new Madone 9 from Trek, the incredible Venge ViAS from Specialized, and the new Scott F02 update to the Foil. A common feature of all of these is increased focus on aerodynamics and comfort. Aerodynamics isn't new, with bikes going back to the Kestrel Talon and Cervelo Soloist Carbon examples of carbon frames designed for aerodynamic efficiency. However, the bikes have never been as popular as was predicted because in the end riders like feeing good on the bike, and a combination of drivetrain efficiency and vertical compliance provides a palpable advantage while the advantage of aerodynamic improvements needs to be carefully measured and is thus less obvious. But perhaps starting with the latest Felt AR a few years ago, aero bikes have received an increasing comfort focus, and it's hard to see them not finally becoming the main design used in the pro peloton.

BikeRadar photo

Cannondale's new Evo isn't an "aero" bike, but is more in the style of the Cervélo R5 which is a lightweight bike designed to be aerodynamic. The previous Evo made a nod to aerodynamics, but in a more subdued way by reducing tube diameters. This is important, but tube shape remained unchanged. That's been fixed here, with the new Evo adapting the now common "Kamm tail" approach of a truncated airfoil shape.

For "comfort", they've taken lessons learned in the Synapse. It's nothing as overt as Trek's adoption of the Isospeed linkage used in the "endurance" class (and tall-stack) Domane to the Madone 9. For example, one change Cannondale made was to reduce the seat tube diameter from the common 27.2 mm to the less common but more traditional 25.4 mm. There was a trend for a few years to make seat tubes ever fatter (my Fuji SL1 uses a mountain-bike-style 31.8 mm) but that makes little sense: propulsive torque isn't applied to the seat tube so a bendy seat tube, within reason, makes for a more comfortable ride. But additionally they've flattened the chain stays, like the Synapse, to provide more vertical compliance.

The fork as gotten an overhaul with a very light fork providing a large portion of the claimed 65 gram system mass reduction (the rest, I think, is from the seatpost). Tour magazine in Germany has been rating bikes on comfort using a combination of deflection at the seat tube and deflection at the head tube, the latter being a "fork comfort" rating which is averaged with the seat tube number. Many bikes have been engineered to score well at the seat tube deflection test but on the fork deflection test it's been common that bikes lose a lot of potential points. Jan Heine likes to emphasize the importance of fork deflection, advocating for the traditional high-rake flared out design which was common on steel bikes through the middle of the 20th century. Apparently Tour magazine agrees it's an important issue and the light, more compliant fork is a welcome modification.

One thing they did not change was geometry. I had thought with the addition of Damon Rinard, formerly of Cervélo, to the Cannondale design team that the stack-reach design philosophy would be adopted, but perhaps Rinard joined too recently for such a drastic change. Here's the Cannondale stack-reach chart compared to Trek's stack-reach-based design. Trek uses two curves, the "H1" and the "H2", for its Emonda and Madone. The special race-geometry Domane now uses the Emonda H1 curve. The Madone had a more aggresssive H1 curve but perhaps that will change with the Madone 9.

Cannondale and Trek geometry comparison

The two Evo curves are fully coincident and thus you can't see the 2015 curve, which is occluded. So the old and new Evo are the same.

Cannondale's approach includes some weirdness. For example, going from 52 to 54, the two points which are of similar reach but different stack 3rd and 4th from the left, they increase the top tube length but decrease the seat tube angle and the result is the reach stays virtually the same, the change in geometry almost all coming in the stack. Additionally the bottom bracket increases. Trail between the two is the same. I'd rather have the 3 mm lower bottom bracket so even though I could use a 14 cm head tube to avoid spacers I'd go with the smaller frame to get the same position with a lower bottom bracket and live with some spacers up front. It's just as well since the smaller frame will be lighter.

The importance of a clean stack-reach schedule can easily be overstated: either a bike fits or it doesn't and if a particular size in the Cannondale fits that's all that matters; I don't care what how the other sizes are designed. Still, I suspect this will be changed next iteration.

