Comparing bike geometry - a new thing we made (2025)

Hello

A friend and I have been working on a website that lets you add geometry tables for any bike you like, then easily compare that geometry side-by-side with another.

It's here: https://geometrygeeks.bike

It started because I got fed up building excel tables to compare different bikes before buying. Too many different layouts, formats, terms for the same dimension... just frustrating.

We started in December 2016 and we've grown to over 1500 bikes. It works wiki-style, so you can add and edit the bikes on there. We've got data direct from some manufacturers (Cannondale, Boardman, Sensa, Ghost... and others) and we and users have added many others. In time we hope it can be the world's biggest database of bike geometry.

I'm posting on here to let you know about it, and also to seek feedback.

What works? What doesn't? What would make it more useful?

Cheers!

Bob

Edit: fixed link (cheers!)

https://geometrygeeks.bike/

fixed your link, Bob.
Love the idea....information is power. i'm going to have a proper look when I'm a bit more awake.

Bike fitting D.I.Y. .....http://wheel-easy.org.uk/wp-content/upl ... -2017a.pdf
Tracks in the Dales etc...http://www.flickr.com/photos/52358536@N06/collections/
Remember, anything you do (or don't do) to your bike can have safety implications

my feedback is the sort you'd expect from the cat in red dwarf "the seats don't squeak!"

personally i think it would be nice if weight was listed also, especially seeing as users can edit the info. wish i could do that on wiggle

also i'd like to add my hybrid but i'm not sure whether it should go in road or MTB (it's a voodoo marasa, i have some stats to c&p and i'll measure the rest tomorrow)

apart from that, i love how straight forward it is. there isn't much to say besides the fact that it works, very well, which is way more important than my notes.

nice work bob! this is going to be very handy!

Good job, though I would advise that bike geometry needs to be compared in relation of many factors, the numbers themselves do not give the whole picture.

I have always sized myself on a bike frame by using my inseam, then checking TT and HT length. I have relatively short legs (82.5cm inseam, for 178cm body height) so I need a TT that is a bit longer and an HT that is not too tall. Shape of the bars can make a huge difference too, some drop bars can add or subtract 2cm of reach.

This is one huge project you've embarked on!

BTW - seat angle, not stem:

https://geometrygeeks.bike/bike/kona-sutra-ltd-2017/

Thanks for the responses, all.

@Chris: good points... I'm sure we can accommodate those suggestions!

@Tim: good idea. Will do.

@Scunnered: That's something many folks have asked for and we agree it would be great. It will need to make a lot of assumptions, eg headset spacer stack height, that have a significant effect on the geometry but are rarely published. That makes it difficult to do WELL, and we'll only take it on when it is good enough to be relied upon. It's on the to-do list!

@Gattonero: Agreed numbers are just numbers. I'd always recommend at least a decent length test ride and better yet, a proper fitting by a pro. But for those of us just dreaming of new bikes, this is hopefully a help

Cheers all, keep it coming!

B

Bonefishblues wrote:This is one huge project you've embarked on!

BTW - seat angle, not stem:

https://geometrygeeks.bike/bike/kona-sutra-ltd-2017/

Thanks, fixed

Did you realise that because it's wiki-style, you could have corrected that error yourself? (I am glad you've told me, and we're very happy to make the corrections ourselves - I'm just trying to understand from a usability point of view, is it obvious to new users that they can contribute and improve the database?)

bobonabike wrote:@Chris: good points... I'm sure we can accommodate those suggestions!

sweet thanks!

i already like it, what used to be a nightmare for me can now be done in one tab.

looking forward to seeing how this grows! especially if you can work in some of the stuff suggested here

Hi
A couple of thoughts, without wishing to over-complicate things:

A stem comparison tool similar to this might be helpful

The pale grey type used for alternative terms in your terminology guide, e.g. "aka: Bottom Bracket Type", might cause problems for some readers with impaired sight

Do you want/need older bike geometries? (I can supply some 2010 info, but I can't imagine that it'll be massively helpful )

Regards
tim-b

@tim-b: Cheers. Good thoughts. Re: 2010 bikes - yeah we'll take anything! Lots of folks 'current' bikes are of similar vintage (mine included) so it is useful.

@mattsccm & others asking about visual tools: There are a smattering of really useful visualisation tools scattered all over the web. The most advanced is probably BikeCAD. We'd love to have that kind of functionality, but to do it well enough to make it accurate whilst also keeping it usable is a challenge! We will get there, but it may take quite a few months.

I can see every day that folks are adding bikes (thanks!), but some are abandoning part way... if that's you, drop us a note to say why. Did something break, or did you come across an awkward geometry table like the fantastically complex Argon 18 PDFs?!

Cheers everybody

B