Crosssports's Weblog

Howdy folks,

Rumor has it that some of my earlier posting on dismount technique has been making the rounds of the interwebs. I’ve been getting a lot of referral traffic from Facebook, but haven’t actually seen any of the discussion (if there is any.) If someone could link me to anything worth checking out, that would be great!

So, what the hell does this have to do with the workout of the day?

Well, it’s Wednesday, and that’s skills day, so I’m going to use this interest as an excuse to go into ridiculous depth on the cyclocross dismount.

Today’s workout, then is –

The Hokey-Pokey

(or, left foot in, left foot out, that is what it’s all about.)

Read all the nonsense below, if  you have the patience. Read Adam Myerson’s blog  –

http://www.cycle-smart.com/blog/2010/08/17/the-last-word

Then, go out and try this stuff. See what works for you.

Have fun!

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On with the dweebishness…

First, lets look at the Pedal/Shoe interface –

All of the clipless pedals commonly used for cyclocross operate on the same basic principles.

A cleat –

Is held in place in a pedal…

…by a hook at the front of the pedal, and a gate at the rear. *

The gate is spring-loaded, in an orientation that provides for extremely high resistance to force in the vertical plane, and extremely low resistance in the horizontal.

The cleat/pedal interface is designed so that lateral or medial rotation of the foot overcomes the spring tension holding the gate portion of the pedal in place, releasing the cleat and allowing for vertical disengagement.

The factors that limit the proper functioning of the pedal in release mode are these –

– Force necessary to overcome spring tension of gate

Can the lateral/medial motion of the foot produce enough force to overcome the spring tension of the gate?

– Range Of Motion (ROM)

Can the foot produce a wide enough range of lateral/medial motion to overcome the spring tension of the gate?

– Resistance multipliers

The resistance of the pedal gate to lateral/medial motion is designed to be low, but several factors can cause substantial increases in the actual force necessary to release from the pedal. For EG –

– Contamination by foreign media

Mud, grit, crap of all sorts in pedals/shoes can jam spring mechanism

– Out of plane cleat motion in act of release

If the foot/cleat is pronated/supinated in the attempt to release from the pedal, it introduces a vertical force component to the cleat/pedal interface, causing potentially significant increases in overall force necessary to trigger disengagement.

OK?

Now, the body –

The rider triggers release from the pedal by rotating the foot medially or laterally –

(Generally speaking, we always try to release using  medial rotation. There are lots of sharp spinning parts providing a disincentive for release motions that lean in towards the bike.)

Medial rotation of the foot is a result of medial/internal rotation of the hip

knee,

…some combination of the two, or rotation of the entire body.

The range of these rotational joint moments is limited. Here are some observed norms, if you’re interested –

http://ovrt.nist.gov/projects/vrml/h-anim/jointInfo.html

OK?

Great!

What the hell does this have to do with cyclocross?

Bear with me.

When we dismount the bike,  We’re trying to get off  (the bike)

Quickly

smoothly

efficiently

without hitting the deck

Knowing how the mechanics of the pedal/shoe interface and the related body parts function, we can think logically about how best to do this.

Here’s how I described a super-basic “Cowboy” dismount in a previous post –

1. Unclip right foot.

2. swing right foot over saddle, behind left leg.

3. Left foot stays clipped in. Right side of leg/ass braces against saddle.

4. r hand leaves bar, braces on top tube.

5. Coast in this position.

6. left foot unclips.

7. DROP to ground. Do not step down, right foot is totally passive. Simply drop to ground as you unclip left foot.

1. Unclip right foot.

Gotta start somewhere, right?

2. swing right foot over saddle, behind left leg.

We’re doing this “cowboy” style. More on the “step through” style later…

3(a). Left foot stays clipped in.

…more on this later.

3(b). Right side of leg/ass braces against saddle.

Bracing the right side of the leg against the top tube stabilizes the body in a position that will allow for sufficient ROM to disengage from the pedal, and provides for an additional point of contact with the bike, increasing control of the bike during the dismount.

4. r hand leaves bar, braces on top tube.

bracing the hand on the top tube reinforces vertical stability of the body, helping to control the tendency of the foot to supinate

during medial rotation. Hand on top tube also helps to control bike, facilitates shouldering/portaging after dismount.

5. Coast in this position.

We use this coasting phase to sight the dismount and to prepare for…

6. left foot unclips.

The body is held stable, in alignment, and within the ROM necessary to release the cleat from the pedal. There should be no difficulty with release unless resistance multipliers are present…

7. DROP to ground. Do not step down, right foot is totally passive. Simply drop to ground as you unclip left foot.

The key is dropping to the ground after cleat disengagement.

By suspending the body in the correct position using the hands and hip (per 1-4 above,) we facilitate the conditions necessary for safe disengagement.

Attempting to step towards the ground, or dismount motions of the body disturbing the established equilibrium can and will result in an increased likelihood of a failure to disengage, and subsequent danger of crash/collision.

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Whatever controversy there is regarding the method of dismount I describe here appears largely to append to my “don’t unclip the left foot first” recommendation.

Please allow me to emphasize that I do advocate releasing the foot prior to making any sort of “exiting the bike” motion. I do not, however, teach the method described (excellently) by Mr. Myerson in his blog entry above.

Here’s what Adam wrote in the comments section of an earlier post –

…I advocate clipping out of the left first when you have time to do so, and don’t need to be on the gas all the way to the dismount point. It’s much easier to step off a bike you’re not still attached to.

I advocate staying clipped in on the left when you have to pedal all the way up to the dismount point, and when you’re not stepping through.

I advocate stepping through ONLY when clipped out of the left already, and when you have ample speed and coasting time to take the extra time needed to step through.

Option 1 works every time, in every condition, and I consider it the default.

Respectfully.

I think -at the most basic level- we agree where it really counts.

Unclip before you begin any motion that leads to or constitutes “stepping off” of the bike.

I can understand why the “Unclip before stepping over” approach works, and is popular with many riders. It’s a good way to get off the bike.

I don’t use it myself, and therefore I don’t teach it.

Why don’t I use it?

As explained well in the Cycle-Sport Blog post, this dismount method -while very effective – is not universally applicable, and is not optimal under conditions such as “…uphill dismounts, deep mud, last minute dismounts….” (I would also add sand to the list.)

Believe it or not (and I know I’m straining credulity writing this after forcing you to wade through this ridiculous post,) I’m all about simplicity.

If I can teach one technique that works all the time, or two techniques, one of which only works most of the time,  I’m going with the one that works all the time.

Honestly, though?

I think this may largely be an East-Coast/West Coast thing. The main reason I don’t use the “unclip first” method is because I learned early on that on the rutty, crappy, chuckhole infested minefield disaster courses of Seattle in the 90’s, if you tried to ride into a barrier hanging off the side of the bike balanced on an unclipped pedal, you were pretty likely to get bounced off the pedal, and flat onto your ass.

It just wasn’t a good default position for the courses out here, and really… it still probably isn’t.

Above all else, figure out what works best for the the courses *you* ride on, practice it, wire it, and go fast.

Nothing wrong with either approach, just…

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*                    Yeah, yeah, I know… “what about crank bros, Speedplay, Time, etc.” The details are slightly different, but in all the commonly used “mountain bike” pedals, the function of the pedal still follows the same basic formula.

**                    “What about the “step through?” Another time. I’m going to sleep…

~ by crosssports on August 18, 2010.

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