One of the tricky aspects to catch in product design is the amount of true value in it between its stages of evolution. Sometimes, last year's model that you bought could have negligible difference in it as opposed to this year's. Its marketing might say its improved, with a new recipe, new look, new shape and so on and in the end, you would probably pay a premium for it as well, all for the same exact thing.
On the other hand, as a credit to product design, it could also be that last year's model could be insufficient for use compared to the current year's release. Dangerous too. So is this really a credit if people are still using last year's product?
Subsystem design is very dependent on the performance of the parent system. Today's illustration is a case in point.
Speedplay's marketing line for the "Platformer" brand of pedal adapters is this : "The innovative Speedplay Platformer is a user-friendly, tool-free platform cover for Zero and Light Action pedals. The Platformer makes it easy to convert from clipless pedals to platforms for riding with street shoes."
Among the disgruntled is an individual (who doesn't wish to be named) whose adapters broke just as he was pulling out of a traffic light last summer. Casual riding wasn't light enough for Platformers. The plastic adapter on his right pedal broke catastrophically with an audible snap. Because of little warning, he lost his balance very quickly and ended up crashing on his tailbone and elbow, right in the middle of a road during rush hour traffic. A crucial red light to one side gave him enough time to get back up in pain, pick up the pieces and vacate the road.
Thanks to light action pedal adapters, he is in miserable condition today. Because a fractured coccyx is an injury with no form of available treatment other than time, five months later he still is in immense pain on a daily basis and can’t sit for more than an hour without feeling discomfort. He calls the sensation "intensely searing". For the weekend racer and an enthusiastic bike geek that he is, this is not exactly the good life.
The gravity of the injury and the possibility that someone else could be hurt in similar fashion made him contact Speedplay on many occasions. To make sure this wasn't some freak event, he even installed a set of the old Platformers on his girlfriend's bike as well. The product lasted approximately 16 minutes before they cracked. Some insults are better off when they come with forewarning. This one was even recorded on video by him.
Speedplay took back his pedals for inspection and has stuck by the quality of their brand. They chose to deny his theories of why they broke and didn't feel much need to return them back to him. They have claimed no responsibility for his injuries and other damaged personal articles. The user has now fixed a date with a Small Claims Court to settle the matter in the interest of full disclosure. He has also had a meeting with the Consumer Product Safety Commission.
I suppose somewhere, someone found out the trouble with the old pair, fixed it, moved on. Meanwhile, old units are still being used by riders.
A Plausible Theory
The concept behind the Speedplay Platformer is to allow the user the option of riding a bicycle equipped with Speedplay brand pedals without having to wear dedicated cycling specific shoes. By creating a larger, stable platform around the pedal, Speedplay Platformers, allow the user to ride in “regular shoes."
A set of Speedplay Platformers consists of six pieces. A complete, individual unit is comprised of two seemingly identical pieces of clear plastic. The difference between the two pieces is found on the “inside” where four tabs fit together in a male/female manner. A metal retaining clip slides through these tabs and locks the Platformer in place around the Speedplay pedal.
Because of this design and the fact that the Platformer is molded to be compatible with only one specific type of pedal, it is virtually impossible for the Platformers to be installed incorrectly. They are either locked in place or they aren’t and this is very obvious to the user. To remove a Platformer, a key, coin, or screwdriver is used to remove the metal retaining clip by sliding the clip from the Platformer. The edge of each Platformer is concaved to facilitate the easy removal of the retaining clip.
At the time the user tried the product, he was 210 pounds and stood a height of 6'1". While this isn't typical of your featherweight climbing maestro, he told me that he's never broken any products before and he's always careful with cycling equipment.
Now clipping in and clipping out of Speedplay pedals cause substantial wear on these high performance pedals as most of us have learned. The right pedal, more so due to clipping bias in start-stops. The user's had between 3000-4000 miles of usage on them. For most people, this is a season's worth of use.
This leads to a plausible theory for why the pedals failed. He wrote to me :
My theory for why they broke is because design of the Platformer didn't take into account worn pedals as they are molded around a brand new set of pedals. Since the pedals I was using were worn down, there was some open space between the Platformer and the pedal itself which lead to much more stress on the Platformer particularly on the "outside."
The following two images show a 3.2% reduction in right side pedal dimension between a brand new and the user's old one.
New right pedal
The following image, of the used left side pedal, shows a 1% difference in pedal dimensions when compared to the right side pedal. This shows that the right pedal wears more due to clipping bias.
Please be aware of this problem and report any of your personal mis-happenings in the comments section. If you also wish to offer any kind words of advice to the user with regards to a broken tailbone, please share your thoughts.
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Sounds pretty bad. There was a mention that he met with the CPSC. What did they think of the situation?
ReplyDelete"Concern for man and his safety must always form the chief interest of all technical endeavors. Never forget that in the midst of your diagrams and equations"
ReplyDeleteIn other words the gap made the clamshell act as a beam and it broke because of the load?
