moxtwelve

Hi all,

New road bike rider here.
Main question: When I'm riding, what can I look for to understand if my bike is too big? If it is just a little bit big, how can I mod it?

I'm 5'6'', F, 30'' inseam, and flexible. A comfortable position for me is sitting with my feet outstretched and folding my torso all the way over. I mention that as I've heard flexibility can be a factor in riding comfort and bike fit.

A few months ago I got my first road bike on clearance at REI: a 2014 Cannondale Synapse Carbon 5 105. It was 54cm. For a first road bike, the price was right. I bought it because I loved the way it handled, and loved the color. But I began to feel cramped on rides. So reluctantly I returned it.

I found a similar one: 2016 Cannondale Synapse Alloy 105 C. It was online only, so I had to take my chances and order it without test riding it. I gambled on the 56cm bike per my last one.

The order arrived today. I took it out for a spin in my neighborhood, and I can't figure out if it's too big. I like the way it handles, and it is more comfortable than the 54cm bike but it does feel a tad oversized. I can stand over the frame fine, and the seat is quite low. It could go down more, but not much more.

I'm going to take it out this weekend for a long test ride, and I'm not sure what to look for in terms of comfort while riding. When my leg goes down on the pedal, it's pretty much straight with the slightest bend. I'm wondering if it should bend a bit more? I've done research and most people seem to have smaller bikes even with taller measurements. But I'm also wondering if that's where my flexibility comes into play.
Luckily I have a year to exchange it, but I don't want to keep it longer than I need to. I also hope to order the 54cm if I need to before they sell out. If I need to do that.
I've read enough to know that all bikes fit differently, so I'm not sure if I should ask, is it too big? It probably is to most people. It would be more cool to be more informed about how you should be feeling on a bike. Especially if there is a learning curve. I'm sure your experience could teach me a lesson on something, so, I welcome input and suggestions! Thanks.

theraggyone

i would of thought a 56cm cannondale was way to big for you. im 5'7 with a 30" inseam and i ride a 50cm (not cannondale but my bike has the same geo as a supersix) and it fits me like a glove. i would expect someone of around 6 foot to need a 56cm

k_kibbler

It's too big for you. You should probably be on a 50, or smaller.

Flexibility can help a taller rider ride a smaller (read: lower) frame because they can handle the posture. Flexibilty can't help a smaller rider ride a frame that's too big. IOW, flexibility doesn't mean stretchy.

It's also difficult to tell you how a properly sized bike should feel like because you have little baseline for comparison.

Get a bike fit. Or, at the very least, run your measurements through a few online bike size calculators, to get a starting point.

rms13

All bikes do fit differently and no two people are necessarily going to fit the same bike based on their height alone as people have longer legs, longer torso etc. I'm almost 5'11 and can fit a 54 or 56 Cannondale but prefer 54. The top tube length is most important measurement to fitting a bike. You can compensate with different length stems but too long or too short of a stem will effect handling characteristics. But I would think 54 would be the biggest size you would want for the Cannondale and maybe even 52 although women's models run a little different than unisex models. REI should definitely fit you to the bike in store. Bring it to them and have them set it up for you and if they say it's too big get a smaller one. Luckily REI has a great return policy if needed

Maelochs

If your bike is too big, you are screwed. If it is a little small, you can make it fit perfectly with readily available and inexpensive parts, or maybe simple adjustments.

When you say the 54 felt "cramped," what exactly do you mean? If the bars were too close, you can buy a longer stem. if the bars were too high or low, you can get a stem of a different angle, flip your existing stem (unless it is 0 degrees of course) or add or remove spacers under the stem.

If the 56 feels a little big (it should, I'd think) then maybe look at the 54 and see how long the stem was, how many spacers it had ... see if there was room to stretch it (assuming that was what you wanted.)

The one fit item which really doesn't change much is saddle behind bottom bracket. Many people suggest starting with what is called KOPS (knee over pedal spindle) and adjusting the seat backwards and forwards in millimeter increments until you feel like you are getting max power with comfort. Once you have the saddle set, the rest of the cockpit has to be adjusted to fit your body from there.

(You can raise or lower the saddle and move it forward and back to get the leg extension which works for you (no knee pain no matter how far you ride, leg should be almost extended for max power but bent enough that you never risk hyperextending---there is a Bike Fit forum here (Fitting Your Bike) where there is a ton of info, or google a few different sites. When you raise the saddle it moves back as well, so you might need to adjust fore-and-aft positioning again.)

Of course there is no universally "perfect" set-up. Everyone's proportions are different--leg length versus torso and arm length---and everyone has a different degree of flexibility. You have to decide for yourself.

