# first bike - correct size?



## Scrodzilla (May 25, 2009)

My apologies for the silly question, but I'm looking for my first fixed/single-speed bike (online...there's a lack of lbs in my area carrying track bikes) and am not sure what size I should be after. As someone who is 5'10" (with about 31" between my crotch and the floor), I'm leaning toward something 52-55cm. Is this correct?


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## pdh777 (Oct 7, 2005)

Tough question due to many variables of each person.

I am 5' 11" with a bike inseam of 33.5". I ride a 56cm. (Bike inseam is the distance between your crotch (with pressure) and the floor in socks

You first shot would probably be in the 54 to 55 range - also keep in mind different manufacturers size their bikes differently.

You should at least fit a standard road bike to get an idea of your best fitting size - this will generally transfer over to a fixed gear / track bike..

Further is it a track bike you want or a street fixie? They can be radically different in tube angles and bar drop etc..


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## Scrodzilla (May 25, 2009)

I'm looking at a Windsor Clockwork from bikesdirect. I'm even thinking a 52 may be better, as the standover info for that bike posted on BD says 30.1".With pressure I'm about 32" from crotch to floor (barefoot). I've read some stuff that says to allow 1-2" of room between your top tube and crotch...how true is this? I'm thinking a first bike that is a centimeter or two smaller will be better than one that is too big. 

(Note...I'm 35 and after a lifetime of bmx riding/racing, this will be my initial jump into the realm of full-sized track/road bikes. Better late than never?)


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## Gregpape23 (Jul 29, 2008)

I'm 5'11" and ride a 56cm frame


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## Dave Hickey (Jan 27, 2002)

Scrodzilla said:


> I'm looking at a Windsor Clockwork from bikesdirect. I'm even thinking a 52 may be better, as the standover info for that bike posted on BD says 30.1".With pressure I'm about 32" from crotch to floor (barefoot). I've read some stuff that says to allow 1-2" of room between your top tube and crotch...how true is this? I'm thinking a first bike that is a centimeter or two smaller will be better than one that is too big.
> 
> (Note...I'm 35 and after a lifetime of bmx riding/racing, this will be my initial jump into the realm of full-sized track/road bikes. Better late than never?)



forget standover as a method of bike fit...... If your inseam is truely 31", you have a long upper torso... you will be very cramped on a 52cm..... I'm 5'7" with a 31" cycling inseam and I'd ride a 52cm 


Before you make up your mind, double check your inseam... Wedge a book up in your crotch and have a partner mark the top of the book on a wall....My guess is your cycling inseam is greater than 31"


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## Scrodzilla (May 25, 2009)

Cycling inseam = crotch to floor, yeah? With a book _tightly_ (and rather uncomfortably) wedged downtown, the measurement is around 32.5". There are a lot of intersections and stuff on my way to and from work where I would need to dismount and don't think I want to have my top tube up my a$$ each time, which is why I feel I should allow myself some clearance. How much clearance (if any) do you guys have on your bikes?


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## wim (Feb 28, 2005)

Agree with Dave—forget standover, and forget the notion that "smaller is better" for a first bike. Also agree with Dave that your numbers could well be off. Your "about 31 inches" in post #1 followed by your "about 32 inches" in post #3 and "around 32.5 inches" in post #5 doesn't exactly inspire confidence.  Do an accurate crotch-to-floor measurement *in centimeter *and start your sizing research from scratch.

As to the dismount: slide off the saddle while you're still rolling, then tilt the bike to one side on stopping. Standover becomes irrelevant unless your dismount style is to jump off the saddle with both feet hitting the ground simultaneously.


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## Scrodzilla (May 25, 2009)

31" is comfortable. 32" is on the border and the 32.5" measurement is pushing it. I think because I've ridden BMX for so many years, my brain is automatically fixed on the fact that I need to be able to put both feet flat on the ground and stand comfortably with my bike upright between my legs. HAHA...I told you I was new to this!

