Help understand geometry reach and stack

[blantonator]

I'm currently riding a 52cm Spooky Skeletor and after a recent fitting a 120mm stem with quite a few spacers(4cm). I'm looking at a new frame, Super Six or a possibly a Madone, depending what the team orders.

Looking at a 52 in the Cannondale and Trek, both have similar reaches 37.8 and 37.9cm, but the Trek has a 2cm higher head tube. With equal stem placements how much longer is the Trek vs the Cannondale. Also, with a 52cm Spooky what stem length would I need with the Cannondale and Trek to get my bars in the right place.

Here are the respective geometries.

Spooky
Dale
Trek

Thanks

[cyclenutnz]

Set up comparison

[ajmit3]

Woah Cyclenutz - how did you do that ? Can you share the spreadsheet ! Awesome work btw....

[blantonator]

Yes! Thank you. It looks like stack only affects reach by a few mm.

[upside]

Me toooo. I am in almost the same situation between bikes. I would be more than happy to PayPal you some $$$ to get my answer.

[cyclenutnz]

I'm happy to post up quick comparisons like this (if I see the question). Or, given I am a bike fitter, I do offer a bike options report (that I charge for) where I go into detail on bikes you are (or should be) considering.