Road Bike, Cycling Forums banner

1 - 13 of 13 Posts

·
Registered
Joined
·
9,079 Posts
Discussion Starter · #1 ·
My question concerns setback v no setback seat posts. The owner of my LBS and his chief mechanic – both veterans of the bicycle wars – insist that the saddle sit “way” back to facilitate what they perceive to be the correct pedal motion, i.e. lots of forward push as opposed to downward. Of course they advocate a full 360 degree action, but with emphasis on the forward stroke. They pay little if any attention to the KOP system saddle position.

Naturally, I will have to make the ultimate decision in regard to my own comfort, etc., but I’m wondering what the general feeling is with regard to the subject. Is there a particular body build which lends itself to one or the other? I am 5’6” and ride a 52cm frame. My apparent optimum saddle height is 26.75” (top of saddle to bottom bracket center).
 

·
papa sboak
Joined
·
1,009 Posts
take w/ 1/2 a shaker of salt

I'm not qualified to answer this but...
(it's online, you don't know how little I know, only I know how truly little I know)

taking into account that while spinning, it's a CIRCLE

the forward push is only a small part (~25%-33% max?) of the rotation. Take into account the anatomy of your lower body.

Gluteus maximus, Quadriceps femoris, biceps femoris

why take away from the efficiency of the GM & the BF(hamstrings) to boost the efficency of the Quads?

Emphasizing one muscle group doesn't seem right to me. Would make more sense to use all of the leg muscles as a group/team to lessen the burden/load. Smooth and efficient is good for cycling.

*I will note that the human body seems to be designed to "push" away from itself better than "pull" toward itself.

Please note that I am not a doctor or bio-engineer guy. Just a guy who got an A in college anatomy/physiology. Never finished that particular major though...
 

·
Registered
Joined
·
10,160 Posts
balancing act...

Your LBS guys are confused I think. Everyone's not the same, so the same saddle position doesn't work for everyone. I've done a fair amount of experimentation and found that a real far back saddle doesn't offer any power advantage that I can tell. It will tend to permit a bit more torque to be apllied, so you might get by with one cog smaller on the hills. A more forward position will promote a higher cadence.

After riding for a couple of seasons with my knee about 3cm behind the pedal spindle, I move it forward 2cm to a more normal position. I climb the mountains just as well, although I may be using one cog lower gear, spinning a bit higher cadence. The bike definitely corners better on the descents.

Your LBS guys should check the weight balance of the bike with the rider in an aggressive cornering/descending position to see how much weight is on the front. The bike will corner better with 45-46% of the weight on the front, rather than only 40-42%.
 

·
Registered
Joined
·
79 Posts
Regardless of correct position, I think ultimately, you have to consider comfort, and ridability.

Unless you are only going to ride very short distances and/or sprints,
I think the latter has to edge out the so-called correct positions to a degree.

Everything written in manuals and books by engineers and tech writers,
do not always relate to real world applications. Like someone previously
mentioned, everyone is different.

I have switched from an offset seatpost to a no offset type. I had to do this
because my arms are short, and no matter what stem length/height combo
I tried, my reach was too far away from the bars. Consequently, it became
very uncomfortable to ride the bike.

With the seat now being closer to the bars, my pedal position in relation to my
knees is not ideal, but it is sacrifice well worth it for me.
I now have a proper amount of bend in my arms, which allow me to absorb the
bumps and vibrations of the road, and I feel more comfortable. Unlike before,
where my arms were completely outstretched to reach the bars. I also feel like
I have more control over my bike now.

Again, this set-up suits my riding style and feel, it may not work for someone else.
You have to adjust and compromise all the bike settings in order to get the best
performance and best feel for yourself. Just my opinion... :)
 

·
Registered
Joined
·
594 Posts
My opinion is it depends on your comfort and needed bike setup.
I'm running a setback post so I can have my seat slightly further back than possible with a zero setback to get the proper position of my knee over the pedal. After blowing my knee once playing soccer, and going through the rehab - there is no way I am going to risk my knees with a bad setup. I'll trust the guys that did my bike fit at Boulder Center for Sports Med. over anyone at an LBS.
 

·
eminence grease
Joined
·
18,538 Posts
It completely depends on what you need and what you like to look at.

I like my saddles mounted as close to the middle of the rails as possible. No reason why, I just like it that way. Given my femur length that means I have no choice to use a setback post on any frame with a seat tube angle of > 72 degrees.

. Sitting "way back" is a completely unscientific way of approaching the problem. No, KOPS is not required, it's nothing more than a starting point. But a position that doesn't stress your knees is. Push the saddle way back and you might find yourself riding with big pain. You need to knowwhat position works for you, because it drives your selection.
 

