How To Choose The Correct Size Of Road Bike Frame

The GCN Bike Fit series continues, with more great insights from three time Olympian and now pro bike fitter Oli Beckingsale, and our own Daniel Lloyd. This week we look at just how a rider should choose the correct size of frame.

Oli talks about the differences between bike frames, and how each size can vary from manufacturer to manufacturer. There are a lot of variables between individual riders as well.

So how can you get the correct size of frame? Well, there is no replacement for swinging your leg over a few different bike manufacturers, but to get you in the ball park, there are some simple tests you can do to see which designs will suit you the most.

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[budmurftube]

I was confused about sizing frames before I watched this video.  Now I am more confused.

[jimmymejia]

Well that was 5-minutes of my life im not getting back!

[Sionnach]

This was so general and vague as to be absolutely useless to me I'm sorry to say. You haven't really said anything definable here, most of what you say is so hugely open to interpretation.
Thanks for trying, but this was a very unhelpful video.

[TimDuggan]

this video actually did not answer 1 question about sizing a bike. Im baffled how you set out a question and then didn't answer it AT ALL. Well done on that front. 

[cliffordbrown]

As someone 5"10' and-a-bit with a 32" inseam that's ridden a far few road bikes over the years every time I try a new bike I get kinda caught between 54/56, M/L. Even trying the same bike I often feel a difference - the 56 will usually feel smoother and comfier, but the 54 super nimble. Some 56s feel too reachy, others bang on perfect. Some bike shops eyeball me and say '56cm' some are convinced I need to be on a '54cm' perhaps with a longer stem. Never gone for a fancy bike fit - maybe now's the time to end this confusion.

[virkelie]

My problem (and I think others have the same problem) is that I live in a small/remote community, with only 1 bike shop, and a very limited selection of bikes.
So with my recent 2 bike purchases - the bikes had to be ordered in (unsurprisingly the shop did not have the models in the store) and I had to choose a frame size almost blindly.
I think for me and others in this situation, actually the most important variable is top tube stand-over height - because this is fixed and there is no way to compensate if the top tube is too high.
So for the 2 bikes I ordered I chose the largest frame size with an appropriate top tube stand-over height.
So far this has worked for me.
Perhaps to be extra sure you're choosing an appropriate frame size (if you don't have a bike to test) is to choose 1 size smaller than the largest frame size having an appropriate top tube stand-over height.

[ygtcbee]

Would be great if you guys could revisit this video. There's a lot of new bike design since 2014 and for new riders or new frame types fresh new take on how to choose the right size will be helpful

[pgong]

My bike sizing tip, for what it's worth, is this:

It's mostly about handlebar height.

If you race, the size with be on the smaller end of the range. If you don't, you may do better on a larger frame. This is because the smaller frame allows a lower handlebar that racers prefer due to the aero advantage and immense power they put out a lot of the time. That power helps support their upper body taking weight off the arms and hands.

A larger frame allows a higher handlebar which is often more comfortable for the rider that doesn't race since they don't put out the same power as a racer. As this video states, you can always get lower by using the drops and bending your arms, but you cannot get higher (if the bar is lower than it should be for comfort). And a too-small frame will not allow the bars to raised into the comfort zone. In fact, I'd say that if you cannot ride in the drops comfortably for, say, at least a couple miles at a time, the bars are too low.

Of course, this is basic and other things like head tube length and stem rise affect the outcome.

[DAlexKablack]

Body does adapt, first road bike I bought, I could have sworn it was too big for me, a couple months later, it fits perfectly.

[SinnerSince]

I've always used a rough rule of thumb that as I sit on the bike, hands on hoods, my vision down would then look at the bars. If I cannot see the front axle, I'm pretty good on that aspect of my fit.

[lewismason]

I started riding a 58cm fixie and I’m 6ft1ish and found that it was a tad to big, went down to a 56cm and feel like it fits much better. It’s mainly down to personal preference and if it feels to small you can always adjust spacers, saddle height, stem reach etc

[JFomo]

For those who are short like me and you can't test it out for whatever reason and you're unsure if you should get a S or M, buy it based on the "Stand-over height".
Measure your inseam, and make sure it is above the "Stand-over height" measurement.

[Itzthe_bobalover]

It took them 5 mins & 20 secs to confuse me more! Thanks! Now I’m more confused! 😭

[BlizzardArthas]

>Makes a video about choosing the right size
>Talks about anything you really don't care about
Those videos are for beginners, just give a straight forward answer, because "what fits you best" is an answer my grandma can give me too. Most people watching your videos are new to cycling, and get no help from a vague answer. Really, you have great videos up, but this is literally the ABC, and you managed to make it a mess with this "expert".

[WingTipAerialFilming]

When I got my new Trek Madone 4.5 this year my LBS selected the frame size and fitted it to me but after riding my 1978 Morrison Monarch for over 30 years it just felt weird. I said to them it can't be right but they said give it a go for a while as I was used to riding with the wrong posture.on an incorrectly fitted bike for so long. It was like going back to being a beginner again but after several long rides something amazing happened, things started to click, and I began cycling more efficiently and more powerfully than I had ever done. It's incredible, my Modane now feels like part of my body, it's more like wing-suit flying than cycling. According to Strava I'm one of the quickest guys in my local area, I'm beating guys half my age.

[Niidea]

Unless you are a dedicated athlete who needs to keep optimal position for performance reasons, the best position is that that you feel comfortable with. Last month I was riding my regular commuter bike, as a small person I ride a minivelo, which works great with the measurements that I usually find comfortable in a bike (it would be a S or XS on a regular roadie, but the small wheels prevent toe overlap) ; anyway, point being I came across a friend, who was very exited with my unusual little bike and asked for a try, the surprise of us both, she was clumsy while riding Aghata (yes, my bike has a name), finding my position too extreme for her, despite she being a full 10 cm taller, and also despite she being easily more flexible than me at half my age.

[NotALizardPerson]

No one ever talks about head angle and seat tube angle. These play a huge role in how far away the handlebars will be. You will be a lot closer to the hbars if you have a steep st angle and a shallow ht angle whereas a steep ht angle will push the hbars further away. The way reach is measured in the industry is completely useless.

[SubaruWRC]

On all bikes ive bought I make sure I can put my toe down only, but have it so I dont have stretch so its comfortable and so my leg is almost fully straight with a slight bend at the knee.

[fastcougar]

Useless, general conversation. I expected direct examples regarding the frame size vs rider's height. 

[Anthony_in_Bloomington_Indiana]

How to choose a frame size for your road bicycle.

Guy on the left: It's a mystical and super complicated process. So go to a bicycle shop and try several bicycles and figure it out for yourself, because I have no clue how to explain all of this in plain English.

He talks like a teen boy who is giving a book report to his class, when he only skimmed through the book.

With an awkward delivery, "Treasure Island is a book about an island, with treasure on it."

I went to a bicycle shop, and the nice clerk said, "You're 6 feet and 2 inches tall. Your frame size should be around 60 centimeters."

The next time I was at the same bicycle shop, I asked a different clerk, and he said, "You're 6 feet and 2 inches tall. So your frame size is 60 centimeters."

There are also loads of websites with frame size charts. Just do a search on:

Bicycle frame size chart.

You will find different versions, based on whether you want a road bicycle or a mountain bicycle or a hybrid. Happy Trails!