This is from another forum with the "latest trend in pro fittings in the pro road peloton"
Written up by Kwalker
The ideal position for putting out power has little to do with drop, reach, inseam length, or knee over pedal spindle, but on the maximal saddle height that one can run that allows full anterior rotation to maintain a neutral lower back position. Basically, look for a back position that mirrors the back squad in weightlifting, the speed skating position, and the blocks position in a track (both running and cycling) start.
This position is essentially limited by saddle height, hip flexibility, posterior chain functionality, and often by saddle choice. In the pro ranks you see riders utilize this position with a lot of different setups, but since Fabian is the example this thread is named after just look at any time he is on the rivet on his road bike and notice that he is fairly far forward on the saddle. He can only get full anterior rotation by running a fairly low saddle height for his height (785 or so) and utilizing the forward padding on his saddle since it lacks any sort of relief or cutout. Unfortunately other riders, such as Contador or Froome, can't accomplish this very well and end up with extremely rounded lower backs. This is often fine for climbing or high cadence riding that stresses the VMO, but it greatly reduces glute recruitment. Boonen is another lack of terrible anterior rotation that has improved with his recent fit changes from the BG Fit program.
I mentioned maximal saddle height, but what I mean is focusing on full rotation first, and then on how much leg extension one can get given their functionality without sacrificing rotation. Its often saddle height not setback that hampers this as most saddles have a decently wide (1cm or so) range where there will not be impingement due to saddle shape, cutout length, or padding density. Its hard to pinpoint height from any sort of formula without seeing the rider on the bike. I'm 6 feet 2 and my seat height has ranged from 79cm to 81cm depending on weight and how much work I do to maintain glute and hip functionality. Jens Voigt is the same height with an 83-84cm seat height, Gesink is in the 82cm range, etc.
Setback comes into play next as it does affect saddle height and rotation often more than people think. Depending on the saddle shape the ischials can "hit" the flare of the saddle more towards the middle and still be supported, which is why the Romin variants are such awesome saddles and the new S-Works Power will likely be as well. Its also why riders can get by with the Arione and Antares decently well. Selle Italia and Prologo have the worst flares in this regard, Bontrager seems to be OK. Generally setback can be within a decently wide range as determined by what kind of riding the rider is doing. For example, my 29er has the seat slightly further back as unweighting the front wheel helps with very technical descending and trail riding.
Hogg talks about pedaling style influencing setback, which is true to a degree, but in most cases riders have extreme pedaling styles just because they adapted to something that is rather inefficient. Generally speaking too much heel drop often indicates a saddle that is too far back or slightly too low, but riders such as Boonen have adapted to this and make it work. Froome is an example of an extreme heel dropper, which is very rare. Thibaut Pinto is as well. Toe down pedalers such as Contador, are often limited by functionality and lose out on torque application and must compensate by increasing rotational velocity to produce the same power. What a rider should strive for is a middle between the two where the ankle joint maintains and applies torque, but does not have to excessively flex to do so. Its not that it reduces power or increases fatigue as Hogg claims, but as a lever it should not be overloaded as it is a rather weak lever due to foot length being small.
Femur length also does not influence setback as Tibia length and the ratio between the two will often determine the overall pedaling circle. Riders with extremely short tibias can get further back and still remain rotated and over the BB simply because their hip angle will be more open. Again Cancellara is a great example but Wiggins is almost the opposite. Geraint Thomas is another good example of both long Femurs and Tibias as is Warren Barguil. The solution in this case, since there really are no standards or guidelines to determine what constitutes what a rider should do, is to monitor hip opening and pelvic rotation across a saddle setback range using the amount of heel drop to determine the knee's path relative to the BB and spindle over the entire pedaling range. Retul calls this "foot forward of crank", but in reality the idea is to not get the rider so far forward that they can't properly apply ankle torque and use their glutes, but not so far back that they rely on either of these factors either.
