Whats a large change in stack/reach?

Hi all,

I’m 5’8", with 33" inseam, riding a Trek Domane SL in size 54.
Had 2 bike fits which put the saddle height at 28.5" (BB to seat top) and I have a 90mm stem.

Looking for a new bike and geometrygeeks shows that practically all bikes are longer and lower than my Domane (except Roubaix) .
For example a Madone in 54 is 12mm longer and 34mm lower!
I demo’ed the Madone and really couldn’t see down the road in the drops :frowning:
Thinking about sizing up to a 56 which is 17mm longer and 12mm lower but everything tells me that frame is too big…?
Also looked at the new Supersix EVO, but that size chart puts me on a 51 which is 4mm longer but 40mm lower!

Whats the biggest change in stack and reach I should consider and is sizing up to get taller stack a bad idea?


Those are race geometry frames you are looking at. They are meant to be lower and longer than your endurance bike. Whether that will work for you, I don’t know. But, unless you’re riding with no spacers below the stem right now, it might be hard to match your current position on a race geometry frame.


Keep in mind that most new frames are routing the cables trough the headset and require more space to accommodate the cables. I don’t know if the stack height is based on the frame alone or if the taller headset is already factored in. Most race bikes are for 20 something athletes and not for every-day Joe and Jane. Altough you can make it work on many frames. Just know what you want and need in a bike.

If you are more leg than torso there are options. TIME ADHX, BMC Roadmachine, Cannondale Synapse, Specialized Roubaix or many other endurance frames should work.

Why are you trying to buy a race geometry frame when you’re presumably happy on your current relaxed endurance geometry one?

It’s not a natural progression over time, they will just never fit well for lots of people. Flexibility, core strength, or purely in terms of arm and leg length vs height.

I’m pretty sure that 33” inside leg and 5’8” is long legs vs height. That alone might be prohibitive.

Your current bike is an excellent endurance bike.

As other have said, do you currently have the stem slammed, have a negative stem angle (-17 is horizontal for most bikes) and do you feel that you want to have the handlebars lower and further away? If not I don’t see why you’d upgrade to one of those bikes.

All fair points, and yes the Domane is an awesome smooth magic carpet that has taken me 20K miles.

My N+1 search is simply to have a different type of bike to ride, something more sporty and exciting to ride, hence the race geometry.

I do have an upright position currently with a full stack of spacers, and at 50 I’m doing A group rides, not racing or getting more flexible. Have ridden other endurance bikes but really couldn’t perceive any difference from my Domane.

You could try what happens if you remove spacers from your current bike, and possibly also switch out the stem. Then see how much change is too much change.


If you’re already in quite an upright position with lots of spacers on an endurance geometry, then your current position likely won’t work on any of the more race oriented bikes.

I disagree with others above though that riding a race geometry is the preserve of 20 something year olds with good flexibility. I know plenty of people in their 40s and 50s riding race bikes with low stack, who aren’t particularly flexible (always amazed how many cyclists can’t even get near to touching their toes!) and without any particular comfort issues. So the question really is whether your desire to try a racier sort of bike is strong enough to explore the significant position changes required to fit on that kind of bike? And if so whether you’re prepared to go see a good fitter that can help you figure out what’s possible fairly quickly, or whether you want to go down the route of trial and error on your existing bike. E.g. Removing spacers, swapping stems, adjusting saddle height and fore/aft, maybe even changing crank length. My personal view would be to go see a fitter as it will end up being a much shorter process (and if you’re looking at bikes like the Madone and Supersix Evo then I’m also assuming that you’re happy to spend some money!). Ideally a fitter with a performance focus who doesn’t just work with elite riders but also with middle aged cyclists trying to get a bit faster on their local group ride or set a fast time on a gran fondo.

I’m not sure what you’re looking for if you’re not even in the most aggressive position on your current bike, with +100mm of stack to begin with.

The main difference in racy bikes is the geometry, they might be a bit stiffer too, but you already have a high end carbon frame which will be plenty stiff.

If you want to play with a more aggressive aerodynamic position, do it on your current bike first. Integrated cables notwithstanding, stems and handlebars are cheap to swap.

Otherwise it just seems like an ill-fated vanity project.

It’s because they have long arms / bodies compared to their leg length.

I’m in my 40s, but can happily ride aggressive frames despite being a little overweight because I have long arms and a long body.

I’ve never not been able to touch my toes and can actually touch my palms flat on the floor in front of me.

You do need to have at least one of: young/fit, flexible, helpful body proportions to ride racy frames.

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Loved the vanity project :heart_eyes:

Have been experimenting with seat fore/aft and dropping spacers (since my last bike fit), just to see what my body will tolerate and if anything feels particularly better/worse.

There’s also some tech reasons: I’m on rim, mechanical, Alu hoops. Could update my frame with new bits or just get a new Domane, but am trying to decide if I can fit to anything other than endurance for a different ride feel.
As I go through this my head tells me race geometry is probably not where I should shop.

33in inseam is very long for a 5’8". You also need to consider your crank/pedal/shoes in your saddle/stack height. You need to consider your handlebars in your reach too. That Madone probably has a 100mm stem too.

Stems and spacers are made to adjust the fit of the bike.

Figure out where you want your hands and then buy the bike. How many spacers do you have under your stem? Try taking 30mm out and put them over the stem. Buy/borrow a cheap 110mm stem for $40- get a steeply angled one if you can’t remove enough spacers. Your bike shop or someone on your group rides might even loan you one.

If you want a more race-style bike I don’t think you necessarily need to give up that dream but as others mentioned there are some differences vs a Domane.

For your reference I went from a Domane SL6 to a Tarmac and it was fine. However, before I made the switch I worked my way down by removing spacers (in 2-3 steps), and then when I was at the bottom I flipped the stem to go a bit lower. Depending on the exact Domane you have you can do this with zero cost, so it’s worth playing around with IMO. I’d only make the jump to a racier bike if you’ve totally maxed out the Domane as low as it goes and it feels good to you. When I moved to my Tarmac I continued dropping spacers and now have it totally slammed. It’s very comfortable and looks great :slight_smile:

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Instead of slamming the front stack on a race bike (which isn’t nearly as low as it used to be), if you can go part way, use a -10 stem (looks aggressive but really isn’t), and spend time in an aero position with 90-deg bent elbows on the hoods—you’ll get the look and performance you’re looking for. Then you can relax on the hoods with straighter arms for endurance and not have hand or neck pressure.

Nothings for free, though. It’ll cost you the development of a core to hold the narrow aero position.

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Took a spacer out so the front is 10mm lower. Felt the need to tilt the saddle nose down a degree to get pressure of soft bits. Feels more cramped than before, and I can see if I continue going lower my thighs will contact my stomach impeding the top of the pedal stroke. Long legs and short arms aren’t a useful combo for my goals!

Yeah, everything is going to move a bit. Make a big change so you only need to do it once. :slight_smile:

Moving saddle forward (and up a bit to maintain same saddle to BB distance) can help with thigh clearance. Though probably also means swapping to a longer stem to maintain reach.

Shorter cranks would also help, though that’s a bigger step than swapping stems.

All with the caveat that don’t know what your current position looks like of course!

Having had 3 professional bike fits (all different people/systems), and experimented with all my contact points I’ve come to the conclusion that I can tolerate large changes in most factors. ±15mm on seat height, setback, reach, stack from my “fitted” position are all ridable with some effects on comfort but nothing noticeable on power or endurance.
The idea that mm’s matter just simply isn’t true for me. YMMV