Sunday, September 4, 2011

Tightening My Handlebar Stem

After I had my crash on the Silver Comet Trail on Friday my boys got me and my bike fixed up and back on the trail in just minutes.  My handlebars had performed an impression of a dowsing rod although my dowsing rod was better at locating pine trees than finding water.  It must have something to do with the drought.

I'm determined to prevent another crash (due to the same issue).  None of my equipment came with installation sheets when I bought my bike last year.  I did some on-line research on my handlebar stem on the manufacturer's website.  That's the best place to find support and technical information.

I found the 2-bolt stem instructions on the VisionTechUSA website.  I looked at my stem to verify the information.  As indicated in the instructions, the information I needed to know was located on the stem itself.  From the image below, this includes 1) an unknown number, 2) angle, 3) length, and 4) torque specifications and handlebar size.  In my case these data are; 0610, 10-degrees, 70mm, and 12Nm and 26mm, respectively.  The stem handlebar clamp bolts are 5mm hex.

Stem technical data markings
I couldn't find a reference to #1.  I thought it might be the model # but after looking at the instruction sheet I'm not so sure.
Stem angle (10-degrees) and length (70mm) data
Stem handlebar torque (12Nm) and center diameter (26mm) data
12Nm equates to 106 in/lbs and 8.85 ft/lbs.  The installation sheet shows the fork clamp bolts should be tightened to 6Nm.  I couldn't find any markings for this on my stem but I don't plan to mess with the fork clamp anyway.
2-bolt stem (5mm)
The installation sheet refers to carbon assembly paste.  I don't have any of that.  Other than the paste, I need a torque wrench and a 5mm hex bit.  I've got plenty of hex wrenches and plenty of hex bits but my 5mm hex bit is lost for good.  I have a ft/lbs torque wrench but no inch/lbs torque wrench.  I've ordered an in/lbs torque wrench on-line.  My efforts to find one locally were in vain.  I've also ordered a set of mm hex bits.  When they arrive later this week I'll put them to good use making sure I don't end up in the woods again.

Disclaimer:  Please refer to the manufacturer's documentation before attempting any bike maintenance or, better yet, use the services of a trained professional bike mechanic.