Documenting Your Bike & Equipment

Aero Bike Fit Form GraphicEarly on when I started coaching cyclists I started making it mandatory that all my clients document their bikes and equipment. I did this partly as an exercise and so I knew specifically what they were riding. But also because I am a firm believer that the more you know, the better decisions you can make. And the better decisions you can make the quicker you will reach your goals. As competitive athletes, we should never stop looking for ways to better our performance and always be experimenting with different products and such to see how they affect how we perform. You never know, you might just happen across that one great change to your equipment that you didn’t even know you were looking for. As a side note I get teased a lot for the number of shoes I have and that I am always trying new pedal systems and saddles. What can I say, I’m addicted to trying new things!

 

Below is how to document the set-up or fit of your bike. Then I list a few other things beyond fit and set-up that you should know about your equipment.

 

First thing you’ll want to do is download one of my fit forms below. We’ll use an aero bike form for this example. And I have also provided links for road bike and mountain bike forms. These are the same forms I use in my fit studio. I’ve tweaked these forms over the years to make it as simple and straight forward as I could for myself. Pages 1 & 2 on all the forms is what I complete when I am doing a fit with a client. You can ignore page 1, but page 2 is where you will record all your measurements. Page three is a grid you can use to keep track of changes you make over time so you can go back if need be. Pages 4 & 5 are the step-by-step for documenting your bike and explain all the measurements that you will take. The following are those instruction that I versioned so that would read better here. All the measurements described below correspond to measurements listed on the fit sheet for aero bikes. Find the letter label to know where to enter your measurements.

 

 

Aero Bike Fit Form
Road bike Fit Form
Mountain Bike Fit Form

 

 

Setting Up

  1. Set up you bike in a stationary trainer make sure the bike is level. Use a long level (4-feet) and run it along one side of the bike from the center of the front hub to the center of the rear hub. Prop the front wheel as needed to get the bike level. This is an important step.
  2. Mark the 80mm width point of you saddle. See below for further instructions.
  3. Take all measurements in millimeters (mm) using a tape measure.
  4. On most bikes I find working on the non-drive side to be easiest.

 

Marking the saddle profile 80mm wide point.

This is my go-to landmark to use for any measurement that is taken relative to the saddle. The nice thing about it is it can be used regardless of saddle brand or model. Why 80mm?: Eighty millimeters is statically the average width between the Superior Rami of the left and right pubic bones when the pelvis is rotated forward in the aero position on an aero bike or an aggressive position on a road bike. It isn’t an absolute, but I have found it to be a consistently reliable landmark. You can easily make a gauge like the one I made for myself pictured here. Use a piece of cardboard and out a notch that is 80mm wide. Then just place the notch over the saddle and slide it back until your gauge stops and is running laterally across the saddle. Put a piece of tape against the back edge of the gauge. You’ll use the front edge of the tape for all your measurements. Keep in mind the specifics of the landmark you use isn’t important as long as you can repeat it and use it all the time for measuring and set-up.
How to find and mark the 80mm wide point on your saddle.
Saddle Height – Measurement A

Start by putting the crank arm on the side of the bike you are facing down at drop dead center – six o’clock position. Measure from the center of the pedal spindle, up to the top of the saddle at the point the saddle is 80mm wide where you marked it with the tape. Use the actual center of the hole where the pedal threads into the crank. You don’t need to take the pedal off to measure to the point. Just run your tape measure along side the pedal spindle. That’ll be close enough.

 

Saddle Set-Back relative to tip of saddle – Measurement B1

Take your 4-foot level or a plumb bob and run it off the tip of the saddle to the floor. Measure the distance from the center of the bottom bracket spindle to the level or string. This is the saddle set-back relative to the tip of the saddle. As long as the saddle you are using is staying the same, this is a very reliable way to measure saddle set-back. I like to capture this measurement to have for if you travel and need to set your bike up out of the case or are renting a bike. It’s easier to repeat in a hotel room and such. And as long as your saddle is not changing, it will work just fine.