I ride a 50 cm Dawes, a 58 cm Raleigh, and a 61 cm Cannondale---all fit nearly the same because of stem and seastpost differences. Each is a little different because of head- and seat-tube angles, fork rake, and chainstay length--but I can comfortably ride them all. (I am 6'1" and almost every one would put me on a 58 or larger, but my short torso and stiff back makes a smaller frame much more comfortable.)

As rms13 notes, Reach is one of the most important aspects of fit.

Reach, which is (I think) defined as distance from BB to stem along the effective top tube, but is basically how far from the seat to the bars, is where most adjustment needs to be done (and it is the hardest to adjust.) Reach determines how bent over you are, whether your weight is over the pedals, how much weight you need to carry on your hands ... all of which Really matters after your first 45 or 90 minutes.

If your hands get numb, your shoulders get tense, your neck or lower back start hurting, depends on reach. (It also affects power output but really, if the rest of the stuff feels right you will be fine unless you are a pro racer and have a pro-level coach who will no doubt have his/her own system.)

The big difference between bigger and smaller frame sizes tends to be seat tube (which is widely adjustable via seatpost,) top tube, which is slightly adjustable via stem length, and head tube, which is adjustable via spacers under the stem. None of these can be made shorter, which is why most people recommend a smaller frame---buy a longer stem and some spacers, and your smaller fame has the identical cockpit dimensions.

I'd check out the 54 again and see how much room there is to adjust it. "Cramped" can mean a lot of things---only you know what you need. Maybe the 54 could deliver if adjusted differently.

Too big cannot be fixed. However there is a whole school of bike fit thinking (the French School, I believe) that puts riders on the biggest frames they can handle, with minimal seatpost exposure and the bars all the way down. The only problem here is that if you want more seat-to-bar drop (the bars significantly below the seat) you need a smaller frame.

After a long ride, you should know better if you are happy with the 56. Most people would say the frame is way too big for you, but yuo are not most people, and if it fits, it fits.

thin_concrete

I agree with @Maelochs - take it out and see. FWIW, I'm 5'8" with a 30" inseam and ride a 53 now. Before that, I rode a bike that was too big for me and I had tremendous upper back pain after rides from stretching out so far.

kleng

I'm on a 53cm or 54cm top tube frame and I'm 5'7 with a 31 inseam.

A 54cm is the max for me even with flexibility.

You must have longer than normal arms to reach the bars comfortably, but if they are normal length, I'd say you should be on a 53cm

Center of the bottom bracket to the top of the seat should be in the 67-69cm range

Here are some basic fit guidelines to start with

BikeFit - Road Bikes

also check out the Cannondale sizing guide for direction

https://www.evanscycles.com/product_d...zing-chart.pdf

Does your 56cm synapse have an extreme short stem ? Normally they are 90 -100 mm

bruce19

Just a couple points. Using the sizing method espoused by Cyrille Guimard (Greg LeMonds' Coach) you would "ideally" ride a 51. This is based on inseam. However, that is a traditional frame and not a sloping TT which I think may afford some flexibility. There are at least three different basic frame sizing methods that I know of. You will find them at the sizing page on Competitive Cyclist. As I recall they are the Race, Eddy and French fit formulas. They will give you a range of sizes that can work for you. In my case, I have a 32 inch inseam and rode a 54 for years. Loved the fit of that bike. I currently have a 55 Guru steel and a 58 Masi Gran Criterium AL that I can ride equally comfortably and well. I will say that the Guru is a perfect fit while the Masi is good with a 90 stem. You might also want to consult a fitter about Stack and Reach to see how that fits into the equation. In general though there is a range of frame sizes and TT lengths that can fit or be made to work.

topflightpro

I'm going to go ahead and say the bike is too big for you.

I cannot imagine any set of body proportions that would set up a person 5'6" to ride a 56 Cannondale. While you haven't posted any photos, I would bet you have the saddle sitting on the top tube to be able to reach the pedals.

rms13

OP has a women's specific Synapse which has an extremely sloping frame. The seat tube is lower than the back tire so if her saddle is all the way down that will be a real big problem

goenrdoug

I'm just shy of 5'11 and I ride a 56cm Supersix with a 90mm stem.. So, yeah, I'd say you're probably on too big of a bike.

You might consider going back to the 54 and putting a longer stem on it and/or bars with more of a drop. Ideally, REI would have suggested this instead of sizing you up to a too-big bike.

dim

These are my measurements:

My Measurements (cm)
Inseam: 74
Trunk: 61
Forearm: 39
Arm: 66
Thigh: 58
Lower Leg: 54
Sternal Notch: 143
Total Body Height:170

I contacted Bianchi and based on my measurements, they said I need a size 53 bike

Erzulis Boat 

Bike is too big. Even with those SPD compatible KISS boots they sell.

