Could the LBS guy be right saying I need a 56?
 

Here is my info from CompetitiveCyclist.com!

Measurements
-------------------------------------------
Inseam: 31.5
Trunk: 27.5
Forearm: 12.5
Arm: 25
Thigh: 22.5
Lower Leg: 21.25
Sternal Notch: 56.25
Total Body Height: 69


The Competitive Fit (cm)
-------------------------------------------
Seat tube range c-c: 51.8 - 52.3
Seat tube range c-t: 53.4 - 53.9
Top tube length: 54.8 - 55.2
Stem Length: 11.2 - 11.8
BB-Saddle Position: 73.8 - 75.8
Saddle-Handlebar: 52.4 - 53.0
Saddle Setback: 3.1 - 3.5
Seatpost Type: NON-SETBACK


The Eddy Fit (cm)
-------------------------------------------
Seat tube range c-c: 53.0 - 53.5
Seat tube range c-t: 54.6 - 55.1
Top tube length: 54.8 - 55.2
Stem Length: 10.1 - 10.7
BB-Saddle Position: 73.0 - 75.0
Saddle-Handlebar: 53.2 - 53.8
Saddle Setback: 4.3 - 4.7
Seatpost Type: NON-SETBACK


The French Fit (cm)
-------------------------------------------
Seat tube range c-c: 54.7 - 55.2
Seat tube range c-t: 56.3 - 56.8
Top tube length: 56.0 - 56.4
Stem Length: 10.3 - 10.9
BB-Saddle Position: 71.3 - 73.3
Saddle-Handlebar: 54.9 - 55.5
Saddle Setback: 3.8 - 4.2
Seatpost Type: SETBACK





So the guy at the shop is convinced that I should be on a 56cm Trek 1500. He put me on the 56 and I told him I felt stretched out. He said that was ok because the rest of me looked good, and that we could put a shorter stem on.

So, he put a shorter stem on and honestly things felt better. I rode a 1500 56 and a 2100 that was a 54. Both felt pretty good after the stem change. The 54 felt good too, but I think it may have benefited from some extra angle on the stem. Putting my hands on the lower bar definately had me pretty leaned over.

However, I got the sense that we were making a bigger bike smaller to fit me instead of tuning the right size. I could be looking way too far into this. I think I may try and visit another trek dealer (if one is close enough) before I make my final decision.

Thoughts?

How short is the stem they put on the 56cm? I feel a bike gets "twitchy" if the stem is shorter than 100.

I would tell you to try the next smaller size. A trek store near me wouldn't sell us a bike that my gf felt most comfortable riding because they claimed it was too small for her yet she fit perfect on it. They measured her inseam and looked in a book that said what size frame goes with what size inseam. Never looked to see if she was long or short legged/long or short torsoed or if she wanted to ride in a upright versus racing versus somewhere in between posture.

Bottom line - it's easier to make a small bike big than a big bike small. Get the one you want. It's your money and your comfort. I don't care what fit system you use.

What size were the original and replacement stems?

The 56 Trek 1500 toptube is 56.2cm, so a little bigger than your "race fits", but right at the French fit. The 54cm toptube is 54.6cm, so slightly smaller than the racer fits from Competitive Cyclist. When in doubt, and in such small numbers like this, I personally would go to the smaller size with a slightly longer stem. But this is the bike that YOU will be riding, not me, not the saleseperson.

So, as long as you don't look like a bear on a unicycle, and you are comfortable on a 54, go with that.

It is possible to be "fit" to be able to ride a few frame sizes by swapping out stems, seatpost, etc.

Personally I recommend picking up the smallest frame you feel comfortable on. In this situation I would recommend you get the 54...

...insert internet forum disclaimer here...

Keep in mind I have never seen you or the bike and really could not tell you more than you already know for yourself.

I have heard about about the twitchiness of shorter stems over and over. From my experience that is not the case. I have been riding a frame which is slightly too large with a 90 mm stem to compensate for over 5000 miles and I don't experience that. Maybe I don't know what twitchy is. That being said ideally when you have the choice you want a stem in the 100-120 (normal) on a bike to feel comfortable. When you go longer or shorter (as I did) you are generally compensating to make up for something else. Either a bike that doesn't fit perfectly or a body which is not normally proportional.

I am very close to you in measurement - same height, same inseam, and I ride a 54 w/ a 110 stem. 56 would be too big for me. When in doubt, go smaller.

In my personal experience, it's been in making turns...which makes sense if you think of the physics of it...longer stem would (in my mind) allow for a more controlled movement along the full arc of angles in turning the wheel, vs a shorter stem.

How sharp are these turns you're making?

It does make sense but if you're twitchy then you have to move more to make the wheel turn left or right, all other things being equal.

