I know, I know, get a professional fit, etc. But first I want to make sure I get the right size.

I'm 5'6 1/2", short 29 inch inseam, quite short arms. Originally I thought that a caad10 in 50 would be perfect, but when I tried it, it felt quite weird. I can't really describe it, but maybe a little bit stretched out, with a 100mm stem (it also had a huge stack of spacers). So now I'm testing a caad10 in 48cm with a 90-95mm stem.

I don't feel cramped on it, it handles well, it climbs well, but I feel like it might be small, with a little bit less reach I need. I will try to put on a 110mm stem on it, move down the bars a couple of spacers just to get the feeling.
In general I like to have big saddle-bars drop and on my smaller bikes feel much more like I "own" the bike during a hard climb. But this might be a little bit too small.

What's your take based on this info? The LBS said that I can be fitted on both frames probably (regular LBS BS).

Well you are not the only person that fits the "between sizes" category so this is not uncommon. I can make a 56 and a 58 fit just right but I prefer the 56 with a longer stem. I would have thought a 50 would be fine at your height, maybe even a 52. You did say you had short arms so that could be an issue. What about switching to a handlebar with a shorter reach? I prefer a shallow drop on my bars as well and that may help you. The 48 just sounds like you're going to small.

+1 that you might just be between sizes. 48cm sounds too small. What about a 90-95mm Cannondale stem on the 50cm with short/shallow bars?

So I used to have a slightly large frame, and I got a professional fit for that. On that frame I had a 80mm stem and wanted to go for a longer stem on my new bike to improve handling. I use a 40cm handlebar, so that was quite twitchy. I got used to that fit and liked it a lot, but I really wanted to avoid going to big with my next bike.

Also I was riding a used 49cm bianchi pista (90cm stem) in the past 3 month and while for the first time it seemed to be small, with an extremely big drop (headtube is 10cm with headset cups), I easily got used to it. I tried it on bit longer rides (30 miles) and still felt ok.
Maybe that's also part of the problem that I was riding the bianchi recently and changed the way I feel on a classic road bike.

The caad10 48cm has 5mm shorter TT than the bianchi, but a less dramatic drop, even without spacers. The reach difference between the 48 and 50 caad10 is 10mm.

Why would it be better to ride a 50cm caad10 with a 90mm stem and a short reach handlebar than to ride the 48cm with a 105mm stem? Longer wheelbase? Better handling? Better weight distribution?

I tried a 52cm CAAD10 earlier and it definitely felt too big. Not super big, but big.

Top tube length is more important, i am fine with a 54cm caad 10 (177cm height, 85cm inseam).

Sounds REALLY short. I run a 50cm CAAD 10 with a 130mm stem and I'm 5'6" with a 31.5" inseam.

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It wouldn't.

Can't the shop swap a longer stem on there for a test ride?

Does the frame (48) sounds really that small if you consider the 51.5cm top tube and 368mm reach?
I just checked a few frame builders' generic sizing chart and Baum has a 361mm reach in a size 52 and 371mm in a size 54 (!).

Thanks. This helps. Do you have longer arms? How flexible are you? how many spacers do you use under your stem? Thanks in advance.


I hope they can. Maybe I will go back and ride a 50 again just to make sure I'm between sizes and I don't buy a super-small frame.

I am 5'5 1/2" with a 29" inseam. I was riding a size 50 CAAD10 with a 90mm stem and the handlebars slammed and the fit is right. I believe its just the CAADs aggressive geometry that is making you feel stretched out.

I'm 5'8 with 29.5 inseam. I'm riding a size 50 supersix EVO, after the GURU fit.

I was riding a size 54 on FELT, which I thought was a little too big for me.

Would you mind sharing your stem length? Thanks

110mm, I have long torso, but short legs.

Alright. Thank you all for the suggestions and recommendations! Let me share the result, maybe someone will find it useful.

I will add a little bit of more closure: this is going to be my second bike and on the 48 I got a very-very good deal.

I went back to the LBS to test ride the 50cm again. Now I'm absolutely sure that my perfect size would be between the two bike, but it's closer to the 50cm. I think I'd be able to have a very good fit with a stem somewhere 90/100mm and a zero setback seatpost.

BUT because I got a very sweet deal on the 48 and it's clear after trying the 50 that I can deal with the smaller size, I will stay with it for now. I will run a stem somewhere around 100-120mm and my current seatpost with 20mm setback seems to be suitable.

I'd be more torn between the two if it was my main bike, but that's not the case now. It was a super interesting experience, because originally I thought I would be between the 50 and 52.

Why did the 48 cm require a setback seat post and the 50 cm didn't? The relationship between your ass and your feet did not change so why would setback change. Cannondale does not change crank size between 48 and 50 cm. If this was just to feel comfortable with the reach to the handlebars, then the 48 cm was really too small! Frame sizing and component sizing should always be based on physiology not on whether or not it was a "good deal."