Thanks for not digging into me too hard.


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## wim (Feb 28, 2005)

Scrodzilla said:


> I think because I've ridden BMX for so many years, my brain is automatically fixed on the fact that I need to be able to put both feet flat on the ground and stand comfortably with my bike upright between my legs..


That makes sense. But think about it—with a narrow road saddle crammed into your crotch for hours on end, how much damage could you possibly sustain from a top tube that merely grazes your package every so often? 

Here's some good (and fun-to-read) sizing instructions. Keep in mind that the frame sizes Rivendell recommends are the largest possible frames you could ride. Other sizing gurus would put you on the smallest possible frame you could ride. The truth, as always, is somewhere in the middle.
http://www.rivbike.com/article/bike_fit/pbh_and_how_to_measure_it


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## Scrodzilla (May 25, 2009)

wim said:


> Here's some good (and fun-to-read) sizing instructions. Keep in mind that the frame sizes Rivendell recommends are the largest possible frames you could ride. Other sizing gurus would put you on the smallest possible frame you could ride. The truth, as always, is somewhere in the middle.
> http://www.rivbike.com/article/bike_fit/pbh_and_how_to_measure_it


Well...by following that rule of pubic bone height minus 25cm, that puts me on a 56. I'm gonna go into the city over the next few days to try to find a decent LBS that isn't full of hipsters (probably hard to do in Boston) and sit on a few bikes. 

I'm getting antsy and want to order my new bike now!!!


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## KellyMo (Mar 31, 2009)

wim said:


> http://www.rivbike.com/article/bike_fit/pbh_and_how_to_measure_it


Hrm, according to that site, I should be using a 59-61cm frame, but I'm on a 53cm and I think it's slightly on the large size. Then again, I'm 175cm with an 86cm distance between floor and pubic bone, so my height is between my pedals and saddle, instead of my handles and saddle. Heck, more than half my height is below my waist. (Now if only I were a guy, that'd be a great pickup line... :ihih:  )


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## Fredrico (Jun 15, 2002)

*54-55 cm, the happy medium.*



Scrodzilla said:


> Cycling inseam = crotch to floor, yeah? With a book _tightly_ (and rather uncomfortably) wedged downtown, the measurement is around 32.5". There are a lot of intersections and stuff on my way to and from work where I would need to dismount and don't think I want to have my top tube up my a$$ each time, which is why I feel I should allow myself some clearance. How much clearance (if any) do you guys have on your bikes?


82.55 is your inseam, x .66 (the largest of the two numbers, .65 and .66, to calculate frame size) = 54.48 cm frame size, with horizontal top tube. The same size with a sloping top tube would be smaller, but the top tube would be about the same, 55 cm. Presumably, these measurements are center to center of the tubes. Some frames are sized by their manufacturers center to top, which adds another cm.

Smaller frames handle quicker, closer to a BMX bike. Larger frames are more comfortable. They have roomier cockpits and there's no problem raising the handlebars to saddle height. Single speed track bikes have steeper seat tube angles, putting the rider up over the crank so his legs can easily follow the crank around and spin at fast cadences. To keep the roughly 90 degree angles of back/upper legs and back/arms, the handlebars can be a bit lower, maybe 2-3" below top of saddle. I'd guess a 54-55 cm, frame would work great for your legs, with maybe a slighly longer stem to accomdate your 5'10" height.


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## Scrodzilla (May 25, 2009)

Thanks, Fredrico...and all others who have responded. I appreciate it. 

I ended up finding a mom &pop LBS nearby. Not much selection but they did have a few Redline 925s in various sizes. The 56 seemed way too big for me (for my legs, anyway) and standover clearance was extremely slim to none. The 54 seemed like a better fit.

Ordering from BD tomorrow and will be rolling soon!

