Translate Old Dimensions to Stack and Reach?
#1
Thread Starter
Senior Member
Joined: Dec 2014
Posts: 547
Likes: 104
From: New Hampshire
Bikes: Pinarello Gavia TSX; Bianchi Intenso
Translate Old Dimensions to Stack and Reach?
The frame I raced on back in the day was measured before Stack and Reach became de riguer. I would love to be able to compare its stack and reach with what i s available in the marketplace. Does anyone know if there is an app online or a calculation that can be done with the old style specifications so that i can calculate the stack and reach of my old frame?
This was an old 2002 Bianchi SL Lite frame (59) and Bianchi provided measurements for the following:
1. Seat tube C to T
2. Top Tube (actual)
3. Top Tube (virtual)
4. Head Tube angle
5. Seat Tube angle
6. Stand Over Height
This was an old 2002 Bianchi SL Lite frame (59) and Bianchi provided measurements for the following:
1. Seat tube C to T
2. Top Tube (actual)
3. Top Tube (virtual)
4. Head Tube angle
5. Seat Tube angle
6. Stand Over Height
#2
#3
Because you don't have the head tube height or the top tube slope, there is not enough information to determine where the top of the head tube is.
There are other methods to compare fit that are as or more useful. What are you trying to do?
There are other methods to compare fit that are as or more useful. What are you trying to do?
#4
Thread Starter
Senior Member
Joined: Dec 2014
Posts: 547
Likes: 104
From: New Hampshire
Bikes: Pinarello Gavia TSX; Bianchi Intenso
#5
Thread Starter
Senior Member
Joined: Dec 2014
Posts: 547
Likes: 104
From: New Hampshire
Bikes: Pinarello Gavia TSX; Bianchi Intenso
Unfortunately that frame is long gone as it was an aluminum frame and I “tore” the BB cluster like a soda can. It was the best fit I felt I ever had so was trying to use stack and reach to come close with a racing frame from today.
#6
Post two geometries and I'll show you what I mean.
#7
Senior Member

Joined: Jul 2005
Posts: 4,992
Likes: 712
From: Boulder County, CO
Bikes: '80 Masi Gran Criterium, '12 Trek Madone, early '60s Frejus track
Not without a plumb bob, a protractor, and some trigonometry. Personally, I can't even remember my stack and reach preferences, but give me dimensions for head tube, virtual top tube, bottom bracket drop, and approximate seat tube angle, and I can approximate the stem height and length.
#8
Not without a plumb bob, a protractor, and some trigonometry. Personally, I can't even remember my stack and reach preferences, but give me dimensions for head tube, virtual top tube, bottom bracket drop, and approximate seat tube angle, and I can approximate the stem height and length.
#9
Randomhead
Joined: Aug 2008
Posts: 25,930
Likes: 4,825
From: Happy Valley, Pennsylvania
If the original bike had a sloping top tube, which is suggested by the "virtual" measurement, then the seat tube length isn't super useful without the top tube angle. Assuming it's not a virtual seat tube length. However, I feel like I could reverse engineer it fairly well without that if given the actual measurements.
Kona used to label their bikes with actual seat tube length, even though they often had sloping top tubes. There was one bike they called a 58cm that I measured as a 65cm. Makes it really confusing, and I know it cost them at least one sale.
Kona used to label their bikes with actual seat tube length, even though they often had sloping top tubes. There was one bike they called a 58cm that I measured as a 65cm. Makes it really confusing, and I know it cost them at least one sale.
#10
Thread Starter
Senior Member
Joined: Dec 2014
Posts: 547
Likes: 104
From: New Hampshire
Bikes: Pinarello Gavia TSX; Bianchi Intenso
Without the frame still in my possession it seems the only way I can learn anything is if someone else has the same frame or 1 like it, or if the dimensions are published somewhere.
From the 2002 Bianchi catalog I found several frames with the same geometry as my SL Lite Alloy. These were:
SL Lite Alloy
Alloro
SL Aluminum Centaur
XL-Alloy EV4
XL-Alloy EV2
From the 2002 Bianchi catalog I found several frames with the same geometry as my SL Lite Alloy. These were:
SL Lite Alloy
Alloro
SL Aluminum Centaur
XL-Alloy EV4
XL-Alloy EV2
#11
Thread Starter
Senior Member
Joined: Dec 2014
Posts: 547
Likes: 104
From: New Hampshire
Bikes: Pinarello Gavia TSX; Bianchi Intenso
I think I stumbled on my answer. In the Geometry Geeks database there is a 2006 Bianchi Giro (59) with identical measurements and Bianchi even provides stack and reach. Now I can effectively compare a potential bike purchase with my current 2014 (59) Bianchi Intenso (endurance frame) with my old race frame, 59 Bianchi SL Lite Alloy.
https://geometrygeeks.bike/bike/bianchi-giro-2006/
Thanks for everyone's input!
https://geometrygeeks.bike/bike/bianchi-giro-2006/
Thanks for everyone's input!
#12
Senior Member

Joined: Jul 2005
Posts: 4,992
Likes: 712
From: Boulder County, CO
Bikes: '80 Masi Gran Criterium, '12 Trek Madone, early '60s Frejus track
Specialized had a line of crossover hybrids sized like that, too, around 2009-10. All the shops ordered as if they were normally sized, so there were a lot of 57s, 59s, and maybe even some 61s, on clearance. A tall guy, maybe 6'6", would walk into the shop and say, "I need a bike for casual riding, don't want to spend a lot." "I have the just the bike for you."








