The advantage of light bikes, and particularly light wheels, from a KE standpoint is that KE only comes into play when speed changes, and there are certainly two cases where lighter wheels should have an advantage: sprints, and corner jumps in a criterium.
In a 250 m sprint from 36 to 47 km/h to (22 to 29 mph), a 90 kg bike/rider with 1.75 kg of rims/tires/spokes increases KE by 6,360 joules (6.4 kilocalories burned). Shaving 500 g from the rims/tires/spokes reduces this KE by 35 joules (1 kilocalorie = 1.163 watt-hour). The impact of this weight saving on speed or distance is rather difficult to calculate, and requires assumptions about rider power output and sprint distance. The Analytic Cycling web site allows this calculation, and gives a time/distance advantage of 0.16 s/188 cm for a sprinter who shaves 500 g off their wheels. If that weight went to make an aero wheel that was worth 0.03 mph (0.05 km/h) at 25 mph (40 km/h), the weight savings would be canceled by the aerodynamic advantage. For reference, the best aero bicycle wheels are worth about 0.4 mph (0.6 km/h) at 25, and so in this sprint would handily beat a set of wheels weighing 500 g less.
In a criterium race, a rider is often jumping out of every corner. If the rider has to brake entering each corner (no coasting to slow down), then the KE that is added in each jump is wasted as heat in braking. For a flat crit at 40 km/h, 1 km circuit, 4 corners per lap, 10 km/h speed loss at each corner, one hour duration, 80 kg rider/6.5 kg bike/1.75 kg rims/tires/spokes, there would be 160 corner jumps. This effort adds 387 kilocalories to the 1100 kilocalories required for the same ride at steady speed. Removing 500 g from the wheels, reduces the total body energy requirement by 4.4 kilocalories. If the extra 500 g in the wheels had resulted in a 0.3% reduction in aerodynamic drag factor (worth a 0.02 mph (0.03 km/h) speed increase at 25 mph), the caloric cost of the added weight effect would be canceled by the reduced work to overcome the wind.
Another place where light wheels are claimed to have great advantage is in climbing. Though one may hear expressions such as "these wheels were worth 1–2 mph", etc. The formula for power suggests that 1 lb saved is worth 0.06 mph (0.1 km/h) on a 7% grade, and even a 4 lb saving is worth only 0.25 mph (0.4 km/h) for a light rider. So, where is the big savings in wheel weight reduction coming from? One argument is that there is no such improvement; that it is "placebo effect". But it has been proposed that the speed variation with each pedal stroke when riding up a hill explains such an advantage. However the energy of speed variation is conserved; during the power phase of pedaling the bike speeds up slightly, which stores KE, and in the "dead spot" at the top of the pedal stroke the bike slows down, which recovers that KE. Thus increased rotating mass may slightly reduce speed variations, but it does not add energy requirement beyond that of the same non-rotating mass.
Lighter bikes are easier to get up hills, but the cost of "rotating mass" is only an issue during a rapid acceleration, and it is small even then.
Sunday, January 23, 2011
Sunday, January 9, 2011
2011
No big races planned so far but maybe thishttp://transrockies.com/trc/ or thishttp://www.sevenbikerace.com/or thishttp://testofmetal.com/ or my first pick if i could make it down there is thishttp://www.cascadecreampuff.com/ because i think it would be the hardest ( check out the times ).My wife wants to go west this year so if i do anything thing it will be out that way somewhere.Besides that i plan on having fun doing some local races and maybe http://www.offroadsyndicate.com/xc8.php to end off the summer.
Sunday, December 26, 2010
Ass Kick Revisited
Wednesday, December 1, 2010
Dallas Eakins
Two decades of involvement with professional hockey never tested Dallas Eakins quite like this.
Caked in salt, his body overheating and his legs throbbing, Eakins had to dig awfully deep to continue pedalling his bike up one Colorado mountain pass after another.
Several hundred well-trained athletes were unable to finish Saturday's famous Leadville 100 race, but the coach of the AHL's Toronto Marlies made sure he wasn't one of them. Eakins spent 11 hours 15 minutes traversing the punishing 160-kilometre course -- having to dismount and push his bike during "multiple" steep, rocky climbs -- before eventually reaching the finish line.
It was harder than anything he could have imagined.
"I trained very hard and long and did it the right way going into this race," Eakins said Monday. "But when you've never raced it before, or when the only kind of background you have on the race is what you've seen on YouTube, I think it's easy to underestimate the race.
