Stem Length Question
 

Is the front axle suppose to be obscured when I'm on the hoods, the flat, or the drops?

My saddle is set correctly using the plumb bob method but I find my self moving forward on the saddle, what should I do with the fore/aft on the saddle now?

Tina from Oakland

I think that is one of those general fit items that are not overly related to anything substantial. It's like KOPS (knee over pedal spindle). It's a good place to start but not a hard fast rule. To answer the question, I think it's when you are the hoods, but I wouldn't put too much stock in it. Focus on what feels right.

how is your saddle tilted? If it's tilted forward, even slightly, you might find yourself shifting forward. That would be the first thing I'd check. I'd start with it dead level (using a level!) and then maybe even adjust it a tiny bit nose up.

As for the other rules of thumb you mentioned:

The KOPS (Knee Over Pedal Spindle) / plumb bob method you used is really only good to get an objective measurement of saddle fore/aft position. It isn't necessarily the correct position. Other than having a professional fitting, the way I've figured this out is just by "feel of balance" over the pedals. I happen to like mine about 1/2 - 1 cm rear of KOPS.

Sometimes the fact that you feel you have to shift yourself back can be related to the level, but also it might be your body telling you that it wants to be a little rearward of your current position.

Or it might be telling you the stem is too long.

The front axle is obscured" method of determining stem lenth: Again, this isn't necessarily the ideal position for you, and doesn't account for stem height (rise or drop w/a a flipped up or flipped down stem). I don't know what to say here except that I personally experimented with 2 or 3 stem lengths, flipped up and down, and just decided what one I liked best. This was after I settled on liking the saddle position mentioned above.

I'd do the saddle level and after you've tried that for a couple of rides (maybe tweaking as you see fit), then try shifting it backwards a little to see if that makes a difference. Then, I'd mess with the stem length and rise.

It's all inter related, and unless you actually have a pro fitter look at you, all you can do is think about these principles and experiment.

Not much help I know, but there ya go...

kops as law is silly. giving one second of consideration to axle blocking is silly.

Yeah! All those silly people who raced and made a living at it, who won TDF's !
For years no less! And all without spending hundreds to have some kid who last week flipped burgers and made lattes tell you what fits......

church of kops? it a decent ballpark but not so smart to take as law.

church of axle blocking?

http://www.bennylingbling.com/wp-con.../21242_540.jpg

Can you cite a source showing which pros live religiously by KOPS and axle blocking? Most pros, 1's and 2's I have talked with actually had their saddles forward of KOPS and didn't give a hoot about the axle.

Also, most fitters I know charging hundreds for a fitting have been doing it for longer than I have been riding a 2 wheeler. Not that a pro fitting is required, but most of these guys don't remember how to flip a burger because they've been playing with lasers and computers for so long.

This, by the way, is coming from someone who has never gotten a pro fitting and DOES live by KOPS, but that's just because my knees demand it. I got more power when I was 1 cm forward, but that does no good when you're sidelined for months due to ITBS.

a life where ive forgotten how to grill is a life i dont want to live.

Your ignorance is astounding.

Hoods.

If it's way off your frame may be too large or small... this can be corrected by a change of stem but your weight distribution(front/rear) will probably not be as the bicycle designer intended. A different stem changes how quickly the bicycle wants to steer, so don't get a really long or short one.

Proverbially speaking, smart ass :P

Huhuh......and what was it you wanted proof for?
I've been riding for over 60 years, never had a fitting and frankly was never tempted to get one. I do find however that when I deviate too much from the above mentioned norms ( whether you believe in them or not) I begin to have knee and wrist problems. Proof enough for me.
As to the ex-burger flippers.....It's a free country, believe whatever you want!

So you're taking your own personal experience and using it to claim that pros in the TdF do it too? Correlation fail, but like you said, believe whatever you want.

edit: And I wanted proof of your claim that pros do it. I have never been paid to race. Plus, I mentioned that I got more power when I was 1cm ahead of cops. It worked when I was 16. Not so much now.

+1 for NOT KOPS

I when I tried KOPS and and Obscuring axle method, I got a scrunched up position with too much weight forward.