My wingspan is 5'6". I can palm the ground, but I also had a hip surgery that gets in the way when I get really low. No spacers, it's on the headset bearings. And I run a -17 stem with compact bars. I hate how high the CAAD 10 geo is so I bought a new bike so I can get lower. But everyone is different, ya know?

CAAD10 sizes 48 and 50 are quite close, and they both seem to fit quite large. The top tube on the 48 is 51.5 cm, that's something you would expect on a size 50, and then the actual 50 is 52.5, so more like what you would see on a size 52 . Also, the head tubes are just 5 mm apart, and the seat tube angles are the same, so the only significant difference is the top tube length. You will be just fine on the smaller frame, even if you need to use a 110+ mm stem in the end.

[MENTION=324755]dudemanppl[/MENTION], what bike did you buy to replace CAAD10? I find the Cannondale race geometry to be quite aggressive, so I'm wondering what did you find that's significantly lower.

You are right, that was just stupid.

TLDR; So to play with the reach on the demo bike I adjusted the seat. I know that's the wrong way to adjust the reach, but I didn't want to have them swap the stem, so I played with the seat fore-aft. I didn't really pay too much attention to my leg positions, because I'm sure I can be fitted on both the 48 and 50 and my issue was the reach. When I wrote the 0 setback seatpost I assumed that the 50 has a different seatpost angle, but it doesn't.

Everything is lower... 50cm CAAD has 115mm of headtube. I used to ride a Tarmac SL4 49cm and now I have a BMC SLR02 48cm. Which both have a stack of around 505mm.

I guess I always looked at the larger sizes - it is lower than the Tarmac in size 56 and above

me personally, i'm 5'7" with a 30" inseam and a long torso with wide shoulders. i'm riding a 52cm Supersix EVO with a 100mm stem and 44cm bars, and the EVO and CAAD have very similar geometries...

i have about 500 miles on that bike, and i will say i really like the fit and the size was perfect.

as far as the OP goes, i definitely think the 48cm would be too small, my mechanic rides two 48cm EVO's and he's only 5'4" with a shorter inseam than the OP. i think the only problem that you're going to run into with the 50cm is that since you have a short inseam, the stand over is going to be higher than you really want and you're not going to have that much seat post showing when you're done with your fitting. me personally, i have 80mm of seatpost showing so i can clamp it on my Park stand, but that's going to happen with the CAAD or the EVO because of their geometry. bottom line, definitely go with the 50cm and just work with the stem as far as the reach goes...

I'm in a similar situation, but I didn't think it was worth starting a new thread since this has a lot of good info.. I'll probably be buying a new bike this year and I am looking for advice on the CAAD10-3 Ultegra. (recreational and club rides) I'm looking at either the 2015 or a 2014 (if it's still available when the warmer weather is here). I have not had the chance to test ride since the weather has turned cold. I stopped in at a LBS and they did a quick sizing and suggested that I look at a size 54. Using the Bike Fit Calculator from Competitive Cyclist website, I have the following measurements (cm.):
Height: 174 Inseam: 84 Forearm: 35 Tibia:53 Trunk:61 Arm: 60 Thigh: 60 Sternal notch 143.
Here's the thing. I will be absolutely working hand in hand with the LBS to make sure that I get the proper fit, but a few of the guys I ride with were thinking that I'd fit a 56 since they are a little shorter than I am. I'm inclined to go with whatever the owner of the LBS recommends. I'm dropping a little more than $2k and will not be buying another bike for quite some time, so I don't want to screw up. The LBS will be doing a number of adjustments after I purchase and ride it for a few months to make sure it fits properly. I will also be waiting for warmer weather so I can test ride a number of bikes from a variety of manufacturers, but so far, I'm liking the CAAD10.

Questions:
1) Any thoughts on the 54 sizing vs the 56 sizing?
3) Is a $200+ body geometry fit really worth it?
3) I hear all the talk about stem length changes and so on. Are these things I need to consider at the time of purchase and are they expensive changes?

If there is anything else I should consider; please let me know
thanks

EDIT - March 3, 2015.. Went in to LBS to purchase the CAAD10-3 yesterday and questioned the 54 vs 56. Luckily they had both in stock and had two sizing/fit stations so they put the 56 on one and the 54 on the other. An hour or so later back and forth on both, I ended up with the 56 size although they did need to change the stem.
... and this is why I like my LBS

You have me wondering. I am in the market for a CAAD10 by the year end. My LBS doesn't have women's versions. So I am going to try a men's. I am riding a 51 Synapse now and have shortened the stem and got a different seatpost allowing me to get closer. Maybe I need a 48? I am 5'4 1/2" and short inseam probably near a 29. Well, Ia m going to test ride hopefully on Thursday so I guess I'll know more then.

I'm 5'8" with a 30" inseam and I recently decided on a 54". It has a snug standover and lower seatpost exposure, but so does my current steel road bike that also has a 54.5 ETT and I've always liked the feel of it. I test rode the CAAD 52 and the 54 and other than standover, I could not tell the difference in fit. I liked the bumblebee color of the 54, so I went with it.