Hey y’all,
A few months ago I began vibe coding some calculator tools (www.xybikecalc.com) based on a spreadsheet calculator I previously made to help mathematically understand handlebar positions based on cockpit configurations. The initial target audience was for bike fitters who utilize X/Y measurements (Cartesian coordinate measurements starting from the BB center) with the intention of helping others make pre-purchase decisions, but I’ve provided a little guide on there so that anyone with a little reading and practice can understand/use the tools.
You’ll need to create a simple login (email and pw; currently free) to access my self-maintained database of bike geometries (>1800 and growing). I can’t guarantee 100% accuracy in geometry numbers, but I try to only import geometries directly from manufacturers when possible. If you want to calculate a handlebar position on a bike that isn’t in the database, there’s a manual entry option as long as you know the Reach, Stack, and HTA of the bike.
I just added a visual feature to the main XY Position Calculator so you can see how the frame+cockpit configurations actually compare.
For those familiar with the classic Stem Comparison Tool from yojimg.net, I’ve recreated that tool as well.
Please check it out!
https://www.xybikecalc.com
(below is an example of the main tool)
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I’ve used this and it’s a great tool as a next step past bike insights type tools. Thanks for making this available!
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Good work. This solves the bugbear I had with the yojimg site, which essentially only worked for different stems on the same bike (HTA)
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Just wanted to highlight that I’ve updated the HX/HY to Frame Calculator and renamed it a “Stack and Reach Calculator”, and created a new Seatpost Calculator. Both have dynamic visual aids to help the user understand what the numbers actually mean. Enjoy1
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Excited to share a few major updates to XY Bike Calc that went live last night!
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I’ve added “Headset Height” to differentiate headset bearing covers/transition spacers vs actual spacers. This should make things a bit less confusing. All drawn visualizations add a trapezoid to depict the headset now.
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New “Bike Position Simulator” is basically a very pared down BikeCAD tool that allows you to get an idea of how a bike position will look. It uses the same bike selection and cockpit/saddle position inputs as the XY Position Calculator, but draws a full bike. Drawings for BB drop, chainstay length, seat tube slope, down tube, and fork rake are drawn as fillers for illustrative purposes only, but seatpost/saddle and cockpit configurations will be to scale.
There are both Cartesian and Polar coordinates provided on there for multiple ways of checking/measuring position
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I updated the Bike Search page with the ability to filter by brand(s) and also filter by Stack/Reach Ratio. The biggest update to it is the ability to add bikes from the search page onto the XY Position Calculator.
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