t-m: a few millimeters, or position

by R Mc on Apr 26, 2009 3:58 PM EDT

This post is NOT about retul or any of the other super high-tech bike fit methods available now.

It is about how absolutely important going by feel, rather than "cool" is for getting a usable fit. Background: I'm flexible, not Mongolian contortionist flexible, but I can place my palms flat on the ground when doing the "touch-your-toes" stretch. I have longish legs and a short torso (and, frighteningly, could be well-fit on a woman's specific design.) These two facts, aligned with a somewhat ridiculous, if understandable desire to have a bike set-up like the 'cool kids' is just about all you need to know for what follows.

Except: when I first started riding in the 80s, I'd tweak everything every couple of weeks until a guy in town (who worked summers etc at Lemond's camp, and had been trained in the Lemond/Guimard 'fit' offered to check out my set-up. My self-selected position coincided almost exactly with the Lemond guidelines. Thus was a monster born.

Because . . . I was no longer just innocently listening to my body, but filtering that through what I thought a cool bike should look like.

Jump ahead to 2000 . . . my wife buys me a new frame because I've begun riding a lot again. So, I set it up. And because I'm so flexible I can make myself ride the abomination (I've got a couple of pictures: my butt's in a different time zone than my arms and there's a near Bartoli-ish saddle-to-bar drop). And thus was begun an 8 or 9 year nightmare: the speed wobbles. No fun, especially not at 40+ in a pack. I know to clamp top-tubes, all the stuff . . . and sometimes it makes no difference.

Through 3 different frames, probably 10 different wheel-sets, a few forks, a bunch of different saddles, etc. I'd get speed wobbles on a few hills (others weren't problems, and strangely, some of these wobbles wouldn't happen the second time through the same hill on a circuit.

Over the years the saddle came way forward, the top tubes on my frames went from 56 to 54, and the drop lessened a bit, but still, put me on a couple of hills the wrong way, and it felt like I was losing control to the front end.

The last straw was a couple of weeks ago at Fort Davis. I sucked on the hill climb, sucked even worse in the time trial (an out and back into a . . . no kidding . . . 30+ mph headwind . . . ouch). And on Sunday's 74 mile road stage (with a couple of passes for fun) I dropped myself on the first moderate descent. Then, stupidly, kept going for the next 50 miles to finish.

On the long drive home, I started wondering about the perception of losing the front end. Next day, I played around at the bike shop on some bikes set up way more upright than mine, and sent off an e-mail to my buddy Richard Wharton (he's a coach--consider this a plug). His answer coincided with what I thought I was feeling on the shop bikes.

So, (and apologies for the long post, here's the action part): I lowered my saddle maybe 2 millimeters and raised my stem 5 (by switching out spacers). A net change of 3 mm. And the difference in how I feel the center-of-gravity and how I can steer and control the bike from the core instead of with head and shoulders is amazing.

Now if someone will just decide they need me to review a set-up procedure for The Racing Post . . .

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Lower saddle 2 and raise stem 3 = 5 right?

If you lower your saddle 3 and raise your stem 2mm isn’t that a net of 5mm different from before? Your butt should now be 5mm closer to the plane your hands are on, right? Or am I misunderstanding?

By the way enjoy your body – from a guy with a long torso and short arms who when I was most stretchable could never touch the ground without inviting back issues,

by Markk on Apr 26, 2009 7:56 PM EDT reply actions

ach - subject is correct lower 2 raise 3.

by Markk on Apr 26, 2009 7:57 PM EDT up reply actions

Shimmy

Yes, if I understand correctly, I would interpret what you did as ‘moving backward,’ meaning:

-the lowering of your saddle moved you effectively back on your frame, and more towards the bike’s ideal front/back weight ratio, thus reducing the shimmy, and

-moving your stem up even slightly pushes you towards using your sit bones more, likely a little more comfy, but in the handling context also shifting more body weight backward, which maybe your bike likes more in relation to your body.

-All the adjustments you made are not big, and its usually not a problem at all to drop the saddle as far as leg fitness goes.

-So, fine. Right?

-The typical woman’s trek has the same geometry as a the Tour de France bikes of the middle of the 20th century.

by thisisntthezodiac on Apr 26, 2009 9:40 PM EDT reply actions

except

that the general trend of position adjustments over the years has been to bring the saddle forward.

I use a 0-set-back seat-post—think about it: because of the seat tube angle, lowering the seat-post/saddle will effectively move the saddle forwards as it moves down the seat-tube angle.

Raising the stem, paradoxically, gives me more front end control because I’m not having to reach forward so much to get to it. That’s the most surprising part to me, because I’ve always preferred to descend in the drops, but there was something about that forward reach that threw my center-of-gravity off and at speed I could feel the front end going out of control.