The result of all these factors that is easily observable on the pro level would be the Giant Alpecin bikes:
The TCR and Defy have extremely slack seat tube angles, which requires most of their riders to run the saddles slammed forward and use a size smaller frame to get it as forward as they should be, which is why you will note that all of those bikes have enough spacers to be the next full size up. On most properly sized frames the saddles would be clamped near the middle of the rails or towards the rear on a normal offset post.
Now check out the pelvic rotation and orientation of Tom Dumolin in the middle photo above or Warren Barguil below:
Edit: Image is very large http://procyclingfanatic.files.wordp...g-barguil1.jpg
Very neutral lower spine with tons of anterior pelvic rotation. You see the same on Adam Hansen's more extreme setup, but also with most of the Etixx and Cannondale team now. Nibali is yet another great example of great anterior rotation with lots of spinal neutrality and stability. The trend in this case is that most riders end up with a similar position over the center of the bike not for handling purposes, but to maintain rotation throughout the entire power band regardless of incline or decline. The rider should simply rotate more or less depending on incline or gradient, which I think is what the OP was getting at with a bit more complex language (not a bad thing, but I'm clarifying for ease of reading).
On a lot of bikes this means a fairly low amount of offset on the seatpost since the standard for a lot of sizes, especially large sizes, is fairly slack seat tube angles. Back in the early 90's before carbon frames and compact geometry a size 58 typically came with a 73.5-74 STA, especially anything Lemond rode. Now a 73 is standard. Furthermore a lot of angles are calculated by the middle of the seat tube, but some seat tubes meet at different places relative to the BB center. Cervelos used to meet towards the front and thus be even more slack. Lastly lots of manufacturers measure offset as center of the saddle cradle to center of the seatpost when its off the bike, but when its on the bike it ends up measuring more from the seat tube angle. The 3T Dorico is a great example as it measures 35mm on my 58cm frame, but 25mm off of the frame just sitting there.
You're seeing a lot more pros with less offset than before due to frame design and most fitting paradigms adopting a variation of this idea as rotating the pelvis forward actually pulls the knee rearward of the pedal spindle and bb, which in some cases can be so drastic that it changes the orientation over the most powerful portion of the pedal stroke. Furthermore, studies now show that the old notion of pedaling the entire rotation or pulling up are extremely inefficient and being a bit forward reduces the chance that the rider utilizes any sort of pulling motion and focuses solely on concentric force application. These studies do not necessarily inform this fitting paradigm, but might indicate why its so successful in practice.
Unfortunately one can only look at examples and attempt to digest this, but in practice too much of a rider's morphology, functionality, flexibility, and proportions will influence how much they can rotate and where this puts them on the bike. I said above that drop and reach do not matter so much in that too much is usually used when a rider is over-rotating, which is common with riders that have weak abdominals but strong erectors, too far forward over the bike in general, or has far above average functionality. Ryder Hesjedal is a great example of the drop being used to solve all of these problems as the only way to not ride with lots of arm weight is to use a ton of drop to allow for more locked out arms to provide stability.
The way to start with all of this is to setup the cleats in a neutral position, set the saddle fairly neutral in terms offset, and lower than normal by about a cm and focus on pedal stroke fluidity with full anterior rotation. What I have found is that seat height being too high will prevent the pelvis from having room to rotate and make the legs feel as if they're pedaling independently of each other like pistons almost. If you get this feeling try lower the saddle 3mm at a time. If it doesn't go away and the top of the stroke begins to feel lumpy, move the saddle forward 5mm. If the lump feeling goes away, then you're closer to being properly rotated over the pedaling axis and not pedaling "behind" the bike as was common in the 80's and 90's and is wasteful as torque is applied too early in the pedal stroke and velocity slows. Certain riders can get away with this, many cannot.
