Nov 24, 2010

How's your bike fit?

"Get a proper bike fit" - it's just one of the things I tell any cyclist who's putting in a lot of hours on the bike, or any cyclist who is a competitive racer. A proper fit can help reduce the potential of injury and it can also increase your abilities on the bike.

Taking my own advice, on Monday I headed for downtown Calgary to hook up with Adam at Speed Matrix for a Retul fit on my 2010 S-Works Stumpjumper FSR. Speed Matrix has an area setup in the Speed Theory retail location just across from Mountain Equipment Coop.


For those of you who aren't familiar with the Retul fit system it's a three-dimensional computer analysis done as you are riding the bike you are being fit on. The resulting data is recorded and stored and can produce various end-user printouts. I'm a fan of cycling science and saw eye to eye with Adam on a number of subjects prior to and during the fit. I've experienced several fit systems over the years but I can confidently say this is the first fit system that provided the amount of recorded data that Retul does, no offense to any other fitters I've worked with in the past (and I've experienced a few fits), Retul captures more data than I've seen before.

Upon arriving, Adam and his assistant Rory had me take off my shoes and socks then they got on with some range of motion tests to determine my cycling specific flexibility. Adam also watched my walking gait, checked my arches and looked at such things as my forefoot angle for signs of forefoot varus. I fall into the high percentage of cyclists who have a need for shimming but luckily my S-Works mtb shoes have a built in varus wedge that works extremely well in my case.

With the bike mounted on the Retul platform it was time to climb onboard.


If I remember correctly, the 3D measurements are accomplished by placing eight measurement points on each side of the body via a harness held in place by sticky velcro pads. The Retul device sits off to the side of the rider at approx 90 degrees and measures the harness points as you ride. The active LED lights on the harness points show things like knee angle, hip angle, ankle movement in space, how the knee is tracking, etc.



Putting things in place only took a couple of minutes, here is an example of a single side Retul measurement being taken, video courtesy of my iPhone. All I had to do during the Retul measurement was adopt my usual riding position and pedal at a medium intensity. I chose a low RPM pedal stroke so I could see what goes on at that cadence.

When one side is done the Retul platform is rotated 180 degrees and the other side is measured. After the first run the numbers are reviewed based on what the Retul 'sees' and any possible modifications to the bike setup are discussed.

In my case, the Retul indicated my bike setup was pretty much perfect but I could benefit from sliding the saddle forward approx 1-2 millimeters, which I had been thinking about doing anyway. The saddle had been feeling 'a bit off' ever since the 24hr Solo World Championships in Australia when my seatpost failed at the 21hr mark. Getting back to Canada and messing around with the new seatpost required a bunch of tweak time to get it perfect, something I didn't do as I knew I was in the ballpark and just wanted to ride while the weather allowed for it.

Once the minor saddle adjustment had been made I knew it was a good call as soon as I got on the bike. I mentally kicked myself for not making the saddle tweak prior to the Retul fit - but my seat tweak laziness helped demonstrate the value of a proper fit.

Adam took a second round of Retul data as I pedaled on the Retul platform, I jumped off the bike once both sides were done and he ran the numbers to see how the saddle had changed things. It was obvious in the number details that the minor saddle change was a good decision. Here's what the data looked like from one side.



Once Adam and I were happy with the saddle change it was time to record the final setup. Adam shot a Zin of the bike for the documented final setup, the results look like this.


What does the Zin process look like?

At the end of the fit I was happy to know that I had been solid before I showed up at Speed Matrix, Adam said it's quite uncommon for someone to show up with such a dialed in setup. Knowing my fit was/is optimized for my body and the particular style of racing that I like is comforting. It took a few years to dial this fit in but I'm glad I took the time to experience a variety of fits and learn a few things along the way. I'm a fan of the Retul system, that's for sure.

Spend the money, get a good bike fit. It's a much smarter purchase than that carbon widget you want to put on your bike so you can shave another 10 grams off it. Look Adam up if you are in Calgary, his background in Biomechanics and his exposure to elite athletes will steer you in the right direction.

Thanks for the fit, Adam!

***Aesthetic alert*** - the red brake hose you see on the bike is only temporary as I'm in the process of replacing it with black. I'll talk more about the KCNC X-7 brakes in a future post.


Andrew said...

Surprised to see you using such narrow bars. Seems to be a lot of push towards wider bars these days.

Shaun Taylor said...

Good eye Andrew, the bar is actually 620mm wide from Ergon bar end to bar end but the inside portion of the bar is 590mm.

I like the narrower bars for tearing through tight singletrack and with my narrow shoulders I find a narrower bar to be nice alignment for the longer rides.

If the single speed 29'er becomes reality I'll be looking for something around 660mm I think.

Andrew said...

Ahh, I see. I use a 600mm bar without bar ends. It's something I'd like to experiment with though, maybe up to the 660-680mm range.