What is the gold standard for setting SADDLE SETBACK?
My minimal understanding of frame fit is that it begins with saddle setback. -On a custom frame there is a perfect position between the wheels to spin the pedals. Some people take measurements, some people look are your previous frame and take your opinion of your old fit, some people use a size cycle.
-It would seem that the ideal position would be set on a size cycle hooked to one of those power meter cranks to objectively measure your power output in different positions of saddle setback and seight height. Is this true or is there an easier way to achieve this without ten years experience? Thanks in advance for your ideas. Cheers, Kane |
The idea of using power output to tweek position forgets about one key point - the body is adaptive. A change in saddle position changes both the mechanical advantage and the range of motion of all muscles used. For instance, if you move the saddle back on the rails the quads are still used, but the angle of the knee has changed. The body adapts to stresses, the best position (only looking at power output here - other factors enter into it when we're talking about the whole fit) is where the greatest power output can be seen AFTER the body has had time to adapt to the position. At that point it gets hard to tell between training gains and position gains as well.
Many people will make the argument for "knee over pedal spindle" or KOPS, saying that you have your greatest mechanical advantage while pushing straight down on the pedal. This is almost true (the SIN(90) is 1...), but look at it from how the joints and muscles work. The glutes rotate the hip, the quads extend from the knee - those are the two major players so let's isolate this case just to those two muscle groups. If the glutes can only move the hip downward, they have no input to the power produced along the X-axis. In other words, when the crank is at 12:00 and the knee is directly over the spindle, the glutes do nothing to power the bike. Along the same lines, the quads only extend knee, which moves the cranks along the X-axis. There is no X-axis gain beyond 3:00, so at that point the quads become inactive (or just plain ineffective). KOPS is a simple model based on one fact, but it doesn't take into account the biomechanics of turning circles from a fixed saddle position. So what's the answer? Simple, let a good fitter do their job, then go on a few rides with an allen wrench and try things out. Make mental notes while you ride about which muscle groups are hurting on hard efforts. As a general rule, moving the saddle back (pedal circle in front of you) allows you to use the quads earlier in the pedal stroke (test show that peak output changes very little, so longer is just like saying more) while moving the saddle forward (pedal circle below you) emphasizes the use of the quads to kick over the top. Start off by marking your original position (setback and saddle height) and take a few weeks to figure out what uses a balance of the two large muscle groups. Lastly (and there are plenty of people who are going to hate me for saying this), the person doing the fit is a resource and a knowledge base. Don't be afraid to use that, it's what you paid for. A lot of fitters will say "I set you up in the right position, why change that?", but they don't have the luxury of taking a month with a power meter and an allen wrench to figure out what that right position is. I would love it if more of my fitting customers did that. My value as a fitter increases as the people I fit ride better. Some people get that, others don't... |
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I sure can't add anything to the bio-mechanical stuff that Ti wrote, but don't forget to take comfort into account. The most efficient position in the world isn't if you can only maintain it for half the distance you like to ride. For me, this means sliding back slightly farther than might be most efficient in order to keep my upper body comfortable enough to do centuries and other long rides. For a track racer, the priority will be different... -Ray |
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TiDesign obviously grabs the brass ring, you da man. When I'm setting up a rider I look at how their femur "swings" in the joint...too much setback or too steep a STA limits balanced use of your muscles. I like to setup as previously said so that you are normally pedaling in a balanced fashion and not biased based on STA + saddle position AND have the option to push back in the saddle or ride the rivet.
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it begins with cleat placement atmo :beer: |
I like to go for what feels comfortable for any given bike. Try a few different combos and choose (unless you have one of those dreaded USE Alien posts... in which case just don't touch anything once you've tightened...)
cheers, -sam :) :D :rolleyes: ;) |
As e-richie stated, cleat position first.