When looking for a feeling of proper anterior rotation try to imagine not only rotating the hips, but pulling the abdominals towards the ground. Think of a back squat where the discs are not compressed and the glutes are used in sync with the quads to drive the body forward. If you are properly over the pedaling axis, which takes some time and generally takes some perceptive abilities you might notice that your seat height is a tad lower than before or than normal. If one simply moves the seat forward they might be reducing seat height slightly, but with normal pelvis proportions you have to think of how much room might be needed to actually rotate onto the IPRs. This is why starting with a lower height than normal is ideal. I personally started 15m lower. From there, once proper orientation and rotation have been established seat height can be slightly raised until it prevents rotation, introduces lateral instability, or reduces pedaling fluidity and the piston feeling comes back. Think of an old locomotive turning over the wheels rather than an engine punching up and down. Punching introduces massive power peaks, but also power troughs rather than a stable application of consistent torque. This is a big reason why you see tired riders often bobbing around when they're dropped on climbs.
Saddle height will take some time to feel out, but once the proper pelvic position is established the rider shouldn't be moving forward and backwards a ton. Next, the drop needs to be established given the amount of pelvic rotation that can be achieved with the rider having a fair amount of room to bend their arms on the tops, hoods, and drops to compensate for terrain differences and riding style. Personally speaking I like a tad less drop than I am capable of so I can pedal hard in my drops for an entire criterium for better brake lever control and to prevent hooking bars. This is why you see a lot of enduro track riders run slightly higher drops with more elbow bend. If I strictly rode on the road I might use a slightly lower position on the hoods with enough room to descend with control or use my drops in certain situations. There is too much drop when a rider closes off the hips under power and/or can't rotate enough to maintain a neutral spine.
Spine neutrality is perhaps the hardest thing to judge. Wiggins rides with a straight spine as does Terpstra, but Boonen does not. Too many factors impact what is considered functional for someone on the internet to establish a guideline, but generally speaking what you need to think of is if you were leaning forward in a chair with good posture and are able to maintain neutral shoulder blade retraction. Reach then comes into play to maintain minimal trapezius extension. Think of pushing the chest out with good posture, but do not force a position that requires excessive effort or ends up putting one too high on the bike. It should feel neutral and natural and can change over time as functionality and posture improve or become worse.
IMO reach and drop can be fudged a CM or even more each way and still be fine, especially for taller riders. Things are often different out on the road and in race situations and sometimes a rider might need a bit more reach for maximal out of the saddle efforts or a bit more drop if they ride at a high tempo and have a lot of pelvic rotation. I advise not trying to set this on the trainer and being too anal about it, but giving it time and moving things in larger increments than you'd think is necessary. For me I tried increasing drop with a -17 110mm stem, increasing reach with a -6 140 and then worked towards comparing a -6 120 with a -6 130. On the trainer the 130 seems a bit "reachy", but on the road its perfect. I could get away with the 120 as well, but the 140 prevents me from retracting my shoulder blades and maintaining my spinal stability when out of the saddle.
So to sum this up:
-Focus on anterior pelvic rotation, which in most fit paradigms requires the saddle to be further forward and usually lower.
-Next focus on spinal neutrality through a range of positions depending on riding style and functionality. Adjust reach and drop in large amounts at first to see how the different parameters effect how you maintain neutrality across the entire range of motion.
-Focus on a fluid pedaling fluidity with both of the above established. Avoid the piston feeling.
-Its better to have more range than too much i.e. less drop and reach. For some with more sensitive backs or different proportions less range i.e. more drop and reach might be better. For taller riders more drop can prevent excessive arm fatigue.
-Focus on constantly maintaining overall neutrality by not needing to shift forward or backwards massively under effort. It should almost feel as if very little weight is on the hands and when riding around one could perform a variety of tasks such as switching out bottles, taking off arm warmers, etc. without needing to shift their weight around on the bars to control the bike.
IMO the rider in the pro ranks that best exhibits all of this is Niki Terpstra. His saddle is low and fairly far forward, good pelvic rotation, great spinal neutrality, smooth pedaling, and he is able to use the entire saddle without massively moving to maintain any sort of position (you don't seem him scooting much, he simply rotates and since his saddle is the right width and flair he has IPR support when towards the front rather than slamming his crotch into the padding). A side benefit is that his position is super aero and he can ride effectively much lower than most riders:
Written up by Kwalker
The ideal position for putting out power has little to do with drop, reach, inseam length, or knee over pedal spindle, but on the maximal saddle height that one can run that allows full anterior rotation to maintain a neutral lower back position. Basically, look for a back position that mirrors the back squad in weightlifting, the speed skating position, and the blocks position in a track (both running and cycling) start.
