ROJA

I am buying one and I am pretty sure that I should ride a 54cm, but there seems to be some doubt versus the 56. The shop said I could go either way, but they don't seem to be experts regarding fit. I am 5'9" with a 30" inseam in my pants. Any guidance on which frame would work best?

Thanks!

R900

The larger frame will give you more rise and a longer top tube, so sort of depends on how much top tube you need/want and how much rise/drop (although easy to adjust with a stem).

John

krazyderek

depends on your upper body reach/flexibility, can you touch your toes easily?

As long as you can straddle the 56 wearing bike shoes then i'd say get that. You can always put a short or long stem on it. Whereas if you have a bad lower back like me, you won't be able to find a stem with a steep enough angle to put the bars up high enough to reach comfortably on the 54 (like my old old bike i had to sell cause of my lower back pain). If you have to use steerer extender's then you should have probably gotten the next size up or a custom.

UmneyDurak

I am 5 9' not sure what my inseem is. I have 54 CAAD8. I am more comfortable on it then on my 56 Specialized Allez. I have a 90mm stem with 10 degree rise thought. Just FYI.

Chopper1

If you get the Six13, you can get it in a 55.

woodcycl

I ride the Six13. I am 5' 6.5" tall with a 28" inseam. I ride the 53cm. I could've ridden the 52 or 54 ... but would've been better on the smaller rather than the larger. If I were you, with what little you've mentioned, I'd lean toward the 54. Too many variables though. Ride both several times ... see what you think.

ROJA

Are you sure? Not according to the c'dale website: https://www.cannondale.com/bikes/07/c...el-7RCT2D.html

canaxer

I bought a 54cm caad8 used about a month ago. it had a 14cm stem on it, no rise. I'm 5'9, 30" inseam. I went in for a lbs fitting a couple of weeks ago, and ended up with a 9cm stem, 8 degree rise. I know it looks a little dorky, but its the best fit for me and its still a bit on the agressive side. My saddle is a couple of inches above my stem, fwiw. One thing about the slice fork is there is not much extra room for spacers, so I had to resort to the rise. I didn't try the 56, so I can't offer you my basis for comparison. I suspect that I'd have bigger issues coping with the reach on the 56 though.

ROJA

I am not very flexible and can't come close to touching my toes. So the 56 has a longer reach, but less drop, while the 54 has a shorter reach, but more drop? The shop guy said to err on the side of getting the smaller frame. Maybe I should secretly visit another c'dale dealer and play dumb and ask what size frame to get.

ROJA

BTW, the reach seemed a bit far as it was, so we put a shorter stem on the 54, which makes me think that is the one I should get because the 56 will have an even longer reach. I am pretty sure I could straddle the 56 with bike shoes on. Is the general rule to get the biggest frame you can straddle?

R900

Your BB to seat distance will be the same on any frame (or should be). On a larger frame the head tube will typically be taller to meet the longer seat tube, given a level top tube, thus more drop on a smaller frame. Now there are a ton of things you can do with spacers, stems, etc... Assuming the standover height is ok, and the reach will work with a 90 - 120 mm stem, yes get the larger frame. But if the 56 requires a super short stem, I would stick with a 54 and a more standard stem lenght.

John

El Diablo Rojo

I ride a 54cm CAAD8/120mm stem, I'm 5'10" w/32" inseam. I have a 4" drop, but I'm very flexible. To me the most important measurment on a bike is the TT length. FWIW I really love this bike, it's light and stiff but still fairly compliant and it handles great. Also the 54cm frames are sloping (very slight) while the 55cm and up are not.

krazyderek

Exactly what he said. The 54's tt is 1.5cm (~5/8") shorter, and the headtube is 1cm lower down. So if you were using a 105 or 110 stem on the 54, you could easily run a 90 on the 56 and have higher & closer bars. If you already had to put a 90 or 100 on the 54 then you might be stuck with the 54, but see how you're reaching if it's mostly downward (bending at the back-you need a taller frame), or forward (huntching your shoulder's reaching out with your arms-you need a frame with really short reach).

Of course i've never seen you on either bike nor do i have any idea of your overall proportions. Heading to another shop for a second opinion on fit might not be a bad idea.