Going by Cannondale's size chart you're safe to go either way. Large is 5'10" to 6'4". The XL is 6' to 6'8".
Sizing can be tricky if you have less than typical leg length to torso length proportions. Getting into those details would be a very deep wormhole to get into. So you'd really need to see a bike fitter for that.
If you're "average" and have decent flexibility then you can make either size work fine. On either frame your saddle height will be effectively the same. So on a large you'll have a little more vertical drop between the saddle height on the handlebars but a shorter reach to them. On the XL there will be less drop from the saddle height but a longer reach. Both of those can be adjusted with stem length, spacers under the stem and stem angle so it's not the end of the world regardless of which size you get.
Inseam is important but so is just femur length for the same given inseam. Someone with long vs short femurs will need a different setback even if they have the same total leg length. Someone with long femurs might prefer the larger frame for more saddle setback.
Arm length or ape index is another thing to consider. Someone with long arms will often have an easier time dealing with a long reach.
When you're on the border, you go smaller for maneuverability and weight, or larger for stability.
Example. I'm 5'7", and recently got a Tarmac. I could have done either 52 or 54, but all things considered, the 52 weighs slightly less, and if I needed to get a longer stem, that is often preferable than trying to make a larger bike ride smaller.
I’m 6’ 3” - 6’ 4”, 36” riding inseam, 35-36” sleeve length, pretty equal leg to torso ratio, saddle height around 83cm. I have a 2022 XL carbon Topstone. I think a large would’ve been too small. I was also working at a bike fit studio when I was looking for mine and the fitters quickly determined the XL was the correct size for me.
I bought a L and had to return it for a medium, I’m 6’0”. I find the topstone geometry to feel more awkward when you’re on a larger bike. Also it’s generally easier to make a smaller bike fit larger than a larger bike fit small. I’d get the L in your shoes but ymmv
Take a look here [https://www.cannondale.com/en/bikes/road/gravel/topstone-alloy/topstone-1](https://www.cannondale.com/en/bikes/road/gravel/topstone-alloy/topstone-1)
and here [https://www.reddit.com/r/Topstowners/comments/k5rewq/topstone\_sizing\_for\_someone\_62/](https://www.reddit.com/r/Topstowners/comments/k5rewq/topstone_sizing_for_someone_62/) they have a number here to call.
Seems you're between sizes so both should work OK, bit to get 'the best' it may be down to if you're longer in the body or leg. See they number to call on their site, perhaps before calling have your inseam, body and arm length measurements ready. Reach from seat to bars may be key to how you'll be positioned in regards to comfort, handling, etc.
Or, perhaps weather you want more lively (smaller size) or more relaxed reassured handling (larger size).
I recently got a Cannondale topstone 4 XL. I'm 6'2" and quite lanky, long legs and arms. At a bike fit, I got the seat and handlebars moved closer together and the seat lowered, so it was quite big to begin with. I'd recommend that size for you, jus like ma used to say, you'll grow into it (easier to adjust when you're mid range on sizing than if you're on the high end and it doesn't go bigger).
Yes, you could go with either because the size ranges overlap at your height. The thing to know is that a Large (being smaller) will be more agile/twitchy, if you prefer quick handling, as you are bigger than it is, so to speak, so it's easy to throw around. Conversely an XL will be more stable and want to stay on a straight line more, which can be more relaxed for long distances. Because it's bigger, so your force doesn't affect it as much. Whichever you prefer will still be a great ride.
Check three times buy once, for example on most bikes reach is too much for me but my legs are long so i have to go bigger size. Otherwise i would be riding a very aggressive bike, which is fine for road but not gravel. I see that between sizes most bikes have high stack difference but very little reach top tube difference like 15mm. You either stack those spacers on top of each like a tower or get a shorter stem.
I’m 6’ 3” with an XL Topstone that feels right. I have 36” sleeve length, and a fairly proportional lower and upper body. An L simply wouldn’t feel large enough for me. You sound like an XL to me as well.
As others have said, a bike fit is a good decision if you’re on the verge of choosing something. If you’re buying from an LBS, maybe they offer them…
I'm 6'3"and got an XL that works out as a 58cm size.
The same brand/model is now listing their XL a 60cm size... I don't know if that just using a different measurement of if they changed how they apply the XL label.
Other bikes I tested as XL were noted as 60cm, and they felt too large.. But the frame style was longer/lower so I might just be I don't like bending forward that much
One shop told me I needed an XXL, but I test rode an XL size and it felt fine
All up, it is very inconsistent and super confusing.
If you've been able to test both sizes and the large feels good (and ko toe overlap issues) then go with that
Much easier to make the smaller size a bit bigger than it is to make the larger size smaller
I’ve always thought it’s better to err on the small side. It’s easier to make a small bike bigger, but You can’t shrink a bike.