The net result of this fairly minimal position adjustment is to bring my center-of-gravity more forward and slightly down, which keeps the front end better “planted”:

by R Mc on Apr 27, 2009 9:53 AM EDT up reply actions

"the general trend of position adjustments over the years has been to bring the saddle forward."

(Sorry, I don’t know how to make the fancy highlight boxes, links and stuff.)

Okay, want to keep it to the shimmy question – bike position thread would be good, but you are correlating your entire body position to the shimmy, which is maybe gonna compromise your riding, where you rather should be concentrating first on maximum use/comfort of your lower half, not worrying about trends, and then finding the comfort sweet spot where your hands drop and rest easily. There is still more than one camp of where the fore/aft position of the saddle should be relative to the rider’s leg/knee position.

Looking at Andy Schleck yesterday, his riding style is so unique – like a circus clown on tiny bike (sitting forward too!), and not appearing to get as much leg extension as others – is just exemplary of how all riders are different, even if it looks wrong.

If one is super fast, or even an aspiring racer, yes, it helps to develop an aero position on the bike, and feel free to experiment and ride as well as you can, but mainly only mortals are gonna read this and so more keeping to biking advice, not race advice. I, not racer, anyways, but just a lowly brevet rider.

Okay, so 4 things:

aa) Your ‘solution’ is exactly what makes the shimmy worse on my bike. My stem is flipped over with 2cm of spacers, how I like it, but my bike (a Look KG381) definitely likes the rider’s hands down low near the front wheel, and just for example if I’m cresting over the top of a climb on a bumpy road, with my hands on the tops and then reach for the water bottle – then yes, sometimes a mild shimmy as the descent starts. So, my bike likes a rider to sit forward too, but the overall handling becomes worse as the rider moves relatively further forward from the vertical plane of the bottom bracket. Recently, I have done a lot of back/forth/up/down saddle experimentation to manage a foot injury, and a bike with a given rider basically handles better with the weight back, one of the reasons you see so many small bikes with a lot of seatpost, compact frame or no, in the pro peloton. On the other hand, you don’t hear so much about MTB shimmy, which is usually a more upright style of riding, so go figure.

bb) Shimmy is usually related to coasting but your situation seems severe – suggest experimentation with a bigger frame and then just use a shorter stem to match your current reach to the bars, which it sounds like already. And if you do get around to experimenting, suggest go a lot bigger – example: get a used Cannondale off ebay for $125, 4cm larger than your bike, if not enough standover height, then get a compact frame. Then, quit thinking about it as too big, and see how it feels to ride it.

cc) There is a belief that some bikes do not shimmy due to well matched rider and good design. Quite a lot out there about this, and I have had bikes that never had a problem at all, so who knows.

dd) You could also experiment with lower tire pressure, but you didn’t want to hear that, did you? Racer!

"I use a 0-set-back seat-post—think about it: because of the seat tube angle, lowering the seat-post/saddle will effectively move the saddle forwards as it moves down the seat-tube angle."

Yes/No – sorry, by lowering the saddle – yes, you are moving the nose of the saddle forward, but you are also effectively making the bike smaller, which is like moving backwards, aka sitting up more. Like ‘The Shark,’as seen here on CN:

http://tinyurl.com/ca2yvj

Celestino shows it is possible to ride fast while more upright, even at that level.

Anyways, you were supposed to at least think about moving your seat back a little when you lowered it, to keep your leg extension and same power.

Good luck!
Mike

by thisisntthezodiac on Apr 27, 2009 11:49 AM EDT reply actions

thanks for the feedback

but these adjustments have worked: I can attack descents that freaked me out a couple of weeks ago.

So, I guess the takeaway point from combining your experiences with mine is that there probably is not one sure-fire fit method out there, but rather a bunch of points of emphases to take into consideration.

Me, I need to feel that I can steer the bike with my core muscles: which is vaguely stated, but has definite implications for saddle and bar placement.

by R Mc on Apr 27, 2009 12:51 PM EDT reply actions

out of curiosity

the wobbles usually kicked in at 40mph+? (Couldn’t figure out if you were talking about speed or size of pack.)

(I know I shouldn’t say this out loud, but I’ve never experienced wobbles on a bike, despite being very good at dropping like a rock on descents. Skateboards, on the other hand . . .)

by Sui Juris on Apr 27, 2009 1:13 PM EDT up reply actions

Yes, it's nice to get a breakthrough like this for your riding.

Well, I’m saying you get the riding position first, and then get the bike to match, and if there’s a problem with the bike, then it’s a ‘bike’ problem, not a rider problem.

It is generally good to get the larger bike idea out there, a little different than the bikes on TV.

I would say another test for you would be to rate your bike fit would be to ride in a high-wind situation, which is really the only time the rider needs his arms to steer the bike. I found out this way my bike was simply too small for me to brace my upper body across the top of the bike to allow me to keep pedaling and not fall over…

by thisisntthezodiac on Apr 27, 2009 1:13 PM EDT up reply actions