How To Choose The Correct Size Of Road Bike Frame

[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.

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?

It's a question of how long is a piece of string I suppose - the stand over height for the 56 frame Specialized Allez is perfect for me and I am every bit 183cm tall. My legs are fine thanks ... I'm pretty sure I'm in fairly good proportion!

The Bike bought was on the Floor, but the funny thing is I went and got sized from a completely different Bike Shop before buying the Bike at another Bike shop where I knew they had a 56 Frame on Sale. Both of the Bike Shop owners completely independantly told me the exact same thing, that different manufacturers can have differences in Frame size between each other and sometimes betwen the models from memory. And it is quite right ... I fit this bike perfectly, nobody was trying to sell me a Bike that was too small ... I have another Bike at home that's a 58 Frame in that Style and it fits me just as well.

I don't make em ... I just ride em ...

RR

[nickobec]

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

I am the same height as the OP, 183cm, reasonable proportioned, slightly longer arms. Started out on a 58cm, bought a steel single speed 55cm and found out I was more comfortable and faster on that than my 58cm geared roadie.

Then accidentally bought a 53.5cm frame, was supposed to medium 55cm not a small 53.5cm frame. My bike fitter looked at the angles and gave up. Fitted a 130mm stem and it is my race bike, faster than any other, prefer the handling (it is an aggressive geometry) and it is fun to ride, even 150km.

[Rural Rider]

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

I am the same height as the OP, 183cm, reasonable proportioned, slightly longer arms. Started out on a 58cm, bought a steel single speed 55cm and found out I was more comfortable and faster on that than my 58cm geared roadie.

Then accidentally bought a 53.5cm frame, was supposed to medium 55cm not a small 53.5cm frame. My bike fitter looked at the angles and gave up. Fitted a 130mm stem and it is my race bike, faster than any other, prefer the handling (it is an aggressive geometry) and it is fun to ride, even 150km.

Hasn't Mark Cavendish gone to a smaller Bike Frame recently also?

RR

[Death_defying]

Im 183cm exactly, and 56cm on my giant fits me perfect. My riding buddy has a tarmac, also 56cm. Hes 182cm....

[TheWall]

No surprise...I am 192cm and comfortably ride the 58cm in the Tarmac.

[cjamescj]

Hi,
It's time to replace my bike and I don't know what geo type it is.

Question:
Is the Scott Speedster S3 a race geometry (say Giant TCR, Trek Madone/Emonda), or is it more relaxed (like a Giant Defy, Trek Domane)?

Background:
A recent service led into a conversation with the mechanic that I was onto my third wheelset. I have worn through two sets of Mavic Krysim Elite (2007) braking surfaces and he suggested I get a new frame. Apparently aluminium frames should be replaces >40,000kms, which that frame has done - I'm open to opinions on that 40,000km statement.

I have a Scott Speedster S3 (2005) 61cm (XXL) frame with Shimano 105 175mm cranks, drops, 7 degrees 90mm stem, running a moderate amount of post and 25mm tires.

Scott Speedster S3 link here. http://www.bikepedia.com/QuickBike/Bike ... 3+27-speed.

I've also been advised that Specialized and Cannondale (I also have a 61cm Cannondale Slice that is a good fit) are the two main manufactures to make frames in my size (the mechanic said he couldn't honestly fit me on any bikes he sold) - opinions on that are welcomed too.

Much appreciated in advance,

Thank you

[Vanny]

I am in the same boat at the moment. My current frame (Giant Propel) is killing my back due to having back issues. I went to my LBS to talk them about getting a new frame and they advised me to get a proper bike fit from a physio before doing anything to determine the required geometry.

[mp1988]

I'm 183cm (6'0") and I just got a 56cm framed roadie - initially I was looking at a 58cm one as that's what my hybrid is.

The shop then recommended a 56cm frame for a roadie, for my height as they're a different geometry from hybrids.

[snafuspyramid]

Height is not very useful in determining frame size. The relative length of your legs (inseam), torso and arms can be very different among people of the same height.

As well as your basic physical dimensions, your level of function affects fit just as much, particularly your flexibility, especially in your posterior chain (broadly, glutes, back and hamstrings). Hip flexibility also matters. For instance, as the video notes, whether you can easily touch your toes will affect your ideal frame geometry a lot.