:cornut:


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## wim (Feb 28, 2005)

*??*



Scrodzilla said:


> The 56 seemed way too big for me (for my legs, anyway) and standover clearance was extremely slim to none. The 54 seemed like a better fit.


You're comparing apples with oranges. The Redline 925 is a compact (sloping top tube) bike; the Windsor clockwork is a traditional (horizontal top tube) bike. To use a compact bike as a sizing tool for a traditional bike isn't really the right way to go about fitting yourself, especially if you're as concerned with standover as you still seem to be. If it all works out perfectly anyway, it'll be sheer luck.


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## Scrodzilla (May 25, 2009)

If the 925 is a "compact" and the 56 felt much too big, wouldn't it be safe to say that a traditional 56cm frame would feel even bigger? That was the impression I was under.


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## Fredrico (Jun 15, 2002)

*True, but:*



wim said:


> You're comparing apples with oranges. The Redline 925 is a compact (sloping top tube) bike; the Windsor clockwork is a traditional (horizontal top tube) bike. To use a compact bike as a sizing tool for a traditional bike isn't really the right way to go about fitting yourself, especially if you're as concerned with standover as you still seem to be. If it all works out perfectly anyway, it'll be sheer luck.


If the sloping top tube Redline is still too high, then the man may be right, the bike is too big. Of course, if the head tube is long for a more upright position, the top tube might be pretty high where you're standing over it.

There's a school of thought, advocated on these boards, that says the way to determine the "real size" of a sloping frame is by measuring the top tube, which will be almost or exactly the same length as a traditional horizontal top tube frame with the same fit. Only two builders I know of, DeRosa and LeMond, depart from this symmetry. They have sometimes spec'd horizontal top tubes about a half to 1 cm. longer than the seat tubes. Traditional frames have the same length seat tubes and top tubes, except for the very small or very large sizes, which may differ, to keep the standard tracking characteristics of a 39'" wheelbase.


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## wim (Feb 28, 2005)

Fredrico said:


> If the sloping top tube Redline is still too high, then the man may be right, the bike is too big. Of course, if the head tube is long for a more upright position, the top tube might be pretty high where you're standing over it.


Agree with that, but I'm having a difficult time believing that a 5'10" tall person with a self-measured 82.5 cm (32.5") inseam has a standover clearance of "extremely slim to none" on a 56 cm compact frame. Something doesn't add up here, and I suspect it has something to do with standover clearance being the one and only consideration in this "fitting" process. I wish the OP good luck.


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## Fredrico (Jun 15, 2002)

*Yes.*



wim said:


> ...Something doesn't add up here, and I suspect it has something to do with standover clearance being the one and only consideration in this "fitting" process. I wish the OP good luck.


Scrodzilla shold realy get on the bike, adjust the saddle to the right height, and take a ride on it, to see how the handlebar reach and drop feels.


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## Scrodzilla (May 25, 2009)

A buddy of mine stopped by my work this afternoon with his 55cm Pake Track and once I lowered the seat a couple of inches to suit me (he's a 6' hipster and likes to ride a smaller bike), I cruised around on it for a while and it felt PERFECT...plenty of standover clearance while providing a comfortable-feeling reach. It figures that the Clockwork only comes in 54 & 56! 
:mad2:


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## Fredrico (Jun 15, 2002)

Scrodzilla said:


> A buddy of mine stopped by my work this afternoon with his 55cm Pake Track and once I lowered the seat a couple of inches to suit me (he's a 6' hipster and likes to ride a smaller bike), I cruised around on it for a while and it felt PERFECT...plenty of standover clearance while providing a comfortable-feeling reach. It figures that the Clockwork only comes in 54 & 56!
> :mad2:


Take a tape measure and get the top tube length, center of seatpost to center of head tube. Then compare it to the 54 and 56 cm frames you're looking at. Also measure the distance from tip of saddle to handlebar tops. You could then replicate that distance with the proper length stem on the new bike. :idea:


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