·
Banned forever.....or not
Joined
·
24,415 Posts
"I’m wondering what the general feeling is with regard to the subject"
.
Since I've never been in the army, all I can say is that you must decide for yourself what position is correct for you. If you find that you are allways "on the rivet", you might need a seatpost with little setback. On the other hand, if you find yourself always hanging off the back of the saddle, you may need a post with lots of setback. This may all change in the next two years. The more people ride, the more their bodies change.
 

·
Registered
Joined
·
1,173 Posts
I can see the setback if you've got a long femur....doesn't mean you need it, just that you could have if it is comfortable. I went by that advice for quite some time and just had a SystemOne fit done by Florida Bicycle Sports in St.Pete, FL. My seat came forward and up over an inch....what a tremendous boost in power! My knees aren't hurting after a hard weekend of riding and I felt much more powerful. I think the overall reason is that I am now recruiting more muscles and because I am over the crank a little more, I am able to spin better.

Get more than one opinion....

The Flash...
 

·
Registered
Joined
·
443 Posts
what was the charge for the fit?

I have been thinking about visiting a Sarasota shop for a fitting, but would like to check around for prices. You seem pleased with your fitting, can you share the cost?
 

·
Registered
Joined
·
27,384 Posts
Those guys are just mashers.

I agree with C-40, that a bit more torque can be applied with the saddle furthur back. You're using the quads effectively to push down on the pedals. But to get up a good powerful circular motion or "spin," you have to be forward, up over the crank.

I have two bikes, one with a 5cm. saddle setback, another with 6.5cm. setback. That's a difference of only about 5/8ths of an inch. Nonetheless, the furthur setback rewards pushing on the crank, sort of like tredaling in an elliptical orbit, not a circle. A fair amount of big gear mashing can be accomplished this way, using the powerful quad muscles to push forward and down on the crank.

But the short setback bike allows one to stomp down on the pedals, using upper body weight, as in a climb or acceleration. You can also get up some hellacious high cadences with the crank more in a vertical plane, using the hamstrings and buttocks as well as the quads, working in a much more circular orbit, which makes faster cadences almost effortless. That's why sprinters always move up on the tip of the saddle in an all-out effort. I think as far as power delivery, that['s more efficient, and easier on the knees, than tredling on the pedals with the saddle furthur back.

Setback doesn't have to vary much more than a cm. from KOPS to work the legs in noticeably different ways. Most seatposts, laid back or not, will get you plus or minus 1cm. from KOPS, unless the frame is too small or you have really long femurs.
 

·
Registered
Joined
·
1,173 Posts
$100 lifetime fit....you can keep going back until you are happy. Probably the most personalized fit I have ever had. I'd skip the FitKit thing as it is useless and only to sell bikes. Serotta has a nice fitting system, but they don't do it on your bike. Give Matt a call at Florida Bicycle Sports. I think you will really like the process there. Took almost 3 hours and a couple of test rides, but he wouldn't stop until I was happy....

Flash
 

·
Registered
Joined
·
3,749 Posts
Experimenting

The only way to really find out where to set your saddle is by experimenting. A lot depends on the geometry of your bike (STA), pedaling style, and anatomy. If you saddle is set all the way back, your are emphasising your back and hamstrings. A forward position emphasises your quads.

You can try for starters, to have someone set you up in a neutral KOPS position. This will put your knee right over the pedal axle. Then you can see where you spend most of your time. If you find yourself scooting back a lot, move your saddle back, if you are moving forward, move your saddle forward. Do all changes in very small increments (mm's). KOPS is just a starting place. I don't use KOPS. I set my saddle a certain distance behind the BB. But I have to take in account which saddle I am using. Each saddle has to be set differently.

They say for long distances, saddles should be set way back as it's more comfortable. But everyone is different. Two riders having the same inseam measurements can have their saddles set in different places (height/fore/aft). Pedaling style comes into account.

What helped me is to find a seatpost that was easy to adjust and offered lots of setback. I used a Salsa Shaft. You can set the fore/aft without adjusting the tilt with the simple turn of a hex wrench.

I also found that I was using the wrong stem length. I ended up going to a longer stem and moved my saddle forward. Which gave me the same bar to saddle measurement, but moved me forward in my KOPS.

I know if I move my saddle too far aft, my back will bother me. Too far forward and my knees will hurt. And I can tell right away just taking off from my driveway.

Keep in mind also when you move you saddle forward or back you will have to compensate in height. Make sure to keep track of your measurements so you can put everything back.

Saddles make a difference also. It depends if you like too ride in the same place or like to move around a lot depending on what your are doing.

If you are not having any problems right now and feel comfortable. Then don't change anything. You are just opening pandora's box. It can lead to injury.
 
1 - 13 of 13 Posts
Top