Sunday, July 31, 2011

How To - Touching Pedals

One of the things that I rediscovered recently is the art of "Touching Pedal". It's not really a necessary thing, it's not really art, but it's one of these skills that helps you become a more fluent racer.

I'll define "Touching Pedal" as a situation where you pedal through a turn and touch your pedal to the pavement.

Optional events include lifting your rear wheel, skidding your rear wheel, and crashing. That last bit would indicate a failed Touching Pedal, just to clarify.

A lot of people, including a lot of racers, will say that touching your pedal is an unnecessary risk in the already risky sport of bike racing. I'll admit it's an extra risk, but it's only one step removed from the risky business of diving into a turn when it's five wide (or whatever), racing in the rain, or any number of other racing scenarios.

I should point out that Touching Pedal is an excellent test of tubular tire glue jobs, clincher to rim tolerances, and tire pressure. A poor glue job, a loose clincher, or low tire pressure can combine with a Pedal Touch to wreak havoc with you and your bike. At best you'll get scared. At worst you'll slide out in a blaze of carelessness.

Keep in mind that Touching Pedal will not cause a well glued tire to roll, nor will it roll a properly fitted and up-to-spec clincher/rim combo, and it won't cause a proper pressure tire to slide like it's suddenly found ice. If Touching Pedal leads to some other event, it's usually because of something other than the Touching Pedal.

You have two goals when dealing with touching pedal, two benefits.

1. You learn how far you can lean before you hit your pedal. This depends on your frame, tires, crankarm length, crankarm design, and pedals, so your experience on your bike when it's set up in a particular way may not relate to another set up, even on the same bike.

2. By experiencing the Pedal Touch in more controlled situations you learn what to expect when confronted with the same scenario in a race, whether it be you touching pedal or someone in front of you. (You really don't care about someone behind you touching pedal.)

So, first up, you learn about touching pedal. I mentioned that you learn how far you can lean before touching pedal, but it's related to your equipment. Everything I mention will alter the angle at which you touch pedal.

- Your frame has a given bottom bracket height. Or, if you are a frame builder, it's a given bottom bracket drop from the centerline of the axles. The lower your bottom bracket, the more stable the bike, but the easier it is to touch pedal.

- Your tires can add or subtract as much as 5 mm in axle height. This changes your bottom bracket height (not the drop). A taller tire will give you more clearance.

- The crankarm length determines how far down the crank goes at the bottom of the pedal stroke. A longer crank will make you touch pedal at a shallower angle. I used to run 167.5 mm cranks; now I use 175 mm ones. The longer cranks make me touch pedal sooner.

- Crankarm design affects pedal touching angles. The "Q Factor" (the width of the cranks as measured from one pedal flat to the other, if both cranks were pointed in the same direction) contributes to the pedal touch calculations. A wider (or higher) Q Factor puts the pedals further out than a narrower (or lower) Q Factor. Campy consistently has had low Q Factors, Shimano high ones. I don't know about current cranks.

An added note - since the right crankarm normally sticks out a bit more than the left one (because it's holding chainrings), it's easier to touch pedal on the right side for those cranks. Some cranks are actually symmetrical, and in those cases one side is no different from the other.

- Pedals can really affect pedal touch angle. I used to run Aerolite pedals, which on a "standard" crank set up could attain about a 4 degree steeper lean angle before touching pedal. If I recall correctly a normal pedal would touch at about 34 degrees, an Aerolite at 38 degrees.

Pedaling through turns, at least in the amateur ranks, is an easy way to gap someone, especially when facing those diesel type riders that never seem to tire. If you can pedal through a turn, creating a slight gap of a few feet, it forces the diesel to accelerate a bit. Diesels hate that.

Okay, to be honest, most racers hate it).

If you can repeatedly accelerate into, through, and out of turns, you can really hurt the other riders' legs. Think of it this way - by powering through turns, you emphasize the accordion effect. It hurts those riders sitting in because they have to accelerate harder the further back they are in the field. (The exception being smart tailgunners, who will coast back into the field after each turn.)

At the peak of my racing life I'd regularly dig my Aerolites into the pavement, this on a bike with 167.5s. That meant I was practically sideways in the turns and still pedaling, usually really hard.

As I got older and less intense about the whole thing, I've actually gone for years without touching a pedal. Then, this year, I started touching pedals again. Remembered what it's like. Etc etc.

Relatively clean pedal, not struck.

Note there's a flat area under the pedal, then it bulges a bit to encompass the bearings. I haven't hit this pedal since I put them on, oh, three years ago? Maybe four. Interestingly enough it's the right side pedal, so it's the pedal that's easier to touch. On the other hand I have very few races that take right turns, so most of my pedal touching is done on the left side.

