# How to tell if a bike is the right size?



## Chris400 (Apr 1, 2013)

I’m trying to buy my first road bike, but I’m getting a little frustrated when comes to finding the proper size for me. I have looked at the charts, which appear to put me in a 56cm or 58cm frame. (I’m right at if not a little over 6’.)

Now I realize that one static measurement may not be able to perfectly map to one frame size, and all the charts say to see your LBS for proper fitting.

Therein lies the rub. I have been to two of my LBSs and in both cases there seemed to be very little attention paid to what frame size is right. They basically had me sit on the bike and then adjusted the seat post until my leg was nearly fully extended on the down stroke. But given the amount of adjustment available in the seat post it seems like you could make a lot of bikes fit.

So I’m trying to figure out how to judge if a bike fits or not. I know people say make sure it feels right, but I’m not sure what I am supposed to be feeling. I realize the best solution is probably keep shopping until I find a LBS that I feel confident in, but I’m running out of options.


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## Cluster (Oct 26, 2011)

More info is needed

What Bikes did they have you sit one and what were the Sizes

What type of bike are you looking for?


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## Zeet (Mar 24, 2013)

Some bicycle shops will adjust any kind of bike to whatever orientation, just to make a profit. It may not even be the type of bike that's in your best interest. Therefore, you must first find a reputable bicycle shop where the staff is both knowledgeable and concerned. It would also help, if the shop is well stocked.

It's really difficult to determine a person's frame size online, because nobody can actually visually observe either the bike and it's geometry, or the cyclist and his dimensions. Since everybody has their own body type, what may fit one person of a specific height, may very well be off for another person of the same identical height, because trunk, arm, and leg lengths all vary. 

One thing is for certain though. If you do make an error when purchasing a bicycle, it would be better to err on the short or small side than the large size. If you end up with a bike that's slightly smaller than your ideal size, you can usually make adjustments for fit. However, if you purchase a bike that is too large, there is generally less that you can do about it. Then you're just stuck until you can sell it.

Therefore, try to find a shop where the staff is focused upon your own personal satisfaction and comfort. If they are not eager to please and serve you, then just walk away!


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## PJ352 (Dec 5, 2007)

Chris400 said:


> I’m trying to buy my first road bike, but I’m getting a little frustrated when comes to finding the proper size for me. I have looked at the charts, which appear to put me in a 56cm or 58cm frame. (I’m right at if not a little over 6’.)
> 
> Now I realize that one static measurement may not be able to perfectly map to one frame size, and *all the charts say to see your LBS for proper fitting.*
> 
> ...


The first bold statement should tell you two things. One, charts aren't as reliable as a knowledgeable LBS fitter and two, based on your inputted data, the best they can do is get you in a size _range_ which (as you're experiencing) can confuse more than clarify.

The second bold statement answers your quandary - leave the fitting to the fitter.

The LBS's you're going to may be fine. You just may not be thinking they are. The reason I say this is because you may be expecting a standard fitting be done for test rides. While this is the case at some shops, IME, they're in the minority. Also, you mentioned seat post adjust-ability. Just because a post can be raised and lowered by several CM's doesn't _necessarily_ mean you weren't properly sized by a given shop.

Additionally, don't be overly concerned with being sized to different frame sizes. Those numbers are relatively arbitrary and vary from brand to brand.. and sometimes with in brands. So, it's very possible that you'll take a 56 in one bike and a 58 in another.

All that said, setting saddle height comes after a fitter determines your reach/ drop requirements. The reasons being, 1) they're key to a good fit and 2) their ranges of adjustability are relatively small when done correctly. 

The 'right' fit is really about comfort, because comfort translates into performance, and many fitters with some experience can (more or less) eyeball someone on a bike and (with feedback from the rider) dial in a good fit.

If, with more info relating to fit, you still aren't comfortable with your local shops, I suggest branching out some. Before making the trek to these other shops, call and ask what a standard fitting consists of - and ask your LBS's that same question. You may find the answers to be similar.


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## AndrwSwitch (May 28, 2009)

It's pretty easy to feel when a bike is the wrong size. Get the shop to put you on a 52. And, try the biggest bikes they've got.

As you observe, there's a fair amount of vertical adjustability in bicycle sizing. This wasn't always true and has influenced some of the guides even now. However, the reach is a lot harder to adjust. Outside of a relatively small range, it can really mess with the bike's handling to try to fit it to someone the wrong size. So in general, you're looking for the bike that can have the saddle and handlebars placed at the right height for you, and that needs the smallest (or no) change from some ideal stem length. Some posters here write that that's 110 mm. The real thing you're trying to get is good weight distribution over the wheels. Too little weight over the front wheel feels twitchy, and I'm smaller than the average American so I can't really say what too much weight feels like, but it's not supposed to be good either. But it's a lot easier to see and measure stem lengths, and bikes within the same class aren't too different from one another in terms of how they respond to different stems.

