Need help making use of bike fit specs

I am getting ready to do the same thing.  You may be able to get something with these specs, but I thought that you needed stack to determine head tube placement.  I guess you could look at seat tube length, then add the inches necessary to get you to 30.76".  This would tell you how far the seat post will be above the top tube.  Then you should be able to somewhat determine your drop to the handlebar.  Keep in mind that the farther your seat post comes out of the frame the effective top tube length increases.

Oh, heck even now I am confused!

Did they suggest any frame sizes based on your fit results?

Ha. I am sorry, I have to chuckle at our mutual confusion.

I am smack dab in the middle of a 54.5" or 56.5". At about 6', and have began my love for tri on a 58" roaddie, I think Ill shoot for the 56.5". (Which is a start!)

Some specs are making a bit more sense. On Trek's site (which is American - go figure), the saddle height and stem actually are apparent.

Can anyone clarify a "Frame Reach" of 16.6" (compared to my reach specs which are 22.3")  Is 22.3" in an areo position with areo bars attached?

Or "Stand Over"? Trek says 30.6". That is pretty darn close to my saddle height measurement. Are these related.

A desperate please and thank you to any knowledgeable helpers!

 

First of all, you do have the basic measurements that you do need to make an intelligent decision regarding a new bike/frame. In 1/2 hr. I kind of doubt you did get a full fitting though... there's just not enough time to do an interview (to determine previous, current state and future goals, plus to understand the type of rider), do body measurements and flexibility, and then finally to check measurements on a bike.

Let me try to make sense of the numbers for you:
Reach: is measured from a vertical line going thru the bottom bracket to a vertical line going thru head tube. This is not the same as actual or virtual top tube, although you can use this measurement (virtual) and deduct the setback to get approx. reach.

Saddle height is measured from center of bottom bracket to top of saddle. If you change the saddle, you will change the saddle height.

Drop is not pointless for shopping. When you combine this with saddle height, you can get an idea if the head tube is short enough to accomodate your drop, or if the head tube is so short that you will need a whole bunch of spacers under the stem. Keep in mind that the angle of the stem, length of stem and height of aerobars all effects the drop. Change one of these parameters and you change the drop

Saddle fore/aft: Again not pointless. You need to know if you can get the saddle back or forward enough in relationship to the bottom bracket.

Crack length is kind of important, but not crucial. Most people are not that sensitive to change in crank length, but some are... what is important is to understand that if you set up your bike with one crank length and then change it, you need to adjust the saddle height as well to accomodate the change in crank length. See saddle height above as same thing applies there. So does change to shoes as sole thickeness changes or change of pedals (called stack height).

The stem length is irrelevant. You need to look at reach and then adjust your stem length according to that. In the perfect world you should be in the range of 90-120mm. Shorter than 80mm may lead to instability and over 130mm, then the geometry of the bike is probably not for you.

Hope this helped you out a bit by explaining what the measurements means and how they relate to a new bike.

Certainly did! Thank you for taking the time to explain. I have a better idea as to how to apply these measurements. 

You are right. The "fit" was more of a prep fit for when I do purchase, as it was emphasized. Thank you for your help.

Try one of the on-line fit guides. They'll give you each and every measurement for your body. www.competitivecyclist.com has a good one which agrees almost perfectly with the sizing I paid for. www.wrenchscience.com also has a good one.

From there, you can compare your 30min quickie, the on-line numbers and numbers from bikes your considering.

A good tool to use, but not a panacea. Only riding a bike set up for you will give you the exact experience. Unfortunately, that's not always the easiest thing to get.

Glad I could help.

The WrenchScience and CompetitiveCyclist fit calculators tend to work ok for most people (i.e. at least they put you on right bike size unless you are built way outside of the norm or in between bikes sizes). What they won't to is adjust for your specific needs.

Both of these calculators are quite a bit off for me. They're putting me on a shorter top tube and a shorter stem (so too short reach). The seat height and set back is very close to what I'm riding, though so they got that correct.

Again, a good starting point, but not a replacement for a good fit.