 

Saddle Set-Back relative to 80mm point – Measurement B2

Take your 4-foot level or a plumb bob and run it from the top of the saddle at the 80mm width point of the saddle profile to the floor. Measure the distance from the center of the bottom bracket to the level or string. This way of measuring the saddle set-back is a MUST and comes in handy when you are switching saddles – different brand, model and or shape. It isn’t an absolute, and there are exceptions to saddles this will work well with, but most of time is a more reliable way to get you in the ball park than using the tip of the saddle when equipment is changing.

 

Saddle Angle – Measurement B3

Take a straight & flat “something”, like a clipboard (that’s what I use) or a one-foot level or digital level (lots of apps for smart phones out there). Put the straight something on top of your saddle from tip to tail. Now use your level to see what the angle of your seat is, either nose-up (+) or nose-down (-). Keep in mind that when you are changing equipment this measurement will not translate from saddle to saddle. You’ll always want to start with the manufacturer’s suggested starting set-up. For example, Specialized saddles are designed to have the middle 3rd of the saddle level and if you take the angle tip to tail many of their saddles will present as nose down by about a degree.

 

Once all your saddle measurements are recorded, we’ll move on to the “reach” measurements.

 

Reach – Measurements C1 & C2

On aero bikes we are concerned with two points with regard to reach – the back edge of the aerobar pad and end of the aerobar extension.

 

Distance to back edge of the aerobar pad – Measurement C1

Measure from 80mm width point of Saddle to the center (side-to-side) of the rear edge of the aerobar pad. This is the back edge of the of the aerobar pad in the center side to side. Since pad shapes can be different, I like to use the back edge of the pad as my reference, so that when I transfer set-ups or replicate a set-up on a different bike, I’m more likely to get things closer.

 

Distance to end of the aerobar extension – Measurement C2

Measure from 80mm width point of Saddle to the end of the aerobar extension where the bar-end shifter inserts into the tube.

 

Drop – Measurements D1 & D2

Now we’ll record the vertical relationship of the cockpit contact points in relation to a level line take off the saddle. This is called “drop”. We’re going to use the same two landmarks on the front end that we used when recording reach above.

 

Distance below or above a level line from top of saddle to aerobar pad rear edge – Measurement D1

Run your 4-foot level from the top of the saddle tip out over the aerobar pads. Measure the distance from the level line to the top of the pad at the pad-rear edge center. If you do not have a level long enough you can alternatively measure the distance from the top of the saddle tip to the floor. Next measure the distance from the aerobar pad at the pad-center to the floor. The difference between these two measurements is your drop or rise.

 

Distance below or above a level line from top of saddle to the aerobar extension – Measurement D2

Run your 4-foot level from the top of the saddle tip out over the aerobar extensions. Measure the distance from the level line to the top of the extension tube where the bar-end shifter inserts. You can use the alternative method mentioned above if you do not have a level long enough.

On aero bikes there are two more measurements that you should record that we don’t do for road or mountain bikes. They are aerobar extension width and aerobar pad width.

 

Aerobar Extension Width – Measurement E

Measure from the center-line of one aerobar extension to the center-line of the other aerobar extension where you grip the bar when in the aero position. This is the center-line of the tubing of the aerobar extension at the furthest point from the saddle.

 

Aerobar Pad Width – Measurement F

Measure from the pad-center on the back edge of the pad of one aerobar pad to the pad-center of the other aerobar pad.

 

So there you have it – a fully documented bike. But let’s not stop there! On page 2 of the fit sheet you’ll see an Equipment section on the right side of the page below where you recorded you measurements. Record all your equipment information as well. And lastly, you’ll want to record the chainring and cassette configurations you are running on your bike and on the wheels you use with it. The number of teeth on a chainring is very often etched right into ring itself. And the tooth configurations of rear cassettes can be a little trickier to figure out. Short of counting each tooth on each cog, you can also just count the number of teeth on the smallest and largest cogs. Email me those numbers and the manufacturer and I’ll email you have the gear configuration you have.

 

Have fun learning about your stuff and never stop trying new things! If you have any questions, let me know.

 

Coach Dave

dave@pbmcoaching.com

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