The best setback position in practice is the one promoted by Steve Hogg over at cyclingnews.com. Check out any number of his excellent articles. |
Twizzlerissimo - you are sooo literal...and correct :rolleyes: Remind me.
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e-RICHIE©™® |
Yeah, But ...
[Ti Designs] Quote:
"So what's the answer? Simple, let a good fitter do their job, then go on a few rides with an allen wrench and try things out. Make mental notes while you ride about which muscle groups are hurting on hard efforts. As a general rule, moving the saddle back (pedal circle in front of you) allows you to use the quads earlier in the pedal stroke (test show that peak output changes very little, so longer is just like saying more) while moving the saddle forward (pedal circle below you) emphasizes the use of the quads to kick over the top. Start off by marking your original position (setback and saddle height) and take a few weeks to figure out what uses a balance of the two large muscle groups." Kane: Yeah, but ... I'm looking at a Ron Cooper Fiftieth Anniversary frame that has sat on the wall of Bicycle Odessy in Sausilito for five years. It has some hand filed lugs with 'gussets', which have probably kept this bike from selling for years. (I doubt that the gussets are structural). I won't be able to test ride the bike. Frankly, it is a challenge to measure the angles on a bike without wheels, hence the idea to use saddle setback as a tool for fitting. eRitchey [Quote]: "it begins with cleat placement atmo" I'm very comfortable with my cleat placement. I already have a road frame, so this purchase is as much for lust and desire as it is for the function of having a new road bike. My road bike's top tube is a cm too long with a 72.5 degree seat angle. The Cooper looks to have a 73.5 to 74 degree seat tube angle with a 54cm top tube. From my memory of someone's post, this translates to a 55cm top tube with and equivalent saddle position. Hence the problem which might be better resolve with a yardstick than an inclinometer. Thanks for any additional insight on saddle setback. Rather than deferring to the insight of a 'bike fitter', the original question still remains, what is the gold standard of fit to optimize saddle setback. Thanks Kane P.S. I was fit by the store manager probably eight years ago on a size cycle prior to a test ride and his optimal position for me was with 56cm top tube vs. the 54cm top tube from two or three other fitters. Frankly, I can't remember the seat angle that formed the basis of any of the fits that I have had done by pro's over the years. I'm not so desperate for a new road frame that I am going to pay custom for one, rather I am looking for an 'off the rack frame' that meets my esthetic desires. While at the same time I am looking for something closer to my ideal fit than my current road bike. I have created a decent fit with my current road bike by the use of a 9cm stem and short reach handlebars, but I don't have enough weight on the front end for descending. |
there is no gold standard.
we're all different and our saddles are too. why are you not content with where your saddle is now? |
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i'll second the point that fit is dynamic. i'm in the midst of a pretty major overhaul of my position. it began with a 90mm shim under my right cleat and yes, a repositioning of my cleats. that was last summer, after years of constant discomfort and occasional real pain. that shim and cleat placement allowed me to begin implementing hip rotation, saddle raising, my back getting flatter, longer and lower, and reach going waaaaay out and up a bit...and yes, e-richie, riding one bike consistently for a month has opened my eyes, and body, to a lot. so, kane, one thought might be to go through a fit session, assess where your body is now, what sort of tweaks you might make, and then test 'em...not leading to a custom, but to "know" with more certainty what stock size is best for you...at this moment. soon, i'll post photos of how far my position has evolved. pretty striking. fit is dynamic.
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and, hey - have a nice day atmo. |
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imho you figured it out for yourself yo....you just let thom and the jerk use the allen keys because, we're professionals at that type of thing.
remember its a pretty drastic change which normally scares the jerk, but its so much better and its what your body has been telling you to do for some time...so anyway, tell all your pals here how the road treats the little experiment and we'll know for sure. jerk |
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damnmn...gotta get mo money jerk just tells doof "go ride 160km and take a 4-5-6...you'll figure it out" what doof gets fo bein po in the boonies |
More than just setback
Almost all the bikes I ride have little or no setback at all. Never had much real "pro" fitting, just years of trial and error. It seems to be much mre dependent on the frame than anything else. I would just fit each particular bike to you, some may have setback, some not.
