bobonabike

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: 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 1600 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

rgconner

Motorcylists have a cool site that lets you get an idea of how you fit on a bike. There might be too many options to make a similar site for a bicycle, but here it is so you can see for yourself:

Motorcycle Ergonomics

bobonabike

That is neat. Never seen that before!

Masque

I was wishing this existed just today.

The use case I have, though, is to compare one bike to multiple sizes of another. Essentially, to answer the question, "Which size of the Bike-o-Tron Descender is closest in geometry to my Velomaster Spokewizard?"

Edited to add: Oh yes, apparently you can do this, though the UI doesn't quite communicate that and I'm not certain exactly how I've done it. Neat tool.

wphamilton

I think it's pretty awesome, although I struck out on all three of my bikes

Maelochs

Awesome. I have doznes of pages of useless geometry comparisons. if this works well ... thanks. If not .... well, just go to sleep. You'll be safe.

JBerman

I think this is a great idea and as long as it gets populated with content, it will be useful. I myself indexed information about my historical bikes for the purpose of ensuring bikes I purchased again would be comparable in fit (especially good for online shopping, like used on ebay).

raisinberry777

I like it.

A useful feature is for those who know their preferred stack and reach, it'd be nice if I could put that in and it could show me a bunch of bikes that fit within that (say, plus or minus 3mm).

bobonabike

@raisinberry777: Cheers. Yeah we're thinking about that kind of search. Technically challenging but certainly on our radar.

@wphamilton: Glad you like it. Which three bikes?

@Everyone else: Thanks for the support

Fett2oo5

Would you consider adding a diagram with labels of the dimensions on the "Compare" pages?
At the very least it would be helpful if you had such a diagram on the "Understanding Bike Geometry Measurements" page. Because as you said, "..... Too many different layouts, formats, terms for the same dimension..... "
A diagram of a bike frame with the dimensions labeled would help to visually define the terms for the users.

p.s. This is a great tool, I've put it in my favorites for later. Thank you for compiling the data. It's a great idea.

corrado33

Cool idea, was hoping there would be a graphic of the frames side by side so you could visually tell which was longer/slacker etc.

Although I struck out on my frames as well, but I'm not surprised, being as weird as they are.

86 Bianchi Limited
1992(ish) Mondonico Diamond
1995(ish) Landshark Roadshark

Although I'm pretty sure both the Mondo and Landshark were custom built so there wouldn't be any specs out there for them.

Doge

I primarily like the GT type bikes and age profile puts me there too.

But I find, after years of cycling, I just feel better leaning forward. So I want the sport position on a GT.

Oh well.

Fiery

Alternatives, can provide some ideas fpr further development:
Stack and reach calculator
https://www.velogicfit.com/ (needs registration but otherwise free)

I use the first one a lot.

Johnny Rad

Agreed, like the online stem comparison tool... Stem Comparison Tool | yojimg.net

Thanks for putting in the effort on this project.

bobonabike

Thanks all for the suggestions and the encouragement.

Yes we've been thinking about a graphical comparison tool for a while, but it's really difficult to do well. It will need to make certain assumptions that turn out to be very significant, e.g. headset stack height, so getting those right it key. It's on the long list of things to do

VaBeachTennis

Nice! Are you going to make a Facebook Page out of it too?

79pmooney

I am one who needs long stems and bikes with short chainstays and long front centers to get reach and weight balance to be good. Years ago, I wrote a Fortran program to calculate stem needed and weight balance for bikes based on the published specs. (I wanted to buy an off teh shelf ti bike, early 2000s.) Very educational but rather depressing. I found exactly zero bikes with "A" level fits. Spending $4000 then for a "B" level? Nah.

I then started using my AutoCAD skills to draw up my bikes, putting each bike on its own layer, making comparing bikes easy. It also cemented things I had been becoming aware of for my fit. Handlebars needed to be here. Seat needed to be there. And I could rotate any position forward to make it better for fix gears (lower and more aero - a huge plus going upwind of back - more comfy.

A few years later, my fortunes changed. I had a good working relationship with a frame builder. I had a bike that was very close to optimum already. So I took it to the builder and said "copy this but jack the BB to xx and pull the headtube forward 1 cm so I can run a stock stem". (And do this, this and this. It was a custom build after all!

5 years later I sent the builder an AutoCAD drawing of my next bike; based entirely on what I had learned from drawing up my frames. This bike was quite different form the first, in position, in handling, in feel. Both bikes were just what I wanted. Somewhere in the middle of all this, Ihad him build be a custom stem for my old Peter Mooney, also coming from the big drawing.

Now, when I go to buy a bike, I bring a tape measure and get enough data to draw it up. Go home and throw that new geometry onto a new layer, turn on the bikes that work and I can instantly see what I need for stem and seapost and issues that bike will have fit-wise.

This not a marketable product. Takes way too many man hours and I am using a program more expensive than my bikes. But it sure works for me. (My Fortran program could have been marketed if DOS had stuck around. Oh well.)

Ben

79pmooney

If you could tie the geometry program to a graphical program, one plus could be that errors/incorrect input assumptions, etc would then be visible. For example, the head tube looks way too high. OK, so they are doing stack to the TT/HT centerline intersection. I thought it was the headtube centerline at the top of the headset. And the like.

Ben

bobonabike

Cheers guys. You're right that the graphical comparison tool is a solvable problem. I like the idea of making assumptions explicit and correctable.
@VaBeachTennis - no FB page yet. Do you think it would attract more users that way?

VaBeachTennis

Heck yeah! Because I would share it with my friends (all 2 of them) and other folks here will share it with their friends and it can expose your product exponentially. Make a page and comment as that page on other cycling Facebook sites and that also help get your product out there. Good luck!

awesomeame

It would be cool if you could select a bike, and then be able to see other bikes with similar specs, without having to compare each bike one by one. Or is there already a way to do this which I'm not seeing?

Matt

bobonabike

I just stumbled across this thread I started 2.5 years ago... so here's an update!

geometrygeeks.bike has kinda blown up and we now have over 6,300 bikes listed, and growing every day.

• We've made it easier to add a new bike. The site tries to automatically extract the geometry table from any webpage you point it at.
• We've added 'search by numbers', so you can search the database by e.g. stack and reach plus a tolerance. Spoiler alert - we charge a fiver for this, to help pay for the site.
• We've added a huge list of bike fitters, all over the world, searchable by location. Fitters can list their businesses for free.

It's still a spare-time project, it's still good fun, and we're still seeking feedback from users on what you'd like to see... so please do get in touch!

(We're still working on visual comparison... maybe in 2020?!)

Best

Bob

Kimmo

Awesome.

dvdslw

Great tool to help us find the perfect fit. Thank you!