Cycling Equipment · Public discussion

TT frame sizing

Aj · 2003-12-16T03:35:17+00:00

Looking at an Orbea Chrono TT frame, but have never owned/ridden a TT geometry frame. Only road geometry. I ride a Eddy Merckx 60cm road bike with a 58.5cm top tube and 120mm stem (all c-c). I've been professionally fitted to it, and have made some minor tweaks, so I feel comfortable with sizing and fit for the Merckx. The Orbea TT frame is XL: 60cm c-c seat tube w/ 59cm c-c top tube. For a TT frame, I would like something shorter than a 120mm stem so I have somewhat less weight over the front wheel. Given my current setup on the Merckx, does it look like I should be able to get an optimal fit with the XL Orbea TT frame? Do I need to consider other factors for a TT geometry?

Started by Aj · 16 December 2003 · Last activity 18 December 2003 · 6 posts · 2,586 views

← Back to Cycling Equipment

Thread navigation

Jump through the discussion

Go to the original post, the replies on this page, or the latest preserved contribution.

01 / Original postTT frame sizingAj · 16 Dec 2003 02 / This pagePosts 1–6Page 1 of 1 · chronological order 03 / Latest replyPost #6Don Vescio · 18 Dec 2003

Thread details

What we know about this thread

Original section: Cycling Equipment
Published: 16 December 2003
Last activity: 18 December 2003
Original author: Aj
Posts: 6
Discussion status: Public discussion
Total views: 2,586
Views / 30 days: 0
Topics: Bottom brackets Frame sizing Stem length Titanium frames Eddy Merckx

The navigation and discussion metadata provide context. Posts remain in their original chronological order.

Original post
Aj
Archived post

16 December 2003, 03:35 UTC #1

Looking at an Orbea Chrono TT frame, but have never owned/ridden a TT geometry frame. Only road
geometry. I ride a Eddy Merckx 60cm road bike with a 58.5cm top tube and 120mm stem (all c-c). I've
been professionally fitted to it, and have made some minor tweaks, so I feel comfortable with sizing
and fit for the Merckx.
The Orbea TT frame is XL: 60cm c-c seat tube w/ 59cm c-c top tube. For a TT frame, I would like
something shorter than a 120mm stem so I have somewhat less weight over the front wheel. Given my
current setup on the Merckx, does it look like I should be able to get an optimal fit with the XL
Orbea TT frame? Do I need to consider other factors for a TT geometry?

Report
Paul Southworth
Archived post

16 December 2003, 03:37 UTC #2

In article <[email hidden]>,
AJ said:
Looking at an Orbea Chrono TT frame, but have never owned/ridden a TT geometry frame. Only road
geometry. I ride a Eddy Merckx 60cm road bike with a 58.5cm top tube and 120mm stem (all c-c). I've
been professionally fitted to it, and have made some minor tweaks, so I feel comfortable with
sizing and fit for the Merckx.
The Orbea TT frame is XL: 60cm c-c seat tube w/ 59cm c-c top tube. For a TT frame, I would like
something shorter than a 120mm stem so I have somewhat less weight over the front wheel. Given my
current setup on the Merckx, does it look like I should be able to get an optimal fit with the XL
Orbea TT frame? Do I need to consider other factors for a TT geometry?
I would want to consider the seat angle and the type of handlebars. You can't assume very much about
the actual riding position on the TT bike until you know where your elbows go.
--Paul

Report
Phil Holman
Archived post

16 December 2003, 07:02 UTC #3

"AJ" <[email hidden]> wrote in message
"]news:[email hidden]...
Quoted message said:
Looking at an Orbea Chrono TT frame, but have never owned/ridden a TT geometry frame. Only road
geometry. I ride a Eddy Merckx 60cm road bike with a 58.5cm top tube and 120mm stem (all c-c).
I've been professionally fitted to it, and have made some minor tweaks, so I feel comfortable with
sizing and fit for the Merckx.
The Orbea TT frame is XL: 60cm c-c seat tube w/ 59cm c-c top tube. For a TT frame, I would like
something shorter than a 120mm stem so I have somewhat less weight over the front wheel. Given my
current setup on the Merckx, does it look like I should be able to get an optimal fit with the XL
Orbea TT frame? Do I need to consider other factors for a TT geometry?
I'm 6'2" and ride a 57cm TT bike so I can get the arm rests low enough. Low enough being 7" below
the seat height. You may want to consider a frame that will give you this capability after working
on your TT position for a season or two.
Phil Holman

