Difference between revisions of "EBB Frame Shell Modification"

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(The EBB Shell)
(The EBB Shell)
 
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[[Image:Light-EBB-14.jpg]]<br><br>
 
[[Image:Light-EBB-14.jpg]]<br><br>
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The bolt bosses are cracking at the weld. The weld may be cracked, but it seems to have plenty of strength for what it is doing. I will repair this when it fails.<br>
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[[Image:Light-EBB-17.jpg]]<br><br>
  
 
The shell mod complete. 2.250" wide & 42 grams off the frame.<br>
 
The shell mod complete. 2.250" wide & 42 grams off the frame.<br>

Latest revision as of 17:15, 19 January 2007

The Problem

After modifying the EBB of my Zion frame to reduce weight, I will now cut the shell of the frame down to 2 3/16" from 2 3/4" to match the new width of the cam. This is a lot of heavy steel that is not being used for anything.

The Cam

The Eccentric Bottom Bracket Modification cam is 2.1875" wide.
Light-EBB-6.jpg

The EBB Shell

The original shell. 68mm 2.677" 2179 grams with headset cups.

Light-EBB-9.jpg

Centered on the DRO

Light-EBB-10.jpg

A boring bar was used taking about 4 passes to face the shell down. This was because it would take too much time to fixture up a nice ridged set-up.

If I had not reamed the shell bore round and fit a shim already, I would use this set-up to bore the shell bore round and to a usable size.

Light-EBB-11.jpg

The final pass of the first side about to happen.

Light-EBB-12.jpg

One side done.

Light-EBB-13.jpg

second side done.

Light-EBB-14.jpg

The bolt bosses are cracking at the weld. The weld may be cracked, but it seems to have plenty of strength for what it is doing. I will repair this when it fails.

Light-EBB-17.jpg

The shell mod complete. 2.250" wide & 42 grams off the frame.

Light-EBB-15.jpg

The finished mod. 96 grams gone. That is almost a quarter pound. I should drill some holes in the shell.

It looks so cool now!

Light-EBB-16.jpg