CF4L

so this is kinda spawned by some comments that DW and Dolface made in another thread, and I got thinkin. They mentioned that Pistaboys bike was too big because he didn't have enough post showing.

I was just wondering how others feel. I don't want this to be another sizing thread, although it is. But does anyone have any specific points to make in this area?? I mean if my "area" clears the top tube when standing, what makes it too big?

also if everyone feels this kind of thing has been beat to death, just tell me so.

mattface 

Within a certain range, a frame can be made to fit right with seat and stem adjsutments. Current conventional wisdom seems to say it's better to go on the small side, and compensate with stem and seatpost.

For my comfort, I prefer the fit of a larger frame with not a huge amount of seatpost sticking out the top. the seatpost sticking way out, with the seat all the way back, and a long stem feels wrong to me.

Anyway, if you're comfortable on your bike the fit is probably not too far off. That doesn't mean it could't be adkusted better though. If your seatpost is only out a couple of inches, and you'r not grinding your crotch on the top tube, you might want to try it a little higher. Most people seem to ride with the seat too low. Crank it up 10mm at a time until you are sure it feels too high, then back off a bit.

Mike552

What it basically comes down to is flexibility. Try this simple test: Standing with feet about 8 inches apart, bend over and try to touch your toes while keeping your legs completely straight (ie no knee bending). If you succeed, you can go for a slightly smaller frame with a stem to compensate. Otherwise, if you're like me (I can only touch my shins) then you will benefit from a slightly larger bike and a shorter stem.

As an example, I am 5'9 180lbs, not the most flexible, and my frame is a 56cm with a seatpost height of 16cm and a stem length of 90mm. If I could touch my toes, I'd ride a 54cm with a seat height of ~18cm and a stem length of ~100-100mm. This is all assuming we are using stems with minimal rise and height. (i.e, normal stuff)

Hope this helps.

onetwentyeight 

yay for the unflexible. I'm 5'10 or 11 (i havent measured myself in a while) and ride a 57. I have just under two fists of seatpost tho (long legs)

ZappCatt

Isn't Pistaboy 15???? He should grow a little..would hate to have an "expert" put him on a bike which fits him at the edge of "perfect" and have him grow out of it to soon. I think he said he paid for the bike with his own money...

The others are guys who bid on Dura Ace 10 pitch

dolface

hey!

classic bike nuts like to have 'one fist of seatpost' showing, 'cause that's how they sized them back in the day (and rivendell and 47x16 like that sizing too).

i like to have two fists, and about 100mm of track-drop stem, but that's an aesthetic thing. i also teach fitness classes, have pretty good core/pillar strength, and can touch my toes.

if the bike isn't hurting you, and you don't feel too stretched out on it, i'd say you're good.

slopvehicle

I'm 5'10"-11" or so and ride a 55cm that feels a hair too big for me. Perhaps I have short, stubby arms ala T-Rex.

onetwentyeight 

I dont think it would hurt me if I went down to a 56, I'm cutting it kind of close w/ the stand over height. Either way though, I love my frame and it gets the job done.

endform

Short answer: Are comfortable on your bike for longer than two hours? If yes, it fits (more or less).

bostontrevor

I go with the fistful of post myself, but that's because with one exception, my frames are too large. My roadie is actually right sized and has maybe a fist and a half.

The fist rule comes from when seatposts weren't as strong as they are today. A smaller frame makes for a stiffer bike and better energy transfer. I happen to like the proportions of a classically sized bike, but there's no strong technical reason for it these days.

sers

i have 2 fists and a 130mm stem on my mark v - there's about 3" difference from seat to bars. i've gotten to the point where the seat is pretty far forward, but there's no weight on my hands when i'm in the drops. i'm not the most flexible guy, but i ride every day - 40+ miles a week. I feel faster shifted towards the front of the bike, and it just seems to suit the way i ride. That said I had to condition myself into it.

wagathon

All three examples are road bikes with the same size frame; however, the pic showing the most exposed seatpost is of a bike with a sloping top tube. Hope this helps

CF4L

so i guess it pretty much comes down to preference again. kinda what i thought. I guess i was just curious if someone was gonna come up with an answer like "it lets the pelvis flex at a greater angle witch allows greater cadence and better speed" or something off the wall like that.

mattface 

Well there's also the fact that Don is exceptionally opinionated for his age. I was shocked when I went to his website, and found out how young he actually is since such strong opinions are usually held by crotchety old farts I forget now, but I think he is maybe 38?

