Force Vectors in Road Pedals

Here is an interesting article about the work that Metrigear is doing with their pedal mounted Vector power meter. Although this is all focused on strain gages in road cycling, it is not too much of a stretch of the imagination to use strain gages in BMX to quantify the loads we place on our bikes. Someday...

Pedal Sustainability

A recent discussion on BikeGuide spurred my interest in the sustainability of component manufacture. At the center of the debate were plastic pedals (1, 2), and their disposable nature. Most people, as soon as the pins have worn off of the pedal body, will simply toss the pair of pedals and buy some new ones. Even if you were to recycle those pedal bodies, spindles, and bearings, we still have to use extra energy to recycle those components, as well as manufacture new spindles, bodies, and bearings. On top of that, many thermoformed plastics are much more difficult to recycle. Note: This last comment about thermoformed plastics is not necessarily true. If you have a link to help, please post it :) -Peter 1/19

So where does this leave us? Can we use plastics in pedals? Yes. Odyssey's JCPC pedals have a good solution by using steel pins to hold the pedal together, allowing the pins to be replaced. Odyssey also provides replacement pedal bodies and spindles. By doing so, we can now replace only the part that fails, reducing waste. Reports are that the nylon used in the pedal bodies are recyclable, which is another plus. Now, in fairness, I should say that these are some of the ugliest pedals I have seen on a bike. 0 sex appeal. And they use a bushing setup, which can develop a bit of lateral play. Some people (such as myself) are bothered by this, but there is little reason it shouldn't work well.

And then we arrive back at the Aluminum pedal. For a long time, these have had replaceable pins, and (on high end pedals) spindles. Although there is a lot less probability of damaging the pedal body, I do not know of any BMX manufacturer that provides replacement pedal bodies. Aluminum pedals, due to their higher cost, and resiliancy, are a longer term investment.

Which pedal is right for you?

The Pedal Grinder: look for replaceable pins, and a tough pedal body. The worst situation is investing in a nice pedal only to knock a chunk out of it on a grind or stall, and not be able to get a replacement. In this situation, Nylon, or a thicker aluminum body is the appropriate choice.

The Spindle Bender: Usually you will see this when someone takes an impact to the end of the pedal. Look for sealed bearings or bushings bearings. Unsealed spindles must be case hardened to slow spindle wear, whereas sealed bearings or bushings allow the spindle to be focused on strength and stiffness. Of course spindle diameter and material play a significant role in strength. Here is a a few measurements of spindles from BMX-U

The Budget Rider: This has been the great aspect of plastic pedals: inexpensive, with fair performance. However, I would argue that this rider would be better served investing in a better plastic pedal (JCPC with all it's replaceable parts is a good long-term investment), or an inexpensive aluminum pedal (Un- or sealed bearings are your choice. Though if you dislike play, go with sealed). Why avoid the myriad of cheap plastics available? The pins. As soon as those are gone, so is your grip. And lets face it, slipping a pedal, even on plastic, is annoying. As more pedals come out, we may see some resilient pins, but until then, replaceable pins are the safest choice.

The Weight Weenie: I know you are looking through catalogs searching for the lightest pedal. I did this too, and ended up with a pair weighing 9 oz! But performance sucked, and the bodies were mangled easily. Even though most plastics are lighter than aluminums, I suggest investing in some good aluminums, for a few reasons: 1) they will run longer without problems; 2) they are available with good bearing systems (i.e. sealed); 3) they come in pretty colors, and BMX is about fashion isn't it ;)

Plastics IN Pedals

After my first post on the prevalance of plastic pedals, I recieved and broke my Odyssey glow-in-the-dark pedals... In one day! I was immediately surprised, as I had used some black Odyssey plastics for a long time without an issue. After some thinking and research, I came up with why there was such a dramaic difference between the two: the black pedals were nylon, while the glow pedals were polycarbonate. This post will focus on a few different materials used in plastic pedals.

Nylon's major advantage is directional nature, and toughness. It was originally designed for use in tooth brushes, and has since been adapted for seat belts, safety vests, and ballistic cloth. What this shows us is the direction in which nylon has developed: to be tough and reliable. The fiber/directional nature of nylon lends to its higher shear modulous.

