Modified Bash Guard

[A bash guard replaces the largest chain ring on a mountain bike to protect the front most gears from crashing into rocks and logs.]

After mulling over this for about a year I finally put the 'guard on the mill and hacked it on Feb 24. I pared down 0.15" of radius to increase ground clearance and reduce weight, then drilled 28 3/8" holes to lighten it further. I removed 68g weight, dropping it to 102g, but I believe I retain all the useful strength. This guard protects my 34t chain ring and is based on a Nashbar part which is reliable but quite heavy. In the picture, an unmodified part is on the left, and my customized one is on the right.

In terms of machining technique, this was the first time I've moved the work piece between drilling operations. I was taught to fix the work then perform all the drill operations (center drill, then 1/8", 1/4", 3/8" drills in succession). This works well for beginners because it eliminates the risk of breaking a drill due to the chuck being misaligned to the previous hole. But in this case it would have taken a lot more time so instead I center drilled all 28 holes, then put in the 1/8" drill and went around again. I had no trouble with it (in the context of a low-precision project).

Now that I've ridden it twice, I'd say the advantages line up this way:

1. It looks better to me, and in a sense I've bonded with it, so riding is a little more fun.
   
2. The clearance and weight improvements are nice, but they don't change the riding experience in a substantial way.
   
3. Milling is always fun.