Anyway, when you nail the weight distribution and reach on a bike, barring having to do something ridiculous to put the handlebars at the right height for you, you're good.


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## Chris400 (Apr 1, 2013)

Thanks all for the great responses. I test rode three bikes. A CADD10 at 56cm, a Trek 3.1 at 56cm and a Specialized Tarmac at 58cm.

I guess the disturbing part to me was that each shopped asked my height and then grabbed the bike size based on that, which gave me the impression they're basically just using a height chart. I realize that the bikes I'm looking at are on the entry-level end of things; nonetheless it's still a significant amount of money to me, so I would like to get the size right on the first try.

I didn't realize that reach/drop is really the first point of measure rather than the seat height. Now that I think about it, this is rather intuitive since the seat easily adjusts whereas the handlebars do not.

Armed with this new information I think I'm ready to go find a bike shop I'm comfortable with and bring home a bike. Again, thank you.


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## dnice (Jul 12, 2012)

try the competitive cyclist size calculator, then take your dimensions to the bike shop and ask their thoughts on a fit using those dimensions. this is not to say that it's gospel, but it's a very good guide that most shops are familiar with and helps point them in the right direction. also try to get a long test ride when you settle on a couple choices. the parking lot just doesn't cut it, i'm afraid.

Fit Calculator - Competitive Cyclist


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## PJ352 (Dec 5, 2007)

Chris400 said:


> Thanks all for the great responses. I test rode three bikes. A CADD10 at 56cm, a Trek 3.1 at 56cm and a Specialized Tarmac at 58cm.
> 
> I guess the disturbing part to me was that each shopped asked my height and then grabbed the bike size based on that, which gave me the impression they're basically just using a height chart. I realize that the bikes I'm looking at are on the entry-level end of things; nonetheless it's still a significant amount of money to me, so I would like to get the size right on the first try.
> 
> ...


I won't go so far as to say the shops were wrong in sizing you to those three bikes, but all three have similar geo, so sizing should be close to the same. 

I completely agree with you on the shops being (essentially) wrong in using height alone as a basis for your sizing assessment. There's more to it than that, including proportions (which is actually more important than height alone), fitness/ flexibility, cycling experiences... so you may want to branch out a little and discuss your concerns with some other LBS's. As I mentioned earlier, ask what their fit process is. I think now you know better what to look for in their responses.

Also, it shouldn't matter how much a customer spends on a bike at an LBS. The services should remain the same. I suspect they would at the shops you visited, which is another reason to continue to shop around.

Lastly, IMO/E online fit calculators serve to confuse more than assist, so I'd pass on trudging through the measurements. Any knowledgeable fitter working one on one with you will get you closer in 20 minutes. As you said in your OP and I bold typed, leave the fitting to the fitter.


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## Chris400 (Apr 1, 2013)

Thanks again. I think PJ352 pointed out the real value of this thread to me. That is, even if I can’t perfectly fit myself; I now feel in a better position to tell if the LBS is going through the right process to get me the right sized bike.


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## captain stubbing (Mar 30, 2011)

for your height those bikes appear to be in the ballpark of being the right fit for you however proof is in the test ride.

make sure that when you do that you are not stretching for the hoods.....so you should be able to have some bend in your arms and your shoulders should be relatively flat and relaxed....not rolled forward.

good luck!


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## Zeet (Mar 24, 2013)

captain stubbing said:


> for your height those bikes appear to be in the ballpark of being the right fit for you however proof is in the test ride.
> 
> make sure that when you do that you are not stretching for the hoods.....so you should be able to have some bend in your arms and your shoulders should be relatively flat and relaxed....not rolled forward.
> 
> good luck!


+1 

Also, when you pedal, your leg should never be in a fully extended position. There should be a bend in the knee at all times. Once the pedal is in the 6 o'clock position, there should be a slight bend at the knee, when the ball of your foot is centered on the pedal.


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## Schneiderguy (Jan 9, 2005)

Find a bike shop you feel comfortable with. The LBS will make more profit off selling you all the goodies you need, now an in the future, than off the bike. And this will not be you last bike if you like cycling. I would look for shops that sponsor a significant club and have weekly organized rides at various levels. Some shops include a basic fitting within the price or for a modest price. For more $ you can buy a more detailed fitting which you probably don't need at this point because your postion will change with time and miles on the bike. But I don't think it unusual for a shop to look at you and put you on a couple of frame sizes in the ball park. As has been mentioned frame sizes differ from manufacturers as to toptube lengths, seattube angles, headtube lengths and headtube angles. IMHO the two most important specs are the toptube length (but this has to be calculated knowing the seattube angle) and headtube length. As long as you can get the proper bend in your knee the seattube length is not as critical. You don't want to have to use a very long or short stem. So Ideally a 100 or 110 mm steam. My problem is finding a production bike with a short headtube as the trend has gone to long headtubes. The compact frame geo makes sizing easier and cheaper for the bike companies because they can build fewer models as these can be made to fit a greater ranger of riders. To rap up-you want a bike with a toptube length, seattube angle and headtube length that you can comfortably ride with a 10/11 cm stem and handlebars an appropriate width for your size.


