I am very confused about how to get a correct fit on a road bike. I am female, 5'5", average weight and proportions, and have a 31" inseam. Recently, I decided to buy a Specialized Ruby after trying out my friend's bike and noticing how smoothly it rides. I was told by one LBS that I should ride a size 51cm or 48cm bike but I feel stretched out. They said it's because I'm not used to the position. When I look at myself in a mirror on the bike with my torso making a 45 degree angle from the horizontal I don't feel comfortable. When I ride with that position on the demo bike I feel stretched out and struggling to support my torso at that angle though my arms don't lock.

Another LBS fitter is convinced that I need a much smaller bike and has tried to fit me on the 44cm. My arms do have a slight bend and I am sitting more upright and don't feel stretched out as much.

So, my question is--who is right? I am also thinking about trying out road racing, so getting the correct fit is crucial.

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    How much time have you spent on bikes before now?
    – BSO rider
    Commented Jul 17, 2016 at 23:43
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    @bso-rider About a year. I have an old 1982 road bike that I use for commuting. It has a 50.5cm tt and when I ride 30-40 miles on it I always have neck pain.
    – MNRC
    Commented Jul 17, 2016 at 23:58
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    Sounds like a general strength issue to me. I think you should get the smaller bike, making sure the seat height is correct. As you develop strength, a larger bike will fit you better. The smaller bike will also be easier for you to control at this early stage of your cycling career.
    – andy256
    Commented Jul 18, 2016 at 0:47
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    IMO, it is better to have a bike that's too small than one that's too large. Commented Jul 18, 2016 at 1:00
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    It could also be a bad saddle position. If your saddle is too far forward (and maybe too low) you’ll need a lot more arm and core strength to support yourself. A picture of yourself on the bicycle would help.
    – Michael
    Commented Jul 18, 2016 at 9:26

4 Answers 4


Honestly, whichever feels most comfortable to you is the one you should go with. Take both of them for as long a demo ride as the shop will let you and don't pay attention to how the fit "looks" in the mirror. Whichever frame you decide on, be sure you get a fitting from a reputable source - ask other cyclists you know to see who has the best reputation in the area.

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    Unfortunately, both LBS are very reputable and were recommended by friends. The LBS trying to convince me to go with a 48cm bike is Zen Bikes in Manhattan (NYC) and the other LBS telling me to go with a smaller bike is Ride Brooklyn.
    – MNRC
    Commented Jul 17, 2016 at 23:40
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    I would use the test rides to determine which bike, but your fellow cyclists to determine who/where to get your fitting done (ie BikeFit, Retul, etc - more involved than just frame size).
    – Ealhmund
    Commented Jul 18, 2016 at 1:23
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    You're absolutely right--the bike that is the most comfortable for your body is the bike you should buy. I tried a bunch of bikes in different sizes and the Specialized Ruby in 51cm gave me the best fit. The store display model with factory settings fit so well it requires pretty much no tweaking at all. Whatta day! I finally found the bicycle of my dreams!
    – MNRC
    Commented Jul 20, 2016 at 21:26

This answer expands on my comment

Sounds like a general strength issue to me.

Especially since you have mentioned neck discomfort after 30 to 40 mile (50 to 65 km) rides.

I think you should get the smaller bike, making sure the seat height is correct.

The correct seat height is also dependant on your strength. As you get stronger the seat can begin to feel too low. If this occurs, raise it by very small amounts (1 or 2 mm). Be vigilant about any knee discomfort or pain; it's a sign that the seat is the wrong height for you. Talk to your shop guy about it immediately.

As you develop strength, a larger bike will fit you better. The smaller bike will also be easier for you to control at this early stage of your cycling career.

You can extend the life of your bike by switching to a longer headstem if the bike starts feeling too small.

You already felt that the smaller bike was better for you, and a couple of answers here support that view. It's important that you feel you've made a sound choice. It helps to have confidence in your equipment. But I recommend talking to the guy who recommends that smaller bike and asking questions such as

  • The other shop suggests a bigger bike. Why is this smaller one the best for me?
  • As I get stronger will my fit change?
  • If I feel the bike is too small what would they do for you?

Happy cycling.

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    It's also good to keep in mind that just because you bought the bike from shop X, doesn't mean that shop is good at actually fitting the bike to you. I can't speak for the NY region, but in my area, the best fitters (by reputation and results) don't have the biggest bike selection. Don't be afraid to look for a third party when it comes to the actual in-depth bike fit.
    – Ealhmund
    Commented Jul 18, 2016 at 11:42

My partner of the roughly the same size had similar fitting issue with the Ruby, tried a different bike and found that more comfortable.

The 48cm felt a little too small for her and the 51cm too large. I think a 44cm would be too small for you in the long run, and would probably go with the 48cm but it's impossible to be sure without actually seeing you on the bike, and knowing the type of riding you want to do.

The main thing really is to find somebody to fit you that you have confidence in. If you get the impression that he's just a salesman, who last rode a bike was 30 years ago, and he's just interested in making the sale - then any form of initial discomfort is just going to niggle at you. If you trust the person, they seem to know what they are talking about, and can assess your strength and flexibility, then you're more likely to adapt to the new position.

If a shop doesn't actually put you on the bike, won't make adjustments to the saddle position, seat height, and handlebar rotation then personally I would run a mile and go elsewhere. If they have none in stock, then any reputable dealer should be prepared to order one in and replace it if it doesn't fit well.

As a side note: although fit is much more important, be aware that on smaller frames it can be impossible to fit two water bottles.


All bikes geometry are different. So only fools will use "bikes cm/inches" for bike fitting. The best reference are "Effective Top Tube". The straight horizontal length from the head tube to seat tube.

The rest are adjustment. Comfortable posture can be fixed easily by raising the handlebar stem or replaced with an adjustable stem (because most of the time , LBS will cut it TOO SHORT to make it looks "cool", instead of using lots of spacer to maintain margin for unknown client) . While the seatpost can be raise and lower depends on fitness and requirement.

For a seasonal bikers, a 45 degree torso angle are insane. Just recall my first fitting that didn't gone right : because LBS assume "correct pro postures should fit for a all typical client".

After reading sheldon brown blog, I realise LBS absurdness(perhaps lazy to think for the client), I get an adjustable stem and raise the handlebar height by 5cm, lower the seat by 1 cm, and most of the pain gone. These two parts heights re-adjusted whenever the body feels ready.

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