Your level of fitness matters enormously too. Do you have good core strength - for instance, can you hold a bridge for 60 seconds without too much trouble? And what about cardio and leg strength - how much power will you put down on the pedals? Are your neck and shoulder muscles accustomed to the additional strain in a more bent over position?

If you're a very strong rider with a good core you'll be much more comfortable, all other things being equal, in a lower more stretched out position, because the action of your legs will tend to support your upper body. Riders who aren't as strong - or who aren't interested in riding a particular bike hard - will prefer a more upright position, to allow more of their body weight to be borne by their buttocks on the saddle and to take some strain off their neck and shoulders.

Although not necessary to select a frame size (so probably a bit OT), your lateral fit - how your feet and hands connect with the bike - matters too. The angle at which your feet meet the pedals, the respective height of each pedal (i.e. whether shims are needed), the fore/aft position of your cleats and - perhaps more controversially - the distance between your feet (Petersen's "q factor") all depend on your particular dimensions, degree of flexibility and functional strength. There's also saddle selection, which similarly depends on individual morphology (pelvis width) and how aggressive your overall position is. These play just as much of a role in preventing overuse injuries and pain as frame size. Then there's the joys of handlebar shapes and sizes...

The point I'm getting to is that a professional fitting is usually money well spent. Once you've got a good ballpark on the key parameters, you can transfer them to new bikes readily (particularly stack / reach) and have a good base for adjustment as your fitness and flexibility improve.

On the other hand, this is an internet forum, so there's a tendency to thrash fairly basic questions to within an inch of their life. Your body has an enormous capacity to compensate for asymmetries, weaknesses or suboptimal fit. It's only where you ride enough to overcome this capacity that fitting becomes critical - so like most bike related pedantry, the more you ride, the more it matters.

If you're just looking for a bike to get around, lose some weight or do the occasional weekend warrior - and you're not dropping a huge chunk of change - near enough is good enough. Find a bike shop that will let you try out a variety of different bikes on a trainer, maybe try some of the online fit calculators for a rough guide, then err on the side of a more upright position (longer head tube / shorter effective top tube).

You'll not regret buying a bike that you can make more aggressive by dropping a few handlebar spacers or just using the drops, but you'll definitely regret buying a bike that's too aggressive. (Incidentally, I love the endurance bike concept, which as far as I can tell is about selling people bikes that aren't cripplingly uncomfortable for unconditioned riders but still look and cost like race bikes).

[Derny Driver]

Im 183cm exactly, and 56cm on my giant fits me perfect. My riding buddy has a tarmac, also 56cm. Hes 182cm....

My son is 183 and rides a 56 road bike and track bike.
As for bike fit, I use the method my dad taught me.
Just look at the rider sitting on it.
Ive been asked on half a dozen occasions who did my son's bike fit. One ex Pro said out of 200 guys at my club, my son is the only one who looks perfect on the bike.
But he was using the old fashioned method too. The eyes have it

[foo on patrol]

That's very true DD. I went to get a fit and the bloke did all the things for the fit and said, nope you don't need any changes and he said in the 10yrs that he'd been doing bike fits, I was only the second bloke that he didn't have to touch. On his FB page he posted that up, with the following comment. Well I had only the second bloke in 10yrs of fitting that I didn't need to adjust anything with and guess what, he was an old school rider.

There has been only one bike that I couldn't get set up on in my life and that was a Fuji 2.0 Track frame and that was because I listened to everyone saying...... The trend is to go for smaller frames now, unlike when you were racing back in the 70/80s. Well guess what, I changed that frame for a bigger one and even before I could fine tune the set up, I felt better.

Foo

[Derny Driver]

That's very true DD. I went to get a fit and the bloke did all the things for the fit and said, nope you don't need any changes and he said in the 10yrs that he'd been doing bike fits, I was only the second bloke that he didn't have to touch. On his FB page he posted that up, with the following comment. Well I had only the second bloke in 10yrs of fitting that I didn't need to adjust anything with and guess what, he was an old school rider.
Foo

Very cool mate. Love it

[Kronos]

The quick way to tell if its the right sized frame is whether you can stand over the top tube and still pull up on the frame with some comfort. This doesn't matter if its only an inch or two. If you can do that you should have a roughly well suited bike frame. From there its a matter of adjusting your seat, stem and handlebars to suit your arm and leg length.