"And I did."
The 43-year-old stopped playing pro hockey in 2004, but has maintained his commitment to personal fitness. He worked with elite coach Dean Golic during eight intense months of training for Leadville and found himself doing seven-hour bike rides in the leadup to the event.
The training schedule also had Eakins arriving at the arena as early as 5 a.m. during the season. It was one of the best times to get in a workout before overseeing a Marlies practice.
All of the work paid off in the most challenging moments of Saturday's race, which Eakins described as a "roller-coaster" that pushed him harder than anything ever had.
"It's the first time in my life that I literally had nothing left in me when I got off the bike," he said. "My coach and my wife Ingrid were there (at the finish) and I just had to go sit in the grass and then basically just lay back. I had nothing left, I was totally spent.
"There was nothing physically left for me to give."
Eakins was one of just 1,022 people to finish the race, which featured climbs of 4,267 metres at elevations ranging from over 2,700 to 3,810 metres.
American cyclist Levi Leipheimer won with a record time of 6:16:37. He completed the Tour de France in July and labelled the race in Leadville as one of his toughest days ever on a bike.
"It's hard to describe the pain and torture that you go through on a ride like that," said Leipheimer. "It's not what I'm used to. It's like a six-hour time trial. There's no sitting in. There's no draft. ... I just couldn't wait for it to be over."
Eakins could certainly identify. He says there were several moments where he was "dying for someone to just take me off that bike."
His race experience was captured by a TSN camera and will air as a feature at some point during the upcoming NHL season.
The most memorable part of the weekend for Eakins was spending time with people in Leadville, a small mining town that relies heavily on various endurance races to keep the local economy going. Many of the locals embrace fitness and the outdoors -- creating an infectious, positive atmosphere.
"There is so much love in this community for the athletes that come in, whether you're Levi Leipheimer or Joe Blow who's come in to see if they can finish the race," said Eakins. "Everyone is equal. The great thing in this race was nobody was racing against each other, everybody was racing with each other.
"It was an awesome experience -- more of a life experience than anything."
Eakins hopes to inspire others to participate in the event, even if it's just as a volunteer. He and wife Ingrid have already discussed returning next summer to help out with a 100-mile endurance run.
In the exhausted moments that came after he crossed the finish line on Saturday night, Eakins never dreamed he'd want to enter the Leadville 100 again. But only 48 hours later he was starting to change his mind on that subject.
Now he's looking forward to the next challenge.
"I think you always need to be testing yourself in some way or another -- just to constantly be finding out who you are and where you can go," said Eakins. "The whole mantra for this race is very simple and it's so true: `You're better than you think you are and you can do more than you think you can.' It's so simple and it might even sound corny to some people, but it is truly the truth.
"I just think we all put such limitations on ourselves. ... We just limit ourselves all the time and I think it's great to go fully test yourself and push
Caked in salt, his body overheating and his legs throbbing, Eakins had to dig awfully deep to continue pedalling his bike up one Colorado mountain pass after another.
Several hundred well-trained athletes were unable to finish Saturday's famous Leadville 100 race, but the coach of the AHL's Toronto Marlies made sure he wasn't one of them. Eakins spent 11 hours 15 minutes traversing the punishing 160-kilometre course -- having to dismount and push his bike during "multiple" steep, rocky climbs -- before eventually reaching the finish line.
It was harder than anything he could have imagined.
"I trained very hard and long and did it the right way going into this race," Eakins said Monday. "But when you've never raced it before, or when the only kind of background you have on the race is what you've seen on YouTube, I think it's easy to underestimate the race.
"And I did."
The 43-year-old stopped playing pro hockey in 2004, but has maintained his commitment to personal fitness. He worked with elite coach Dean Golic during eight intense months of training for Leadville and found himself doing seven-hour bike rides in the leadup to the event.
The training schedule also had Eakins arriving at the arena as early as 5 a.m. during the season. It was one of the best times to get in a workout before overseeing a Marlies practice.
All of the work paid off in the most challenging moments of Saturday's race, which Eakins described as a "roller-coaster" that pushed him harder than anything ever had.
"It's the first time in my life that I literally had nothing left in me when I got off the bike," he said. "My coach and my wife Ingrid were there (at the finish) and I just had to go sit in the grass and then basically just lay back. I had nothing left, I was totally spent.
"There was nothing physically left for me to give."
Eakins was one of just 1,022 people to finish the race, which featured climbs of 4,267 metres at elevations ranging from over 2,700 to 3,810 metres.