Perhaps stem length vs. twitchiness has more to do with where the weight over the front axle is vs. an absolute length?

Might be time to try some other bikes.

Remember that the C-C seat tube length on a 56cm Trek is not 56cm. It is more like 53-54cm, which puts you in the range of those fit calculators. Buy the frame that puts your handlebars in the right position for you (reach and drop). If you need a huge stack of spacers to get the handlebar up to your desired height, then you should probably look at bigger frames. If you prefer a very low handlebar, then look at smaller frames.

Oh, these weren't my bikes...which, yes, you certainly have to factor in with my "shorter stem = twitchy" opinion.

Or get a stem that has a higher angle on it and un-flip it.

I'd tend to think the 56 would be right for you simply because my measurements are similar to yours and that's what I ride. My Tarmac fits me like a glove (110mm -6 rise stem).

My CompetitiveCyclist Fit for a 56
 

AbsoluteZ3RO,

Here is my info from CompetitiveCyclist.com and I fit a 56 Tarmac (stem 100) perfectly. You decide...

My Measurements
-------------------------------------------
Inseam: 32
Trunk: 24.5
Forearm: 14.5
Arm: 26
Thigh: 24
Lower Leg: 21.5
Sternal Notch: 56.75
Total Body Height: 71


Your Measurements
-------------------------------------------
Inseam: 31.5
Trunk: 27.5
Forearm: 12.5
Arm: 25
Thigh: 22.5
Lower Leg: 21.25
Sternal Notch: 56.25
Total Body Height: 69

I'm an inch taller, but I have a shorter legs and a longer torso. I just couldn't stand over a 56 cm comfortably. I ride a 54cm Trek 5200 with a 115mm stem and about 8 cm of saddle to bar drop (more of an Eddy fit).

Your measurements are nearly identical to mine and I ride a 53-54. If I were to ride a trek I'd ride a 54.

I currently ride a Ridley in a small (47cm c-c and 51 cm c-t, and 54.5 effective tt) with a 120mm stem.
My last bike was a Felt in a 54CM (54 cm c-t, 51 cm c-c, 54.5 cm tt) with a 110mm stem (seat angle was 1 degree steeper, hence the need for a longer stem)

I am more flexible than average though and I like to ride with the bars low.

Did you ride the bike with a longer stem first?

I've moved to a much shorter stem (120 to 80 I think was the change), and while I fit the bike much better now, it was much more 'twitchy'. I got used to it pretty quickly, but the handling was much better for me with the longer stem.

I've since gone with a longer stem on a smaller frame, and I'm much happier.

To the OP, I'd go to other stores and ride more bikes. I went back and forth about 56/58 for my frame, and I always felt better with a 56. But, until I rode a few I wasn't really sure.

All this mumbo-jumbo simply means this:

Ride both a 56 and a 54. You make the call.

I hate to contribute nothing but a question, but I have to ask, why do these three fit systems provide such different specs? I'm a bit of a newbie, but by the looks of things, the measurements the OP entered produced three different rides, right?

I realize a test ride is the best way to tell what's what, and the systems probably have their own structures to determine fittings, but is any one "better" than the others (maybe an expert could look at the different sets of information and determine that)?

Again, apologies to the OP for creating more questions than answers.

Are you only interested in a Trek? You might want to continue doing your own research on what the perfect size\geometry frame is for your body. You might find that another bike fits you better. There are lots of variations between manufacturers when it comes to what they offer frame size\geometry\proportions wise. Lot's of decent info on this site, do some searches. Also check out:http://www.sheldonbrown.com/frame-sizing.html. You'll be glad you educated yourself on this stuff before you purchase. Online calculators are a good place to start but you are gonna want to suplement what they spit out with test rides and more research on proper fit.

Go to http://www.competitivecyclist.com and read their description of the fits, the explanation they give is a decent starting point.

The most important size is the 'top tube length', not the 'seat tube range'. So, I would take 54 because it has top tube length that is closer to your measurements. It is harder to fix top tube length problems that it too long than that is too short.

Test riding before (at least some) fitting doesn't mean a thing. Chances of finding perfect top tube length, perfect stem length and saddle height just out of the store is 0.

Try both frames, ride them for as long as they'll allow & then make your decision.

Think about your riding style. A smaller frame will most likely have a more agressive position & may handle better. A larger frame will have less seat to bars drop & a more relaxed position.

Pick the one that feels good & fits your needs.

I tested a 54cm Specalized Allez. Liked the way it felt a lot, but they seems to have lower end components for the same money. I haven't ruled it out completely, but I'm bothered by the lower end components. I'm wondering were the extra money is going if it's not in the drivetrain.