bhayes505

In search of my 1st road bike and have a question concerning frame size. I went to Performace the other day and they sized me on a 56cm Fuji. Today I went and test road a Trek 1.2 and they are sizing me on a 58cm. I was comfortable on the 58 but didn't ride it for long. I have found a used 58cm 2008 Specialized Allez Compact for less than either of the above bikes. Does Specialized run similar to Trek as far a sizing goes. Thanks in advance for any advice.

Meek

Sadly, I've seen LBS's try to make a quick sale by sizing whatever they had on hand (including Performance). What is your height, inseam, etc? You can, of course, always swap stems, go for a set-back seatpost etc. to make the bike 'fit', but it'd be nice if it was close from the get-go... I am guessing you are around 5'11...

bhayes505

Sorry, I should of put that info in my first post. I am 5' 11 1/2" to be exact. My inseam is 32.5".

Fox Farm

How are they measuring the seat tube? Center to center or center to top? AND, what are the measurements of the top tube? More important as you can move that seat post pretty easily up and down. Adjusting stem reach in not as easy and moving the seat forward or back will mess with your knee to crank arm/pedal ratio.

Meek

As general as general can be, I'd lean towards the 56 assuming an approximate 56 effective TT. It'll probably come with a 110mm stem, which can be easily changed to a 120 if you feel the need to be more stretched out...

Where are you?

FWIW It's also usually better to choose the slightly smaller bike to the larger... assuming you are between 2 sizes...

bhayes505

To be honest I really don't know. I know at Performance they really didn't do much. All they did is pull down a 54cm, had me stand over the bike and said it was to small. Pulled down a 56cm and do the same thing and said that's what I needed. When I went to Cycling Spoken Here it was a lot more involved. They had a 56cm and a 58cm in 1.2. When he put me on the 58 he could tell right a way the seat needed to be raised. He put the bike on a trainer, had me get on the bike and made the proper adjustments before my test ride.

bhayes505

I am in Cary, N.C. It's a suberb of Raleigh. Great cycling community here and I can't wait to get more involved.

Meek

Cool, my new brother-in-law and sister are in Durham; both PhD students (Duke and UNC). And my parents just retired to Wilmington.

bhayes505

I sure would hate to be in that house during basketball season.

OCRider2000

https://www.bikeforums.net/search.php?searchid=6024708

DaveSSS 

A few points to consider. Frame size numbers are rarely comparable between brands, so don't even worry about the "size". Look at the head tube length, with the headset to better determine the true vertical size of the bike. Some models now have 15-30mm taller head tubes, but have the same size number as the racier models with the same frame reach.

The TT length, without a seat tube angle to go with it, means nothing. It's often advised to by a frame by TT length, but what you really want is a specific reach. A frame with a 55cm TT and 74 degree STA will have about the same reach as a frame with a 56cm TT and 73 degree STA. Reach is the horizontal distance from a vertical line through the center of the bottom bracket to a specific point at the head tube. That point can be defined as the intersection of the TT and HT centerlines or the top-center of the head tube. Cervelo and Trek use the later definition. The problem with reach values is that they are only valid for one given stack height or head tube length. If the stack heights are not the same, compensation must be made to equalize the stack.

Your questions about the various models can be answered by reviewing the geometry charts for each model under consideration. It's rare when those cannot be found at the manufacturer's website.

https://www.trekbikes.com/us/en/bikes/road/1_series/12/

https://www.specialized.com/us/en/bc/...=38496&eid=115

https://www.fujibikes.com/Road.aspx

bhayes505

Thank you! I really appreciate the info Dave.