Then I read http://www.peterwhitecycles.com/fitting.htm and http://www.stevehoggbikefitting.com/blog/.

They suggest the balance method to determine saddle setback and subsequently stem length. I am now behind kops and have a longer stem. Also note that the handlebars you use and the tilt you use them can affect reach to the hoods by as much as 3cm. So right there, the obscuring axle method is screwed already.

I have followed a lot of the advice from the blog and it has solved all the problems I had. Especially shoe insoles, shims, varus shims, cleat position, crank length etc. It took me a few months of testing, but my position now is awesomely comfortable AND fast. I suggest you give it I try. :thumb:

Those KOP and obscure of the hub aren't methods to an end, only guides. If you end up really scrunched up with those fit method there is a very good chance you have statistically odd body proportions.

I'm going to bite my tongue about steve hogg and shoes, suffice to say i'm not impressed and won't be mailing away my money to a certain german shoemaker.

If you do a lot of research about KOPS...you will find that strong riders tend to want to be in front of it and weaker riders behind it. Sheldon Brown writes about it.
For all you guys that discount conventions...conventions come into being for a reason...they are norms extrapolated from the masses.
Do they work for everybody? No. I am right around KOPS and when on the hoods, my handlebar obscures my front hub.
So these conventions work for me. I don't set up to either but that is where I end up for the best combination of performance and comfort.
Also..regarding the Lemond seat height convention or formula of .883 X inseam...I ride with a lower seat than this.
So his formula doesn't work for me or comport with a 25-30 deg knee angle at the bottom of my pedal stroke either. Conventions are a good starting point then thru trial and error find your best fit.

you are not kops when you move to the drops or tops?

Ride and experiment. If you can't get comfortable, get a pro fit. There is no single fit.

Expert fitters will be trying to either fix the problem(s) you describe, optimize for something you ask for (aerodynamics, power, comfort), or just doing what they do best. Even if they're trying to achieve the same end goal I have my doubts that two fitters would give the exact same setup for a given person and their bike.

it all changes dependin where you are on the bars, cause as the torso rotates so the relative location of the hip socket.
hip/femur scribes an arc around the point of rotation - the contact point of the sitzbones

KOPS, like lemond saddle height formula, a std reference point, a start, not the necessarily the answer.
when I was doin a lot of crits - I preferred forward of KOPS. I got tired of spendin most of the races with the horn up my ass.
Since I'm now at, and have been for some yrs, 30.5 cm behind BB (sitzbone contact), I would prolly find myself Heisenberg close to KOPS; if I actually gave a crap.
For many it's a good start. Others will find themselves well off. You gotta start somewhere?

OP - do ignore the axle obscura thang, it's total BS. That it happens is random, like a squirrel crossing your path at the same instant a dog walker decides to let his dog loose and a seagull drops his load directly over you...
Get the saddle positioned for what works best for you in most of your riding, then move on to deciding bar dims and placement.

it just seemed interesting that he specified that. the ranges of upper torso angles for those three hand positions overlap greatly.

Personal experience?

The whole hub obscuring theory kinda throws me off a little too...I mean- On my hoods, if I lean back more upright on my bike my front hub is behind my bars a bit...Only when I hunch forward in a more agressive position(without being in the drops) on the hoods is my hub completely covered. How would you know? Is there a set angle degree for your back to be in to make this rule apply?

exactly why that particular rule of thumb is total crap.

It might not be your stem length. it might be your cleat placement. I too had issue with creeping forward on the seat. found out my cleats moved back 2.5cm. I moved them forward and now seat position is normal. just my experience.

At the risk of pointing out the obvious, it also really depends on how well your frame is sized to you. If you are compensating for a too long or too short top tube with stem length, that will change the visual perception of the bar and hub alignment. Bar height plays into this as well.
But to answer your original question, on a frame that fits me the handlebar generally blocks the hub when I'm on the hoods, which is where I ride mostly. If you are built proportionately it's an excellent place to start.
Get your saddle where it's comfortable (height, KOPS), then set bar height and reach. Don't use either one to compensate for the other. Allow a week or two of riding between small adjustments to allow your body to adapt and give comfort feedback.