46x17

Yes it is all preference.
I am six feet even and my first Mark V was called 59cm. However, c to c it only measured 55cm. After riding this for 6 months I managed to exchange it for a Mark V Pro that is called a 62cm. However, c to c is only 58cm. The new one fits a lot better. I don't think a 58cm frame (with a level top tube) is excessive for a six foot person. There is about a fist and a quarter full of seatpost.
A lot of it also depends on riding style. If I built a bike exclusively for the track I would go with a slightly smaller frame and a drop stem with track drops. If I built a bike for tricks only I would go for a lower front end too, but with wider tires, etc. The current setup is a do everything kind of bicycle, since I only own one. I can do tricks, switch the stem and take it to the track, and still feel comfortable after riding it for 75 miles.

Re-Cycle

Uber exposed seat tubes / stems flex. I personally like a frame thats a bit big so that not much tube needs to be extended.

ZappCatt

DF and DW, you guys know I was just kiddin, right?

I am a couple handfulls of seatpost guy myself..36 in inseam will do that to a guy....

r-dub

I'm 6'1" and ride a 61c-c (seat tube)x 59 c-c (top tube) with 7 fingers (meaty ones at that) of seatpost showing. Yes, it's a matter of preference, but it's also a matter of what fits. For my height, I've got rediculously long legs and a stubby torso. Some folks, though, would just look at my overall height and put me on a 57. I keep my hbars about 1.5 inches below the saddle (not quite to rivendell spec, but much higher than the trackies) and am comfortable on 100 mile + rides.

Phillio

I'm about 6'0....would a 54 cm frame be too small for me? I'm guessing yes, it's just that there's a cool frame on ebay right now with a buy it now feature at a good price, but I wouldn't want to get it if it didn't fit.

lyledriver

I'm 6'1" and riding a 54cm frame. ITS WAY TOO SMALL.
Granted, I'm pretty flexible, and I've got a pretty long stem, and flipped North roads on it, but I can't stand riding it for over 2 hours.

mattface 

I'm 5'10" with a 32" inseam, and 54 is at the bottom end of my range. It might fit you OK though depending upon how much of that 6' is legs, and how much is torso.

Phillio

Hmm, might have to pass on it then. As sweet as the frame is I'd rather have something that fits me right....56 is probably at the bottom of my range. Right now I'm riding a 57 or 58, not sure. Fits nicely but I'd like something with less slack geometry...if anyone's interested, the frame on ebay is a 54 cm Specialized Sirrus, '84...something like that that takes 700c wheels would be ideal. Oh well.

squeakywheel

That plan works for most 15 year olds. Didn't work for me. I have a mid 1970's Raleigh Grand Prix that's still too big for me 30 years after I bought it.

huhenio

6f 1', 32 inseam, riding a 58, tons of seat tube showing, 1 1/2 inch stem

I guess I must be flexible

ultraman6970

Hi

Well I think it 1st it depends of the frame. Diferent brands have different sizes... U know because of the center to top stuff, regular stell frame, aluminum, compact geometry... and because of how oversized the tubes are too. I have a friend that usually in steel uses 54 and with raleigh and Fuji for some reason he has to go for 51 - 52 or the bike will be too short.

In my case Im an average size person, 5,10 - 6 feets tall depending on which Liquor store im walking out from. And i been always using 56 - 57 (stem 11) frames all my life. A 54 as someguys sugested results too short for me... and after 1 hours or so i have pain averywhere, eventhou everything its in the right place (longer stem).

About the seat tube?... well it depends too as long as the person it is comfortable.. but all have "tolerances" i think. Everybody have seen those 6 feet guys in frames too small, eventhuo the seat and the stem are the right ones(extra large seat tube and stem), the frame it is too short. Or the opposite... guys too small riding huges frames... someguys like to kick their knees on the stem for some reason.

My advice at least when choosing the frame size nowadays is... go for the lenght of the frame, or virtual lenght of the frame (for those who likes compact geometries, sloping) not for the size of the frame because nowadays it is a mess that nobody undesrtand. What have always been a rule is the inseam size less an x number that usually is like 25/30 cms (maybe im wrong about the numbers but u guys have the idea, IM OLD OK? I forget stuff!!!), that it will give u the size of the frame (old skool system).

About how hight the seat it has to be... like 10 years ago or so in a magazine i saw a formula... the problem is that i cant remember exactly how was it. at at least in my case it was perfect. i think it was like..0.89xtheinseamwithciclynshoeson then that number it should be the same between the center of the BB and the upper part of the seat (just like when measuring the size of the frame). Maybe somebody remembers the magazine.

thanks ....