Sizing go big or small, Who is right
 

So I went to several LBS today but at two of them I got some different suggestions on bike sizes. The first store said that you can always make a bike bigger but not smaller and had me at a 53 or maybe a 55 (He only had a 53 on hand). The second store told me that for touring he tries to get the biggest bike the customer can fit on due to the time one would be on it riding. He suggested size 57. So who is right, the one who would err on the side of smaller frame or the one who would err on the larger frame?

Well, just right is the best :) Ride both sizes and see which one fits the best.

I would err on the side of larger, personally. If the bike is too small it will be hard to get the handlebars high enough to be comfortable for touring.

It isn't all that hard to get bars a bit higher. There is a wide variety of stems and extensions available. It is much harder to get bars low on a larger frame.

I would try to optimize the fit based on your preference for handlebar height, but err slightly on the small side if in doubt. Not all of us want their bars high on their touring bikes. I like them the same 3"-4" or so below the saddle as on my road bike, hence a smaller frame works better for me.

The tolerance (or lack of it) for an aggressive riding position is more a matter of conditioning than anything else. So I fail to see why when I am on a tour riding long hours everyday I wouldn't be better conditioned to the lower bars than any other time.

Everyone is different though, so ultimately you will have to answer the question for yourself. Do you like an aggressive posture on the bike? Do you like the bars at or near saddle height? Do you like the bars really high? If you have a definite answer to that it will go a long way toward answering the question of frame size.

Were they both the same bike? It's entirely possible that a 55 in one brand would have the same TT length of a 57 in another. What bikes were they?

Sizing is a little bit complicated, especially since there isn't exactly a universal sizing method these days.

However, unless you have really unusual proportions (e.g. long legs and short arms, or vice versa), I'd try to get one as spot-on as you can. Don't settle for a smaller frame just because that's what they have in stock.

Also, if they don't have the frame size you need, they can always order it for you.

Not sure my opinion is worth anything, but if it was me, I would get the smallest frame that will allow you to get both the saddle and the handlebars where you want them, without having to resort to any extreme seatposts or stems. Of course, you have to know where that is, which is something only you can decide. Generally-speaking, you can't go very wrong by using the standard method for determining frame size (inside leg measurement multiplied by .65 for centre-to-centre). In my experience, this standard method sizes neither tall nor short, but just right if you want to have about an inch or so of crotch clearance (assuming a level top tube). If you go larger, you won't have any crotch clearance (I know some say this isn't a problem but I prefer to have some), and if you go smaller, you will have a hard time getting the handlebars at a decent touring height (about an inch lower than saddle), and you may not be able to get the fore-and-aft of your saddle where you want it without the seatpost clamping onto the extreme forward end of the rails. But it's likely that for any frame, you will be able to fit on at least one size up or down.

IMHO, don't err either on the large or small side - get it right. Set up the bike in the shop exactly as you would take it, then ask to ride it for a couple of hours to be certain.

It's probably fair to say that most people are more comfortable touring in a slightly more upright position than they would use for commuting, for instance. Wind resistance is less important, weight on hands is more important.

Steve

dont buy either one of them ,if its to big its to big ,if its to small its to small ,you need to be measured for a bike even an off the peg one .a couple of centimers either way will make a big difference .if your only going to be running down to the local shop then buy what ever but for touring you need to get it wright or you will suffer.over stretch sore back,cramped sore neck, knees,wrists..

it depends largely on how you're proportioned.

in my case, i have long legs for my height and a short torso. most people would put me on a 58cm frame but when it comes down to it, I have found that a 58 cm TT is just too long for me, but if i go with a 56, i will have tons of seat post and I won't be able to get the bars where i like them (even with the saddle). This is why i just picked up the perfect frame for my size and proportion - an 85 specialized expedition with a 58 seat tube and a 56 top tube.

when it comes to touring, bike fit is absolutely the most important thing. when you spend hours and hours on the saddle, the slightest annoyance will become extremely painful. you will not have a good time on the wrong size frame.

my advice is to spend a good amount of time test riding bikes or even borrowing friends bikes so that you get an idea of how you're proportioned. I would say that top tube length is the most important measurement on the bike. there are ways to raise the bars if need be.

Also, do not get attached to one brand or make of bicycle because certain people will fall en-between a manufacturers frame sizing and neither frame will work.

My 2 cents; big feels good for the first ten miles but at 40m+ the overextention becomes pure misery. I think many have bought into a 'SUV mentality' about frame size, resist the urge to go big if you plan on distance riding.