For those that have more than one bike, say two roadbikes or mountain bikes (n+1 remember!), have you ever noticed how one “feels” different? I’m not referring to the ride quality but how one bike might seem “smaller or bigger”. Maybe one bike feels better on long or hard rides compared to the other. It is likely because your position is different on one bike compared to the other.
Here’s are a few tips to make sure you replicate the set-up more accurately from one bike to another.
Measure from a fixed reference point and adjust for the difference in bike geometry.
Bike brands will have slightly different frame geometries, notably on the seat tube and head tube. The angles and lengths of each of these may vary so it is important to take them into account and then to adjust for it when replicating the set-up onto another bike. The other important thing to remember is to always measure from a fixed point.
“. . . even if you set up two bikes to the exact same saddle height . . . those two bikes will have different saddle positions if you did not account for the seat tube angle and saddle setback.”
Bike Fitters and some shops may have special tools or even jigs to help them capture an existing set-up and then replicate on another build. At 2Wheel Nation Cycling for example, we use a device called VeloAngle, which measures both the distance and the angle between two points measured relative to the bottom bracket. We do this to record the saddle position and the handlebar position relative to the BB. It is as precise and accurate as you can measure because the BB is a fixed point on any bike.
So, if we were to record the saddle height for example, we would measure not only the distance from the center of the BB to the top of the saddle, but also equally important is the angle of that line measured (i.e. saddle’s position angle) and where we measured it on the top of the saddle. Where we measure on the top of the saddle can vary, so it is also good to take note of the exact point on the saddle where you take the measurement (this assumes you will have the exact same saddle on both bikes). We refer to that point of measurement on the top of the saddle as Saddle Depth.
An alternative to measuring the saddle’s position angle is to measure the saddle setback or the distance between the tip of the nose of the saddle and the center of the BB. Saddle setback refers to how far forward or behind the BB the saddle is positioned. To do this, you would need a plumb line (or a Bosch Lazer) and a measuring tape. Place the plum line so that it drops from the tip of the saddle to below the BB. Then measure the distance between the string to the center of the BB.
This method accounts for the differences in the seat tube angle and the saddle setback. To be clear, even if you set up two bikes to the exact same saddle height and were consistent on where you measured on the top of the saddle, those two bikes will have different saddle positions if you did not account for the seat tube angle and saddle setback.
When you have the saddle position set up accurately, then you can move on to the handlebar position. Different bikes will likely have different head tube angles and head tube lengths, so even if you put the exact number of spacers and get the same stem and handlebar from your original bike, the position may still not be accurate.
Once again, we have bike fit specific tools here at 2Wheel Nation Cycling to accurately measure and replicate the handlebar position by measuring the distance and angle of the center of the BB to the center of the handlebar
The key things to measure here for those who prefer to DIY is the saddle to handlebar drop and the distance from saddle tip to the top center of the handlebar. Quite often, riders or mechanics will simply try to replicate the latter without accurately measuring the drop. Even worse is that they did not have the saddle position set up accurately in the first place which means everything is off from the beginning.
To measure the saddle to handlebar drop, you’ll need a long level ruler placed on the top of the saddle. From there, you will be able to measure the gap between the ruler to the top center of the handlebar which gives you the saddle to handlebar drop. Make sure your level ruler is level when you take the measurement.
The common way to adjust for any difference in handlebar position is to use spacers under the stem or through the stem itself. Different stems may vary with regards to length and stem angles to help a rider achieve their desired position.
Double check the geometry on your prospective bike.
Ideally, before you pull the trigger and spend your hard-earned money on that new bike, you would have compared the geometry and fit-sizing of your current bike with the prospective bike. This is to make sure that you can get as close as possible to your current set-up and that the new bike will fit properly. This also informs you where the differences will be between your current bike and the prospective new machine. Is the seat tube more slack (i.e. it has a lesser angle)? This means you will have to adjust your saddle setback more forward. Is the headtube more slack? This means the reach to the handlebar will be slightly closer assuming you can achieve the same stack height, ergo, you may have to use a longer stem. Is the head tube on the new bike taller or smaller? Then you may have to adjust the number of spacers underneath your stem.
