Cutting carbon handlebars

I've been trying out different handlebar widths on my mountain bike lately. I rode a flat, 580mm wide bar for about a decade or so before trying out a 635mm wide low-rise handlebar earlier this year. It was love at first ride. I built up a second mountain bike for myself this past spring. The trend has been toward ever-wide bars. My LBS encouraged me to check out a 685mm wide bar. So I did. The results? Eh, not so good. For the tight, twisty, cross-country riding I like, 685mm felt just too wide. I actually grazed the end of the bar on a passing tree at high speed a while back. I didn't crash, but I decided 685 was not for me.

That said, the beauty of a wider bar is that you can always cut it shorter. I finally cut mine down the other night. Here are some photos and notes...

First time posting photos in my blog. My apologies if I screw this up:

My carbon bar, clamped and partway through cutting

So, first things first: when cutting carbon, you always want to wrap the area to be cut with electrical tape. This reduces the chances of splinters when cutting and results in a cleaner cut. Hard to tell from my photo, because it's black on black, but I taped the bar before cutting. I used my Park SG-6 saw guide to get a nice, square cut. It's intended for cutting fork steerer tubes, but works equally well on handlebars.

After cutting both ends, I measured the cutoff pieces to see how evenly I had trimmed the bar:

cutoff #1



cutoff #2

I started out at 685mm, and the goal was to end up at 660mm. I can always cut more off later if I decide 660mm is still too wide, but why not try it? So, I had to cut 12.5mm off of each end. As you can see from the photos, the cutoffs are a little short of 12.5mm, but what you don't see is the material removed equal to the thickness of the saw blade. I'm right in the ballpark.

A little sanding and reassembly, and I'm ready to ride! I'll let you know what I think about 660mm in a future post. Happy trails!