So this is a really cool bike. I really think 2016 is bringing a tangible advance in bike design from the big companies and my 2008 Fuji SL/1 seems more than another year older. It's more than good enough for me, however.... alas.

Wednesday, June 24, 2015

Garmin Edge 25: simpler, lighter, smaller equals better

SCRainmaker has a "hands-on" (as opposed to an "in-depth" review; still way more in-depth than any other reviews on the web) of the new Garmin Edge 20 and 25. These are, finally, Garmin addressing the simpler/lighter-is-better market for GPS.

On bikes, a huge amount of attention and money is directed towards minimizing weight. The best way to minimize weight of a GPS unit is to ride without a GPS unit. But the prominence of social networking website Strava has increased the value of GPS data. So for many, GPS has become a virtual requirement. What's the point of riding if you can't get kudos?

Yet despite big push for lighter bikes, and with real estate on the handlebars and stem so limited, Garmin has seemingly ignored the value of lighter-and-simpler-and-smaller by producing a series of increasingly complex, heavy, and bulky GPS units. The Edge 500 came out more than a half-decade ago, and yet it has remained the lightest and most compact unit provided by the company until these new units. And the Edge 500, while still a "current" product, has been abandoned for firmware upgrades, the firmware remaining buggy and now not supporting the Vector pedal dynamics metrics which were made available on larger/heavier Edge 510, a unit with a poor reputation for reliability. Indeed, it's remarkably the company ever produced the 500 in the first place: it's simply too elegant, compact, and functional. It must have been an anomaly.

So I was surprised when I saw these new units, which come it at half the weight of the already light (57 gram) Edge 500. There had to be a catch....

And there is. First, the Edge 25: that has ANT+ Sport support and also low-energy Bluetooth. But these are supported only for heartrate straps and for communications with phones. Obviously if you can trade data packets with a heartrate strap you can do the same with a power meter. But the unit refuses to communicate with power meters. Was this an engineering decision or a marketing one? On the engineering side, you might argue that communicating with a power meter would be too large a drain on the battery, which is rated at only 8 hours. After a hundred or so charge-discharge cycles surely that will come down, making the unit barely able to survive a fast century ride. Road races are shorter, so for racers the battery might be sufficient, but add in the extra drain of power meter support and that's pushed a bit further. But they are willing to communicate with a heartrate strap.

So I think this is likely marketing. If they put too much power in the 25, they believe, that will take away sales of more expensive, complex units. But this is monopolistic thinking. In a competitive market, suppliers are compelled to make all of their products as good as possible, otherwise competitors will do so and outsell them. In a monopoly, you're competing mostly against your self or against "none-of-the-above", in which case you can afford to play games like this. I think the GPS market is competitive, so these market-slicing games are a mistake which will in the end cost Garmin marketshare. After all, power meter support will differentiate the units from what might be the #1 competitor to low-end GPS units, which are smart phones and, increasingly, watches.

Another missing feature is a barometric altimeter. Barometric altimetry, as opposed to GPS altimetry, is much more reliable especially in situations where the GPS signal is compromised, for example wooded hillsides or canyons. Barometric altimetry is susceptible to errors from weather fronts, but in conjunction with GPS, those errors can be minimized. The two together are better than either by itself. And good altitude data is really useful for estimating power on climbs when power meter data is unavailable.

A subtle feature of the new units is they are listed by DCRainmaker as being "smart recording" only. Smart recording can result in gaps between data of up to 8 seconds, which is terrible for Strava segment timing and possibly even segment matching. This seems silly because it's a software-only issue. The motivation for having provided 1-second recording on the Edge 500 was analysis of power data. Initially 1-second data recording was available only when power meter data was being recorded. But they eventually allowed 1-second recording as a general option, most likely because of Strava. But this unit has taken a step backwards by being smart recording only. For Strava fans, this alone should be a deal-breaker.

So give me a compact unit with a barometric altimeter and at least minimal power meter support with one-second recording and I'm all over it. I don't need fancy displays. I don't need access to a huge number of data fields at once. I want to see distance and power and I want to record everything else. These are the key things.

