Hi,

I'm currently looking at the Cannondale f300 as my first mountain bike. I am just a little confused as to what size I should get. Two sales people from the same shop told me two very different things. I'm about 5'7" with a very short 28" inseam.

On the small I was very comfortable, but one salesperson said I was a little too upright. My legs were positioned correctly when seated, but the seat post was quite high. Also, I had good "crotch clearance" from the top bar.

The medium was comfortable as well, but felt a little big. My position was a little better, as I was leaning a little more forward.
My crotch barely cleared the top bar.

Here's a link to the Cannondale site, so you can get a better idea of the sizes I'm talking about.

https://www.cannondale.com/bikes/03/geo-4.html

What would my disadvantages of going too small/too large?

Thanks in advance.

I'm 5 7 as well. I initially bought a cannondale med size and it gave me good control over tight turns but I stunk on bombing down hills since my center of gravity was way above the bike's. I finally got a large cannondale f700 and had to adjust on the tight turns but i can climb and downhill better. My inseams are 31"

If you are comfortable on the smaller bike, have no groinal clearance on the bigger bike and this is your first "offroad" bike then the smaller one is a better choice. Strictly opinion without having seen you on the bike.

cbhungry...you really ride a large and like it better than the medium? Our inseams are only 3" different...I would think that would be too large.

One salesman told me the small was perfect, another told me the medium fit me a little better.

The general consensus was that I'm in between sizes, so it all boils down to preference. What are the advantages/disadvantages of going big/small?

On a MTB if you feel reasonably comfortable on a small and a medium, I would go for the small. This is assuming that you are getting the bike for off road use. The bike will turn quicker because of the shorter wheelbase. Your testicles will also than you from time to time.

i'm the same height as you, w/a 29ish inseam. the medium was more comfy for me just cause of my long torso. i also flipped the stem over for a negative angle just so i can stretch out a bit more. the cockpit of the small really felt a bit cramped. but that's just me. i think you're gonna know better than the salesmen what works best for you.

Maybe the bike is the wrong shape for you, and you would be better off with a different manufacturer.
The ratio of height to length varies between manufacturers. You seem to need one which is quite long for the height. Get your legs over a small Gary Fisher for comparison, these have quite a long design. Im not sure if there are any other makes you should look out for. Take a tape measure to the 'dale, and get a figure for saddle-nose to bars which you like. You can tweak it a bit with replacement stems, but that may change the handling characteristics.
Its OK to ride with plenty of exposed seatpost, esp if you are a smaller, lighter rider, as long as the --MAX LIMIT-- line does not show.

Dome, I have a 28" inseam, I ride a small frame, Ive just flipped over the stem for climbing, but I dint feel that the frame is too short. but then the C'dale I looked at were F600 and F800. I'm not 100% sure if the top tube's are longer on those bikes.
I prefer having the top tube clearance, because when you think of it, on trail, you leg is not always straight when you straddle the bike!

If I do go for the Cannondale, I think I'm going to get the small . In all honesty the frame size just seemed to fit me better. I got on and was comfortable immediately. I guess that's the important part.

If I do find that I'm riding a little too upright, I can always flip the seat post, as was recommended or go for a bit of a longer stem.

Thanks all for the replies. You've got a newbie friendly site, with a lot of friendly and helpful members. Thanks again, and please add any more input, it's all been beneficial.