I've lurked around here a bit with particular fascination with the members who ask whether or not such-and-such bike is a good deal. Invariably, someone will reply with "Does it fit?"

What exactly do these people mean when they ask that? Are they simply concerned whether the frame is the right size, or is there a deeper question being asked?

They are asking is the frame is the right size for them. I personally think bikes are like clothing when it comes to fit; you have to try it on to know for sure.

I ask that question because ...

1) Frame size is very important. Men especially seem to have an inclination toward huge frames even if their inseam length is no more than mine (an average sized girl). I know of a few who have been somewhat surprised to discover that the bicycle that actually fits them, and is comfortable, is a fairly small bicycle. There's no point forking over a bunch of money for a "good deal" if you've got to ride with the saddle as far forward as possible and resting on the top tube because the frame is way too big and there's no room for adjustments, or if you've got to buy an extra long seat tube because the frame is too small.

2) I personally struggle with the reach on bicycles, and I'm sure there must be others out there with the same problems. I have a very short torso, and bicycle manufacturers (even those who produce small bicycles) have a tendency to make very long top tubes. Then bicycle shops like to put the longest stems on them as possible, so that the handlebars are so far in front that I can hardly reach them. That's something you have to get on the bicycle to check. No point buying a bicycle with a setup like that, where you'll be riding around with arms fully extended all the time. If that's how the bicycle is set up, you can negotiate with the shop to change the stem for a shorter one ... and that is part of the "is this a good deal or not" question. If the shop won't change anything to make the bicycle more comfortable, then maybe it isn't a good deal after all.

Those are the two main parts of the question, however, some underlying parts might be ...

3) A good bicycle shop will take the time to go through a bit of a fitting with you. If they don't, are you sure you want to deal with them?

4) Do you know how to do your own fitting, or are you planning to buy a bicycle that looks approximately right and just start riding?

What I've always thought is once you got a fame size that was appropriate, there are always seat tube, saddle and stem adjustments to get you to your optimal fit. I tried out a Specialized Allez the other day that I could barely reach the hoods. The LBS assured me that they would swap a shorter stem for me, or I could pay the difference on an adjustable if I wanted.

It's the opposite actually.

The frame size is not an exact science but it does have to be Right. Machta mentioned that Most men ride a larger frame than necessary. Most women have shorter torso's than men and this is why Women Specific Frames are now made. Same height or Standover on the two frames- just a difference in top tube length.

Two things I look at on bike fit and the first one is Standover height. If I do not have good clearance on a road bike between the crotch and the top tube- then it is too big. Then the feel of the bike once I am in riding position. I know I can change bar stems and adjust fore and aft on the saddle, but if it is not nearly comfortable in standard form- then the bike does not fit and look to a different Size or different Model.

Once the frame size is sorted then you can think about changing parts to "Finetune" but I bought a road bike this year- I am a mountain biker. Only parts I have changed are the Bar stem to one 20mm longer and the pedals. This is probably due to 15 years of MTB where a more upright stance is used. It fitted Correctly in the shop and I will not be buying a new one that fits better next year. Picvture attched but this is a Compact geometry frame so looks wierd- and was before changing the pedals and stem but this bike fits. This is the first bike that has the Saddle central on the rails and not fully forward or fully back so is probably the first frame that is my correct size aswell.

Funny you mention the seat is centered on the rails. It's not actualy centered on the post given that you have a setback seatpost...

I find that most women are riding frames to big and most men , too small. It is only old beardy men with sandals who ride oversized 1970s style frames and I wouldnt dream of telling such a rider what to do.

The current trend is for small frame swhere the critical dimension for fit is length, not height.

You can make a bike fit with selection of seatpost and stem. The range of components is much wider now than in the past so frame angles are less critical then they used to be. If you have a particularly extreme proportion (torso/legs or upper leg/lower leg) you may need a frame of different proportions to normal.

Well, "old beardy men" have had about forty or fifty years of experience riding bikes. They know what works. The "oversized frame" and sandals are both assets to really being comfortable on a bike. The beard is optional.

I have to agree. I always get a chuckle see a big guy riding a small frame with a large amount of seat post showing..

See now, I'm 6'3", my inseam is 34" barefoot, the standover on my 62 cm bike is 34". Good thing I wear shoes right? But I am in the market for a longer seat post. I need an extra 1/2 inch to be really happy, but the bike fits like a dream, my back doesn't hurt, I'm not completely stretched out even in the drops, its just comfy.

There is a deeper question. It's a nice way of saying, "The question that you asked is one that is often asked by people without a lot of cycling experience. What you probably don't realize is that if a bike doesn't fit you, it doesn't matter how good a deal it is. Our experience is that if you end up with a bike that isn't the right size for you, you won't be happy"

Doesn't it depend on use also?
I am a 33 inseam 5'11"
I have a 56cm road bike
58cm tour bike
Small comfort bike (which I insist is to small but got it free from bicycle Mag)

An inline seat post would put the seat mounting above the Post instead of a bit further back- But I would call an inline seatpost a "Non-Standard" item and if required would come into the Fine tuning part of setting up a bike. I attach a pic of my Bianchi- that is the same size as the Giant and as you can see- on this bike I should really get an inline post. Then again on my Tandem I have a Thudbuster Seat post which is a bit different. Once again the Seat is as far forward on the Mounting as possible, but there is no way I will stop using the thudbuster on the T

Maybe I'm showing my age, but a lot of the guys I've known get large bicycles because, after all, they are tall ... so they must need a large bicycle.

One guy I knew was actually insulted when someone in a bicycle shop suggested that he needed a bicycle the same size as mine (a "Medium" or 50 cm Giant) because his inseam was the same as mine. He wanted to buy the "Large", despite the fact that it was obviously a bit too big for him, because he was a GUY, and he was a little taller than me.

Look around at the bikes that people are actually riding in your area. What you are looking for are seats that are down on the top tube, seatposts that stick up way high and goofy stuff like that. If the bike looks funny, it doesn't fit the rider unless the owner is a funny looking person.

Scan the posts for awhile. You'll find frequent posts from people who are looking for longer seat posts or the seat post with the most set back or "Can I turn my seat post around the other way?" "How can I raise my handlebars?" "What's the longest or shortest stem and will it screw up my handling?" The short, correct answer to all of those questions is: Buy yourself a bike frame that fits you.

While basic fit can be pretty simple, the more that you get into it, the more interesting and involved it becomes. Seat location, pedal location and handlebar location are all interelated. Anything that you do to adjust one will affect the other two. The truth is that most people can be fit onto more than one size bike but, if your handlebar reach (either horizontal or vertical) is off by more than an inch or two, you'll have a very hard time getting everything exactly right. There is simply no substitute for starting with the right sized frame.