On the plus side they did include the same level of navigation support provided by the Edge 500. And while that's flawed and error-prone, it is nevertheless extremely useful when the GPS signal is strong. I used it extensively when riding out of Switzerland last year. So perhaps real-time navigation isn't part of my claimed support for "simpler" but I'll use it if it's there. It can always be ignored.

It's perhaps ironic that the low battery life, good enough for road races but not good enough for century riding, combined with the exceptionally light weight could well have made this an excellent "race day" GPS unit. But then they crippled it with a lack of power meter support and lack of 1-second recording, neither of which would require additional hardware. So instead you have a unit which isn't particularly good at anything. It's unfortunate.

So while this is a good start, but Garmin needs to go further. The smaller-lighter-simpler = better philosophy has been long neglected at Garmin, and it would be great to see it get attention again.

Wednesday, June 10, 2015

Golden State Warriors down 2-1

The Golden State Warriors lost to the Cleveland Cavaliers in basketball last night. They're now down 2-1 in the series. The first team to win 4 is the champion.

I don't care about basketball but there's one thing I like about the game and that's that scores generally increase relatively at random (I hope -- I hope the near miraculous comeback yesterday from a 17-point deficit after three quarters wasn't programmed), and that games are won to some degree seemingly at random. I like random.

As an aside, I do find it remarkable in basketball how often a team with a big deficit claws its way back only to lose in the end by a small margin. I'd like to see a statistical analysis of this. A huge amount of money is at stake for games not being a total blow-out. I do wonder at this. Basketball has long seemed to me to be more about the show and less about a fair contest. And that makes it very difficult for me to care about the result. But this is an aside.

Assuming games are fair, what's the chance of Golden State winning the series?

Assume each team has an equal chance to win games. You can weight results under different assumptions but this is simplest.

Then the key to solving this problem is to recognize that while the series is terminated when the first team reaches 4 wins, this is irrelevant to the odds of who wins. It's easier to calculate the odds of winning if you assume the series always goes 7 games. If you assume that, it becomes a simpler probability problem.

Then all sequences of win-loss are equally probably. Each has a chance 2-n, where n is the number of remaining aims. And since 3 games have been played, 4 remain (I'm assuming we always play the full 7). So I need to count how many of those possible 4-game sequences result in the Warriors winning.

There's one sequence where the warriors win all 4. They win the series then, 5-2.

There's four sequences where the warriors win 3. Then Cleveland wins 1. That win can occur in either game 4, 5, 6, or 7.

The rest of the possible sequences the Warriors fail to win at least three games. So they win the series in 5 of the 16 options. Since each is equally likely to occur, they win in 31.25% of the possible results. That's their chance to win the overall, assuming games are completely random.

To calculate it assumingt he series ends as soon as one team gets to 4 is more complicated. You'd need to start with the odds the warriors win the next 3 games. Then consider the odds they win exactly 2 of the next 3 but then win the 4th. Then add these together.

I can do this: the odds of winning 3 in a row is 1/8 = 2/16. The odds of winning exactly 2/3 is 3/8 (there's 3 ways to lose one game of 3, and there's 8 ways total the 3 games could end up, so that's 3/8). Then I need to divide by 2 because they then need to win the 7th game, which has 50% chances. So that's net 3/16. So the total chances of winning are 2/16 + 3/16 = 5/16. This is the same answer as I got before but is more convoluted.

The principle that cutting the series short can have no effect on the winner, assuming results are random with a fixed chance for each team to win, has more implications than just simplicity in calculating the odds. It also means the sequence of home versus away games doesn't matter. There's been a lot of debate in various sports whether a 2-3-2 sequence of teams A and B being home, which generally has an advantage, is more balanced than a sequence 2-2-2-1. After all, 2-3-2 could result in team B having 3 home games to team A's 2 home games if the series ends after 5. However, if I view it as the series always goes 7 games then it seems the sequence should not matter. And since going to a full 7 never changes the result I therefore conclude the sequence doesn't matter. You can just as well go 3-4. The home field advantage for the series is alwsys with the team with 4.