Bike frame sizes and fit

[Raging_Bulls]

5'8" here with 30.5" inseam, and all my bikes are set up for my height.

Scott : 46cm (18.1") C-T and 42 cm (16.5") C-C
Bulls : 47cm (18.5") C-T and 40 cm (15.76") C-C
Sbike : 46cm (18.1") C-T ... and 23 cm (9.1") C-C ... yup, X-frame

 

[mvd1974]

It's typically recommended that you size bikes by top tube length as a priority, then by seat tube.

I agree on that... I'm 6 feet tall and prefer an effective toptube of 23" to 23.5" so the size of my bikes vary (in my case) between 16" (for my AMP) to 19" (for my Specialized).

 

[02gf74]

rough rule for road frames (horizontal top tube) is 1/3 height or 10 inches subrtracted frm trouser length.

for mtb frames, subtract another5 inches.

I am 6 ft 1, mtb frames 1 x 18 in, lots of 19 in and 1 x 20 in . Top tube is in the region of 600 mm for most of them.

 

[sylus]

6ft 3 and inside leg of 32 so most of my height is upper body that's why the top tube is almost as important to me as the seat tube when it comes to sizing

 

[My_Teenage_Self]

I'm 5'8", but long legs, short body. I ride 16-17" frames, with short stems and looooooong seatposts.

 

[SaracenSteve]

6ft and ride 20 inch in pre 1990 MTBs

 

[Osella]

5'11, 32" leg and anything from 15" to 19" is comfortable with a load of TT clearance! Just a long seatpost, with layback if necessary, & a stem to account for the toptube length. I don't believe in 'frame sizes' determining whether you 'can or can't' ride a bike - unless it's absolutely one extreme or the other.
I measured 4 of mine the other day, just as an experiment, and discovered that they are all virtually the same measurements of ground-seat, ett, seat position and cockpit, despite ranging 4" in seatpost size!