American cyclist Levi Leipheimer won with a record time of 6:16:37. He completed the Tour de France in July and labelled the race in Leadville as one of his toughest days ever on a bike.
"It's hard to describe the pain and torture that you go through on a ride like that," said Leipheimer. "It's not what I'm used to. It's like a six-hour time trial. There's no sitting in. There's no draft. ... I just couldn't wait for it to be over."
Eakins could certainly identify. He says there were several moments where he was "dying for someone to just take me off that bike."
His race experience was captured by a TSN camera and will air as a feature at some point during the upcoming NHL season.
The most memorable part of the weekend for Eakins was spending time with people in Leadville, a small mining town that relies heavily on various endurance races to keep the local economy going. Many of the locals embrace fitness and the outdoors -- creating an infectious, positive atmosphere.
"There is so much love in this community for the athletes that come in, whether you're Levi Leipheimer or Joe Blow who's come in to see if they can finish the race," said Eakins. "Everyone is equal. The great thing in this race was nobody was racing against each other, everybody was racing with each other.
"It was an awesome experience -- more of a life experience than anything."
Eakins hopes to inspire others to participate in the event, even if it's just as a volunteer. He and wife Ingrid have already discussed returning next summer to help out with a 100-mile endurance run.
In the exhausted moments that came after he crossed the finish line on Saturday night, Eakins never dreamed he'd want to enter the Leadville 100 again. But only 48 hours later he was starting to change his mind on that subject.
Now he's looking forward to the next challenge.
"I think you always need to be testing yourself in some way or another -- just to constantly be finding out who you are and where you can go," said Eakins. "The whole mantra for this race is very simple and it's so true: `You're better than you think you are and you can do more than you think you can.' It's so simple and it might even sound corny to some people, but it is truly the truth.
"I just think we all put such limitations on ourselves. ... We just limit ourselves all the time and I think it's great to go fully test yourself and push
Friday, November 26, 2010
Ever wonder what i do for a living? (check out this story i was in)
Current Issue
Improve your Storage Improve your Storage Facility
Recommendations and tips from the pros.
For whatever reason—expense, simplicity, space, time constraints—growers may consider upgrading storage facilities over building new. Several experts offered Spud Smart suggestions on improving existing structurally sound facilities for successful potato storage.
Insulation
Storage facilities that are properly insulated and well sealed will keep temperature and humidity at the desired levels and prevent problems in storage from condensation, such as disease. “Dealing with your building envelope is really important,” says Doug Small of DGH Engineering in Winnipeg. “If you don’t have a good envelope with a high R-value, you are going to get condensation and dripping and that’s going to cause problems with storage.”
Todd Forbush, an engineer with Techmark Inc. located in Lansing, Mich., recommends insulating to a value of R-35. This is equivalent to 250 millimetres (10 inches) of fibreglass or 150 mm (6 inches) of polyurethane insulation. Closed-cell foam insulation board or highdensity, spray-in-place urethane insulation are the most commonly used materials for upgrading storage insulation, says Forbush. “Good insulation is critical to proper storage performance,” he says.
Ventilation
Proper ventilation is crucial to maintaining the correct temperature, relative humidity and air quality in storage, and for managing problem lots and the build-up of carbon dioxide, all of which affect tuber quality. Ventilation systems usually consist of intake doors, fans, air plenums, ducts, exhaust louvers and a control system.
“Over the past 30 years the required air flow rates for potato storage have doubled,” says Small. “If you have high-quality, healthy potatoes you don’t need a lot of air flow—the older rates were fine—but you need the higher air flow rates if you have some problems in the bin,” he says. “The two typical issues are disease or frozen potatoes in the fall. Either way you will need more air flow because in each condition the potatoes are under stress and giving off heat and you have to remove that or the whole pile will heat up and at some point you could lose the whole thing.”
Plains Potato Ltd., a cooperative that stores potatoes for its grower members located at Portage la Prairie, Man., recently completed an upgrade to its storage facility, which included the installation of a new ventilation system designed to double its air flow rate.
The new installation meant incorporating bigger fan housings into the building itself—but according to Cory Smith, manager of Plains Potato, the renovation was worth it. The new system gives Smith more flexibility by allowing him to increase the number of climate zones in the building from four to six. “We now have 21 separate bins across six zones, each with 15,000 bags apiece. Each bin has sensors inside to monitor the heat and relative humidity, so it’s a lot easier to control the conditions in each individual bin,” says Smith.