Polycarbonates, although exhibiting excellent impact resistance, lacks in shear strength. This is where my pedal failed. The right hit, at the right angle cracked the pedal. There must be advantages in polycarbonates for BMX, right? Well, yes, they have a lot of pretty colors, including UV activated and glowing, and are increasingly used in other industries (reducing prices).

So where does that leave us? Well for me, the colors are not worth the annoyance of changing pedals often... even at such a low price. That leaves me leaning toward nylon. In thinking about it, though, I wondered if there were pedals out there using fiber reinforcement (i.e. composites). Quickly, I came across Eclat, a brand I am becoming more fond of. They are using fiberglass reinforced nylon in their Surge PC pedals. Although I would prefer carbon fiber, it is a definite improvement. The weight is virtually the same, and the price is still low (that's where the fiberglass has the advantage). Now the real question is which semi-transparent color...

EDIT: I just saw that Fly is also coming out with nylon-fiberglass ruben pedals. Woohoo! But I need pedals now, not December, so Eclat here I come.

EDIT 2: As Martin pointed out in the comments, Eastern is using carbon fiber re-enforcement in their pedals. Though, they do not list what type of plastic is used. We'll have to see which pedals survive in the market, but CF is not a bad idea.

Plastic Pedals

In the past few years, plastic pedals have become much more prolific in BMX. My first experiences started by just grabbing some Welgos from the shop to try saving a bit of weight. I never had much trouble with the grip of even those! And the weight savings was substantial. Since then, Odyssey, Animal, and virtually every company with a pedal has a plastic version available too. Why am I so excited about this?

1. They're cheap, and lets face it, BMX is full of cats who want good components, for as little money as possible.
2. They're light, light, light. At around 13 oz per pair, who can complain?
3. The colors man, the colors! Odyssey has really shown the potential with using polymers in pedals (and seats, but that is another discussion). A wide range of colors are available from most manufacturers. Odyssey even offers Glow-in-the-dark, and Chameleon (UV activated, color changing) . Lets face it, aesthetics do play a role in our component choices. And rightfully so, if you like the way your bike looks, you're more likely to get motivated to hop on it.
4. Grinding/sliding, whatever you want to call it, is more Kosher with plastics. If you ever get bother for hopping on a ledge, just point at you pedals and say plastic. Certainly, there are some thick-headed people out there who will still give you trouble (because their "girlfirend" left them, no body calls to see if their ok, and they generally have personal issues they feel you are responsible for).
5. You can finally stop feeling bad for riding a bike... wait a minute... Haro Recycled plastic pedals

One thing I will try to do throughout this blog is to show both sides of the story. Plastic pedals are not for everyone. There are definite trade-offs with plastics.

1. Grip. Some people complain that the little "pins" in plastic pedals either do not give enough grip, or wear down too quickly, so there is no grip. This is a fair concern, as some people prefer more grip than others. I would say it comes down to riding style. I thought I had seen something like the Hoffman Solemate pedals, where a nut and bolt are used as pins, avoiding the whole "what?!? Stripped? I didn't even tighten it! ARRRGGGG!!!" problem. Edit: The new JC pedals from Odyssey will have an interesting new pedal design:
2. Weaker spindles. When these pedals first started coming out, people pointed out that the spindles were just run-of-the-mill, cheap steel spindles. This is a big concern to pedal destroyers. However, since competition in plastic pedals has increased, companies are putting in the same grade spindles as their aluminum-bodied counterparts. I still think pedal spindles are designed backward, but that is for a future post (after some CAD work).
3. Having such cheap pedals may lead some people to the idea that it is ok to just toss them out every month or so. Which is fine, as long as you find a new home for the old ones. Donate them to some new rider, or use them in a side project. We should avoid the idea of disposable products.
4. No Anodizing. And lets face it, ano is sexy.

Conclusion: Plastic pedals are great for BMX. Their low cost and low weight fit right in. However, we will likely never see them owning the market, as some people will want the look, grip, or feel of aluminum-bodied pedals.