OK, you just bought a new bike, and the shop doesn’t do fittings or you bought it online and you’re not a bike fitter. You want to ride it now regardless. What steps would you to take to set up a new bike and in what order?
There are two answers to this question. The first is for anyone who already owns a bike that fits reasonably well. The second is for anyone starting from scratch.
So let’s suppose you already own a bike that fits reasonably well. The thing to do is to try to mirror the setup. The measurements to take are saddle height along the seat tube. It’s easiest to run a tape measure from the pedal axle to the top of the saddle. Before setting the saddle height, take a moment to try to replicate the saddle angle and its position of the rails at the seatpost clamp. That will make it easier to measure to the same point on the saddle on your new bike. Once the saddle tilt and position are identical, set the saddle height.
The next step is to set your handlebar position. To do that, you take two measurements. You’ll measure from the nose of the saddle to the center of the handlebar, and then from the ground to the center of the bar. It’s helpful if you’re using the same pedals, saddle and tires. To replicate an existing handlebar position, you may need to replace your stem and possibly swap some spacers above or below the stem. This process is applicable for road bikes, mountain bikes and gravel bikes.
With saddle height and bar position sorted out, you’re ready to ride. There may be additional tweaks to make, like handlebar tilt, but with your butt and your reach figured out, you’re well on your way.
If you don’t have an existing bike to work from—and I’m really hoping you’ve sold your existing bike because you just bought a new one—the procedure is essentially the same, but with considerably more guesswork. After leveling the saddle (a spirit level helps a lot) and centering the rails in the seat clamp, you can set a pretty decent saddle height by first positioning the crank in line with the seat tube, steadying yourself against a wall or in a doorway and then placing your heel at the center of the pedal spindle. Adjust the saddle up or down until your leg is perfectly straight with your heel on the pedal spindle. It’s a rough guide, but not a bad one.
For upper body positioning on road and gravel bikes, the easiest way to adjust the bar height and reach is to put your hands on the hoods and check the angle your elbows make. Most riders will want that angle to be 90 degrees. With mountain bikes, as long as the bar height isn’t too much lower or too much higher than the saddle, that’s good enough to get out the door.
My last note regards bar angle and my advice there, no matter what sort of angle your hands adopt when you reach for the bar; rotate the bar to match the natural fall of your hands.
Once you’re out and riding, you’ll feel what needs to be adjusted. We’re just trying to get most of the setup done quickly, so you’re not making massive changes out in the real world. Even if you have a fitting scheduled for later, getting the bike most of the way to right will save time and make the session more effective in fine tuning your riding position and bike set up.