Use similar or the exact same components.
Different components may have different shapes and geometry which could have a significant effect on your bike position. We will look at some reasons why the saddle, handlebar, crank arm (length), pedals and even shoes matter with regards to bike set-up. Yes. I left out the stem. More on that below.
Let’s first look at the saddle. Allow me to go a little deeper into this since this is arguably the most sensitive contact point on the bike.
“It is more likely that a saddle is not comfortable for a given rider because . . . their position is not yet optimal. . .”
Saddles are engineered for specific rider interaction and body position, which is why saddles have a multitude of shapes and sizes. It is more likely that a saddle is not comfortable for a given rider because they do not interact with the saddle in the way that it was designed for, or more often is that their position is not yet optimal (e.g. saddle is too high, too low, too far forward or back). So, saddle choice should also be determined by your optimal body position and not by comfort alone. Whether you sit more upright, at 45degrees, low and aggressive or either forward or towards the rear of the saddle, should be considered when finding the right saddle.
You can take two exact same bikes with the exact same frame, handlebar, stem, pedals and groupset but have different saddles and chances are that each bike will have a very different optimal set up for a given rider. One of the saddle positions will be either higher or lower, more forward or back depending on its shape.
The next contact point is the handlebar. Like saddles, handlebars have different shapes and geometries as well. Besides width, which is often our determining factor for choosing a handlebar, the shape can also vary quite a bit. Some handlebars will have a more compact drop, meaning the transition from the top bend to the hoods is closer (i.e. shorter reach). Some will have a shallow drop, which means the distance between the top of the handlebar to the lower handles is smaller, which allows the rider a less aggressive or higher position in the drops. Some handlebars may also have proprietary shapes that sweep back towards the rider for instance rather than having a straight transition from the stem to the bend.
Make sure you have the same crankarm length between your old bike and new bike. If you decide to run a shorter crank, say a 165mm vs a 170mm crank, on your other bike, then the saddle position should be slightly higher ~5mm and slightly forward by ~2mm and you may also have to adjust your handlebar position to compensate for the changes in saddle to handlebar drop and reach.
I’ve known some riders to have different pedal systems on each of their road bikes. Pedals such as Look and Speedplay, for example, will have different stack heights, i.e. the gap between your foot to the pedal spindle when you are clipped in. Make sure to account for this difference when setting up either bike. If you are one of these people, remember to adjust the saddle height appropriately to the pedal system if ever you swap them between bikes on occasion. My advice, better to stick to one pedal system when you have multiple bikes.
The shoe is also an essential element. I know this is not part of the bike set up but it is worth noting that some shoes will have different stack heights as well given their soles, insoles and foot-bed construction. Make sure your shoes fit properly and you have the center of the cleat positioned just behind the ball of the big toe on all your shoes. When you check your set-up on the other bike, use your favorite and most often used shoe to check.
Why did I leave out the stem? Well, as I mentioned in the first section above, given the likely differences in frame geometries, the stem and the spacers are where the adjustments are likely made to compensate for differences in handlebar position, i.e. handlebar stack and reach between your two bikes. You may require a different stem and might have to add or take out a few spacers to match your old position.
Get a professional Bike Fit
Before you replicate your set-up on another bike or even before you buy a new bike, it may be a good idea to initially have your bike fit checked by a certified bike-fitter. After all, you would want to replicate the optimal set-up and know the exact specifications for the components you need rather than buying everything ahead only to find out you need to replace one or several of the items. Trial and error can be expensive in cycling. Furthermore, if you have any discomfort or injuries that are being caused or aggravated by your current bike set-up, it is worth addressing those beforehand.
- Measure from a fixed reference point and adjust for differences in geometry
- Double check the geometry on your prospective bike, ideally before you buy it
- Use the same or similar specification on components, except for maybe the stem
- Get a professional bike fit to verify your optimal set up
As always, we are here to help.
Keep safe and strong. Ride well!