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Finding road bike with tri bike fit metrics
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How can I find the "right" road bike using my recent tri bike fit metrics? Is it possible to use one set of measurements to find a road frame that will fit me for an aggressive road riding position and be convertible to a solid aero fit?

(Fully expecting to get roasted for not searching enough...I did find Dan's road bike fit article from a bunch of years ago, but that's all I can really find for how fit a road bike).

Here's the reasons for asking. I have a 2013 Argon 18 E116 that I'm considering selling for an aero road frame. I am not really doing much racing, and I bought the Argon for 70.3...I just got a good fit on the Argon but I think I'd get "more" out of a road bike I could use clip-ons with, and it's more likely I'll be able to do local Olympic distance courses a few times a year at most. Obviously the Venge comes to mind and it's pretty low stack in my size. I do most of my training indoors and if I'm outdoors I'm likely to be on a fair amount of hills and/or roads with stoplights. I do like riding in aero though, it just feels good to crank out sessions in that mode.

I'm 5'6" and yeah I need to slim down some which will help the fit. Stack and reach pre-Feb 2017 fit session were 591/412 to back of pads. New fit: 532/422 to back of pads. I barely can make this fit on my XS Argon frame (frame stack/reach are something like 490/397) , using a -44 stem setup. ST stack/reach database shows the Venge in size 52 is something like 528/385, so this seems to imply it's going to be tough with a -17 stem to get low enough. Scott foil in size 52 is almost exactly the same as the Venge.

I have no idea how to figure out the stem length I'd need to get the right reach for road riding, given my new stack/reach of 532/422. Really note sure how to use these numbers to find a road frame. In fact I'm generally confused about what TRI frame I would need to get to achieve a solid fit with these numbers too - without using a wacky stem setup like I've got, which makes it difficult to run a BTA bottle for example.

Any help would be appreciated.
Last edited by: jeremyebrock: Apr 23, 17 11:38
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Re: Finding road bike with tri bike fit metrics [jeremyebrock] [ In reply to ]
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You *almost* don't need anything from your tri bike fit to get a good road bike fit. Just your saddle height.

Road bike saddle height should be 5-10mm lower than tri bike. Dan thinks even as much as 15mm, but I disagree. But whatever. That's relatively minor.

This from a discussion Dan and I had on email:

Dan Empfield wrote:
Measure this:

.72(overall height) - .78(saddle height)

For you probably be in the low to mid 70s.

Then I want you to measure from the nose of the saddle directly to the handlebar trough, which is the low point in the hood, right before the upturn. This isn’t an x/y measure, just a straight line from the saddle nose to either saddle trough.

D

In my case, this works EXACTLY.

So what this will do is (roughly) give you the stem length you need given an existing set of road bars. Does that makes sense?

"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp
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Re: Finding road bike with tri bike fit metrics [Rappstar] [ In reply to ]
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I thought it did but now I don't know.

Although I watched "Hidden Figures" last night and I'm feeling very inadequate with my math skills ;)

So for me, with my height of 165cm and a road saddle height of 683 (15mm lower than tri saddle height) here's what I've got:

.72(1650) - .78(683) = 654.5

This output is what?

Where does the stem calc come in? I don't currently have road bars, so I'm guessing on stem length still at this point. What am I missing?
Last edited by: jeremyebrock: Apr 23, 17 12:45
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Re: Finding road bike with tri bike fit metrics [jeremyebrock] [ In reply to ]
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My tri bikes frame is cracked so I did ironman texas yesterday on a converted road bike (cannondale supersix)

I bought and installed the redshift seatpost and it worked very well to get me more forward
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