BCD of sickbikeparts freewheel crank?

Qwiksand

100 W
Joined
Nov 10, 2009
Messages
160
Location
Bowie, MD
Hi guys,

I searched, but to no avail...Does anyone know the BCD (bolt center diameter) of the the sickbikeparts.com freewheel, heavy duty or standard- they look like the same BCD on their site.

whitefw.jpg


http://www.sickbikeparts.com/catalo...ducts_id=62&osCsid=9krljtnmhr480dejk1smdulgm5
 
Its the common 2-21/32nd" bcd :mrgreen: ????????
 
To quote Jim from Sickbikeparts

"The hub radius is 1.06 inches or a 2.12 diameter. The hole spacing is about
1.33 radius or 2.66 diameter in a 5 bolt pattern."

= 67.733333mm BCD

however, the word "about" doesn't exactly inspire confidence in the accuracy. :|
 
From Wikipedia http://en.wikipedia.org/wiki/Wheel_sizing
Some basic geometry is needed to find the center of a 5-bolt pattern: But basically, the PCD can be found by multiplying the center distance between any two adjacent holes by 1.701. Generally, the PCD can be calculated for any wheel from the number of bolts (n) and the measured center distance between two adjacent bolts (d) as; PCD = d / SIN(180°/n).

I believe what they call PCD is BCD
 
boostjuice said:
To quote Jim from Sickbikeparts

"The hub radius is 1.06 inches or a 2.12 diameter. The hole spacing is about
1.33 radius or 2.66 diameter in a 5 bolt pattern."

= 67.733333mm BCD

however, the word "about" doesn't exactly inspire confidence in the accuracy. :|


I am mesuring this for an hour now and measured this:
Measuring is made according to ISO17025 :)
Measured with 3 different

hub diameter is oval and it is between 53,68 and 53,73mm
Then I measured from top of the hole to outher dia (2,62) and measured hole (5,25mm). I measured outher diameter and found out it is 77,78 so calculated BCD:
77,78-(2x2,62)-5,25 = 67,29
Then I measured from one hole to another and calculated BCD from pentagon and the result was 67,31mm

Then I repeated all starting with different hole each time.
maximal result was 67,82mm
This pissed me off that I couldn't measure diameter so I am taking it to 3d probe on Monday.
I guess the circle with holes is not concentric with other circles.
 
The hub radius is 1.06 inches or a 2.12 diameter. The hole spacing is about
1.33 radius or 2.66 diameter in a 5 bolt pattern." = 67.7mm BCD

He should be beaten.

OK...(facepalms)...what are the diameters of the holes? and...

Is the interface the same as the ACS Crossfire flanged FW from Bikemotive/Staton?
$(KGrHqNHJEwE-uwKHetMBP)BRkF(!Q~~60_12.JPG
 
On the crossfire's there are 5mm tapped holes & through holes with clearance for a 5mm bolt.
Yes they all line up..Eno, dicta & crossfire.
In English the bcd will measure 2.63"






I friggin hate the iPod auto spell! :!:
 
I friggin hate the iPod auto spell

AH!...me too!

I was texting my ex-wife, and when I typed in "best of luck, and say hi to the kids when you see them",
it auto-corrected to:

"you ruined my life and left me penniless, you heartless monster"
 
:mrgreen:
 
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