This position is essentially limited by saddle height, hip flexibility, posterior chain functionality, and often by saddle choice. In the pro ranks you see riders utilize this position with a lot of different setups, but since Fabian is the example this thread is named after just look at any time he is on the rivet on his road bike and notice that he is fairly far forward on the saddle. He can only get full anterior rotation by running a fairly low saddle height for his height (785 or so) and utilizing the forward padding on his saddle since it lacks any sort of relief or cutout. Unfortunately other riders, such as Contador or Froome, can't accomplish this very well and end up with extremely rounded lower backs. This is often fine for climbing or high cadence riding that stresses the VMO, but it greatly reduces glute recruitment. Boonen is another lack of terrible anterior rotation that has improved with his recent fit changes from the BG Fit program.
I mentioned maximal saddle height, but what I mean is focusing on full rotation first, and then on how much leg extension one can get given their functionality without sacrificing rotation. Its often saddle height not setback that hampers this as most saddles have a decently wide (1cm or so) range where there will not be impingement due to saddle shape, cutout length, or padding density. Its hard to pinpoint height from any sort of formula without seeing the rider on the bike. I'm 6 feet 2 and my seat height has ranged from 79cm to 81cm depending on weight and how much work I do to maintain glute and hip functionality. Jens Voigt is the same height with an 83-84cm seat height, Gesink is in the 82cm range, etc.
Setback comes into play next as it does affect saddle height and rotation often more than people think. Depending on the saddle shape the ischials can "hit" the flare of the saddle more towards the middle and still be supported, which is why the Romin variants are such awesome saddles and the new S-Works Power will likely be as well. Its also why riders can get by with the Arione and Antares decently well. Selle Italia and Prologo have the worst flares in this regard, Bontrager seems to be OK. Generally setback can be within a decently wide range as determined by what kind of riding the rider is doing. For example, my 29er has the seat slightly further back as unweighting the front wheel helps with very technical descending and trail riding.
Hogg talks about pedaling style influencing setback, which is true to a degree, but in most cases riders have extreme pedaling styles just because they adapted to something that is rather inefficient. Generally speaking too much heel drop often indicates a saddle that is too far back or slightly too low, but riders such as Boonen have adapted to this and make it work. Froome is an example of an extreme heel dropper, which is very rare. Thibaut Pinto is as well. Toe down pedalers such as Contador, are often limited by functionality and lose out on torque application and must compensate by increasing rotational velocity to produce the same power. What a rider should strive for is a middle between the two where the ankle joint maintains and applies torque, but does not have to excessively flex to do so. Its not that it reduces power or increases fatigue as Hogg claims, but as a lever it should not be overloaded as it is a rather weak lever due to foot length being small.
Femur length also does not influence setback as Tibia length and the ratio between the two will often determine the overall pedaling circle. Riders with extremely short tibias can get further back and still remain rotated and over the BB simply because their hip angle will be more open. Again Cancellara is a great example but Wiggins is almost the opposite. Geraint Thomas is another good example of both long Femurs and Tibias as is Warren Barguil. The solution in this case, since there really are no standards or guidelines to determine what constitutes what a rider should do, is to monitor hip opening and pelvic rotation across a saddle setback range using the amount of heel drop to determine the knee's path relative to the BB and spindle over the entire pedaling range. Retul calls this "foot forward of crank", but in reality the idea is to not get the rider so far forward that they can't properly apply ankle torque and use their glutes, but not so far back that they rely on either of these factors either.
