I am begging anyone who reads this blog to do your friends, family, co-workers, arch-enemies, accountant a favor and tell everyone you know to get a proper bike sizing (by a professional) before they buy a bike.
It happened again -- I saw a client late last week that had just spent $3500 on a bike and it is the wrong size. They said that the salesperson claimed they would do a bike fit to make certain that the client got what they needed, but after some digging it appears the "bike fit" consisted of little more than watching the client ride around the parking lot and declaring, "Looks good!"
It can be difficult to know who to trust. My advice: Don't trust the guy (or gal) who is trying to sell you the bike in front of you. Especially if they don't spend at least 20 to 30 minutes figuring out what size you need. They should be asking you all sorts of questions about you and your riding:
How often do you ride?
How many miles per ride? per week?
Do you plan to road race? Triathlon?
What don't you like about your current bike?
Any injuries, related to the bike or otherwise?
And about 2 dozen more to boot.
At this point it'd be okay to get you on a bike or, even better, on your current bike (preferably on the trainer) and watch you ride. This is where I differ from most bike shops -- I don't think a "quick fit" suffices, in which they have you on the bike for about 5 minutes total. This is the time where the fitter should be asking a lot more questions while you are on the bike as they watch you pedal from multiple angles. I usually hook up the Retul and take a shot of each side to get more information. If you are on a bike less than 15 minutes, or if the fitter isn't asking appropriate bike specific questions you should be wary of the fit advice you are given by this individual.
Even if you are buying a bike for $1200 or less, it is worth getting a bike fit/sizing. I charge $250 for my bike fit service, but that includes a pre-purchase bike sizing session (which usually lasts about 45 minutes and even shows you how to measure the bikes you may look at to make sure they are the best fit for you, if you don't plan on buying a bike from me), a complete dynamic bike fitting (about 1.5 - 2 hours) and a follow up (again about 45 minutes) a few weeks down the line to put the final tweaks on the set-up.
But the bike is only $1000? And the fitting is a quarter of that cost -- that can't be worth it, right? Well, I've seen a lot of bikes in the wrong size, and whether it's $1000 or $7000, if it doesn't fit, then it can become a rather expensive coat rack out in the garage.