Speaking of which...

Pedal after a pretty hard dig. Plus about 20 or 30 other "touches".
Left pedal so it has (I think) more clearance than the right.

I took this picture after I had about as hard a pedal touch as I've ever had. Unfortunately I really don't have a picture of this pedal before the dig. It's clear that I shaved a bunch of material off the pedal body. You can't tell by the picture but I definitely lifted the rear wheel when I dug the pedal into pavement. I didn't go down, didn't go sideways, just kept riding.

How do you practice touching pedal?

The first thing you do is to look at your bike when it's in Touching Pedal position. If you want to be totally accurate, clip your shoe in place. Sometimes the shoe will hit first. On some pedal systems the cleat touches before the pedal. So on an so forth.

Rotate the crank until it's at the bottom of the pedal stroke, straighten up your pedal (it's inevitably upside down, especially if you have your shoe clipped in), then lean the bike over until the pedal touches the floor/pavement/whatever.

Wow, right? It's really leaned over.

Try it on both sides so you have an idea what it's like. You can even stand over the bike to get an idea of the angle between the bars and the floor.

It's really pretty sharp, over 30 degrees in most cases.

For your reference you should note the shoe angle that gives you best clearance, especially if the shoe hits first. Although you probably won't alter your pedaling style in all situations, you may adjust the downstroke on the inside pedal when pedaling through a turn, just to give you a bit more clearance.

Next, and this is the tricky part, you need to find a clean/swept set of corners in a quiet place where you can ride about 25 mph through said corners. Unfortunately it's pretty much impossible to effectively touch pedal at slower speeds because you almost never lean that far over while pedaling.

(Yes, you may lean that much when making a u-turn in a driveway, but often you turn so quickly that you can't get the pedal down before you start straightening up.)

Then you sweep into the turn, keep pedaling, and keep leaning a bit more until you feel the pedal touch.

When that happens just act normal. Don't slam on your brakes. Don't jerk the bars. Just keep riding. Your bike will keep turning.

(By the way this is all theoretical. If you go and actually do this and crash, don't blame me. And, theoretically, if you were to do this, of course you'd be wearing multiple layers of long sleeves on your arms and legs and be wearing a good helmet and long finger gloves. Theoretically.)

Personally I can't get motivated to touch pedal when solo. I need some more incentive than just practice. I also find it hard to go fast enough solo. This means I generally practice when I'm riding with other people (as long as I'm the last one in line, for safety sake). I'll sometimes sit at the back of a race and try touching pedal through some of the turns. If I'm not at the back and I touch pedal, it's because I'm not practicing, it just happened.

A normal Touching Pedal is NOT a major event. The pedal touches. The rear tire might lift a bit, even as much as a couple inches, which would also force it to skip outwards a few inches. If the rider just keeps riding, the bike will self-straighten.

With most of today's pedals made of plastic, you can dig them pretty hard without any weirdness. Metal pedals (or cleats) aren't as forgiving, so if the first part of the pedal/shoe/cleat combo to hit is metal, be a bit careful. Metal doesn't shave away as easily so the bike will lift more.

With the old fashioned toe clip and strap pedals, it only took about 28 degrees of lean to touch pedal. Everyone's pedals showed the scars of Pedal Touch. Collectors would jealously guard pristine pedals simply because such pedals were virtually non-existent (just Google Campy Nuovo Record pedals). Touching Pedal was totally normal. You dive into a turn in a packed field, someone's rear wheel would skip sideways a bit, and everyone pretty much ignored it. No biggie.

It's a bit more significant at more extreme lean angles because slamming a pedal at 38 degrees could potentially cause you to lift the bike so much it'll start to slide when it lands. I've never seen that happen and frankly, to dig a pedal really hard at extreme angles takes either a moron or a clueless rider.

Or me, on my 167.5s, Aerolites, and desperate to try and make a move stick.

In general my pedal touching only occurs in races. I don't pedal through turns when going really fast on training rides (the "really fast" part usually doesn't happen when training).

Pedaling with the bike leaned over is just another one of those "overcome your instinct" things you need to learn to become a more fluent cyclist. Hopefully this gives you some ideas when it comes to cornering at speed.


Anonymous said...

God help me if any of the CAT 4's in the Denver area read this and start to apply this in our races.

Aki said...

Hm, I didn't think of that.

Err just to clarify, it's more of an emergency on-the-limit skill.

Most importantly you shouldn't learn it when you're at the front of a bunch of riders. You learn it on your own or when you're at the back of the group.