Poor ventilation and air distribution, caused by incorrect sizing of fans, ducts, air inlets or distribution slots, will lead to inconsistent potato quality and/or potato rot. “As you put more air flow through, if you have an older shed that has an under-designed ventilation system, your ducts are going to be too small and so it is a challenge to get the extra capacity in your air plenums and ducts,” says Small.
And if the potato bin walls also form a part of the actual air ducts in the building structure, replacing those ducts can be extremely problematic. In that case, Small recommends the average grower should consult a specialist.
Power consumption of the main ventilation fan is also crucial in storage upgrades. A variable frequency drive can control the speed of the fan motor, allowing the volume of air moved by the fan to match the needs of the potatoes, saving energy and money.
“It’s important to take the total ventilation system into account when utilizing a VFD,” says Forbush. “Slowing the fan speed can save energy, but may cost quality in the long run if the system is not designed to operate with lower fan speeds.” Although the variable speed fan can reduce energy consumption, it must have a good control system to monitor the need for ventilation, especially when fans are operating at lower speeds.
Smith went with VFD fans, but because the upgrade was just completed this year, he knows it will take a while for those savings to start showing a positive impact on his bottom line. “I know I have saved some money on hydro already,” he says, “The drive can slow down the air flow and the control panel monitors it continuously and adjusts it automatically according to conditions in the bins.”
A qualified ventilation contractor can perform a storage ventilation analysis for a grower in order to determine what is needed to improve the air distribution within a structure.
Controls
There are many different types of controls available, from a straightforward single insulated damper that controls the blend of fresh and returning air, to systems that also combine carbon dioxide sensors with humidistats.
Forbush recommends a system that integrates control of fans, air inlet, humidification, refrigeration, heating and air exhaust fans or louvers. This will maximize storage energy usage, while controlling temperature, relative humidity and carbon dioxide in the storage facility. “A storage control review will help the storage manager determine if the existing equipment is sufficient, or if there are benefits that can be obtained using new storage control technology,” he says.
Smith’s state-of-the-art system is a microprocessor-controlled unit called the Agri-Star, made by the Gellert Company in the United States. It monitors and controls the entire environment inside the storage facility through the use of sensors, and adjusts temperature and air flow as needed to maintain temperature and relative humidity, which must be kept above 95 per cent.
Smith is impressed with the features and the capabilities of the system, which comes with easy to use, proprietary software. “The panel itself has a full-size, colour, touch screen display, with on-screen graphing, multi-modes, a carbon dioxide control—and it basically gives plug and play internet ready communications,” he says. “It gives a lot more flexibility and I can monitor everything from my computer. It has really fine-tuned the control system. The older system had a lot of fluctuation and it wasn’t as responsive. You can keep the temperatures exactly where you want them.”
Upgrading an existing storage facility is not cheap: the cost to upgrade its storage cost Plains Potato approximately $700,000. Now, the facility houses 325,000 bags of potatoes. But, at the end of the day, keeping customers happy was a factor in making the decision to upgrade the facility. “One of the big reasons for upgrading was to keep the processors happy,” says Smith. “It’s security for them to see that you are willing to invest in the upgrades so you can do a good job of supplying them with what they need.” Angela Lovell
Improve your Storage Improve your Storage Facility
Recommendations and tips from the pros.
For whatever reason—expense, simplicity, space, time constraints—growers may consider upgrading storage facilities over building new. Several experts offered Spud Smart suggestions on improving existing structurally sound facilities for successful potato storage.
Insulation
Storage facilities that are properly insulated and well sealed will keep temperature and humidity at the desired levels and prevent problems in storage from condensation, such as disease. “Dealing with your building envelope is really important,” says Doug Small of DGH Engineering in Winnipeg. “If you don’t have a good envelope with a high R-value, you are going to get condensation and dripping and that’s going to cause problems with storage.”
Todd Forbush, an engineer with Techmark Inc. located in Lansing, Mich., recommends insulating to a value of R-35. This is equivalent to 250 millimetres (10 inches) of fibreglass or 150 mm (6 inches) of polyurethane insulation. Closed-cell foam insulation board or highdensity, spray-in-place urethane insulation are the most commonly used materials for upgrading storage insulation, says Forbush. “Good insulation is critical to proper storage performance,” he says.
Ventilation
Proper ventilation is crucial to maintaining the correct temperature, relative humidity and air quality in storage, and for managing problem lots and the build-up of carbon dioxide, all of which affect tuber quality. Ventilation systems usually consist of intake doors, fans, air plenums, ducts, exhaust louvers and a control system.
