jamstu123

I'm looking for some advice. I've recently purchased a road bike and been advised by the bike shop that a 55cm frame is the right size. Having reviewed sizing charts i'm a littler concerned that the next size up might be the better option as thats what the charts suggest (57 cm).

I'm buying a Bianchi - not sure if relevant.

The advice for the 55cm frame was based on being a recreational cyclist and typically being in a more upright position when riding.

Any advice would be appreciated.

Thanks

ClydeClydeson

Are you comfortable riding the bike?

Generally, there are three sizes that fit in any bike model (with a reasonable number of sizes). There may be an 'ideal' size, and most cold easily get comfortable on one size up and one size down.

If there are specific concerns you have, for instance, you feel too stretched out, then there are adjustments you can make to get it dialled in.

In general, if you feel like you need to swap parts to non-standard ones to get the bike to be comfortable - like an extra long seatpost to get proper leg extension, or a zero-reach stem to keep from feeling too stretched out, the bike may be the wrong size. If, however, you feel like adding 10 or 20 mm or a bit more/less rise to the stem will make it better, the bike is fine and just needs adjustments.

jamstu123

I'll be sitting on it for the first time on Friday....didn't have stock to be able to test prior to purchase. I can exchange if not the right size but wanted some advice to make sure I wasn't been directed to a bike that is too small

Iride01 

Bigger the frame you get the less you'll be able to drop the bars in relation to the seat height. Not so big a deal for those that want what they perceive as a relaxed fit, but it means you won't be able to get as low and aero comfortably if you ever are so inclined to do that.

As previously stated, you'll fit on several different frame sizes. If you never ride the other, you'll never know. Also, a frame size you like for a short ride might not be the frame size you like for a long ride. Again, if you are not able to compare before you buy, then don't compare afterward unless you can swap at no great cost to you.

bruce19

How did the bike shop determine that a 55 was the right size?

Germanrazor

They were I assuming going on your height and maybe stand over height aka, inseam. To be honest, some bike shops do not do science fitting so they go by the general measurements then pull a bike from the floor and you ride it around the lot. To be honest, you need to ride it for roughly a mile total to get an idea of the bike’s feel to you the rider.

Now if your LBS has a for real fitting resource they will measure you and apply those to the equation to get pretty darn close.

Still the best way to know is go for a ride and not just in small circles in a parking lot. Good luck.

zatopek

I am 6’0”, 33” inseam. Sizing charts typically indicate 56 or 57 cm frames for me. Of my many road racing bikes, the 55 cm frames fit me best as I build them up from frames and can dial in the correct fit by choosing the correct stem length coupled with bar reach. My 2 cents recommend choosing a frame at the smaller end of the sizing spectrum for a person’s height. If you buy a frame that turns out to be a bit large, there is little you can do to adjust your fit. A wee smaller frame and you can easily switch out parts to obtain a best fit. Good luck.

y2zipper

I'd second this. The advice my trek shop gave me was that when you're in-between sizes of a brand, you should typically go for a smaller size because a bike can be adjusted to feel a little bigger but a frame that's too big can't be adjusted to feel smaller.

nomadmax 

You can make a smaller bike larger but you can't make large bike smaller.

leo95se

I wouldnt invest in a bike if I can’t sit on it. Even if it’s sized well what if you don’t like the geometry or dynamics?
As an alternative maybe find a shop that can measure you on a machine? I just got fitted and they used my bike and a serotta. Pretty eye opening.

otherwise I agree with others - size down

jamstu123

By look, asked what height I was and then reviewed the sizes available. The two chaps had a bit of back and forth and said 55. They had 57 available so not like they were trying to sell me what stock they had. Taken from their experience I expect.

Germanrazor

Still in the end you need to ride whatever they place in front of you to get an idea. And like I said, not just in circles around a parking lot. I can ride a Shriners mini bike around a parking lot and find it fun but long term it would be a nightmare.

topflightpro

If the 57 is available, go back and take it out for a spin.

berner

Agree with post #13 .

mpath

A spin around the block won't tell you much. All your touch points - hands, arms, legs, etc., and neck and back - will let you know after a longer ride whether you're too compressed or stretched out.

Iride01 

If you don't have a lot of previous experience with a road bike, then even a test ride might not tell you much. Especially if it is any less than an hour or 10 to 15 miles.... for each bike.

Between a 55 and a 57 there isn't enough difference that can't be resolved by changing things. And as stated by others you can adjust fit more for you with a smaller frame, but there is not as much that can be done with a larger frame.

aliasfox

Do both sizes come with the same crankarm length? Also, might want to make sure there’s a little extra steerer for maybe an inch of spacers, just in case the 55 ends up with a bit too much handlebar drop for your saddle height. Everything else can pretty much be taken care of with stem and seatpost swaps.

The last thing, and I don’t even know if this is an issue with your particular bike, is that the smaller size is more likely to have toe/front wheel overlap (for things like stoplight trackstands). Minor annoyance - or not, depending on how you feel.

ultrarider7

I have a Bianchi Infinito CV 57cm frame. I am 5' 11" with a 33" inseam. It seems to fit me in all directions including reach.

Atlas Shrugged

To be a bit of a contrarian I feel many people ride bikes which are too small. Many of the riders I see around and pictured on this forum have very extended seat posts, lots of stem spacers and sharply upward angled stems. Upsizing gives a rider a more stable ride, reasonable Seatpost extension and minimal stacking of the cockpit. Modern race fit is a small tight frame with a serious saddle to stem drop and long stems up to 14cm. This is not how a vast majority of riders ride. A rider should be able to comfortably ride in the drops for an extended period of time without extensive stacking of the cockpit.

big john

If you've never ridden a road bike it would be good to start with a cheap bike and figure out what you do and don't like about it. Sure, you might get the perfect fit on your first bike ever but sometimes conventional fit doesn't work and your fit will change as you ride more and will change again as you age.
Also, 2 different brands in the same "size" may fit differently due to different top tube lengths, stack height, and reach. This is much more pronounced with mountain bikes but road bikes don't have any universal size standards.

genejockey 

I noticed this looking at bikes on Craigs List. Even very nice bikes seemed very often to have a stack of spacers and the stem flipped up. I wonder if people got talked into buying smaller bikes then having add height to the bars to get comfortable?

And when I recently bought a bike from Canyon, they recommended a Medium for my 6' height and 34.5" inseam. I spent a lot of time with their geometry tables and took repeated measurements of my own bikes, and determined I needed an L, which still has a shorter cockpit than my other bikes, but fits because of the longer reach on modern brifters. And I ended up moving the stem down 2.5 cm, and might go another 0.5.

mpath

Or look at the bikes on TheProsCloset. It often lists the pro rider of a particular bike - and suffice to say their known height is at huge disparity to their bike size relative to us mere mortals.

ultrarider7

I fully agree. Before I got back into serious cycling, the last new bike I purchased was a Trek 410 in 1985. Fast forward 30+ years, I went to REI where I had bought outdoor gear, and I thought I could get started without spending a fortune. They sold me a too small bike, which no matter what I did with seat height, reach, etc. never felt right. After riding it for almost 500 miles, I took it back for service, and the tech told me the bike I had purchased was for someone 5'6" tall and I was a little over 5'11". A good company, they stood by their mistake and gave me a complete refund. I then bought a Cannondale flat bar bike and last year bought my Bianchi.

I would get two opinions! And if possible, ride your new ride for a while and see what you like and don't like about it. Being too tall for a frame gave me cramps. You want it to fit your leg length as well as your reach. Plus you want to be able to get into a posture that you can be comfortable with for at least a couple of hours.

Just my two cents.