Uploaded August 2026 | Updated September 2026, 2 weeks ago
Buying a new bike is exciting, but figuring out how to replicate your perfectly dialed-in riding position on a brand-new frame can be a nightmare—especially with modern integrated cockpits! You can easily look up a new frame's geometry online, but how do you know exactly what stem length and how many spacers you need to match your old bike?
In this video, we show you how to easily measure your current bike’s Reach and Stack at home using just a wall and a tape measure. Then, we walk you through the math to reverse-engineer your setup so you can buy the exact right components the first time. Stop guessing and start riding!
Don't want to pause the video to write down the math? We have put all the trigonometry and formulas from this video into a handy guide on our blog so you can work through it at your own pace:
👉 mapdec.com/blogs/words/handlebar-reach-and-stack
⏱️ Video Chapters:
00:00 - The New Bike Fit Dilemma
00:15 - How to Measure Your Frame Stack
01:27 - How to Measure Your Frame Reach
02:39 - The Math: Reverse Engineering Your Stem & Spacers
04:42 - Calculating Handlebar Stack & Spacer Setback
05:27 - Testing the Math (Wilier Accu-Fit Example)
05:39 - How to Measure Your Handlebar X/Y Coordinates
06:15 - Get the Equations & Mapdec Custom Builds
🚲 Looking for a custom build or professional bike fit?
If doing the math isn't your thing, we can do all this heavy lifting for you! If you are commissioning a bike with us at Mapdec, we ensure your new ride fits like a glove from day one.
Get in touch with us:
Email: team@mapdec.com
WhatsApp: wa.me/mapdec
Website: mapdec.com
Buying a new bike is exciting, but figuring out how to replicate your perfectly dialed-in riding position on a brand-new frame can be a nightmare—especially with modern integrated cockpits! You can easily look up a new frame's geometry online, but how do you know exactly what stem length and how many spacers you need to match your old bike?
In this video, we show you how to easily measure your current bike’s Reach and Stack at home using just a wall and a tape measure. Then, we walk you through the math to reverse-engineer your setup so you can buy the exact right components the first time. Stop guessing and start riding!
Don't want to pause the video to write down the math? We have put all the trigonometry and formulas from this video into a handy guide on our blog so you can work through it at your own pace:
👉 mapdec.com/blogs/words/handlebar-reach-and-stack
⏱️ Video Chapters:
00:00 - The New Bike Fit Dilemma
00:15 - How to Measure Your Frame Stack
01:27 - How to Measure Your Frame Reach
02:39 - The Math: Reverse Engineering Your Stem & Spacers
04:42 - Calculating Handlebar Stack & Spacer Setback
05:27 - Testing the Math (Wilier Accu-Fit Example)
05:39 - How to Measure Your Handlebar X/Y Coordinates
06:15 - Get the Equations & Mapdec Custom Builds
🚲 Looking for a custom build or professional bike fit?
If doing the math isn't your thing, we can do all this heavy lifting for you! If you are commissioning a bike with us at Mapdec, we ensure your new ride fits like a glove from day one.
Get in touch with us:
Email: team@mapdec.com
WhatsApp: wa.me/mapdec
Website: mapdec.com
