Barrettscv 

I can adjust the stem & saddle to provide a good fit if the horizontal top-tube is between 590mm and 620mm. I use the same pedal and the same pair of cycling boots for all bikes, the cleat was fitted by a pro based on video analysis. The relationship from the crank axis to the saddle always stays the same on all bikes and is the first adjustment I make when adjusting a bike. Adjusting the stem length and handlebars finished the fit. Seat-tube length and standover is not considered.

This classic has a 64cm seat-tube and a 600mm top-tube. The tall headtube provides a comfortable reach with a 100mm stem.



This cyclocross bike has a 58cm seat-tube length and a 590mm top-tube. The compact handlebars shorten the reach. The long fork and tall headtube provides a comfortable and sporty reach with a 110mm stem.



This cyclocross bike has a 60cm seat-tube length and a 610mm top-tube. The long fork and very tall headtube provides an upright position and comfortable reach with a 110mm stem.



This road bike has a 60cm seat-tube length and a 590mm top-tube. The compact handlebars shorten the reach. The bike provides comfortable and aerodynamic fit with a 110mm stem. The aero-bars improve aerodynamics while giving the hands a rest. They are only used while riding solo.




This classic has a 63cm seat-tube and a 590mm top-tube. The tall headtube provides a comfortable and sporty reach with a 120mm stem.

DX-MAN

My old Dakar had a 610mm top tube, I ran a 120mm stem; bar is always in the range from saddle-level to 1" below, 'KOPS' adjustment 10mm or so behind the spindle, and saddle height (measured from pedal at lowest to top of saddle) is .96 meter. The position on this bike was a touch more upright than I liked, but it was good enough.
The Kona has a 625mm top tube, 110mm stem; other adjustments identical. The position is as near to perfect as I can ask for. (NOTE: bar/stem have been changed from this pic)

I don't have a fleet of bikes; I'd rather put all my 'bike love' into one good-as-it-gets-for-me machine.

sreten

Hi,

Though for several bikes that all fit you the seat-tube length
is directly related to the standover clearance, and the typical
recommended 6 or 7 inches of seatpost should yield the right
sort of standover height for most people.

For most people a bike you cannot standover is unlikely to fit.
Should only be an issue with short legs and a long torso.
Conversely long legs and a short torso should have
loads of standover clearance and a long seatpost.

rgds, sreten.

Barrettscv 

The idea of this thread to to explain why a certain bike fits a certain person. This is about the application of theory, using concrete examples.

For me, I rarely see a bike that would cause standover issues. Most manufacturers don't even make a standard frame with a standover greater than 34 inches. At 6 feet, standover height is not a real issue.

Can you provide a bike-fit example?

bikemig 

I can pretty much always fit a bike that has a 56 cm top tube with a 12 stem or thereabouts. I was in a bike store recently and I really wanted to fit a 54 cm Surly LHT because it was green and at a good price since it was an older model. Try as I could I couldn't quite dial in the fit. Yes I could put in a longer stem but then my weight was farther forward than I liked. The one thing I should have tried but didn't was to try a saddle with really long seat rails like a selle anatomica but it's a drag having limited choices on saddles. My point is that it takes time to dial in the fit and that the importance of top tube length is underrated when it comes to bike fit. I also think Greg Lemond's Complete Book of Cycling is very good on fitting a bike. Racers know something about bike fit.

Here are two bikes that are set up and fit me nicely (this thread is an excuse for more bike porn, right?

My Soma cross is set up with a triple and 700 by 38c tires; it is a compact geometry that gives me a 56 cm top tube. My Bridgestone RB-1 is a 56 square which fits me well:

Bandera

Indeed, here's an old school fit that works perfectly well today.

1992 Vitus 979, 56 CT/56 TT w/ 12cm stem, 40cm bars & 172.5 cranks. Road raced in the day, saw lots of club miles.
At 5'10" it gives the relaxed elbows bent position for efficient control and good power delivery.
Recently converted to 10 speed components seatpost/saddle, bar, stem & crank positions re-lubed & returned to exact original positions.

-Bandera

Barrettscv 

Nice bikes, and yes, bike porn with an informed bike-fit narrative, like yours, is the format :-)

Nice bike and comments concerning fit!

sreten

Hi,

My bike has a compact style frame with a sloping up top tube.

I'm 5'8" and a 32" inseam in the footwear I use for biking.
Clothing inseam is 29". I'm also 50+, slim for my age.
(Average weight for my height, lower recently.)

Have been riding it since Easter.

My budget bike claimed to be sized for 5'6" to 5'10".

Standover is ~ 1" (a little more) as usually recommended.

New saddle is set to the 0 position marker on the rail.

Saddle height is set using a straight leg and instep on the pedal.

Seat tube to the rails is 6", 8" to the lower sloping downtube.

Front tube is a substantial 7", but the bullhorn bars are
now set to the lowest position on the threadless headset.
They are ~ 3" below the seat. Bars are tilted down a little.
(Started off set highest, with the stem flipped up.)

On the bike on the back of the saddle the bars obscure
the front spindle, normally I can see the front spindle
a little ahead of the bars, theory says I need a longer
stem, but I don't think so yet, as I don't use the
longest reach of the bullhorns much as yet.
(Starting to ease into using that hand position.)

Elbow on the front of the (11") saddle and the tip
of my fingers to the bars centre is about 3", very
ballpark for a very old school sizing method.

rgds, sreten.

Crank centre to seat top is 29" *, front tube centre to
seat tube centre horizontally 21.5", stem centre to
centre 3.5", bars centre to front wheel axle centre
is 23", the effective frame size I estimate as 22".

But the last figure take with a pinch of salt, front to
back matters more and its a compact geometry bike.

* I would never have thought it was that much,
the same as my clothing inside leg, so I checked
my folder, and that is set to 28.5". I think I've
discovered another bike sizing "rule of thumb".