How To Choose The Correct Size Of Road Bike Frame

[RonK]

Ok, this is an faq on the forums, and this video by the Global Cycling Network has gone some way to helping you answer it. It's well worth your while to subscribe to the GCN, and invaluable if you are a beginner cyclist, as they have produced an excellent range of videos to address many of the faq that arise over and over, such as how to perform a basic bike fit, how to position cleats, what tools you need, and how to clean your bike, and many, many more. If fact there are very few questions I can think of that are not answered. And there's some great humour too. Check them out.

Mods please make this thread a sticky.
Agreed, pedal spanner with 1m breaker bar applied, it aint going nowhere, ever!

[Blinding]

+1 I have also subscribed to GCN and they have helped me to understand a lot more about cycling as a noobie myself.

[tron07]

This is a good video as well

[cyclebee]

Ok, this is an faq on the forums, and this video by the Global Cycling Network has gone some way to helping you answer it. It's well worth your while to subscribe to the GCN, and invaluable if you are a beginner cyclist, as they have produced an excellent range of videos to address many of the faq that arise over and over, such as how to perform a basic bike fit, how to position cleats, what tools you need, and how to clean your bike, and many, many more. If fact there are very few questions I can think of that are not answered. And there's some great humour too. Check them out.

Mods please make this thread a sticky.
Agreed, pedal spanner with 1m breaker bar applied, it aint going nowhere, ever!

There were a lot of talking in the video, but frankly, I did not think it answered the question - "How to choose the correct size road bike frame?"

[Jason1170]

I am after advice in relation to buying a 2014 Giant TCR, I am 189cm tall and going by the Giant sizing guide I should need a large. I have got mixed advice from bike shops who have said I need a large or I could ride a M/L. Can anyone give me some advice.

[ValleyForge]

I am after advice in relation to buying a 2014 Giant TCR, I am 189cm tall and going by the Giant sizing guide I should need a large. I have got mixed advice from bike shops who have said I need a large or I could ride a M/L. Can anyone give me some advice.

Probably best in a separate post, rather than tagged on here.

Too many variables to consider. On the face of it, yes you would be an L. But you could ride some brand's M/L quite happily, say in a flat bar configuration with a long stem and a lot of seat setback and be pretty OK for rides < 1Hr. But I doubt that's what you're looking for!

And there is fashion to consider - when I was working in my LBS in the 80s, you encouraged buyers up a size - better chest expansion with more reach, lower profile, more aero. Then maybe 10yr ago it was more like a M frame, put the pole up a lot, sitting forward on the seat, stack slammed down.

Don't ask me now where the fashion is! You just need an LBS which will listen to you and give you a good test ride.

[ozbiko]

I am 194 cm tall and started getting a back ache riding a giant L size... Taking a break from cycling to avoid further damage to my back

[singlespeedscott]

Hight alone is not your best indicator for size. Some may have long legs and arms paired with a short torso so generally would be better on a smaller frame with its shorter top tube. Stumpy legs and arms with a long torso would see you looking for a longer top tube do a larger frame would suit. Don't get cuaght out with a to short or long a stem trying to make the wrong sized frame fit.

[ProBikeFit]

There are a number of variable in choosing the correct frame size, inside seam x .67 and Torso + Arm length / 2 = top tube would be the easiest calculations. These do not give you a saddle height or handle bar stack height they are a good a place to start and do not take into account the variation in Head tube length (effecting number of spacers under stem) to achieve desired back angle. I would expect on a 52cm or smaller bike an 80 to 100mm stem on a 54-56 90 to 120mm 58 up 100 to 130mm.
If you are ave height say 180cm a 54 to 56cm frame would suit keep in mind Italian frames and Cannondale run traditional shape frame (shorter steerer tube) while Cervelo and Trek use longer steerer tubes on equivalent size frame to Italian. regards ProBikeFit
PS what is wrong with your back?

[Dufer91]

Hi guys just wanted to get some general advice without a sales pitch attached to it. I'm looking at taking up riding as a hobby to lose some weight I emailed away to a retailer asking them about a bike that would be suited to me. I'm 6"1 and on the southern side of 150kg (143) I'm not wanting the spend a great deal as once I know I'm committed to it I will look at upgrading and so on. The bike they suggested to me was
2016 Polygon Path 2 - 29er City Bike https://www.bicyclesonline.com.au/2016- ... -city-bike" onclick="window.open(this.href);return false;
What do you guys think?

[Harrys767]

Hi Dufer91,

Good on you for getting the motivation to shed the kgs. That's why I got into cycling initially. I don't know the specifics of that model, but in general so,etching like that bike will be a good starting point. It's a relaxed posture and you won't need to worry about damaging the frame. As you get lighter, more flexible and faster you will start to naturally look around at "better" bikes. ie bikes that suit your riding style more (road, hybrid etc). I've just purchased my first proper road bike and am loving it.

I'd recommend that you buy a basic bike computer as the data will be a big motivator (distance and average speeds etc). But make sure includes a heart rate monitor as you have the ability to monitor your heart rate zone and can keep it in the best band for weight loss.

I'm a relative newly, so plenty of other will have opinions too.

Good luck!

[Dufer91]

thanks very much and good on you too i might go in store and check it out, just shopping around at the moment until i move closer and can actually consider riding to and from work

[AlMac]

The simple answer is to get a Bike Fit.

