OldsCOOL

Most of us have different and varying sizes and types/purposes of bikes in their collection they regularly or occasionally ride. I'm wondering what your range of sizes is that you would casually or even thrash now and then.

For me, I have 3. The optimum, perfect frame is the Cdale Crit with 54cm and fits me better than any other 54 I have owned. Then comes the Trek 760 that is one size down at 52. The seat post is a bit more exposed but the racing/crit geo fits just fine. From what I understand it was a common practice among racers in the day. Lastly, the '77 Colnago is my tallest. At 57cm it isnt too tall for comfort and is easily manageable. I'm able to hop from one to the other and feel at home but only that perfect fit 54cm Cannondale goes out on the open road, though I would take any of them for the pure joy of it.

How about you?

qcpmsame 

My Medici is a 57cm height, the CAAD 10 is a 56cm, no explanation as to why both work, but they both feel right to me.

Bill

Spaghetti Legs 

When I think or talk of frame sizes I refer to top tube length. I tend to ride frames that most people would probably think too small for my height but it's what works for me. (6'2" with long trunk, short legs, short arms) My sweet spot is probably a 57, most of my bikes are 56. My smallest is my Eddy Merckx Pro with a 55 top tube but I think officially a 56 frame. My biggest is my Tommasini with a 57.5. I had a Bianchi 63 CT, 58.5 TT that should technically be my size but felt way too big, so I replaced with the same frame in a 57 TT and it is perfect.

Almost without fail, all my bikes, every ride, I think "this is a sweet bike".

3alarmer 

...depending on purpose (thus position on the bike), setup, and some fiddling, I regularly ride anything from about a 57-58 setup as an upright town bike to a 62 road bike I can just make the standover on. I think maybe I have one MTB that's even smaller.

I've never understood the fixation on frame size..

SkyDog75

My usual comfort zone is the 53-55 cm range, but I've ridden a few bikes outside that range that could've been adjusted to fit without too much fuss. My current bikes all happen to be the same size:

53 cm 2006 Bianchi San Mateo / 53.5 cm effective top tube
53 cm 2011 Diamondback Steilacoom CCX / 54 cm effective top tube
21" 1986 Trek 300 Elance / 54.5 cm top tube
21" 1972 Peugeot UO-8 / roughly 55 cm top tube IIRC

I recently came across a 50 cm 1984 Miyata 1000 that was too nice a bike to pass up. It's a little short, so I've got a fair amount of seatpost and quill showing, but it has a 53.5 cm top tube just like my Bianchi. The Bianchi fits great, so I figure I'll give the Miyata a shot.

OldsCOOL

Oh man, I dont even want to mention the super small 2002 Trek 820st with seatpost above safe range. Or the other MTB, a 58cm Univega Alpina Uno. But those are just fun-bikes.

79pmooney

I look at: where does the BB sit relative to the wheels, ie how is my weight balance? What do I have to do to [place the seat and handlebars where I want them? Can I do it with off the shelf and reasonably inexpensive parts? Am I willing to spend more/go custom on those parts?

Notice that frame size never enters directly into any of these questions. My preference is 58-59 with steepish angles and long top tubes but my commuters (horizontally dropped early to mid '80s bikes have twice been 25" frames. I don't get to pick when I have to shop for the next one. They die violent deaths. I also have now a considerably smaller Raleigh Competition that with a 140 stem I happened to have and a 60 mm setback seatpost I happened to find for $15 is a sweet fit. 21 1/2"? I measure up the frame to be, enter it into a drafting program with all the rest (to see what seatpost and stem will be needed) and call out the dimensions, but make zero attempt to remember them.

So right now, roughly, I have (2) 59s and a 58 (all custom), a probably 58 commuter and a 55? (the Raleigh).

Ben

ddeand 

2015 Cannondale CAADX = 56cm
1985 Gazelle AB frame = 60cm
2015 Cannondale Trail SL 1 29er = large

Measurements indicate a 58cm frame would be best for me fir a typical road bike.

nlerner

The key measurement for me is 73cm from the center of the crank to the top of the saddle. I can achieve that on frames ranging from 56-61cm seat tubes.

plonz 

My bikes range from 57cm-62cm. 60cm seems to be the best size for me but for some reason I prefer 58s with longer seat posts and stems.

iab

Seat tube 55-58cm ctc.

Top tube + stem 68-69cm ctc.

John E

In a traditional road frame, 55cm C-T is my size. (Bianchi and both Capos.) I get a full, non-stretched leg extension with my heels on the pedals, I can just touch the handlebar with my elbow against the nose of the saddle, and I am just about at knee-over-pedal-spindle. Works for me.

The UO-8 is 53.5cm C-T, but with a disproportionately long top tube, so that also works.

Dave Cutter

I have an old '88 Trek 360... that I believe it may be a 55cm, and I have a Fuji that I think is a 57cm. I have (another) Trek that is a 56cm as well as a 56cm Cannondale. All the bikes vary a little bit in top tube and seat tube measurements.

