Sam12345

This is from another forum with the "latest trend/studys" and what I'm trying to achieve



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 https://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:

Sam12345

Just to say, im not copying his exact position, but to get forward pelvic rotation as ive suffered 5 years of lower back pain from a posterior tilt and uncomfortable saddles that made me flex at the back alot, until i got the Selle Smp

Carbonfiberboy 

That last was a good video. Looks good. Remind us of what the problem is?

Post 26 was quite a long discussion of what is really not that complicated an issue. The bolded paragraph at the top is certainly correct. I look at it a little differently. A road bike position is different from a TT position why? Because on a road bike you aren't supporting your upper body weight on the forearm pads, so the ability of the hands and arms to comfortably and controllably support some upper body weight has to be factored in. So first I look at balance. I want my relatively skinny arms to be able to handle the strain of long rides. If they can't, the whole game is off.

So given acceptable balance, the next goal is seated power production. Seated power production has two aspects: muscular and aerobic. I don't agree with the premise that fore-and-aft saddle position has a great affect on muscular power production, i.e. "pedaling behind the bike." Look at recumbents. If that isn't pedaling behind the bike, I don't know what is. Yet recumbent racers pedal them just fine. What they lose on a recumbent is the ability to stand and of course circulation in the glutes.

No, what changes with fore-and-aft saddle position, given the same pelvic rotation, is hip angle or better, the thigh/chest angle. IMO the point of the TT position is to open this angle because the more open it is, the better one can breathe. Moving the butt back closes this angle and somewhat inhibits breathing. Again, given the same pelvic rotation. The road bike position closes the angle even though it hurts breathing simply to get that balance which enables one to ride for many hours with road bars.

A negative effect of moving the saddle aft is that the hip flexors are more shortened and can't supply as much upward force on the pedals. However given that this upward force is very seldom applied, this seems to be an OK compromise for most folks. A positive effect is that the glutes are more involved in force production. Be all that as it may, the force production by particular muscles in particular ranges of motion is trainable. Thus power reading changes during position changes need to be taken with a grain of salt. Total force production when climbing will always be limited by VO2max, which is the reason that skinny cyclists usually climb faster and attacks are usually done standing. Be that as it may, the more muscles that a cyclist can involve in the pedal stroke, the greater the endurance, and that is one of most trainable aspects of cycling performance.

I do agree that saddle height has a great effect on force production. This is not particularly trainable because it's a result of leverage and mechanics. I set my saddle height to get the greatest sustainable power when climbing. I want to have good force production through the bottom of the pedal stroke, which depends on having an exact amount of knee bend at the bottom. I suppose losing this is what the writer in post 26 is talking about when he refers to getting a piston-like action with the saddle too high.

Your position in that latest video has quite an open hip angle, so open that some might question if your cranks are long enough for you. There being no proven link between crank length and power production, I guess it's fine. As long as your balance is fine with the saddle that far forward, I don't see a problem. I do think that you might benefit from more reach. One of the things I look at is that I like to have my upper arm at a 90° angle with my chest with forearms level because I think that gives the least muscular strain.

Sam12345

It is the forward pelvic rotation that pulls the knee back that can prevent the most part of the pedal stroke then its a possibility that pulling up on the stroke that will happen

My problem is due to my function and flexbility/mobility I can over rotate and then it affects my spinal erectors I have noticed moving the saddle forward prevents some of that over rotation from occurring If you sit with a posterior tilt when the saddle moves back I believe the knee wont get pulled back as much compared to moving it back aswell and forward rotation also I think a higher saddle takes weight off the hands aswell it could be that more force to the pedals from a high saddle is allowing to unweighed the upperbody also I only have 1 sitting position on the selle smp, as they are designed to be ridden at the back and never on the nose

Sam12345

I have 175s on my TT bike, i don't really like them I find it to be more efficient with 170s and easier to spin. a smaller guy at like 5ft 8 might be more efficient with 175+

Even the pros now are trending to smaller cranks to open up the pelvis

fietsbob

Pelvis is a big bone.

MassiveD

I measured it out at 71.35 in my CAD. Confirms the other number as there is nothing super accurate about measuring a photo.

Sam12345

Well i got a new seatpost, goes a little more forward and I put on a 140 -17 stem on, I think its actually 147mm as its a 3T

Will see how it feels over the weekend

Leisesturm

They say a little knowledge is a dangerous thing. By that measure this thread must be lethal. Creesh... 71.2 degrees? Has there ever been a production road race frame with a 71.2 degree seat tube angle? I don't think so. An earlier poster said that that seat tube does not look slack and I agree. I think its rather steep actually. I don't think 73* or 74* would be that far off the mark. Billions of production frames have those seat tube angle. And they don't need 130cm stems to get 6'3" riders in an optimum position. I am 5'10" and I have 175mm cranks. Should a 6'3" rider be using 170's??