The result of all these factors that is easily observable on the pro level would be the Giant Alpecin bikes:
The TCR and Defy have extremely slack seat tube angles, which requires most of their riders to run the saddles slammed forward and use a size smaller frame to get it as forward as they should be, which is why you will note that all of those bikes have enough spacers to be the next full size up. On most properly sized frames the saddles would be clamped near the middle of the rails or towards the rear on a normal offset post.
Now check out the pelvic rotation and orientation of Tom Dumolin in the middle photo above or Warren Barguil below:
Edit: Image is very large http://procyclingfanatic.files.wordp...g-barguil1.jpg
Very neutral lower spine with tons of anterior pelvic rotation. You see the same on Adam Hansen's more extreme setup, but also with most of the Etixx and Cannondale team now. Nibali is yet another great example of great anterior rotation with lots of spinal neutrality and stability. The trend in this case is that most riders end up with a similar position over the center of the bike not for handling purposes, but to maintain rotation throughout the entire power band regardless of incline or decline. The rider should simply rotate more or less depending on incline or gradient, which I think is what the OP was getting at with a bit more complex language (not a bad thing, but I'm clarifying for ease of reading).
On a lot of bikes this means a fairly low amount of offset on the seatpost since the standard for a lot of sizes, especially large sizes, is fairly slack seat tube angles. Back in the early 90's before carbon frames and compact geometry a size 58 typically came with a 73.5-74 STA, especially anything Lemond rode. Now a 73 is standard. Furthermore a lot of angles are calculated by the middle of the seat tube, but some seat tubes meet at different places relative to the BB center. Cervelos used to meet towards the front and thus be even more slack. Lastly lots of manufacturers measure offset as center of the saddle cradle to center of the seatpost when its off the bike, but when its on the bike it ends up measuring more from the seat tube angle. The 3T Dorico is a great example as it measures 35mm on my 58cm frame, but 25mm off of the frame just sitting there.
You're seeing a lot more pros with less offset than before due to frame design and most fitting paradigms adopting a variation of this idea as rotating the pelvis forward actually pulls the knee rearward of the pedal spindle and bb, which in some cases can be so drastic that it changes the orientation over the most powerful portion of the pedal stroke. Furthermore, studies now show that the old notion of pedaling the entire rotation or pulling up are extremely inefficient and being a bit forward reduces the chance that the rider utilizes any sort of pulling motion and focuses solely on concentric force application. These studies do not necessarily inform this fitting paradigm, but might indicate why its so successful in practice.
Unfortunately one can only look at examples and attempt to digest this, but in practice too much of a rider's morphology, functionality, flexibility, and proportions will influence how much they can rotate and where this puts them on the bike. I said above that drop and reach do not matter so much in that too much is usually used when a rider is over-rotating, which is common with riders that have weak abdominals but strong erectors, too far forward over the bike in general, or has far above average functionality. Ryder Hesjedal is a great example of the drop being used to solve all of these problems as the only way to not ride with lots of arm weight is to use a ton of drop to allow for more locked out arms to provide stability.
The way to start with all of this is to setup the cleats in a neutral position, set the saddle fairly neutral in terms offset, and lower than normal by about a cm and focus on pedal stroke fluidity with full anterior rotation. What I have found is that seat height being too high will prevent the pelvis from having room to rotate and make the legs feel as if they're pedaling independently of each other like pistons almost. If you get this feeling try lower the saddle 3mm at a time. If it doesn't go away and the top of the stroke begins to feel lumpy, move the saddle forward 5mm. If the lump feeling goes away, then you're closer to being properly rotated over the pedaling axis and not pedaling "behind" the bike as was common in the 80's and 90's and is wasteful as torque is applied too early in the pedal stroke and velocity slows. Certain riders can get away with this, many cannot.
