Bike

Bike
637 Days To Go is my blog, which was originally started with exactly 637 days until the start of the London 2012 Paralympic Games. And now it's been re-started with 637 days until the Rio 2016 Paralympic Games.



Wednesday, 25 April 2012

Pace comes through again

Last year I wrote extensively about the creation of my cycling-specific prosthetic leg, courtesy of the folks at Pace Rehabilitation near Manchester (see article here: Winning is All About Your Pace). The leg catapulted me from a top-10 rider to a World Champion in less than a year. OK, there might have been a bit more to my rise to the top than just the leg, but without a doubt, it was one of the greatest factors. 

But not one to be content, I went back to Pace after the World Championships in Denmark and challenged them to do even better. If I was going to have to step up my game in the next year, I wanted to make sure my equipment was up to the challenge as well. And, as my next challenge was to be the Track Cycling World Championships, I wanted a leg that could help squeeze every last millisecond of time out of me. On the track, races are won or lost in tenths of a second so it's crucial to make sure you don't give any extra time away if you don't have to.

The project (dubbed 'Mark II') was born out of an encounter that Howard Wooley and I had while presenting at a prosthetics conference in Scotland. Howard is the prothetist at Pace that I have worked with this past year in creating my first cycling leg. At the conference, we met another presenter, Bryce Dyer and immediately the wheels started turning. Bryce is a Senior Lecturer in Product Design at the School of Design, Engineering and Computing at Bournemouth University. His primary interest is with the development and use of technology within elite level sport. As an avid cyclist himself, he had a keen understanding of the forces and aerodynamic issues surrounding the design of a cycling prosthetic.

Bryce was (correctly) convinced that while the first leg Pace created was superb, we could still take the design much further and maximise power transfer, aerodynamic efficiency and reduce the weight. He agreed to consult on the project and lend his expertise in the design process. I had a rough idea of how the leg should look (and have to admit that much of what I wanted came from an examination of Jody Cundy's leg), but it was going to be up to Bryce and Howard to bring it to life.

The project took a while to get underway, and with the Track World Championships taking place in early February, we were under the gun to get the design completed and manufactured in time. I would need it a few weeks before the event (as I was travelling to L.A. to prepare and needed some time to try it out and get used to it before competition.) Howard and Pace were going to have to work quickly.

Fortunately, Pace were able to use the socket moulds from the first leg to begin work. This saved a fair bit of time straight away (especially since this part of the leg would stay the same). The time-consuming work would mainly come from developing the lower half of the leg. I had drawn up on paper how I thought this portion should look and Howard and Pace faithfully produced the first prototype based on my drawing – but it was completely wrong. Not that they did anything wrong – but my concept was completely wrong. Sometimes you have to see something in person before you realise it won't work.

Over the next few weeks we began to fine-tune the design and hone in on what would become the final product. After a fair bit of revision, we managed to get the shape right; in particular the cleat placement and transition shape from the top half of the leg to the bottom. This was a sticking point for me as I needed something fairly specific in order for it to feel right when actually riding it. I kept sending it back to the workshop until I finally got something that felt right, and to their credit, the folks at Pace didn't lose patience with me. Howard even came with me to the velodrome to test out the final prototype and make adjustments to it track-side so that we could keep the process moving along as quickly as possible.

The next step was to work on the aerodynamic profile, and this is where Bryce's expertise came into play. If you are at all familiar with cycling and the UCI (the governing body for cycling), you may be familiar with the 3:1 rule. Essentially it states that no part of your bike frame can be more than 3 times deep as it is wide. It doesn't apply to things like wheels but comes into play for most everything else. If you imagine the wing of an airplane and the teardrop shape, especially how wide that teardrop is, you might begin to understand why something flat and wide can be beneficial from an aerodynamic point of view. The 3:1 rule limits the benefit you can get from aero tubing on your bike or bars.

And whilst there is no specific rule on the books saying that this also applies to prosthetics, I didn't want to be the guy that caused the UCI to bring in a rule. So we decided to keep our leg within the confines of the 3:1 rule. However, Bryce was able to come up with a way to keep the leg 3:1 legal, whilst making it as wide and as aero as possible. I'm not going to give away the solution, but it's a solution being used by some bike manufacturers already in developing their frames.

The final piece of the puzzle was the weight issue. In the first leg we made, the inside of it (under the carbon fibre) was a foam shell. The hard foam shell is light, but still adds weight. For Mark II we were looking to eliminate any extra weight that we could, so Pace came up with a way to make it completely hollow. The outer carbon fibre shell was still as strong as the first leg, and despite it containing more material (due to the increased bladed shape), Mark II came in significantly lighter. Pace worked tirelessly to finish the project in time and with just days to spare before I had to leave for L.A., I collected the final leg and headed off to the track in Manchester for it's maiden voyage.

I don't know if it was the excitement of trying something new, or that I was nearing peak fitness before the World's, but the first runs I made with the new leg were extremely promising. By my calculations, I was nearly a half a second faster PER LAP than I was with the previous leg. Some riders train their who lives to gain that sort of an advantage. I got it in one foul swoop. I would still need to spend some time with the leg to get fully comfortable with it, but I could tell straight way that it was going to be a winner. 

And the rest, as they say, is history. In L.A. I won the individual pursuit by 6 seconds in the final. Over 12 laps – that equates to half a second a lap. Coincidence? Perhaps. But as I said at the start: I didn't want to leave anything to chance.

Since the Track World's ended I have gone back to training on the road for road racing and time trialling. I still use Mark I on a daily basis, but have been so pleased with Mark II that am now using it on race days. (And I no longer call it Mark II but have lovingly named it 'Zeus'.) It's not a practical for walking around in so tend to keep it for 'special' occasions. And in preparation for what will hopefully be a gold-medal winning performance, the folks at Pace decided to bling it up a bit. It was recently given the midas touch and painted in gold. The first attempt wasn't quite perfect, so we will be refining the paint job in coming weeks, but you can see that now, more than ever, it stands out from the crowd. A bit like the folks that helped create it.

So, my heartfelt thanks goes out to Howard and the whole team at Pace that worked hard to get it done to my satisfaction and on time, and to Bryce for his input in making it as aero as possible. I'm not sure if there will ever be a Mark III for me, but if, as they say, "third time's a charm", then I feel sorry for my competition if it even comes to be!