Fortunately I'm neither very tall nor very short so have lots of options at 54 or 55, medium, or medium-large. The very short and the very tall will have some more issues finding the right sized frame, but keep searching around until you do.

While the trend is going for smaller frames to save weight its a stupid trend and it leads to an ill fitted bike where you will either be bent over with your bum in the air, or cramped up like a hubbard on an ill fitting bike. While you can adjust all the other components around it, there is no substitute for buying the right sized frame in the first place. Leave the 52s for your kids.

[Jawa]

Taking things sideways but still on bike fit. Was in LBS store recently being sized up for the new rig (was too afraid to buy online) but in one configuration my hips were rocking and legs/knees were slightly hyper extending .. like they were jumping on the down stroke. First thought though, saddle too high. However mr bicycle man made a tweak and raised the saddle a smiggen and im thinking no way this is going to work. But straight away it just worked and my pedal stroke was all that smooth again ... there’s no way in hell I understood how that worked but clearly shows im not smart enough to do these things myself.

[foo on patrol]

Morayfield Super Cycles. My Lezyene Track pump started blowing the face glass off and I found out that it was a problem with one batch. Took it back to them and said.......Sorry I don't know where my receipt is. They went back through their transactions and found it and now I have a brand spanker.

Foo

[Rhinosaur]

I’m 186 cm tall and quite broad and always felt most comfortable on XL sized bikes, or 58 cm or thereabouts. I’d say I have slightly shorter arms than average for my height & an average torso to legs ratio.
My brother is maybe 2 centimetres shorter than me and typically prefers the feel of L sized bikes. (Approx 56 cm)
Personal preference plays a large part in it.

[oreo15]

About 198cm here, ride a 59 Casati. feels comfortable for me.

[dare007]

Yep, 186cm and normally ride a 58cm

[Mofra]

I'm 187cm and my 58 fits great. I replaced the 100mm stem with a 110mm stem and I'm absolutely shocked at how much better the total fit of the bike feels. It goes against the whole more upright = more comfortable theory but I'm able to ride for longer in the slightly more aggressive position and even spend a little more time in the drops than previously.
I'm long limbed for my height which makes a difference too. I will replace the saddle at some point, have tried the three that I have and the 'hardest' but flattest of the saddles seems to be the best fit so far.

[pedalleur]

If I can adjust the saddle so I can comfortablty rest one foot on the ground when stationary, it's all good.
I'm 6ft and 58cm roadies does the job.

Not keen on sloping top tubes down towards the front, though, I do have a Giant Kronos and slide the stem up to it's max.

[SlowUpSlowishDown]

Has anyone created a website yet that allows you to enter certain criteria such as riding goals/styles plus body geometry that then spits out a suggested list of the best fitting bikes/sizes?

I've had my gravel bike professionally fitted to myself and I'd like to get a road bike, however I'm not 100% sold on a single manufacturer at this point. I'd much prefer one that fits my style so having something to narrow the search would be a lifesaver at this point.

[Retrobyte]

Has anyone created a website yet that allows you to enter certain criteria such as riding goals/styles plus body geometry that then spits out a suggested list of the best fitting bikes/sizes?

I don't think so, but there are a few sites like this one where you can compare geometry of different brand and model bikes in different frame sizes .... https://geometrygeeks.bike/

There is a section where you can input frame geometry and it gives you some suggestions .... https://geometrygeeks.bike/advanced-search

[nickobec]

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

Disagree, I am 184cm tall and my preferred frame is a "small" with an effective 53.5cm TT. I have had a couple of bike fits, including a pre and post purchase of a "medium" 55.5cm effective TT "medium" off the latest model of the "small". After riding both for a couple of season, I prefer the small as I like the weight distribution.

ps my first bike has a 57.5cm TT and I am stretched out with a 90mm sten.

[AndrewCowley]

Disagree, I am 184cm tall and my preferred frame is a "small" with an effective 53.5cm TT. I have had a couple of bike fits, including a pre and post purchase of a "medium" 55.5cm effective TT "medium" off the latest model of the "small". After riding both for a couple of season, I prefer the small as I like the weight distribution.

Do you go close to max seat post extension? Must be surely.

[warthog1]

I used this fit calculator way back when.
https://www.competitivecyclist.com/Stor ... orBike.jsp
Worked for me.