Guide To A Proper Bike Fit
Bike fitting is an art and a science. While there is no replacement for an experienced bike fitter, we have put together a pretty straight forward guide to get you riding as efficiently and comfortably as possible on your current set up.
We have generalized a lot of the info, skipped over some delicate parts, and given suggestions based on the majority of the people we fit on a daily basis. If this doesn’t work for you we highly recommend getting a professional fit.
Make sure you follow this guide step by step and don’t jump ahead.
The Completion Level of Your Training.
Technology and Equipment Needed
Her is a short list of apps that will aid in the process of fitting in order of our preference:
- Bike Fast Fit – $4.99
- Dartfish Express – $6.99
- Hudl – Free but less useful
There are other free options, but they don’t offer the accuracy or measurements that Bike Fast Fit offers.
Other Video Equipment
The only other things you will need is a tripod of some sort for your tablet or smartphone and a way to attach the device to the tripod. These are the items we use for attaching a phone and iPad to a tripod.
Smartphone Tripod Mount on Amazon
Trainer and Block
You will need an indoor trainer and some sort of leveling block. We find that a piece of 2×4 gets a bike pretty level with most “wheel on” trainers. You will need to make sure you level your bike after you get it into the trainer.
Here are our recommended trainers of you don’t own one yet (you need to!):
Here is a normal list of tools you will need for fitting a bike, and our recommendations if you don’t own them:
- Soft measuring tape
- 4, 5, and 6mm hex head wrenches OR
- Torque wrench with 4, 5, and 6mm hex head
- Plumb bob
- Phillips and/or flathead screwdriver
Before and After Measurements
What to Measure
Here are the things you need to measure BEFORE and AFTER you start and finish your fit session. This insures you can reverse any changes you may not have gotten right.
- Seat Height – From the center of the bottom bracket, up the seat tube, over the top of the saddle to it’s center.
- Seat Fore/Aft – From the tip of the nose of the saddle to the center of the fork compression bolt. If you have an integrated front end, pick a static point on the stem that is easy to hit the same mark each time.
- Hood Reach – From the tip of the nose of the saddle to the crux of the hood. Make sure the bars are pointing straight ahead.
- Bar Height – From the center of the front skewer to the top edge of the crossbar.
- Saddle nose height – From the bottom edge of the tip of the saddle to the center of the bottom bracket.
How to Execute a Fit Session
This can be a time consuming process, but you want to make sure you only make small changes at a time. Like 1-2mm at a time. Change, recheck, and so on. One change can affect 3 or more different body angles so there is a delicate balance always at play.
Don’t get set on making all the changes at once. You can make small changes, ride it for a week or two, and then come back and make a couple more until it feels dialed in.
Your fit may change throughout the year as you get more or less fit, flexible, and aggressive in your riding. We generally suggest visiting your fit at the beginning of the winter, and then once mid riding season.
To execute a bike fit session you will first want to get on your bike and do at least a 10 minute warm up. This should include high and low cadence riding.
Check Knee Position
Spin a normal cadence at a moderate effort with your hands on the hoods. Then stop one side at 3 o’clock, with the heel level with the ground, and place the plumb bob on the boney process below your knee cap. The general position for most riders is the line falling through the pedal spindle. Many people will want it slightly in front to help the timing of the hamstring through the bottom of the pedal stroke. Very few people go behind the pedal spindle. If this is off, make a small adjustment and recheck until you get it close to center or just in front.
Take a Video – Dynamic is the Key
Make sure your camera is set up to take a full body shot. If you have Bike Fast Fit, align the bike with the guides to get a great shot.
Note: Make sure you have good lighting! This can make or break your ability to take accurate measurements.
You will film yourself for a minimum of 3o seconds of ride time. Hands will be on the hoods for now. Start at a moderate effort and a sweet spot cadence. Every 10 seconds, go about 2 gears harder and start ramping your effort. The final 10 seconds should be very hard but totally controlled, focusing on driving your heel down on the downstroke and keeping a smooth pedal stroke. Stay relaxed and look forward. Don’t want to hit any cars!
