You finally decide on that new bike. You can’t wait to assemble it and take it for its maiden voyage. There’s one thing in the back of your mind that’s nagging you, and that is matching the measurements from your current machine, where you’ve had no problems, over to the new bike. You want to make sure the fit feels the same and doesn’t give you any biomechanical problems. Well, it’s really not hard to match the measurements and get them extremely close, in fact, it’s pretty simple. I’ll explain how.
Step 1 – Take measurements of original bike
First, there are only four measurements taken from the old bike, which correspond to the picture below:
A. Seat Height – Center of bottom bracket (BB) to seat, going straight up the seat tube. I usually take the measurement to the dip in the saddle.
B. Saddle Setback – Tip of saddle to center of BB. You can do this by dropping a plum line from the tip of the saddle, down past the BB and measure the distance from that line to the center of the BB. Do it a couple times and from both sides of the bike to get an accurate measurement.
C. Top of Saddle to Top of Stem/Bars – From top of saddle to the top of the bars. Can be done two ways:
-Use a 4 ft level on the saddle, so it extends over the bars. Now you can measure down to the bars.
-Take a measurement from the saddle to the ground and also a measurement from the bars to the ground and take the difference.
D. Tip of Saddle to Center of Bars – Measure from the tip of the saddle to the center of bars or where the stem clamps the bars together.
Step 2 – Transfer measurements to other bike
A. Seat Height – First transfer the seat height to the new bike.
B. Saddle Setback – Then, do the saddle setback and then do another quick check on the seat height, as moving the saddle fore and aft can change the first measurement ever so slightly.
C. Seat/Bar Drop – This will determine how many spacers you will need to raise the bar/stem combo and cut the steering tube accordingly.
D. Tip of Saddle to Middle of Bars – The key here is to find the right size stem that corresponds to the new bike’s angles. You may need to change stem length to get this measurement correct. Now do another quick check on the seat/bar drop and adjust accordingly.
Also, some people like to take a measurement from the tip of the saddle to the brake hood or measure the brake hoods to the floor, so the location of the shifters on the bars can be set properly.
So there it is, pretty simple. Keep the measurements on file, so you can transfer to any bike you want. Maybe you are visiting a friend and you don’t want to travel with your bike; you can take these measurements with you and apply them to your friend’s extra bike. You might only need to bring your shoes and pedals!
Bruce Hendler created AthletiCamps to provide cycling specific coaching and training to athletes and cyclists of all levels. Find out more at www.athleticamps.com.