Measuring bike frame?
 

I just bought a new Raleigh Road bike, the bike is a 60cm (and marked as such) but when in measure it get 57.5cm (22 5/8")

Also my old bike, Felt 45, which I bought used was sold to me as a 58cm (it is not marked with the size), but I measure it at 56.5cm (22 1/4")

Are bike labled taller than they actually are?
Is this common?

I am measuring from the top of the seatpost, in a straight line to the center of the crank

Trying to sell my old bike, but not sure if its a 58cm, like I was told, or a 56cm

Thanks!

Does this bike have a horizontal (traditional) top tube? If it is a modern, sloping top tube, you have to measure from where a traditional top tube would hit a longer seatpost. (I don't know if center-to-center and center-to-top terminology is still used. If it were me, I'd go c-c. I'd measure center of the top tube/headset intersection to the ground, then mark that height on the seatpost. Now measure that new bark to the BB.)

Ben

Thanks Ben
My new bike does have a little slope to the top tube, so that makes sense why I am measuring it a 57.5cm and not 60cm

My old bike (Felt 45) is horizontal
Guess it is a 56cm after all

I bought a 60cm based off of the idea that my old bike was a 58cm
All if fine though, I like the fit of my 60cm

I just want to make sure I am listing the size properly for whoever buys it

For a level top tube bike like your felt, you generally wouldn't measure to the top of the seat tube (where the seat post goes in), but to the point where the top of the top tube intersects the seat tube. This is called a Center to Top measure. Some bikes are measured to the center of the Top Tube - Center to Center. That's more of a Euro thing.

The best method is to find the geometry chart for your model year and measure the Top Tube, which is always Center to Center. Your bike is older than 2005, the oldest catalog I can find, but you might use the F-series geo chart on the last page - it is likely to be similar (C. TTL - Horizontal):
http://2010.feltracing.com/Resources...05Road_Cat.pdf


If I had to guess based on looks (and you measured to the black seat post clamp), your F45 is a 54cm.

This is what a 56 looks like. Check out the gap between top and down tubes at the headtube compared yours:
https://knowyourbike.com/img/cache/f...400&height=300

When I list a bike, I always tell how I measured it. IE. Center of crank to top of seat tube.

I figure that at least lets me off the hook for those that think of sizing differently. Old bikes had several different places they'd measure to depending on the whim of the manufacturer. Commonly the top of the seat tube, but some measured along the seat tube to the extended centerline of the top tube or the extended top of the top tube. For most bikes back then that wasn't but 1 to 1.25 cm difference anyway you measured.

My 78 Raleigh Competition is supposed to be 59cm as the previous owner told me. It measures 59 cm to both the top of the seat tube and the top of the extended line of the top of the top tube.

I just changed my listings to tell where I measured (Center of Crank to Top of seat post)

Thanks!

Then you'll want to revise it because you mean "seat tube", not "seat post". The seat post is the thingy between the seat and the frame.

Frame Builders Use Tube Centerlines .. indicating C to C,

..C to T is to the top of the top tube where it meets the seat tube..

some sellers may go to the top edge where the seat band clamp on the frame is..






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