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## AndrwSwitch (May 28, 2009)

Riders' reaches do correlate to their heights, but are really hard to measure with something other than a test ride. Weight distribution is even worse.

If I had a shop, I'd probably just guesstimate a customer's size by eye, put him on a bike, and then try to improve upon my initial guess based on talking about how it felt.

I don't have a bike shop and maybe with time I'd learn that I needed to impress my customers with a little ritual involving a measuring tape and a goniometer. But I think I'd just be doing that as window dressing, and my real process would be to try to get customers on bikes that felt right.

Now, I don't know what happened after you rode those 56 cm and 58 cm bikes. If they just tried to sell them to you, maybe find another shop. But fit is as much art as craft, so if they tried to have a conversation with you, follow the process a little further and see what you end up riding. It's not like you're committed until you actually agree you are, and they should have plenty of bikes sized in that range already on the floor and waiting to be ridden.


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## Chris400 (Apr 1, 2013)

This forum continues to be a wealth of knowledge. I can appreciate that the best approach may be to ballpark the frame size and then make the necessary adjustments from there. I guess at the end of the day it came down to the fact that I wasn't confident that either LBS was going to get me into the right frame size—that's not to say they wouldn’t have.

To their credit both bike shop asks me how the bikes felt after the test ride, and in both cases I answered as honestly as I could. Basically, that they felt okay, but I really didn’t know what it should feel like. I realize that doesn't give them a lot to go on, but the conversations seemed to stop there. There was no hard sell, but just a "what do you want to do?"

I did find a bike shop that has some fancy fitting system and they will do a basic fitting to get you into the right bike for a nominal cost, which is then refundable with a bike purchase. So, I'm going to give that a shot. Maybe it's a dog and pony show, but I'm hoping it will give me the confidence I need to settle on a bike size.


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## Zeet (Mar 24, 2013)

If the top tube is completely horizontal and NOT sloped, while straddling the horizontal top tube, you should be able to place two of your fingers between your groin and the top tube. If you have fat fingers, one is enough!

That said, the only genuine experiment that will serve as real evidence of a truly good "fit", will be your comfort when riding. I've known cyclists who still weren't satisfied with their bicycle comfort, even after being fitted by so-called "experts". The only real "expert" is you. 

That's not to say that getting properly fitted does not serve a purpose, because to some of us, that service is absolutely necessary. However, most cyclists don't actually get professionally fitted. It is not an exact science and it is not a prerequisite!

My advice would be to visit as many bike shops as possible, and test ride a whole bunch of road bikes, just to get a baseline of comfort from which to judge all of the bikes in the pool. Take your time.....There's no rush to buy a bicycle that you may very well end up owning for the next decade or so.

Eventually, one of those bikes will call your name! :thumbsup:


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## BostonG (Apr 13, 2010)

Size and fit is different. A salesperson worth their salt will have no trouble looking at you and making the right choice of which size is right. From there it's up to you and the peron who does the fitting (if you choose to get one). 

So different bikes that are both the right size for you can still feel different to you when riding them. Assuming the size is correct (that is the easy part for a salesperson), choose the bike that feels best to you. Then, when the fitting session comes, the fitter will make adjustments based on whatever method he/she uses. My fitter used no fancy gadgets - he used an interview, his eyes, and some basic tools like a ruler and plumb line. There were a good amount of adjustments made but the real test was how I felt on the bike afterwards, which was great.


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## Hooben (Aug 22, 2004)

In my shop the panel of experts gathered around me up on a bike on a magnetic trainer. Everyone looked and discussed and measured. Then a consensus was taken and a bigger frame was needed. Finally after much discussion, everyone agreed I looked good and the bike indeed fit. Nobody has ever disputed that fitting and I have felt great on the bike for years now. That's probably the way it should be done at your shop.


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## Zeet (Mar 24, 2013)

Hooben said:


> In my shop the panel of experts gathered around me up on a bike on a magnetic trainer. Everyone looked and discussed and measured. Then a consensus was taken and a bigger frame was needed. Finally after much discussion, everyone agreed I looked good and the bike indeed fit. Nobody has ever disputed that fitting and I have felt great on the bike for years now. That's probably the way it should be done at your shop.


+1

While this is the ideal situation for any prospective road bike customer, this is NOT what usually happens in the avergage LBS. We all wish we could get this kinda treatment.


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