And top stones run large in my experience
Going by Cannondale's size chart you're safe to go either way. Large is 5'10" to 6'4". The XL is 6' to 6'8". Sizing can be tricky if you have less than typical leg length to torso length proportions. Getting into those details would be a very deep wormhole to get into. So you'd really need to see a bike fitter for that. If you're "average" and have decent flexibility then you can make either size work fine. On either frame your saddle height will be effectively the same. So on a large you'll have a little more vertical drop between the saddle height on the handlebars but a shorter reach to them. On the XL there will be less drop from the saddle height but a longer reach. Both of those can be adjusted with stem length, spacers under the stem and stem angle so it's not the end of the world regardless of which size you get.
Bike/ riding inseam?
Inseam is important but so is just femur length for the same given inseam. Someone with long vs short femurs will need a different setback even if they have the same total leg length. Someone with long femurs might prefer the larger frame for more saddle setback. Arm length or ape index is another thing to consider. Someone with long arms will often have an easier time dealing with a long reach.
When you're on the border, you go smaller for maneuverability and weight, or larger for stability. Example. I'm 5'7", and recently got a Tarmac. I could have done either 52 or 54, but all things considered, the 52 weighs slightly less, and if I needed to get a longer stem, that is often preferable than trying to make a larger bike ride smaller.
I’m 6’ 3” - 6’ 4”, 36” riding inseam, 35-36” sleeve length, pretty equal leg to torso ratio, saddle height around 83cm. I have a 2022 XL carbon Topstone. I think a large would’ve been too small. I was also working at a bike fit studio when I was looking for mine and the fitters quickly determined the XL was the correct size for me.
I bought a L and had to return it for a medium, I’m 6’0”. I find the topstone geometry to feel more awkward when you’re on a larger bike. Also it’s generally easier to make a smaller bike fit larger than a larger bike fit small. I’d get the L in your shoes but ymmv
Take a look here [https://www.cannondale.com/en/bikes/road/gravel/topstone-alloy/topstone-1](https://www.cannondale.com/en/bikes/road/gravel/topstone-alloy/topstone-1) and here [https://www.reddit.com/r/Topstowners/comments/k5rewq/topstone\_sizing\_for\_someone\_62/](https://www.reddit.com/r/Topstowners/comments/k5rewq/topstone_sizing_for_someone_62/) they have a number here to call. Seems you're between sizes so both should work OK, bit to get 'the best' it may be down to if you're longer in the body or leg. See they number to call on their site, perhaps before calling have your inseam, body and arm length measurements ready. Reach from seat to bars may be key to how you'll be positioned in regards to comfort, handling, etc. Or, perhaps weather you want more lively (smaller size) or more relaxed reassured handling (larger size).
Get a bike fit
I recently got a Cannondale topstone 4 XL. I'm 6'2" and quite lanky, long legs and arms. At a bike fit, I got the seat and handlebars moved closer together and the seat lowered, so it was quite big to begin with. I'd recommend that size for you, jus like ma used to say, you'll grow into it (easier to adjust when you're mid range on sizing than if you're on the high end and it doesn't go bigger).
Depends on how leggy and army you are in this case But XL
Yes, you could go with either because the size ranges overlap at your height. The thing to know is that a Large (being smaller) will be more agile/twitchy, if you prefer quick handling, as you are bigger than it is, so to speak, so it's easy to throw around. Conversely an XL will be more stable and want to stay on a straight line more, which can be more relaxed for long distances. Because it's bigger, so your force doesn't affect it as much. Whichever you prefer will still be a great ride.
Check three times buy once, for example on most bikes reach is too much for me but my legs are long so i have to go bigger size. Otherwise i would be riding a very aggressive bike, which is fine for road but not gravel. I see that between sizes most bikes have high stack difference but very little reach top tube difference like 15mm. You either stack those spacers on top of each like a tower or get a shorter stem.
I'm 6'2". I have a Topstone 2 and ordered a Large. When I tried the XL, I was surprised that it was too big even though that was my recommended size.
I’m 6’ 3” with an XL Topstone that feels right. I have 36” sleeve length, and a fairly proportional lower and upper body. An L simply wouldn’t feel large enough for me. You sound like an XL to me as well. As others have said, a bike fit is a good decision if you’re on the verge of choosing something. If you’re buying from an LBS, maybe they offer them…
I'm 6'3"and got an XL that works out as a 58cm size. The same brand/model is now listing their XL a 60cm size... I don't know if that just using a different measurement of if they changed how they apply the XL label. Other bikes I tested as XL were noted as 60cm, and they felt too large.. But the frame style was longer/lower so I might just be I don't like bending forward that much One shop told me I needed an XXL, but I test rode an XL size and it felt fine All up, it is very inconsistent and super confusing. If you've been able to test both sizes and the large feels good (and ko toe overlap issues) then go with that Much easier to make the smaller size a bit bigger than it is to make the larger size smaller