Looking to change handlebar, what do these numbers mean?

[krashTest]

I'm looking to replace my straight bar for a riser. I'm looking to keep my stem but how do I ensure that the stem diameter matches my new handlebar?

I'm also curious as to the number 6N-m and 5-Nm found on the stem and what do they mean.

Thanks in advance.

[Painkiller]

The number and letter combinations you see are nominal torque specification
http://www2.bsn.de/Cycling/Torques.html

your bar will be 25.4 or 31.8

[Joe_W]

(10-24-2012, 11:43 PM)painkiller Wrote:  your bar will be 25.4 or 31.8

Hint: That is the diameter where you clamp the bar in milimeters (mm). For our non-metric minority: 25mm is about an inch.

[Painkiller]

(10-25-2012, 02:27 AM)Joe_W Wrote:  

(10-24-2012, 11:43 PM)painkiller Wrote:  your bar will be 25.4 or 31.8

Hint: That is the diameter where you clamp the bar in milimeters (mm). For our non-metric minority: 25mm is about an inch.

yes Joe, 25mm is about an inch. Because 25.4mm is an inch
just divide mm by 25.4 and that will give you inches and thousandths

so your 31.8 would be 1.251 or 1 1/4 inch +.001 over
your 350mm seatpost would be 13.779 in. or .029 thousandths over 13 and 3/4 inches in a nut shell thats all one has to do to convert mm to inches/thousandths

[nfmisso]

And definitely use an appropriate size/range torque wrench to tighten those bolts on your stem - or you will be buying a new stem too. Those aluminum die-casting are very unforgiving.

[krashTest]

Thanks for the replies everyone!

Thanks nfmisso for advising me on the torque wrench! I would bypassed it altogether.

[xerxes]

(10-27-2012, 12:59 PM)krashtest Wrote:  Thanks for the replies everyone!

Thanks nfmisso for advising me on the torque wrench! I would bypassed it altogether.

To be honest, I've never used a torque wrench for bicycle maintanance - no problems so far. :S

[nfmisso]

(10-28-2012, 09:08 AM)xerxes Wrote:  To be honest, I've never used a torque wrench for bicycle maintanance - no problems so far. :S

I hadn't either until this past summer when I stripped out the screws on the stem when re-installing the handle bar on the front of our tandem, and had to purchase a new stem.... Bought a small torque wrench at the same time. 5 N-m is a very low value, much less than I can apply with a simple screw driver.

[Bill]

[Joe_W]

Yeah, Sheldon Brown wrote something along the lines of "in the old times we needed a torque wrench with steel components, now in the age of carbon, why do people think they can get away without using one?". There has also been an article on bolts on slowtwithc recently:
http://www.slowtwitch.com/Tech/Bolt_Tech_-_Will_Torx_Win__3170.html
found this an interesting read, especially since I actually disliked the Torx.

[RobAR]

Along with what Joe said - it's one thing for me (as a veteran bike mech turning wrenches on my own bikes in my own garage and trusting my instincts honed over 20+ years) to risk my own equipment and health.
The Lawyers and Insurance companies don't see it the same way when I charge you for my labor and you get hurt - even if no fault of mine, I get to spend Quality Time in Court defending my reputation! Pretty sweet, huh??!
Labor charges at your LBS have risen in recent years not because mechanics or owners are raking in the $$. It's because INSURANCE on just about every sporting related business has gone ballistic in the past 10 years. On top of that, if I file a claim with Company XX that a product of theirs broke upon assembly of a new bike, the 'Burden Of Proof' is on me to prove it - as if flawed goods never get past their QC chick. Most companies that your reputable LBS deals with won't go to that extreme but, just that it is a Maybe ticks me off. I now have to purchase a special tool to keep out of Trouble. Problem is - I really get into my job and I want it done correctly. Some mechs buy the tool and hang it on the wall to cover their A$$.

Oh wow. I had best stop now. Might be some Attorney types lurking here.
Can anyone tell I have had a bad day??