But once adjusted (including a shorter stem on the Fuji) they all measure pretty much the same when I put a tape measure to them. And they all feel really comfy. But they all ride differently as well.

DMC707

5'8 (but my internet dating profile says i'm 5'9 -- wink) -- I ride 53 or 54 --- and can adequately stretch it to a 55 at the most if the ancillary bits are sized right (crank length, stem, bars etc)

gear64

I've been thinking lately about all the threads on fit, and I that regularly switch back and forth between a 52 and 56. Additionally, the 56 has a much longer stem. Both are perfectly comfortable. Really it's just a matter of being more upright, or not so upright. I have a couple others I don't ride nearly as often. Not sure what they are exactly, but reasonably sure within the range of the first two. I have another that's still project stage, a 54. Maybe I'll find that's a sweet spot.

Loose Chain

All of my road type bicycles seem to have a 22 inch top tube. The seat tube can vary between 54 and 56cm. For MTBs I seem to wind up on bikes in the 17 to 18 inch seat tube range.

Steve Whitlatch 

Miyata 912 - 62 seat tube, 58 top tube and a 90mm stem (deep drops)
Witcomb - 60 seat tube, 58 top tube and a 110 stem
Schwinn Fastback Pro - 56 seat tube, 56 top tube and a 120 stem (lots of seat post showing)

All fit well and feel great. Strava says I am equally slow on all of them.

Prowler 

The key measurement for me is from the top of the pedal spindle to the sit bone location. I don't actually know what that is but I made a 'gauge' that has that and I use it on all my bikes so it's set the same. ST and crank arm lengths vary, even saddle heights vary (though most of them are Vetta TriShock) so this gauge (story stick) gives me a quick check. My best fits are 57/58cm but I ride a 61, a well slammed 62cm Moto and the well stretched Trek Mtn bikes.

My story stick also has a mark for sit bone to back-of-the-brake-hoods which helps determine needed stem length and seat set-back. Between these two measurements my basic triangle of contact points is about the same on all 8 bikes. Works for me.

T-Mar

For me, size is dictated by the combination of seat tube angle and top tube length. I'm typically in my zone with a 56 cm (c-t-c) but I've found road and track frame combinations with horizontal top tubes that have worked well as large as 58cm and as small as 48cm.

bradtx

@OldsCOOL, In short, 56 cm to 60 cm. My ideal size is ~58 cm, depending on TT length.

I try to balance KOPS, leg extension, and TT length more so than ST length. Reach is adjusted with the stem and handle bar combination. The 60 cm bike is my distance bike and I switched to it from a 58 cm frame to make a better compromise fit between using drops and aero bars (It can be windy around here.).

I have to also mention my son's 64 cm French Fit Olmo. It's way out of range for his 6' height, but accommodates his muscular physique wonderfully. It was my first attempt at such a project, but with using one of the 58 cm bikes as a test bed came out perfect.

Brad

thinktubes 

57/58. Anything else requires too much futzing around.

cycleheimer

58cm to 62cm. I usually prefer a larger frame with a longer top tube. For loaded touring I'll take a 58cm frame.

fietsbob

My Brompton Only comes in One size.

Though the Mk4 is longer than the Mk2.

ollo_ollo

Measured C to C, my favorite rides measure from 51 cm to 54cm, with top tube length from 53cm to 55 cm. All are quite comfortable after my compensating of saddle height/position and stem height/reach. I once checked to see if the bar to saddle to pedal center measurements were the same, but they vary by 1/2 to 3/4 inch. Interestingly, the longest top tube (55 cm) is on my 52 cm Bianchi and the Bottom Bracket to ground measurement varies by 1 1/2 centimeter from bike to bike.

For the Clunker Challenge, I am riding a 1966 Schwinn Super Sport which Schwinn calls a 24" frame. That would be around 61 cm, but they measure from crank center to top of the seat tube, which extends quite a bit above the top of TT. Center to TT Center, the bike measures 22 3/8" which is almost exactly 56 cm. I can stand with both feet on the ground and clear the top tube by about the thickness of my shorts. NTL, it is a comfortable ride now that I replaced the original vintage stem with a cheap, short reach SR stem.

In the past, I have ridden a 49 cm Eisentraut framed bike with the aid of a long seat post and North Road bars hung on a long stem. I traded that bike for my 84 Specialized Expedition Touring. I also had a 55 cm Zeus for a while, but eventually gave it to my 6' tall son when his 58 cm Super Le Tour was stolen. We had to add a tall seat post to make it work for him. My son will likely end up with both of the Super Sports I recently acquired. Don

horatio 

54-58cm range for me. The bike shops that have "fitted" me both recommended a 54cm frame. At this point my 55cm frames are most comfortable, and I don't have to worry about toe overlap that comes with the 54cm frames. At the larger end of the spectrum, I think geometry is more important for ride quality. For example I have owned both an Ironman and a Bianchi in 58cm. The Bianchi was very comfortable to ride. The Ironman, not so much.