When looking for a feeling of proper anterior rotation try to imagine not only rotating the hips, but pulling the abdominals towards the ground. Think of a back squat where the discs are not compressed and the glutes are used in sync with the quads to drive the body forward. If you are properly over the pedaling axis, which takes some time and generally takes some perceptive abilities you might notice that your seat height is a tad lower than before or than normal. If one simply moves the seat forward they might be reducing seat height slightly, but with normal pelvis proportions you have to think of how much room might be needed to actually rotate onto the IPRs. This is why starting with a lower height than normal is ideal. I personally started 15m lower. From there, once proper orientation and rotation have been established seat height can be slightly raised until it prevents rotation, introduces lateral instability, or reduces pedaling fluidity and the piston feeling comes back. Think of an old locomotive turning over the wheels rather than an engine punching up and down. Punching introduces massive power peaks, but also power troughs rather than a stable application of consistent torque. This is a big reason why you see tired riders often bobbing around when they're dropped on climbs.
Saddle height will take some time to feel out, but once the proper pelvic position is established the rider shouldn't be moving forward and backwards a ton. Next, the drop needs to be established given the amount of pelvic rotation that can be achieved with the rider having a fair amount of room to bend their arms on the tops, hoods, and drops to compensate for terrain differences and riding style. Personally speaking I like a tad less drop than I am capable of so I can pedal hard in my drops for an entire criterium for better brake lever control and to prevent hooking bars. This is why you see a lot of enduro track riders run slightly higher drops with more elbow bend. If I strictly rode on the road I might use a slightly lower position on the hoods with enough room to descend with control or use my drops in certain situations. There is too much drop when a rider closes off the hips under power and/or can't rotate enough to maintain a neutral spine.
Spine neutrality is perhaps the hardest thing to judge. Wiggins rides with a straight spine as does Terpstra, but Boonen does not. Too many factors impact what is considered functional for someone on the internet to establish a guideline, but generally speaking what you need to think of is if you were leaning forward in a chair with good posture and are able to maintain neutral shoulder blade retraction. Reach then comes into play to maintain minimal trapezius extension. Think of pushing the chest out with good posture, but do not force a position that requires excessive effort or ends up putting one too high on the bike. It should feel neutral and natural and can change over time as functionality and posture improve or become worse.
IMO reach and drop can be fudged a CM or even more each way and still be fine, especially for taller riders. Things are often different out on the road and in race situations and sometimes a rider might need a bit more reach for maximal out of the saddle efforts or a bit more drop if they ride at a high tempo and have a lot of pelvic rotation. I advise not trying to set this on the trainer and being too anal about it, but giving it time and moving things in larger increments than you'd think is necessary. For me I tried increasing drop with a -17 110mm stem, increasing reach with a -6 140 and then worked towards comparing a -6 120 with a -6 130. On the trainer the 130 seems a bit "reachy", but on the road its perfect. I could get away with the 120 as well, but the 140 prevents me from retracting my shoulder blades and maintaining my spinal stability when out of the saddle.
So to sum this up:
-Focus on anterior pelvic rotation, which in most fit paradigms requires the saddle to be further forward and usually lower.
-Next focus on spinal neutrality through a range of positions depending on riding style and functionality. Adjust reach and drop in large amounts at first to see how the different parameters effect how you maintain neutrality across the entire range of motion.
-Focus on a fluid pedaling fluidity with both of the above established. Avoid the piston feeling.
-Its better to have more range than too much i.e. less drop and reach. For some with more sensitive backs or different proportions less range i.e. more drop and reach might be better. For taller riders more drop can prevent excessive arm fatigue.
-Focus on constantly maintaining overall neutrality by not needing to shift forward or backwards massively under effort. It should almost feel as if very little weight is on the hands and when riding around one could perform a variety of tasks such as switching out bottles, taking off arm warmers, etc. without needing to shift their weight around on the bars to control the bike.
IMO the rider in the pro ranks that best exhibits all of this is Niki Terpstra. His saddle is low and fairly far forward, good pelvic rotation, great spinal neutrality, smooth pedaling, and he is able to use the entire saddle without massively moving to maintain any sort of position (you don't seem him scooting much, he simply rotates and since his saddle is the right width and flair he has IPR support when towards the front rather than slamming his crotch into the padding). A side benefit is that his position is super aero and he can ride effectively much lower than most riders:
