"the most incredible gift you could imagine."

This is a blog posting from a customer who really enjoyed his Fit Werx experience…  Thank you Marc!

B12 Bike Fit and Wind Tunnel Testing

For winning the MN Rider of the Year award for Cat 3’s my wife gave me the most incredible gift you could imagine. It started with a new time trial bike of my choice, but that was not all. It included a trip to Boston to get a professional fitting at Fitwerx in Peabody, MA and, yes I just said and… a session at a Wind Tunnel through Speed Merchant Aero in Plaistow, NH.

We went out for my birthday weekend and I spent all day between Fitwerx and Speed Merchant Aero getting fit and fast on the new TT bike.

This all started in September when I went to my local shop, Gear West to talk to Kevin about a new TT bike. I looked at Trek, Felt, and Cervelo. I also considered Fuji, Scott, and Giant. After spending a lot of time online, talking with my friends, and Kevin at Gear West, I decided on the Felt B12 with Zipp 1080/808 wheels. The B12 has the same frame as last year’s DA, minus the bayonet fork. It’s set-up with SRAM Red and Felt’s aero cock-pit. It’s a reasonably priced ride that let me invest in a great set of wheels to go along with it.

I shipped the B12 out to FitWerx and upon arrival at the shop, I met Dean the owner and local pro triathlete. Dean is a mechanical engineer who rowed at the Naval Academy and has been a strong athlete his whole life. Holding several course records in and around Mass. We started out with Dean and I just talking. We discussed how my TT’s went this year, how my road bike is set-up, what my goal races were and what I wanted to get out of the fitting. He took measurements of my body, tested my flexibility and took a look at my gait to get a sense of my body type.

He then went about measuring my the current set-up on my B12. FitWerx uses the Dartfish fitting system, but also uses the Retul as well. With Dartfish, they set up a fit bike, which allows the fitter to fine tune the bike fit and easily take all the measurements that are then transferred to your personal bike. The fit bike looks like a funny trainer, something you would see in an old gym or something. What is cool about the bike is you can quickly change crank lengths, tube lengths, seat post height, etc.

After Dean got the fit bike set-up like my B12, I hopped on the fit bike and we took some video me riding. The video immediately went into the Dartfish system, where Dean could draw and set lines on my legs, hips, back shoulders, elbow, and forearms. He could fix those lines on my body and they would tell him the angles of my joints on the bike. It was pretty apparent just from looking at the first video how upright I was on the bike. You could see that I looked like a wall try to speed through the wind. I was blocking more of the wind than cutting through it.

We started to get me lower on the bike. We tweaked the seat position, stretched me out more on the TT bars, and changed the seat height as well. I would spin for 5 minutes at a time as we changed the position and would give feedback to Dean. He would then take more video and put the measurements on my body to get the angles. Based off of industry data and Dean’s experience he knew when the angles on my body were getting to aggressive. I could quickly tell as well as the position was hard to keep or I would feel tightness in my hip flexors.

As we got the position dialed in we realized that I would have a more effecient pedal stroke if we went with a 170 crank vs. a 172.5 crank, which what I had on the bike. We took another video of the new position and you could see immediately how much lower I was. The top of my head was now in line with the top of my back. You could see how the wind could flow over and around the body vs. my body sticking up like a brick wall. The position felt good and Dean and were pretty satisfied. We then started to talk about what I could get done in the Wind Tunnel.

We talked about what the experience would be like. Dean felt pretty good that he got me into a really good position on the bike. He said that I might be able to get a bit lower and will be able to determine a few different positions on the current fit that will allow me get the most aero. We also talked about helmets and that each helmet fits differently on each person and that I should test several of them in the tunnel to determine which gives me the least amount of drag.

From there I was off to Speed Merchant Aero to meet Armand, the owner of the tunnel. Armand is an electrical engineer by trade and has built this wind tunnel in New Hampshire. He is a passionate cyclist and has been playing with aero positions for years. The wind tunnel lets him validate his experience and help other riders get more slippery in the wind. I was not sure what to expect when I got to Armand’s place. The wind tunnel he build is met for cyclists. Unlike many of the research tunnels at universities are built for broader research than just bikes. The tunnel itself is on the second floor of a warehouse space in a very unassuming building. There are two large industrial fans on either side of the tunnel that pulls air in from the front and across the rider vs. blowing it directly at the rider. The tunnel is made out of wood and drywall, just as your house is. The shape of the tunnel forces the wind directly down to the rider. The tunnel is a narrow space that really just fits the rider. The bike is placed on a platform that enables part of the measurements that are taken to calculate aero drag and coefficeint. Armand has build proprietary software that allows him to capture in real time your drag coefficeint, speed, power and cadence. He projects this software on the floor of the tunnel just in front of the rider so you can see the numbers you are outputting in real time. This allows you to see the impact of your position or slight body movements immediately. Our goal was to get my drag coefficeint between .26 and .23, which would be pretty damn good.

Immediately, Armand stated how good a job Dean did by getting me into a relatively aero position down at FitWerx. We did minor adjustments on the bike, mainly we took a few spacers out on the stem, dropping the TT bars down a bit and we brough the bar extensions in, making my arms a bit more narrow. We also testing different positions by having me stretch out over my shifters, keeping my head up, pushing the tip of the helment onto my back, and adjusting my shoulders. All of these adjustments got my position directly between .25 and .234 depending on how aggressive I was getting. I would then try pedaling in the position to see how it felt. It will take some time on the trainer this winter to adjust to the new positions, but I feel really good about the work we did.

Once we got the position dialed in we tested several aero helmets. These included the Giro, Catlike, Spuik, and Lazer helments. They all felt good, but the most comfortable and the helmet that did not impact my drag coefficeint was the Giro. The great news about that, is that it was also the least amount of money.

After about 2 1/2 hours in the wind tunnel, I was all done and set to go. The time with Armand was a dream come true. You really felt like a pro as you tested out your position and took a look at different equipement. Armand and Dean believe that I will shave minutes off of my TT times assuming the same fitness and similar conditions. As I have upgraded to a Cat 2 racer, hopefully this will let me be in the mix on the TT’s instead of dead last. The final touches on the fit will be to get a snug fitting aero skin suit, shoe covers and to pick up that Giro aero helmet.

Working with Armand at Speed Merchant Aero was definitely worth it. If you ever want to really dial in your position and verify it with some science, check Armand out. His prices are a fraction of what you would spend at a research based wind tunnel like San Diego or MIT.

FitWerx is an awesome bike shop. Dean is an amazing fitter, but Marty his partner is an enthusiastic and personable guy who really made this experience come together. Fitwerx has some unique bikes, they carry Felt and Cervelo, but also the following:

Serotta Cycles – Saratoga, NY
Guru Bicycles – LaValle, QC, Canada
Parlee Cycles – Peabody, MA. Some Manufacturing: Asia
Ellsworth Bicycles – Ramona, CA. Some Manufacturing: Asia
Independent Fabrication – Offices, Design & Manufacturing: Somerville, MA
Gunnar Bicycles – Waterford, WI

The Guru bikes were pretty cool and can be customized to any color you could imagine.

A huge thank you to Dean, Marty, and Armand for making my experience simply amazing and big, huge, awesome thank you to my wife Pam for letting me indulge in my passion.

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