Bicycle Mechanics - Proper Bike Frame Size

I am 5'11.5" with a 33" inseam. I would classify myself as having longer arms and being very flexible in my hips, hamstrings, and lower back.

Currently I am riding a 2007 58cm Trek 1000 as my winter "beater bike" and raced last season on a 2010 57cm Fisher Rail Super. I have been fit on both bikes and do not feel aero or aggressive, I feel crunched and unable to really flex and open up.

At my lbs today, I tested a 60cm 2010 Madone 5.2. The salesman was very hesitant to put me on it bc he felt it would be to big, without even giving it a chance. I explained I have been riding a 58 cm for some time and feel crunched. After riding it in the lot, he mentioned my stroke looked good on the 60 but that I looked to be reaching a bit, which I did not feel as I felt comfortable. My plan would be to put a shorter stem on the front and possible a shorter seat stem. However, after a quick spin in the lot I did not feel the 60 frame felt much bigger than my 58 frame. My thinking is that, perhaps, the 2010 madone frame is running a tad small... anyone heard this?

I am going back to the shop tomorrow for a fitting. Does anyone have any advice for me? Does it sound like I need a 58 frame or could I possibly go to the 60? What would be the pro's and/or con's of going to the larger frame? Again I felt comfortable on it, as I felt like I could open up and stretch. My thought would be to put a shorter stem on the handlebars and bring them a bit closer and get aggressive.

Am I way off? Thanks for any help!

I am 5'11.5" with a 33" inseam. I would classify myself as having longer arms and being very flexible in my hips, hamstrings, and lower back.

Currently I am riding a 2007 58cm Trek 1000 as my winter "beater bike" and raced last season on a 2010 57cm Fisher Rail Super. I have been fit on both bikes and do not feel aero or aggressive, I feel crunched and unable to really flex and open up.

At my lbs today, I tested a 60cm 2010 Madone 5.2. The salesman was very hesitant to put me on it bc he felt it would be to big, without even giving it a chance. I explained I have been riding a 58 cm for some time and feel crunched. After riding it in the lot, he mentioned my stroke looked good on the 60 but that I looked to be reaching a bit, which I did not feel as I felt comfortable. My plan would be to put a shorter stem on the front and possible a shorter seat stem. However, after a quick spin in the lot I did not feel the 60 frame felt much bigger than my 58 frame. My thinking is that, perhaps, the 2010 madone frame is running a tad small... anyone heard this?

I am going back to the shop tomorrow for a fitting. Does anyone have any advice for me? Does it sound like I need a 58 frame or could I possibly go to the 60? What would be the pro's and/or con's of going to the larger frame? Again I felt comfortable on it, as I felt like I could open up and stretch. My thought would be to put a shorter stem on the handlebars and bring them a bit closer and get aggressive.

Am I way off? Thanks for any help!

There's no point polling for random guesses on the internet.

A real fit in the real world will be the final say, which you are going to do. Modern sizing, if between sizes is to go smaller and use a longer stem if you're flexible and/or racing. Shorter stem with a slightly larger frame... meh.

Have you tried putting a longer stem on your current bike, maybe one with a bit of rise and flip it upside down for a more aero position? I'd do this before buying another bike. Another 10 or 20mm could be what you need. If it doesn't work, then go look at that Wreck. And see if you can take that Wreck on a longer ride than just a parking lot, maybe 10 miles. Taking a spin around the parking lot doesn't really tell you too much about how a bike REALLY feels.

I've heard that the Trek 58cm frames used to have a slightly different geometry than the other sizes because the 58cm frames were designed for Lance. That way Trek could design the frames for him and still conform to the UCI regulations.

What matters for fit is the relative positions between the "contact points"; the crank, saddle, and bars. Assuming a frame isn't way off, these can be set by proper selection of components and adjustment. Usually, the choice is between stems and steerer spacers. Sometimes, you may need to select a seatpost with more or less setback.

I see no reason why your 58 Trek couldn't be made to fit correctly and as desired with proper selection and adjustment of components. I think what you'll find if you look around on the web is that large majority of pro riders tend to use smaller rather than larger frames and extended the seatpost and install a long low stem to achieve the desired fit and riding position.

I've heard that the Trek 58cm frames used to have a slightly different geometry than the other sizes because the 58cm frames were designed for Lance. That way Trek could design the frames for him and still conform to the UCI regulations.

Huh?

It's very easy to predict the difference in the fit, if you post the geometry and the setup of your old bike - including the amount of spacers, stem length and angle and the type of seatpost used.

The first thing I look at is the total stack height at the head tube - that's measured from the base of the head tube (or headset if the fram uses a conventional press fit headset), to the top of the spacer stack under the stem.

If the 33 inches is a cycling inseam, then the 58 and 60cm sizes would both be too large. A 33 inch (84cm) cycling inseam would only mean a saddle height of about 74cm and it would also mean that you have short legs for your height. If that's a pant's inseam, it's worthless information, but it would suggest a much greater cycling inseam.

Even if you can straddle the 60, it's going to be too long and the stem will be too high. Wait for a 58.

I'm 5'11" and a half, too, but with 35" inseam, long arms, and I ride with a very flat back, and my size on a Madone is 58 with a lot of seatpost showing and a 12 cm stem.

Don't worry about what 'size' the bike is... if it is comfortable and you don't bag yourself on the top tube then it will work. All the fitting calculations and experts in the world can only get a 'ballpark' fit - it is up to you to experiment with minute adjustments to make yourself comfortable.

If I were you I would experiment with different stem lengths and rises with your current bike until you find one that feels perfect, then when you buy a new bike, have it set up to match the old one.

Huh?

conspiracy theory.

Cannot see you and how you fit on the bike, from this text.

do you want that ride in a pack at 30 mph all day, low bars high saddle riding posture, .. for racing?

or should you even look at a top of the range racing bike for your riding needs

Given how many bikes Trek sold using their putting Lance

on their bikes at the highest profile part of his racing , the [Tax Deductable?]

part of their frame design development, for him, paid for itself.