Choosing a frame size and geometry

How do I choose frame size and geometry for my body type ???

The first bike I bought it was determined years later through experience it’s too big for me. I’m 5’6 and I ride a 54 trek madone 3.1. So fairly aggressive ride. I feel like I’m constantly reaching even when the stem is reduced. And I have had a really hard time getting comfortable on the bike due to asymmetrical interactions with the bike. Was it caused by the too big frame? Maybe? I’m in a much better place now.

I want to avoid similar issues. Give me your best advice please:)

The first question is what is your purpose for this bike? Racing, Gran Fondo, TT, other?
Each use case can have different answers as to what is good for you.

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See a fitter with a stand-alone jig and get them to find your best-fit position on that From from this you’ll get some measurements, such as stack and reach, that you can use when considering frames.

Demo or borrow some bikes and see what you like.

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Ahhh of course I’ve left important information out!!!

I race on zwift but also want to be able to do training rides up to 2+ hrs also.

So, you are looking for an “indoor-only” bike setup?
Or are the “training rides up to 2+ hrs” outside?

There can be different choices or suggestions if you aim to stick inside vs mixed used in and out.

I’d say mostly inside. 80% of the time!

And for the outside, just basic road riding or any other special considerations?

Where I’m hinting at is determining if you may desire a “race” type bike, and “endurance” type bike or even branch towards something like a “gravel” bike.

Each of those offer unique geometry for riding considerations, but also closely connected to rider fit and position. Changes in frame Reach & Stack specifically are huge with your issues, so making sure the outside use is a decent crossover with the larger indoor use is a good thing to review, IMO.

Me heading into my typical “lots-o-details” side of life, but there are so many ways to go with a rather open ended start, it helps to nail down some key interests to narrow the search.

Thanks for your help Chad.

Due to medical issues no outside racing for me. It would be endurance riding outside. Only road . That’s why I love racing inside. Safer for me.

My current bike trek madone 3.1 54cm I always feel like I’m reaching no matter what stem I put on. Yes, I’ve done lat stretching and upper/lower mobility.

If I can find someone with a jig I will go that route if you think it’sa good option. I’m trying to find someone with a smaller frame that I can try since this bike has been a nightmare.

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  • Do you happen to know the year and if this was the WSD (women’s) frame? I will track down the geometry chart for that so we can plug it into one of the many comparison tools, to make better suggestions on not only frame size, but bike type to hopefully get you more comfy.

Example of some years and models:

These might all be the same geo, but getting the year and WSD or not will make sure we have the right reference point to start.

It’s possible that more info about final bar setup with stem, bar and spacer setup will be needed, but starting with the frame is good for now.


It would be great if you found someone with an adjustable fit bike. Short of that, heading to a shop with various models and frame sizes, for quick spin on a trainer is a decent starting point too.

My gut says an “Endurance” bike like the Trek Domane, Specialized Roubaix, Giant Defy, Cannondale Synapse and many more might be the right starting point. They all tend to have shorter Reach and higher Stack vs a Madone which typically has the “long & low” approach.

It’s the trek madone 3.1 2013 model and it is NOT wsd frame

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My first road bike was well picked out for size by the LBS and I’ve went down a similar route for subsequent purchases.
There was one lbs that craic’d me up though. I was sitting in their cafe with bike that had done around 25,000 miles in comfort and was a identical geometry replacement for its predecessor which also did circa 25,000 miles in comfort. I have the same geometry frame in aluminium for a winter bike and have done circa 10,000 miles on that. When the shop manager came out with a tape started measuring it, eyeing me up and diagnosed it was too big. I was about to do the Mallorca 312 so it got me a bit worried so I googled some fit systems and by the most aggressive sporting fit it was indeed too big for me, about 0.5cm too big, by others it was spot on, and by a ‘French Comfort’ fit it was actually 2cm too small. In the end did about 41,000mile in comfort on that bike before having a custom geometry measured up and subsequently bike built :joy:

FWIW I’m 5’9" and the original bike was a 54cm and I think the custom bike is about the same.

Just to share one comparison, here is your bike (middle) and two examples of the current gen Domane SL, in 52 (left) & 54 (right).

This shows the delta values as compared to your current bike:

  • Either of the new Domane (Trek’s Endurance bike) sizes will be shorter Reach and higher Stack, which seems like a direction you want to go. The magnitude between these is key to selecting between these or any other similar comparison with different brands and models.

This shows the raw values:

I definitely recommend seeing a fitter and getting your measurements. In my case, even though I’m nearly 6’ tall, my legs are a little longer and torso a little shorter than average, so I’m more comfortable on medium / 54 sized bikes whereas most manufacturers would recommend a large / 56.