TRI BKE FIT = TOM et al, Need Advise

[gigs]

Tom et al,

If there is one thing I have learned on this forum, it is that fit matters most when selecting a new TRI bike.

I had my measurements taken as follows:

Height = 70 inches

Sternum Notch = 58 inches

Inseam = 31.5 inches

Arm Length = 23 inches

SHoulder Width = 17 inches

Flexibility = 5 inches

Weight = 158 lbs

Shoe Size = 10 US

Based on these measurements, he wrenchscience.com fit calculator, it told me that I needed a road bike (not tri bike):

    ![http://wrenchscience.com/WS1/help/images/handlebarwidthroadsm.gif](http://wrenchscience.com/WS1/help/images/handlebarwidthroadsm.gif) ![http://wrenchscience.com/WS1/Secure/Fitting/images/pixgifs/transp.gif](http://wrenchscience.com/WS1/Secure/Fitting/images/pixgifs/transp.gif)      Y<u>our Handlebar Width is</u> ::  44cm Center-to-Center
    ![http://wrenchscience.com/WS1/help/images/overallreachroadsm.gif](http://wrenchscience.com/WS1/help/images/overallreachroadsm.gif) ![http://wrenchscience.com/WS1/Secure/Fitting/images/pixgifs/transp.gif](http://wrenchscience.com/WS1/Secure/Fitting/images/pixgifs/transp.gif)      OVERALL REACH :: Overall Reach Road = Effective Top Tube length + Stem Length. 

Your Overall Reach is :: 66.865cm Center-to-Center
FRAME SIZE :: Frames are measured different by each manufacturers. There are two typical ways to measure a frame Center-to-Top and Center-to-Center.
Your Frame Size is :: 54cm Center-to-Top / 52cm Center-to-Center
RECOMMENDED SADDLE HEIGHT ::

Your Recommended Saddle Height is :: 70.65cm How do I determine which TRI Bike best accomodates my measurements? I am potentially interested in Blade, Tiphoon, P3C, Guru Crono.

Is it possible to tell which of these bikes and what frame size in these bikes would best fit me?

Thanks.

[Tom_Demerly]

You’ve done a good job of using the resources at your disposal and of gathering some relevant information. What you’ve accomplished here is better than what many shops may be able to do, although shops are becoming increasingly aware of bike fit so that is changing.

I am a little bit wary of any system that sort of blanketly says a tri bike isn’t for you. That very well may be the case, and it is the case for some people- but it is somewhat unusual.

This is why I am interested in seeing more information: Many fit “systems” don’t understand or don’t incorporate the primary reason why a person may be better served to ride a triathlon geometry bike. Our understanding of just *how *a triathlon bike works better in some instances is very new, and based largely on a very few real studies, such as the Garside Study that Dan Empfield frequently cites.

When fitting for a bike used in multisport a key concern is not just what happens on the bike but what happens when a rider climbs off the bike to run. Additional conerns are facilitating digestion on the bike for longer events, and building in reasonable handling and stability in the aero position.

So, does this (or any) fit system take into account the effect of the riding posture, bike fit and frame selection o the bike/run transition? No, it does not. And therein lies a shortcoming of many packaged bike fit “systems” or somewhat myopic fit philosophies that so quickly dismiss steep seat tube angles.

Bike fit isn’t difficult, mystic, or really even all that scientific in nature. As other posters on this forum have (correctly) pointed out, bike fit- as it stands now- is *not *a science but a craft. And it makes sense that the growing numbers of fitters around the country who have been doing triathlon fitting for years and also have functional, practical experience doing triathlons themselves offer an insight not available through someone or something lacking those qualifications, i.e.- a “fit system” that doesn’t take into account a broad view of the person using the bike, how they will use it, where, when and what their goals are.

In watching some of the best fitters work with their customers one thing I notice is them asking similar questions: “How will you use the bike? What kind of athlete are you? What are your goals? What kind of experience- if any, do you have?” This “soft” information needs to be correctly interpreted into the bike selection and the rider’s positioning.

