Wildlab.com

Let’s begin to build a new bike from scratch. This time, I chose a bike named “Z80″ made in Germany which  has reasonable price for me and has enough geometrical informations (see below please).

size	51	54	56	58	61
HA	72	72.5	72.5	72.5	72.5
SA	74.5	74	73.5	73	73
TT horiz	525	545	560	575	595
TT C-C	507	526	540	553	574
Head Tube	140	160	180	200	220
ST C-T	470	500	520	540	570
ST C-C	425	545	465	485	515
BB Drop	70	70	70	70	70
CS	415	415	417	417	417
Front Center	584	595	605	615	635
Wheelbase	988	1000	1012	1022	1042
Rake	50	50	50	50	50
Standover	719	738	757	777	803
Crank Length	170	175	175	175	175
Stem	80	90	100	110	110
H-bar	400	420	420	440	440
Seat Post	27.2 x 350mm	27.2 x 350mm	27.2 x 350mm	27.2 x 350mm	27.2 x 350mm

1.Enter Name, size and maker info.

Enter “New Bike” screen and type bike’s name and size for identification.

2.Open “Bike Builder” and input first parameter (wheelbase).

Target size is “51(cm)”, so lookup for “wheelbase” section at first column. Answer is “988″.

3. Find diameter of tyre.

This bike’s tyre-diameter is not shown in the geometry table. But we know the tyre is “Vittoria Zaffiro 700c x 25c”. You can find it at “technical info” section (on same web page for Z80).

Please tap “Tyre size list” button. You will find actual (but approx.) diameter for “700×25c” in next screen.

Choose your tyre and tap “Done”, then you will see “672mm” in previous screen.

4.Chain-stay length (= Rear to Center length)

OK, let us go to next step.

At the 2nd page in “Bike Builder”, you have to entry only chainstay length. Lookup for “CS” section for “51″ column. The value is “415″mm.

You do not have to input “Front Center” length, because you already enter “Wheelbase” in previous page. (Front center length is automatically calculated from Wheelbase, RearCenter and BB-Drop length)

5. Crank length and BB-Drop.

Go to 3rd page please. And lookup and enter two values for “Crank Length (=170mm)” and “BB Drop (=70mm)”.

Now you can see three circles (wheels and crank).

6.Seat tube and saddle.

Go to 4th page please. In this page you input all three values. From bottom, Seat-tube angle is found as “SA” in the table. Value is “74.5(degree)”. Next, Seat tube length is shown as “ST C-T”. This means “Seat tube length from CENTER of BB to TOP of seat tube”. The value is “470mm”. Now you will see the seat tube in the screen.

Do not worry that you can not find “Saddle height” in the table. You can enter any value here. I choose 200mm. The result is ..

7.Frame section

This section is difficult a little. MisterCharlie told me how to say in English in such situations.

You’ll need to pore over the actual geometry measurements of your prospective steeds to determine the right machine, which makes Test Rides more of a helpful number cruncher than a true “fitting room”.

The good news is that detailed geometry specs are available online for many better bikes. The bad news is that they aren’t always measured in the same way so you’ll have to do some sleuthing.

[WIRED 2009.8.21 Thanks MisterCharlie!]

After sleuthing, did you find your answer?

First, please select sloping style frame in toggle button(if horizontal type is selected). Then enter three values “ST C-C(=425mm)”, “TT C-C(=507mm)” and “TT horiz(=525mm)”. “ST C-C” means “SEAT TUBE length from CENTER of BB to CENTER of top-tube”. “TT C-C” means “TOP TUBE length from CENTER of top-tube on head-tube to CENTER of top-tube on seat-tube”.

After this step you can see,

…Coffee or tea?

8. Front section

The first and only missing value for this bike is “Folk length”. We can see the name of this component is “Carbon Design with 3K Carbon Fiber Blades” at tech-spec section on the web-page. But I can not find out actual length from this name. There are two way to find it. One is “ASK TO MAKER” and the other is “DO NOT FUSS OVER SMALL DETAIL”. I selected the latter and my value is “370mm” .

So values which you need to enter in this section are, “HA(Head-tube Angle)=72(degree)”, “(Folk) Rake=50(mm)”, “Head Tube(length) = 140mm” and “Folk length = 370mm”.

We are almost at the finish line.

9. Head section

In order to draw head and stem, we need three values but there is only one “Stem = 80mm”. Please do some more sleuthing again. Photos of the bike will give you good hints.

But I found more info in tech-spec section, “HEADSET: Cane Creek type 1 1/8″ Integrated with 20mm Cone and 3 X 7.5mm Spacer Stack” and “STEM: F 2.1 Adjustable 6061 3D Forged Ø31.8mm with +/-(6 or 14) Degree Rise”.

I entered “Head height = 70 = 20+3×7.5+α(mm)” and “Stem angle = -6(degree)”.

In ver.1.2.0 or later, you can adjust head height and swap stem in Fitting view. So you do not have to spend your time to find these values.

CONGRATULATIONS!! You made it.