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doof is going to go off on all you morons who haven't got it yet years ago, doof didn't listen to anybody. he slammed his seat back, put his bars ow enough so his back was flat, and had a proportional stem. then the guys he worked with started telling him he didn't look right. too far back, they said. you look low, they said. doof was fast and the bike handled and he thought they were idiots. slowly, slowly, their pernicious "knowledge" sunk in...doof sold his stock bike. he got two, count em, two custom bikes that were designed around a new, better, "scientific" position. they were expensive garbage. doof talks to jerk. doof talks to ritchie. they give no answers. doof starts to understand the question. they nod, digitally. doof moves his contact points back to where they were around 1997 before he started listening to idiots. everything is now good again. here's the rub "most of us begin in a less than ideal position" -- then why the feyuck do you go buy a $5,000 custom bike? it starts with your body, kids...if stock bikes were effed up then every middle-aged italian would be riding some wack-job POS with a straight post, weird geometry, and the bars 2cm above the seat...no...they are riding stock pinarellos and getting more tail than the now-dead pop icon of your choice. geeesh. its no use saying this. someone will go to great pains explaining to the doof why he adds nothing, why he just doesn't understand the special needs that some dork has (the same dork(s) who feels that a thread about which $200 tire is best for those 15mph jaunts is valuable discourse) and why they need that wacked-out bike that cost more than the doof's '88 truck. yep. its a lost cause. get a stock bike get a proportional stem put the seat height where your knees dont hurt and your hips don't rock start with the saddle in the middle of the rails on a setback post put the bar drops in the middle of the HT move crap around until you are comfortable do your crunches do your stretching ride your damnmn bike enough so that you get somewhere with it (advice not valid for the 2% of the population with serious anatomical abnormalities or permanent disability which precludes the use of a traditional bicycle design and setup) now go away doof loves you, doof blesses you, doof is going to do a race on the fuji cross today |
bru I agree now go kick som booty doc. cheers :beer:
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yo fixed
that pic looks familiar did we wake up on the same corner last week? |
bro duu i can't remember but if tou says so bro . fricken thunderstrom this a.m. wet all day and crashout my old work bike friday cheers :beer:
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rough bro
firckin rainin up here in the 803 first time ever racin off the hard stuff boo-yah |
doof, what you say is true...as a place to get to...to end up. the tricky part, the human part is...how do you get there? some people, the lucky people, start out there, either on their own or guided there by wise, experienced ones. other folks start out someplace different. and they ride toward the "truth". ranting about the path that other riders are taking to get to a better place isn't, perhaps, the best way to share knowledge. also, as an aside, please note how often in your posts you mention money, how much others may or may not spend, and your relative lack thereof. teaching is a noble profession. my mom taught for over 30 years and drove a pinto for a good number of those years. she made peace with her career choice. i sense you may not have. but perhaps divorcing the issues of cycling knowledge and your economic situation might be an avenue to consider.
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aw climb
that's just the schtick dofo has worked in many a shop over the summer...he brings up the money thing because american manufucturers and skilled salesmen have the money=scientific=better=you need this BS *down.* it takes time and work to get "there" as you say but it should never take zoot to get there doof's gripe is that many have bought the BS and seek to convince themselves of this ridiculous custom=fit logic (custom is not merely fit, as has been said and said and said), or people want to find something as silly as the "gold standard" (ironic bit of word choice) for saddle setback. your body and the bike together will give you the answers you simply have to learn to listen |
we violently agree on the above. ;)
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can doof hug you?
cradle your skinny ribs in his long, mantis-like arms? |
in a manly sort of way, sure. who knows, we might get an oscar nomination out of it. ;)
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brokeback mountwashington |
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