portland376

I posted this i the Fitting your Bike section as well, but figured I'd give it a shot here as well as I know there's plenty of knowledge (and ridicule) to be gained in this corner of the forum. I'm looking at purchasing a BMC SLR01 Team Machine which I can get a great deal on.....unfortunately I don't have a local dealer to actually get out and test ride the two sizes back to back. From what I can tell, I seem to be between the 56 and 58. Following are my measurements from the competitive cyclist fit calculator using the "competitive fit" as well as a link to the BMC website with geometry numbers at the bottom of the page. It should be noted the BMC comes with a setback seat post. According to the fit calculator if I went strictly by top tube measurement I'd be on a 56....but the seat tube measurement seems off. Any fit experts with advice on frame size or whether the geometry in general seems compatible. I've driven myself crazy trying to wrap my head around the numbers. I fancy myself a competitive rider (with minimal fit knowledge) and would be using the bike as a daily rider and racer. Thank you in advance for any help/advice offered.


Link to BMC page with geometry details on bottom of page:
teammachine SLR01 Dura Ace Di2 ? road ? BMC Switzerland

My Measurements (inches) per Competitive Cyclist Fit Calculator
Bike Fit Calculator | Find Your Bike Size | Competitive Cyclist

Inseam: 34.25

Trunk: 25.25

Forearm: 14

Arm: 26.75

Thigh: 23.5

Lower Leg: 22

Sternal Notch: 58.75

Total Body Height: 71.75
Fit style
The Competitive Fit
Top Tube Length55.7 - 56.1 Cm
Seat Tube Range CC56.3 - 56.8 Cm
Seat Tube Range CT58.1 - 58.6 Cm
Stem Length11.5 - 12.1 Cm
BB Saddle Position79.7 - 81.7 Cm
Saddle Handlebar54.6 - 55.2 Cm
Saddle Setback5.4 - 5.8 Cm
Seatpost TypeNot Setback

nemeseri

Always get the smaller frame. Always. Except if you can't handle the saddle to handlebar drop.
It's stiffer, lighter and there is nothing you can't fix with a proper stem (especially in this size). Check out the reach/stack of your current bike (+ stem and handlebar). Compare it to the BMC. You want to aim at a 100+ mm stem.
It's all based on that you put yourself in the competitive fit category.

loimpact

I'll shoot.......

Take the seat tube with a bit of a grain of salt. Most all sloping top tubes today confound that measurement a bit. Some more so than others....(Tarmac anyone?). You can always expose more or less seat tube. You've got a long inseam and some decent length arms so, yes, you could fit either. I'd probably push you toward the 56, especially since you're looking at competitive fit.

It'd probably still be worth a test ride but those top tube lengths are fairly common these days for their appropriate frame "named" size number. Just running it in comparison to Cannonale, the 56 stack & head tube length are a little taller on the BMC than an EVO when going 56 for 56 and I know a kid 5'11" with long arms & legs who easily fit the EVO in 56 so I'd say you can easily do it. And he's even got some back issues.

But you'd be fine on the 58
And you'd be fine on the 56 too
But there's nothing wrong with you on the 58
And the 56 is perfectly reasonable too.
Not that the 58 isn't perfectly acceptable.
Or the 56 for that matter.
Meaning the 58's just fine
And the 56 is just as fine

Hope that clears it all up for ya.

portland376

Solid advice all around.....sprinkled with a little ridicule....what more could a guy ask for?! Thanks! Anybody else with thoughts?

Bah Humbug

Ignore the meaningless "sizes" and tube measurements. Go by stack and reach. That's what actually matters. The rest is noise.

portland376

Stack and reach is what I've gone by in the past (meaning one occasion) in going from an old bike to a new one. I've never had a full formal bike fit, but have never had any unusual aches/pains when biking beyond the ordinary. Wondered if my stack/reach measurements were correct beyond paying for a full formal bike fit.....is it actually possible to calculate theoretical stack/reach measurements from the above numbers?

Fiery

You could mock a theoretical bike with those measurements in Stack and reach calculator and see what the stack and reach will be. The CC calculator doesn't give ST and HT angles, but the average for that size would be 73°-73.5° for both.

In any case, I'd go with 56 if I were you. You may need a few extra spacers compared to the 58, but in my experience, the 56 will handle better and simply feel better to someone of your height and proportions. Of course, ideally you should test both before making the decision.

What bike do you have now, and how is it set up?

link0

I agree. They are lighter, more attractive looking, and it's easy to get a longer stem if you need it.

Looigi

I'm 69" with 34" bike inseam and ride a 55cm SLR01 with 110mm stem, 10cm saddle to bar drop with a -17 degree stem and no spacers. Mine's a few years old and their size designations have changed since. Mine has a stack/reach of 565/392mm which is equivalent to the current 56cm. I figured I could easily fit a 53 (current 54). If you ride in aggressive position, a 56 would likely be right for you.

Shuffleman

I can't agree with this advice. I understand the logic but my personal experience has been the opposite. At 6'02 I find myself a tweener in most bikes. I rode a 61 Felt and a 59 Colnago. The Colnago is sloping so as another stated it is a little different. I feel more comfortable on the larger end of what is recommended as opposed to the smaller end. That could change as time goes by and I age but at 47 it is still my preference. Good Advice but it is not Gospel.
This does about sum it up. I doubt that you can go wrong either way. The bike can be made to fit you within certain parameters. If you are a tweener, you just have to make sure that you get a good fitting.

Good luck with it regardless of the size that you choose.

Looigi

FWIW: The frame size number is a red herring, especially across models and between brands. Stack and reach are primarily what are relevant to fit.