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Home > Forum > Triathlon Forum > Measuring "my" Stack and Reach

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Measuring "my" Stack and Reach
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gymrat
Feb 29, 16 18:32
Post #1 of 7 (2548 views)
Hello Gang:
I am hoping for a bit of an assist as I am starting to inch for a new bike, but I do not want to make some of the compromises I have made in the past due my height and what I wanted (A Cervelo). I know the Stack and Reach of bikes, but I want to get an idea on how I would fit onto the bikes.

So if I were to measure "MY" stack and reach off of my current bike set up, I would?
* Measure from Aerobar Pads to Floor for my Stack
* For reach, would I use the virtual vertical center line of the BB to the back of the aero bar pad for reach or go to the center of the stem cap?

For reference I have a 61 2012 (old) P2. with Zipp Alumina Aero Bars with 50mm stack. I have a full allotment of spacers as well. I am 6'4" with 37 inch inseam.
So I am trying to figure out if the New Felt B12 or 16 (I do not want electronic shifting) frames, Scott Plasma 10 - 20, or the new Cervelo P2 / P3: with a taller Aero Bar (Profile Design Aeria) would give me a clean fit with less spacers and exposed Cables. All 3 frames have a higher stack than my current P2, which is why they are chosen.

This will decide how much I really "Want" a new bike because custom is not in the budget. If I cannot clean the cables I do not want to get a new bike.



Thanks,
Pete
2017 Cervelo P2
2017 Cervelo S2
itraininla.com
#itraininla
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Re: Measuring "my" Stack and Reach [gymrat] [ In reply to ]
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carlwithac
Feb 29, 16 18:45
Post #2 of 7 (2532 views)
You're on the right track. For tri/TT fitting, the golden measurement is PadX and PadY. Those coordinates are effective distance vertically and horizontally your pad is relative to the bottom bracket.

PadY = (top of pad to ground) - (center of bottom bracket to ground)
PadX = dead center of your pad back towards your bottom bracket

For measuring PadX, it is best to use a level, perpendicular to the floor, lining up with the center of your BB.

Once you know PadXY, subtract the stack and reach of your aerobar to find HXY(cordinate of the middle of your base bar bore). With Hx and Hy, use the Slowtwitch Bar to HT Calculator to work back towards the Stack/Reach point of the frame in question. Assuming the frame in question has a 73 degree headtube angle, you will want a -17 degree stem.

Do you plan to use whatever aerobar comes stock on the bike, or reuse the Zipp?
Quote Reply
Re: Measuring "my" Stack and Reach [carlwithac] [ In reply to ]
Quote | Reply
gymrat
Feb 29, 16 18:56
Post #3 of 7 (2510 views)
Thank you.
The plan is to swap out the oem bars and go with a Profile Design Aeria setup or perhaps a tri rig. I will not be using the Zipp bars and will sell with the bike once I take delivery and I am comfortable on the new bike.
2017 Cervelo P2
2017 Cervelo S2
itraininla.com
#itraininla
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Re: Measuring "my" Stack and Reach [gymrat] [ In reply to ]
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carlwithac
Feb 29, 16 19:11
Post #4 of 7 (2500 views)
gymrat wrote:
Thank you.
The plan is to swap out the oem bars and go with a Profile Design Aeria setup or perhaps a tri rig. I will not be using the Zipp bars and will sell with the bike once I take delivery and I am comfortable on the new bike.

From the profile website:
Stack: 55mm-135mm (highest stack available of any Profile Design model)


Reach:-60mm, -45mm, -30mm or -10mm with the bracket flipped

Between the adjustment range of the aerobar and your stem length choice, obtaining the correct reach configuration probably won't be the determining factor in your frame choice.

Here is a simple method for comparison.

I'm assuming you're already running a -17 degree stem and low profile(10mm or less) topcap on your current bike.

Start with the stack measurement of the frame you are looking at, X. Add 10mm to X for topcap stack. Add another 19mm for the stack added just from mounting a -17 degree stem. Now you are at X+29mm. The Aeria has a minimum stack of 55mm. Now you're looking at a PadY measure of X+84mm without using any pedestal spacers under the aerobars. Subtract (X+84mm) from the PadY of your current bike, and that's how many mm of pedestal spacers you need. Repeat that for each frame and pick the frame that requires the least amount of pedestal spacers. Then double check the configuration to make sure that you can get a comfortable PadX measurement using that frame.
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Re: Measuring "my" Stack and Reach [carlwithac] [ In reply to ]
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gymrat
Feb 29, 16 20:45
Post #5 of 7 (2446 views)
Thank You Carl.

Good Info to get started with making a decision for a Pre Fit. The Felt and the Scott are very close and the Cervelo should be good with a rising stem.

Thank you,
Pete
2017 Cervelo P2
2017 Cervelo S2
itraininla.com
#itraininla
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Re: Measuring "my" Stack and Reach [carlwithac] [ In reply to ]
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Titanflexr
Mar 1, 16 0:29
Post #6 of 7 (2393 views)
carlwithac wrote:
You're on the right track. For tri/TT fitting, the golden measurement is PadX and PadY. Those coordinates are effective distance vertically and horizontally your pad is relative to the bottom bracket.

PadY = (top of pad to ground) - (center of bottom bracket to ground)
PadX = dead center of your pad back towards your bottom bracket

For measuring PadX, it is best to use a level, perpendicular to the floor, lining up with the center of your BB.

Once you know PadXY, subtract the stack and reach of your aerobar to find HXY(cordinate of the middle of your base bar bore). With Hx and Hy, use the Slowtwitch Bar to HT Calculator to work back towards the Stack/Reach point of the frame in question. Assuming the frame in question has a 73 degree headtube angle, you will want a -17 degree stem.

Do you plan to use whatever aerobar comes stock on the bike, or reuse the Zipp?

If you don't have a level that large, you can roll the back tire against the wall then measure from the wall to the pads and BB.
ECMGN Therapy Silicon Valley:
Depression, Neurocognitive problems, Dementias (Testing and Evaluation), Trauma and PTSD, Traumatic Brain Injury (TBI)
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Re: Measuring "my" Stack and Reach [gymrat] [ In reply to ]
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shoki
Mar 1, 16 2:12
Post #7 of 7 (2364 views)
http://specialized.com.uy/.../SHIVStack-Reach.pdf
A nice chart for measure points.
Does the felt bike come with he bayonet 3 bar? Looks kinda adjustable to me.
-shoki
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