Inseam and Frame Size
 

Seems there has been a few threads recently (OK, all the time) about "that frame size is to small" or "Whoa...your frame is way to big". So I was curious as to what size frame everyone is riding and their corresponding inseam.

31" inseam
54 cm

Someone ran a similar thread a few months back and got a bunch of replies. The problem is, many newer road bikes don't follow traditional geomentry, with a top tube that is horizontal to the ground, and the seatpost clamp just above the top tube. So, a guy would post to say "My inseam is 32 inches, and I ride a size 52 bike." Quite unlikely that guy was riding a tradional bike, as his correct frame size (if his slack's inseam is 32 inches) is more likely to be around size 56 (for racing) or size 60 (for touring or commuting).

The second problem in the thread was that some people were referring to inseam as being the inseam on their slacks (32 inches) and the next guy, who also wears 32 inch slacks, was using inseam to mean leg length from the pubic bone done to the floor (35 inches). Without a shared understanding of what "inseam" means, the posted measurements were not very helpful.

The Rivendell website is helpful in relating leg length to frame size. They explain how to measure total leg length from the public bone to the floor. And, they have a chart suggesting frames sizes. Rivendell's chart assumes that their customers are not buying their bikes to race, and so their suggested sizes are about an inch higher than what many bike shops would suggest (many bike shop clerks fit bikes as if every customer will be racing in the Tour de France next July).

32" / 54cm

31.5" inseam
54cm (or 53cm) frame

38"

Small trek 63cm frame

30' inseam

53cm Lemond (proper fit)

49 or 50 cm Trek 2300 (sold to me by an overenthusiastic salesman before I knew about proper fitting - but I bought a long stem to compenstate)

60 cm Nishiki (knew it was a bit too big - but mainly use it for leisurely rides)

+1

30 inch inseam
56 Trek

Giant TCR's are sized with letters (i.e. S,M,L). For a rider who is 5'8" 160 and has a 30" inseam which of the Giants would you choose? (2005 sizes)
S = 44cm
M = 50cm
L = 55.5cm

Thanks in advance
Josh

35 inch inseam, 61 cm frame, 175mm cranks (yes, it matters).

34.5" inseam
58cm cannondale six13 , perfect fit for me,with a 120mm stem and 175mm crank.

33 inseam, 55cm Bianchi and a 57cm Orbea

~29in inseam, 52cm Felt (90 stem, sloping), 51cm Basso (120 stem, traditional)

32 in inseam, 56 Trek

alan is so right about this, look at the variances in the replies, they are all over the place. It's all about measuring your inseam PROPERLY, then gauging frame size from there.

Here is a start -Giant Compact Sizing BUT please visit a Giant dealer and get properly sized.

34.5 inseam riding 63 cm trek 1000. it may be a tad too big. later.

32" inseam..............56 Trek Pilot 2.1

Inseam only puts an upper bound on the seatpost dimension and really isn't the most important dimension for me. I'm 6' 2" with a "pants size" 32" inseam, hence I have very short legs for someone of my height. Since I haven't won a Lotto I need to get as large a frame "off the rack" as possible without risking some "vital organs" because of my long torso. Maybe someday I'll get a custon frame, but currently there are other priorities in my life that need the $'s more. As of now I have an old (1986) Cannondale 58 cm (c-t-t) and a newish (2002) Lemond Zurich 57 cm (c-t-c) as my road bikes. Both are OK in terms of fit, but I sure would like the top tubes to be just a little bit longer.

Ditto...we agree. Must not be a national thing. ;)
George

34" inseam (32" pant size)

58cm Trek 1500 (not a compact frame)

34" inseam, 57cm LeMond, could have went with either a 56 or 58 Cannondale with proper stem.

36"
58cm van dessel kermis

32" on a 54cm felt