Make Adjustments As Needed
See below for the adjustments guide. Always tackle your cleats first, then the back end of the bike, then the bars.
Repeat Filming and Adjustments
Remember, only small adjustments!
Take Final Measurements
Don’t forget this step! If you get it right, and something slips, you will want to be able to put it back. It’s also useful to have if you travel and ship or rent a bike.
Adjustments Guide – The Major Stuff
Notes – IMPORTANT
Again, make sure you work your fit in this order
- saddle position – height, fore/aft, and tilt will all be worked together
- bar reach and height
- bar tilt and hood position
- Due to seat tube angles, coming down with the saddle also brings you forward, and vice versa. The same goes for lowering or raising the bars.
- Tilting the nose down affectively drops the saddle height based on where you are on the saddle.
- If you are inflexible, don’t even try to make your bar drop aggressive. You will be doing yourself a disservice. Alternatively, work on your flexibility first, and then drop those bars and get aero!
- This is just to remind you why you only make small changes at a time. You’ve been warned.
Keep in mind these are suggestions based on averages. If you have an odd body type, you may need to consult a professional.
Most shoe manufacturers put the cleat mounting system too far forward to really accommodate the majority of people. The more forward the cleat, the more quad and calf engagement you will get. This is great for those who do a lot of sprinting and out of the saddle climbing.
For everyone else, a more rearward cleat position is optimal. We want to elicit a lot of glute engagement and take the pressure off the knee joint. We will generally slam the cleats all the way back to start and then adjust forward if we see a reason to do so. But that is rare.
Other than SpeedPlay brand cleats, there isn’t a lot of width adjustment in most cleats. The width or stance adjustment helps better align the hip, knee, and ankle during the pedal stroke. So for the sake of getting you set up ASAP, we suggest putting the cleats as inward as they will go (pushing the shoe outward), with the exception of kiddos and petite ladies. In that case, you would start with the cleats centered horizontally.
If you are using SpeedPlay pedals with no float adjustment, skip this part. You are free to go ride. If you are using SpeedPlay pedals with the float adjustment, we suggest starting with the heel in side adjusted only to stop you from hitting the crank arm, and the heel out adjustment as open as possible to allow maximal float. You can adjust this later if you feel you like less float.
If you use Time, Shimano, or another flat plastic cleat with little float built in, you will need to adjust the rotation a hair based on your normal standing position. If you stand heels in, you got it, rotate the heels of the shoes in just a little. If you are neutral, keep them neutral, and if you stand heels out, adjust the heels out a hair. This is to help with a more natural hip, knee, ankle alignment.
Saddle Fore/Aft – Knee Over Pedal Position
Again, most people start at what we call KOPS, Knee Over Pedal Spindle. Too far forward and you risk knee pain and excessive quad fatigue. Too far back brings another host of issues and requires a drop in the saddle height.
Ultra Endurance Riders: Might be slightly behind, but rarely.
Triathletes and TT Specialist: Will generally be in front, but NOT past the toes.
Adjusting for Optimal Pedal Stroke Timing:
Sometimes you will need to break the rules to get better timing from your hamstring at the bottom of the pedal stroke. When looking at the bottom of the pedal stroke (more explanation in seat height section) you want your heel to be parallel to the ground and the crank arm to be very close to 6 o’clock. This insures the hamstring doesn’t kick in early and energy is not wasted pulling against the crank arm instead of with it. Generally, if you are getting poor timing, a slight adjustment forward will do the trick.
Saddle Height – Knee Max/Min Angle
Seat Height/Knee Max
The seat height is determined by your maximal leg extension at the bottom of the pedal stroke.
