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Discussion Starter · #1 · (Edited)
how much difference to my fit would result in a .2 degree reduction in STA, a 1 cm increase in TT length, and corresponding 1cm increase in ST length?

If I'm running a 110 mm stem and have a good fistful of seatpost available out of the frame, will I be able to make this glorious frame I'm looking at fit me nicely? My saddle is also fairly far back on the rails.

I'm desperately close to pulling the trigger because it is such a great deal but I wonder if I should be nervous about the size increase? But shouldn't I be able to replicate my old fit on this bike rather easily? I figure the saddle is in a more natural position, 90-100mm stem, little less seatpost showing, no problem at all... I'm also running about 3 1/2 inches (9cm) of saddle to bar drop, with stem dropped down on steerer with no spacers below it.

It'll be a race bike...thoughts anyone? For all of you, could you all make a +/- one size increase without too many troubles? Will this potentially affect handling/whatnot or will this really not be difficult at all?

I'm 5'8", longer legs but pretty normal overall build, considering this new frame with 54cm ST, 55 cm TT (both c2c), and 73.5 ST angle. My current bike has a 53ish ST, 54cm TT, and I'm not quite sure of the ST angle. It's a pretty stable geo overall.
 

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info...

If the STA is numerically smaller (more laid back) it actually reduces the reach by about 1cm per degree, so .2 degree is no more than 2mm. That makes the net increase in reach about 8mm, but it's still one stem size.

You didn't mention your stem angle, but that is important, as is the total head tube length, with the headset. If the new frame has a taller headtube, with the headset, you'll have to change the stem angle to get the same bar height, if you're using no spacers now.

You'd have to know a lot more about the total geometry, particularly the steering geometry to draw any conclusion about handling.
 

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Discussion Starter · #3 ·
Gotcha. Right now I'm running a 110mm stem with -6 or -8 degrees of drop, can't remember.

Is the head tube length measured from end of headset to end of headset?
I've got a CK threaded headset right now; do I measure from end of silver cap to end of silver cap, if that makes any sense?

From outside to outside, as in the bottom of the CK silver headset to the top of the CK threaded "nut" thing on the headset, it appears that the two HT lengths are identical; 6 inches (15.3 cm) to 15.3 cm on the new frame. But I don't know how the frame mfgr. measures their HT size; it's just "15.3 cm" and I'm not sure if that's end to end or what.

i appreciate your help C-40, I wish I was more knowledgeable about all of this (and that I had these numbers/angles for my frame and fork as well).
 

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Htl

Head tube lengths are usually listed with no headset. A CK headset will add about 30mm to this length.

You also need to consider if the new frame uses a conventional headset, like a CK, or an integrated type. Integrated headset can add as little as 8mm to the bare head tube length or as much as 20mm, depending on the type top section.

A bare HTL around 150mm would be too tall.

I'd want a race frame to be the smallest I could ride, not a larger one.
 

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Discussion Starter · #5 ·
That's exactly what I was thinking; I think I've decided against the frame purchase.

The main reason being that:

As far as seat tube/seat height/setback, my current setup is about perfect. A fistful of seatpost seems pretty ideal.

My reach is right where I want it; in the 100/110 mm range, with a decent amount of drop; plus, on my current frame, I have the option (which I'm going to take) of getting a steeper slant on my stem to lower my bars even more and get in a more aero position for racing. A larger frame could make that adjustment more difficult.

I think the moral of the story is: wait for EXACTLY what you want. Haha. Not just in the "omg love of my life bike lust" but also in the size : )

Just got to keep waiting for another Merckx Team SC to walk into my life.... : )
 
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