It will help you get the right frame and then set it up comfortably.

Well worth the investment.
One of the best you can make.

[Ant_S]

I personally have found that you need to find a bike shop with staff you trust, or at least be very careful not to be caught out by stores wanting to clear floor stock or scared to order a bike in for you to try.

I've bought 3 bikes new and all have been big to varying degrees, the latest cost me over $2k and is about right with a 90mm stem. However it took me to work that out and buy & install the stem...

None of the staff offered me any fit services, none of them set the bikes up for me properly to test ride (they just eyeballed the seat post at best) and overall I've done my own 'fit' just from riding.

I do agree totally on the Bike Fit side, I got a basic $50 fit done on a wind trainer at my trusted LBS and that alone confirmed my thoughts. Sadly though you sometimes have to buy where the deal is best so you have to rely on your own knowledge & instincts.

I think being careful of effective c-c Top Tube is important, as some frames are fairly 'square' while others are more stretched.

[CyclingPat]

The simple answer is to get a Bike Fit.

It will help you get the right frame and then set it up comfortably.

Well worth the investment.
One of the best you can make.

I would second this.

Bought a MTB a while back from a proper bike shop. Unfortunately I was naive, knew nothing about bike fit and the salesman sold me whatever and I was on my way. Wasn’t long before I was getting lower back and right hip pain. Fast forward to second bike (roadie) purchase from a different LBS who knew their stuff and took to time to do a proper bike fit. Ordered in the right sized frame, not just what was sitting on the shop floor, and made all the adjustments needed. Long term, rides like a dream.

[cyclebee]

Anyone had a 'bad' bike fit?

[TheWall]

Anyone had a 'bad' bike fit?

Yep...was new to riding roadies and bought a bike that was simply too small...they "fitted" me alright ..was pressured by the LBS and I felt compelled as colleagues parents owned it...anyways did my best and even did the 165k Brisbane to Noosa in 09 on it but was so broken by the end of that ride I did not cycle for almost three years...when I bought a correctly sized bike...and was fitted correctly!

[bikingburrito]

I've found that buying a few cheaper bikes, riding them, and getting the feel for frame sizes.

My last bike was a trek 7.5fx 51cm and my current bike is a Cube sl cross pro with a 56cm frame
and it fits better and is more comfortable than the 51cm.

Each bike brand has a unique size and you have to experience a few different bikes for yourself
as the previous comment states that a "bike fit" is not the total be-all and end-all solution.

You can make a smaller frame suit a larger rider but you can't make a bigger frame suit a smaller rider.

[Ivanerrol]

When I started out cycling aging earlier this year I bought two bikes off the great auction site - cheap - to determine if I'd like it or not.

I was fortunate that one of the bikes was the right size but with trial and error got it comfortable.
The other bike I put up with for a few hundred K's until - it just wasn't the right size - put it back on the auction site.

I went to one of the LBS's were the owner, not only being the main fitter was also a fitness instructor, Pilates instructor and had studied bone structure and chiropractery.
I learned more in one hour than years of self trial and error would ever achieve.

First question was very important - what sort of cycling do you want to do?

I was fitted up with my hybrid. However the flat bar roadie was completely different.

Endorsement for Bike fit. Make sure you go to an LBS who insists on one before choosing the size.

[RobertL]

I'm 190 cm tall with average leg to torso ratio but quite long arms.

I presume that for whatever style of bike, from whatever manufacturer, I could safely just buy the biggest frame size option. Would that be right?

[singlespeedscott]

I'm 190 cm tall with average leg to torso ratio but quite long arms.

I presume that for whatever style of bike, from whatever manufacturer, I could safely just buy the biggest frame size option. Would that be right?

No. At 190cm your not the tallest cyclist that I know and you would best served visiting a reputable shop or bike fitter to determine what size frame you require. The style of riding you wishto do will also influence the size frame you will ride

[silvinator]

Just subscribed, thanks for the link. This will be so useful for a shorty like me ^_^

[Rural Rider]

Bike Sizing? Don't believe the manufacturers advice on Frame Size. I just went through this with all data and charts telling me that at 183cm tall, I am a size 58 Frame! Went to the Bike store and right away the Sales cat says ... 'Oh no you're not' ... in complete contradiction of what the Manufacturing Frame Data states. Turns out I was absolutely perfect for a 56 Frame size and one size smaller than what that very Bike Company stated I should be on. So bottom line ... if you can, go physically sit on the bike - you'll save yourself a lot of trouble.

RR.

[owly]

From memory, manufacturer website fitting guides I've looked at; none of them took into account ones' inseam, nor arm length.

If you have a tall inseam relative to your height (like moi) and arms a bit on the short side, you can forget about those charts!

[singlespeedscott]

Bike Sizing? Don't believe the manufacturers advice on Frame Size. I just went through this with all data and charts telling me that at 183cm tall, I am a size 58 Frame! Went to the Bike store and right away the Sales cat says ... 'Oh no you're not' ... in complete contradiction of what the Manufacturing Frame Data states. Turns out I was absolutely perfect for a 56 Frame size and one size smaller than what that very Bike Company stated I should be on. So bottom line ... if you can, go physically sit on the bike - you'll save yourself a lot of trouble.

RR.

56cm is a very small frame for a someone as tall as you. Do you have short legs for your height/

Out of interest was the bike already on the floor or did they order it in after sizing you up?