Where to stop the video:
You will go straight to the harder section of your video, the last 10 seconds, and wait for the moment the knee stops dropping. You will likely need to go frame by frame. You should then see the hamstring kick in as the heel moves backward. That moment right before the hamstring fires is the bottom of the pedal stroke. This is where you will take your measurement.
What to look for:
Make sure the heel is close to parallel to the ground. This ensures the glutes are firing well. If you notice your heel is very high still, you likely need to drop your saddle a decent amount.
What to measure:
You will be measuring from the side of the hip (about a hands width down from your hip bone), to the bony process on the side of the knee, to the bony process on your ankle.
Road Bike: 136-150 degrees depending on how hard you are going. Easier would be smaller angles and harder would be the higher end. Shorter people tend to fall on the lower end of this scale, and taller people on the higher end.
TT or Tri Bike: 140-150 degrees. Most end up on the mid to upper side of this scale regardless of height. You have to also consider the chances of the hamstrings tightening up, so going lower on the scale is not bad.
Seat Height/Knee Min
The knee minimum measurement is just to make sure you are not bending the knee too much and asking for knee problems.
Where to stop the video:
What to measure:
The same points as knee max
Really just looking to be greater than 70 degrees. Anything smaller suggests the seat is too low.
Saddle Tilt – Reducing Pressure
The saddle tilt is a delicate balance. The main thing you want to be sure of is that you are comfortable rolling your pelvis forward when in the lower hand (drops) or aerobar positions. If you are experiencing too much pressure in these positions, there is little chance you will do it while riding. Without proper pelvic roll, you will decrease muscle firing and increase lower back tension while in your most aerodynamic and powerful positions.
Our suggestion is to start with the saddle level, and then if pressure exists in the lower chest positions, tilt the saddle down by .5-1mm at a time.
Note on split nose and cut out saddles: Most split nose saddles are best set by leveling the saddle frame rails and not the saddle itself.
Bar Reach – Arm and Shoulder Angles
You can lengthen or shorten your reach by changing the stem length. The goal with reach is to have a fairly straight back (means core is engaged), and have a slight bend in the elbows for a basic road bike setup.
You can use any section of your video to take measurements. If you see a profound round in your back and straight arms, you likely need to shorten your stem. On the other side, if you have a big bend in the arms and/or a rounded back when on the hoods, you may need to lengthen it.
Where to Measure:
Bony process on the side of the shoulder, to the bony process on your elbow, to the bony process on your wrist.
Road Bike: 150-160 degrees
TT or Tri Bike: 85-105 degrees (less important than shoulder angle)
Where to Measure:
From the same point on the hip as the knee angles, to the bony process on the side of the shoulder, to the bony process on the elbow.
Road Bike: ~90 degrees
TT or Tri Bike: 85-105 degrees (want the forearm as vertical as possible)
Bar Height – Hip Angle and Chest Height
The main ways can adjust your bar height is by adding/subtracting spacers under the stem, or changing the stem to a steeper or shallower rise (also affects length). Chest height (torso angle) and hip angle are the major players in aerodynamics and muscle activation. Super low and you are aero but total shut down muscle wise. Too high and you have good activation, but you are a sail in the wind.
You need to get back to the bottom of the pedal stroke before taking measurements
Where to measure:
Bony process on the side of the knee, to the same spot on the hip, to the bony process on the side of the shoulder.
Keep in mind, your flexibility and riding focus come into play here.
Road Bike: ~90 degrees
TT or Tri Bike: 95-105 degrees
This is the real measurement of chest height.
Where to measure:
Horizontal to the ground from the spot on the hip through the bony process on the shoulder.
Comfy Road Bike: 45 degrees or more
Balanced Set Up: 35-40 degrees
Racing Set Up: 25-35 degrees
TT or Tri Set Up: Varies based on focus, but most fall under 20 degrees unless focusing on long course triathlon
What is Your Main Issue?
Let us know your main issue via the Members Only Facebook Page, or shoot us an email. We are here to help!