Buying a used bike vs. new

you'll have a fitting done (or should ) with your first bike.

honestly, some may argue this but you will know very little about a bike from a test ride around a parking lot, and even less if yo uare new to it.

you go in, they measure all sorts of things, and then tell you which bikes in which sizes will fit.

FWIW i have never test ridden a bike that i bought (on bike 5 right now).

So after you buy the used bike you take it for a fitting?

I am 5'11" and there is someone selling a bike that is 5'10", is that close enough?

what you normally do is you go into a bike shop and they take the messurments and then put you on a fit bike (adjustable bike0 and get the rest of the numbers on where you should be. from there you can either adjust the new bike to match or take it in to them.

is it a road, tri, or mountain bike you are looking at?

for most ppeople a road bike from someone of a similar height will fit.

Many bike stores will have you stand over a bike and if your crotch doesn't hit the top tube they will say it fits. But that is not correct there is much more. Stem length and height, saddle position, placement of cleats etc. A proper fit should include measurements as two people of the same height may have very different proportions. Also men's bikes usually have a longer top tube than women's designs.

I'd advocate buying used because if you do get the wrong size you won't be out as much money and can probably resell for as much as you paid.  Height is a very general rule of them,  but top tube measurement is much more important.  As long as the frame size is fine you can dial it in with a new stem or such.  If you can get to a bike shop to try a few, or at least see what they recommend, that'll help a lot in your search.

Go to a shop and let them size you to a bike. I would buy used, many good deals out there right now. You'll get a much better bike for the price.

I bought a used road bike for 200$. I used it for three years. It probably wasnt the perfect fit for me but for learning basic bike handling and doing my first few races it was fine. After two summers of dong tris I started visiting bike shops and actively looking for a new bike. After my third year I knew what I was looking for and I had saved up money to pay cash. I ended up getting another used bike for 900$ that I think incorporated alot of what I wanted/learned in the previous seasons.

I bought a used bike that was in good condition first then I bought a new bike.

I was fine with the used one until I decided to start racing.

Thanks everyone. Very helpful responses. I am going to try to get to the LBS next weekend. The used road bike I am looking at sounds like an okay deal as it comes with odometer and clip-on aero bars.