“Over the past 30 years the required air flow rates for potato storage have doubled,” says Small. “If you have high-quality, healthy potatoes you don’t need a lot of air flow—the older rates were fine—but you need the higher air flow rates if you have some problems in the bin,” he says. “The two typical issues are disease or frozen potatoes in the fall. Either way you will need more air flow because in each condition the potatoes are under stress and giving off heat and you have to remove that or the whole pile will heat up and at some point you could lose the whole thing.”
Plains Potato Ltd., a cooperative that stores potatoes for its grower members located at Portage la Prairie, Man., recently completed an upgrade to its storage facility, which included the installation of a new ventilation system designed to double its air flow rate.
The new installation meant incorporating bigger fan housings into the building itself—but according to Cory Smith, manager of Plains Potato, the renovation was worth it. The new system gives Smith more flexibility by allowing him to increase the number of climate zones in the building from four to six. “We now have 21 separate bins across six zones, each with 15,000 bags apiece. Each bin has sensors inside to monitor the heat and relative humidity, so it’s a lot easier to control the conditions in each individual bin,” says Smith.
Poor ventilation and air distribution, caused by incorrect sizing of fans, ducts, air inlets or distribution slots, will lead to inconsistent potato quality and/or potato rot. “As you put more air flow through, if you have an older shed that has an under-designed ventilation system, your ducts are going to be too small and so it is a challenge to get the extra capacity in your air plenums and ducts,” says Small.
And if the potato bin walls also form a part of the actual air ducts in the building structure, replacing those ducts can be extremely problematic. In that case, Small recommends the average grower should consult a specialist.
Power consumption of the main ventilation fan is also crucial in storage upgrades. A variable frequency drive can control the speed of the fan motor, allowing the volume of air moved by the fan to match the needs of the potatoes, saving energy and money.
“It’s important to take the total ventilation system into account when utilizing a VFD,” says Forbush. “Slowing the fan speed can save energy, but may cost quality in the long run if the system is not designed to operate with lower fan speeds.” Although the variable speed fan can reduce energy consumption, it must have a good control system to monitor the need for ventilation, especially when fans are operating at lower speeds.
Smith went with VFD fans, but because the upgrade was just completed this year, he knows it will take a while for those savings to start showing a positive impact on his bottom line. “I know I have saved some money on hydro already,” he says, “The drive can slow down the air flow and the control panel monitors it continuously and adjusts it automatically according to conditions in the bins.”
A qualified ventilation contractor can perform a storage ventilation analysis for a grower in order to determine what is needed to improve the air distribution within a structure.
Controls
There are many different types of controls available, from a straightforward single insulated damper that controls the blend of fresh and returning air, to systems that also combine carbon dioxide sensors with humidistats.
Forbush recommends a system that integrates control of fans, air inlet, humidification, refrigeration, heating and air exhaust fans or louvers. This will maximize storage energy usage, while controlling temperature, relative humidity and carbon dioxide in the storage facility. “A storage control review will help the storage manager determine if the existing equipment is sufficient, or if there are benefits that can be obtained using new storage control technology,” he says.
Smith’s state-of-the-art system is a microprocessor-controlled unit called the Agri-Star, made by the Gellert Company in the United States. It monitors and controls the entire environment inside the storage facility through the use of sensors, and adjusts temperature and air flow as needed to maintain temperature and relative humidity, which must be kept above 95 per cent.
Smith is impressed with the features and the capabilities of the system, which comes with easy to use, proprietary software. “The panel itself has a full-size, colour, touch screen display, with on-screen graphing, multi-modes, a carbon dioxide control—and it basically gives plug and play internet ready communications,” he says. “It gives a lot more flexibility and I can monitor everything from my computer. It has really fine-tuned the control system. The older system had a lot of fluctuation and it wasn’t as responsive. You can keep the temperatures exactly where you want them.”
Upgrading an existing storage facility is not cheap: the cost to upgrade its storage cost Plains Potato approximately $700,000. Now, the facility houses 325,000 bags of potatoes. But, at the end of the day, keeping customers happy was a factor in making the decision to upgrade the facility. “One of the big reasons for upgrading was to keep the processors happy,” says Smith. “It’s security for them to see that you are willing to invest in the upgrades so you can do a good job of supplying them with what they need.” Angela Lovell
Monday, October 4, 2010
Friday, October 1, 2010
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