IMO trying to get any further forward on that bike is... unwise. Time to scrap the script and start working the other way. I don't need to read heaps of theory to know that. FWIW.

McBTC

True... the seat tube angle on my old Trek CF large frame (63cm) Pilot was pretty slack but that came in at 72.1° and on a classic Lemond BA (ideal for those with long upper bodies) was 72° and I needed a shorter not longer stem... I think when you have a frame that is too small to begin with nothing makes sense after that.

Leisesturm

Photo's are indeed misleading. The second photo of the same bike has the seat tube appearing much less steep. Not as slack as some are assuming since production frames simply do not exist in those angles. Not production race frames and as far as I can tell the Cadex was sold as a TT/Tri machine. 71* seat tube? Really? But I don't know for sure. What I do know is that even if a rider could find some kind of happiness with a seat slammed forward to the stops on a zero setback post AND a 140mm stem. The forward weight bias of such a configuration probably makes for an interesting lesson in vehicle dynamics. I wouldn't want to be the o.p. in a situation where the performance envelope of that bike is put to the test.

I cannot see a downside to moving the rider back a bit. Leonard Zinn is an expert in fitting tall cyclists. All his bikes come with 180mm cranks standard. The o.p. could learn a lot from reading what Zinn has to say about fitting talller riders. He is one. Not that 6'3" is really all that tall. It isn't. But in America it is. There is less mainstream knowledge around.

Leisesturm

I think you are right. I've realized with just one more look at that second photo what part of the problem is. With seat post extension comes rearward movement as a byproduct of the seat tube angle. The o.p. is running considerable seat post extension. Unless he gives up on this frame and gets one better sized for him crank length may have to be the way he gets KOPS or something approaching it. Not that KOPS is magic. Being behind KOPS as I understand it will bias things towards a lower cadence. Bias things. Nothing is abolute. Shorter cranks bias things towards a faster cadence. One could say with some accuracy that 170mm cranks are short for a 6'3" rider. I don't know... all this discussion... do we know anything about the o.p.'s dimensions? I mean... we know plenty about the frame. What about him? Besides his height what else do we know? A lot of pictures of other bikes and videos of other riders. What about him. I'm not going to try and guess anymore without actual frame and rider dimensions to work with.

Sam12345

The frame is a 58.

Saddle height currently is 82cm. climbing in the saddle doesn't feel too fluid.. feel too high when it comes to hills..
Leg inseam is 91cm
Feet size 11.1inch..
Reach saddle nose to centre stem 58.5cm
Saddle behind centre BB is 6cm

I think the frame is probably at least 20 years old?

with a SMP that is probably 7cm-8cm (butt position)

The saddle is a selle SMP they are said to be place more forward then a normal saddle as you only have 1 butt postion which is shoved right to the back
In this position also I feel like im stretched out too much too.

I think I need to go back to the 130 stem 6degree angle

The current stem is 140cm -17degree angle which usually is an extra 2cm drop and the 3T 140s -17 usually are 147mmdue to way 3T make these so I have heard

If I move the saddle back I feel like Im over rotating my pelvis forward which pulls my knee even further away from kops
I am already over kops slightly too

Leisesturm

Have you tried putting all your vitals into the Competititve Cyclist fit calculator and seeing what it comes up with? It might be instructive. If you google "what size frame for 6'3" man" you will get many hits. None specific, but what I get from them is that a 58cm frame is not out of the question. Interesting because I have a vintage road bike that wasn't originally sized in CM but if it was would be a 59 (c-c). It came with a 110mm stem and I have changed it to a 90mm. Compact bend bars (80mm reach) and I'm good.

I have a tandem (XL captain compartment) that is much more recent (2005) and I don't think its seat tube height has any relevance. The saddle height is 75mm. The saddle nose to center stem is 50mm. I really don't know... ... You are taller than me. Are you that much taller that your numbers should differ so much from mine? That is for a tool like the CC Fit Calculator to decide I think. Do you have a quick release collar on your seat tube? You might should get one. If your saddle feels high climbing... lower it? Downhill riders have trick seatposts that go up and down on the go... whoa. Probably weighs a bit, but downhill... anyway, I'm not sure why you suffer with the high saddle. And yes, the 140mm stem was bound to prove too long. Maybe even the 130. The bikes I like the best are bikes that would have been sold to guys your height. I've had to replace stems with shorter ones, but you should not have to replace anything. That you have, and gone so far beyond "stock" for bikes in your size should have tickled your "Spider Sense". Even the discomfort didn't do it, you kept going away from "stock" in (IMO) the wrong direction. But I'm not an expert.