Never underestimate the human body's capability to adapt, but there are reasonable limits!

chasm54

Miles too big. With a 30" inseam I'd suggest looking at a 52cm rather than a 54cm, and experimenting from there.

RonH

Sounds like its way too big for you. I'm 5'-11" (30" inseam) and all 3 of the Cannonades I've had were 54cm. Test rode 2 different 56cm models and felt stretched out and uncomfortable. Did you buy from a bike shop and/or get fitted?

rms13

by most people's responses, it doesn't seem clear that OP is female and talking about Women's specific Synapse which has geometry that runs different than the unisex model. The women's 56 is between a 54/56 in unisex. The 54 that she originally had is between a 51/54. But I would still guess she should be on a Women's 51

OP, this fit calculator can give you a good starting point

Bike Fit Calculator | Find Your Bike Size | Competitive Cyclist

And compare to the geometry chart for your bike

Product size chart - REI.com


Then take it back to REI and have them exchange it for the correct size and have them do a basic fitting to set up saddle height and fore/aft and handlebar height. And consider that you may still need to swap the stem to get a "perfect" fit

jtaylor996

That has to be wayyy to big for you. I'm 6" taller, but with the same inseam, and ride a 54 synapse. I miiiight be able to stretch it to a 56 on the EVO geometry, but then again, my torso is 6" longer than yours to do that.

bikebreak

Yes, a flexible short rider can ride a bigger frame. Should you though? Depends.
A 56cm is kind of pushing it. I am about your height and I have ridden a size 55 which had a 57cm top tube, I had to have the seat way forward and use a 9cm stem on top of an inch of spacers (every 30mm in spacers reduces effective top tube about 10mm). I now ride a 54 with a 10cm stem. According to many size charts you and I should be on a 51-52.

For a short rider on a bigger frame, the disadvantage is that your arms are going to be stretched out in front of you, and shoulders rounded forward. In extreme cases you will look like you are time trial position, but without the pads to support your arms. This can lead to arm, shoulder, and core muscle fatigue.
A smaller frame is going to bring your upper arms backwards and more under your shoulders and hands lower. This may help if you are having upper body fatigue.

Pictures of you on the bike in a trainer would help here.

Modern "Race" fit has riders on a shorter small frame with a lot of drop from saddle to bars. On a bigger frame you have a longer horizontal reach and less drop. Some prefer this fit, look up French fit and Eddy fit

In the meantime, try varying hand positions - resting hands on the tops (the closest part) of bars while climbing or just moseying along will rest your shoulders a bit. You will probably want a smaller frame in the long run but you don't need a tiny frame with lots of drop.

RJM

It's too big for you. At 5'6", which is about what I am, you should be riding between a 52 or 54 in that cannondale.

moxtwelve

Awesome, thanks. I'm reading everyone's input here and it's informative. Also realized I should have specified it's a women's bike.
I actually tried to have the REI bike clerk do a proper fit, but he didn't seem to care too much and was mostly reciting information at me. I'm thinking he may not have known how.

Based on the measurements of the Bike Fit Calc, I do need the 54cm? 51cm may be too small.

For reference, in case anyone's curious to compare, these are my measurements:


Actual inseam: 30 (though I think it may be closer to 31)
Trunk: 22
Forearm: 11.5
Arm 23.5
Thigh: 19
Lower leg: 21
Sternal notch: 52
Total height: 66

And this is what the bike fit calculator came up with:

dtrain

I'm piling on at this point - but I agree that the 54cm with proper fitting and stem length would be pretty darn close. I don't think you should have sized up. How long ago did you return the carbon 105...is it still in the shop (and an option)? Did they have other 53-54cm bikes you could try? Best wishes.

dcsix

Before I chose my 54 Spesh Roubaix, I rode a 54 Carbon Synapse and it fit about the same as the Roubaix. I am 5' 8 1/2", you probably just needed to to a proper fitting to the 54 you had. If you were "cramped" on it, then a longer stem, seat further back, etc etc; I think that's your size, fwiw.

Stratocaster

I'm the same height as you. When shopping for my own bike, I had to narrow it down between the 52 or 54 Cannondale CAAD 10.
They both felt pretty good, but I opted for the 52. I just fits that much better.

With you being female, I'm not sure what that might mean...but I'm guessing 51 for you.
By the way, the Synapes has a longer head tube I believe...more "relaxed" fit perhaps.
Just throwing that out there.

jtaylor996

I'd say you need to try the 51 for a while. You're going to be pushing it so close with a 54 and a 90mm stem (which is what I ride, btw). The Synapse has a longer frame than traditional geometry, and it comes with a longer stem than this calc is recommending. I say get the 51.

kevmk81

5'8" and on a 51 cannondale. had to install a pretty lengthy stem, but it all fits great!