It’s my opinion that, while better than nothing at all, an elaborate software routine, displays of impressive lasers and large measuring devices, complex looking fit bikes, etc. doesn’t present the entire picture.

This is very good information you have here. Certainly enough to get a bike that isn’t 100% wrong, but potentially not enough to get a bike that is as close to optimal as is possible.

When you’re spending this kind of cash, I think “as optimal as possible” is a reasonable expectation. Your qualified local triathlon specific (and road qualified too) bike fitter may be able to provide that to a much greater degree than I can here, even given your dilligent information.

[gigs]

Thanks, Tom.

Just a point of clarification (as I was not clear in my previous post), the fit calculator opined on what size frame I would need if I was interested in a road bike. It does not have an algortihm to size a tri frame. So when I said “road bike as opposed to tri bike” I was not suggesting that it recommended for me to ride in a road geomtery as opposed to tri geomtry, but rather that if I was looking for a road bike, this is what it would recommend.

My question to you, albeit poorly phrased, was really designed to ask how, short of going to a local FIST-certified fitter, how can I translate the recommendation for the size and fit of a road frame based that the calculator gave me into a recommendation for the size and fit of a triathlon bike.

[crisscross]

that size is to small you should have a 56 or 57 frame
.

[Ready2run]

Call the guys at Nytro or All3sports and they will work with you on sizing. You have the data so it should be straight forward. Alot of bike shops like to make it mysterious and expensive.

[Tom_Demerly]

OK, I’m sorry- I didn’t answer that question.

Hmmm. How to translate road position to tri position. I would take the 5th on that one too my friend, with another apology for not being of much help.

I think I could use a lot of data from a person’s road position and fit as a start point for a good tri-specific fit, even if their tri specific fit put them on a road bike. Data like their existing saddle height and so forth will be relevant but not directly transferable necessarily.

[Horatio]

Hi

The important thing to remember is that those numbers serve as a starting point in a fit analysis. They do not represent the finished product in most cases. One of the folks mentioned to give Nytro a call and talk size. I think that while that is a viable alternative I do not believe that it will be the best one. It is very important to go into a shop with real people and have your fit done. If there are not a lot of shops in your immediate area, it would be well served to call around and find one that will get you what you need. When a customer calls up our store and says there is something wrong with the bike, we have a running joke that asks the customer to hold the bike up to the phone so we can get a better look at it…Anyway…

If you were coming into our shop with those numbers. I would most likely fit you again. I would ask you what you are riding currently and see if you could bring it in for comparison reasons. The numbers that the Fit Kit come up with or Wrench Science do not account for the variables of sex, age, flexibility, skill, etc. The first bikes I would suggest would be the Blade and the P3C. Both have a longer top tube and would serve you better. We would have to experiment with stem length. From the measurements I would guess anywhere from 90 - 110 mm. I would be looking for the upper arm torso angle of 90 degree. I would also look for a pair of aero bars that fit your length. For test purposes we have the adjustable aerolites on a sizing bicycle to help accommodate this. For the blade I would look at the 53 with a 53 top tube at 78 degrees. One factor with bikes that have extended aero seat posts making sure there is enough exposed seatpost. I am sure this could be argued but I believe that the more seatpost showing…to a degree of course…the better the ride. The 54 P3C has a 53 top tube in the 78 degree position and a 56 in the 75 degree position. The next step would be to let you take those out for 30 minutes or so to get an idea of how they feel. This is a long process but it fine tunes the numbers we get from the math. And…we also work with you,fine tuning your fit as the season progresses.

I am not sure this is what you wanted but it should be the natural progression of a fit…in person with folks who understand tri-geometry and their customers desires.

[Tom_Demerly]

“The important thing to remember is that those numbers serve as a starting point in a fit analysis. They do not represent the finished product in most cases. One of the folks mentioned to give Nytro a call and talk size.”

I agree with that 100%.

[gigs]

Thanks, Horatio. Where is your store located?