Report
Nick Payne
Archived post

16 December 2003, 07:02 UTC #4

AJ said:
Looking at an Orbea Chrono TT frame, but have never owned/ridden a TT geometry frame. Only road
geometry. I ride a Eddy Merckx 60cm road bike with a 58.5cm top tube and 120mm stem (all c-c).
I've been professionally fitted to it, and have made some minor tweaks, so I feel comfortable with
sizing and fit for the Merckx.
The Orbea TT frame is XL: 60cm c-c seat tube w/ 59cm c-c top tube. For a TT frame, I would like
something shorter than a 120mm stem so I have somewhat less weight over the front wheel. Given my
current setup on the Merckx, does it look like I should be able to get an optimal fit with the XL
Orbea TT frame? Do I need to consider other factors for a TT geometry?
For the same stem length, aero bars normally put your elbows further forward than for the same
length of road frame and bars. You will need to try it and see. Also take into account (if you will
be riding any sanctioned events) that there is a UCI limit of minimum 5cm between saddle nose and
bottom bracket and maximum 75cm between saddle nose and forward end of bars.
FWIW, I ride 61cm or 63cm road frames with usually a 130mm stem, and a 58cm TT frame (Cervelo P3)
with Cinelli Angel bars. With the saddle nose the minimum allowed 5cm behind the bottom bracket, I
have the fore-aft adjustment of the bars and elbow pads pretty much at the rearmost position, and
that just fits within the 75cm limit. I don't know offhand the top tube length of the Cervelo, you
could probably find out on their web site www.cervelo.com.
Nick

Report
Mark Hickey
Archived post

16 December 2003, 20:08 UTC #5

(AJ) said:
Looking at an Orbea Chrono TT frame, but have never owned/ridden a TT geometry frame. Only road
geometry. I ride a Eddy Merckx 60cm road bike with a 58.5cm top tube and 120mm stem (all c-c). I've
been professionally fitted to it, and have made some minor tweaks, so I feel comfortable with
sizing and fit for the Merckx.
The Orbea TT frame is XL: 60cm c-c seat tube w/ 59cm c-c top tube. For a TT frame, I would like
something shorter than a 120mm stem so I have somewhat less weight over the front wheel. Given my
current setup on the Merckx, does it look like I should be able to get an optimal fit with the XL
Orbea TT frame? Do I need to consider other factors for a TT geometry?
I have found that for me at least, a similar cockpit length (top tube plus stem) works on the road
and TT bikes. In my case, that's 56cm for the TT and 11cm for the stem (a very middle of the bell
curve bike).
But it's important to know the relative seatpost angles, since an even steeper seat tube will
require a shorter top tube, and a slacker seat tube will require a longer top tube. In my case, the
road seat tube is 73.5 and the TT 78.0 degrees.
Another thing to consider is that a steep seat tube frame is taller than a typical road bike "of the
same size" because, well, the seat tube is more vertical. If your standover clearance is marginal at
all on the Merckx, it's going to be negative on a the Orbea (if it's got a seat tube in the 78
degree range).
Mark Hickey Habanero Cycles habcycles.comhabcycles.com Home of the $695 ti frame

Report
Don Vescio
Archived post

18 December 2003, 06:07 UTC #6

I normally ride a 53 cm c-c road frame and have been sizing my TT frames 47-48 cm to achieve a
proper position.
D
"Phil Holman" <[email hidden]> wrote in message
"]news:[email hidden]...
Quoted message said:

"AJ" <[email hidden]> wrote in message
"]news:[email hidden]...
Quoted message said:
Looking at an Orbea Chrono TT frame, but have never owned/ridden a TT geometry frame. Only road
geometry. I ride a Eddy Merckx 60cm road bike with a 58.5cm top tube and 120mm stem (all c-c).
I've been professionally fitted to it, and have made some minor tweaks, so I feel comfortable
with sizing and fit for the Merckx.
The Orbea TT frame is XL: 60cm c-c seat tube w/ 59cm c-c top tube. For a TT frame, I would like
something shorter than a 120mm stem so I have somewhat less weight over the front wheel. Given
my current setup on the Merckx, does it look like I should be able to get an optimal fit with
the XL Orbea TT frame? Do I need to consider other factors for a TT geometry?
I'm 6'2" and ride a 57cm TT bike so I can get the arm rests low enough. Low enough being 7" below
the seat height. You may want to consider a frame that will give you this capability after working
on your TT position for a season or two.
Phil Holman

Report

Active in the last 60 minutes

Active in this thread

0 users · 0 guests ·0 bots ·0 total

No signed-in users are active right now.

No known search crawlers active right now.

Jump through the discussion

What we know about this thread

Continue through CyclingForums

Active in this thread