ReplyDeleteI used to have some similar adapters for my Eggbeaters which look to be made from the same clear plastic (polycarbonate?). I installed then, rode round the block and thought they were too slippery so I took them off but the plastic cracked from the pressure of removing them for the first time.
ReplyDeleteFunnily enough Crank Brothers don't sell them anymore.
I keep meaning to get some old cleats and bolt them to some metal to make something similar but just haven't got round to it. The protruding bolts could act as pins to stop your feet slipping.
@Mark
ReplyDeleteMeeting with the CPSC was an interesting process. Back in November I did an online submission and within a couple of weeks I received a copy of my complaint to sign and verify.
The included letter explained that the CPSC doesn’t have time to investigate every complaint so it seemed like from this point luck of the draw would be playing a factor.
In January and I received an email from an investigator. We met for about an hour and when he saw the Platformers, he shook his head and said “They used the wrong kind of plastic.” We then went through about a 20 page questionnaire that was pretty broad. The investigator had an engineering background but didn’t know too much about bikes, so I ended up helping him through the questions. I dropped him a note back in March to see if anything was happening further and all he had to report was that my complaint was now in the hands of their head bike guy in Washington DC. Overall it was a good experience. The investigator was super nice and was great to see the government takes these kinds of things seriously.
@Trackasaurus- That’s my theory anyway. I still have two more sets of them that I’m going to test out to see if they break in the same way.
Yesterday I did hill intervals on my Zero pedals with running shoes, as I'd forgotten to take my cycling shoes with me to work. Power for the 5-7 minute intervals was off around 10% compared to what I'd expect with cycling shoes. So I think Speedplays work fine with regular shoes, even without special platform adapters.
ReplyDeleteIt would be fun to compare pedal force profiles with a Metrigear vector for riding with plain shoes versus with cycling shoes.
Dj : I wonder if that shows that the 10% was lost on the upstroke. Whatever happened to "pedaling in circles". Even Jobst Brandt doesn't have much faith in upstrokes. He kept telling me that the downstroke phase is where its at! Thank you anyway for the comment.
ReplyDelete@ Bod : Are you sure this is polycarbonate? I'd like to know what plastic this was.
ReplyDeleteNot 100%, my job involves working with plastics and it looks like it but I'm making a bit of an assumption. I'll see if I can find my Crankbrothers ones and check what they're made of although I may have thrown them out.
ReplyDeleteRon, I think your scale is wrong in the pictures. Should it be labeled in cm, not mm? but regardless 0.5mm is not a big difference. I would think if the platforms are snapping form that small deflection but need to use a more elastic plastic
ReplyDeleteYes cm. Boy I must be getting tired.
ReplyDeletegreat post, found this is very interesting to read and this is really awesome.
ReplyDeletethanks
chevy 350 engine
I've never understood the appeal of these pedals in the first place. The shoe mounted "cleats" jam up with dirt or sand and the originals were super slippery so folks fell down all the time trying to walk in them. I'm amazed this outfit's still in business.
ReplyDeleteFifteen minutes ago, I was out running errands on my bike equipped with the older style clear-blue platformers. My right platformer cracked quite severely but I did not experience a full failure of the unit. However, my confidence in them is now nil. Oddly enough, my right platformer cracked but I bias my left pedal when clipping in and out so I don't necessarily believe that worn pedals contribute that much to the issue. As well, the platformer cracked on both sides from the outside, in. The crack starts on the outside edge and extends roughly through the center of the platformer to about a half inch from the inside edge. I suspect if the crack had reached all the way to the inside edge that I would have experienced a failure. I am currently writing Speedplay to request a new, updated pair. Hopefully they will exercise good faith and recognize that this product was not only faulty, but posed a serious risk of injury. I am a third year law student and products liability, or marketing of an inherently dangerous product is a strict liability tort. If Speedplay knew of this problem, they should have recalled the product.
ReplyDeleteI own a small machine shop (hey, I also own a Pinarellao FP7 with full SRAM Red and Speedplay Zero S.S. pedals) and own several types of precision measuring instruments. Using the dial caliper as done for these measurements is problematic, as they have inherent imprecision, even to 3 decimal places. The knife edge that contacts the pedal is very sensitive to pressure, i.e, it can dig in a tiny amount quite easily, causing off-readings. Far better to use a (digital) micrometer that has an automatic pressure stop built in to it - thus limiting its final pressure on the measurement, and more importantly, providing EXACT reproducibility at all measurements. I for one do not the measurements, and as they say, this is one thing I would only trust to myself. Oh, and a small amount of wear would not likely cause any abnormalities in pedal play at least. But that is another story. But isn't this all moot anyway, as the material was changed by SP, thus correcting the problem? I do feel sorry for the rider...
ReplyDelete