As I shop for a torque wrench, it seems most I’m coming across are rated for inch pounds. How do I convert this to the metric nanometer? Also, should I buy 1/4" or 3/8" drive? This will be used for making the required torque adjustments on my P2C (i.e. 4nm for the seatpost clamp and 12nm for the seat assembly).
I think you actually want newton meters not nanometers.
google “50 newton meters to foot pounds” and at the top of the list of search results you will get
50 newton meters = 36.8781075 foot pounds
you mean newton meter right? otherwise, you might as well convert hours in pounds
1lb-in = 0.113 nm
Yes, my bad. The seatpost clamp does show NM=Newton meters. So how do I convert NM to inch pounds?
I’m fairly sure that if you look carefully in my previous post, there is some indication of how to do that 
.
So about 35 pounds/in = 4NM?
Where did you find your torque wrench? To avoid creating problems with the seat, I’m thinking of getting one, too. I did a real quick search and ended up with some very expensive options, but I’m hopping I was looking at the wrong thing.
yes.
I am still lookng but plan on going to Sears later today to look at this one and see what else is available.
In further review of the product specs, this one won’t work as it only goes up to 75 in. pounds and the seat assembly requires around 106 in. pounds. I’ll keep looking.
Buy a 1/4" torque wrench for bicycle repairs. There is no need for the larger 3/8" torque wrench. On top of that, the 1/4" wrench is going to be shorter and the head will be thinner and easier to maneuver in tight locations, like when your tightening the clamp under the seat.
Torque wrenches are most accurate in the center of there torque range, so keep that in mind when shopping for one.
As for coverting inch pounds to newton meters, all you have to do is google “conversion charts” and you’ll get a number of sites that will help you covert all possible measurements.
Hope this helps.
The torque wrench you posted actually goes up to 75 foot pounds and is too much wrench for bike repairs.
Do not mix up foot pounds w/ inch pounds, otherwise you’ll be stripping and breaking bolts.
1 foot pound= 12 inch pounds
If possible, try and get a clicking type torque wrench. The I-beam wrenches are a pain to work with. With the clicking wrenches, you set the torque you want. Once the wrench reaches the desired torque, it clicks and lets you know the desired torgue setting is reached.
Thank you very much for the advice and explanation. I will look for the clicking type you described.
Some info from Park Tool:
I use this at work to convert to/from different units
http://joshmadison.com/software/convert/
Syntace makes a very nice click type torque wrench and its highly accurate, but you’re going to have to pay for it…arguable the best you can buy…
Also check your Home Depot/Auto parts and tools store - they sell torque wrenches for working on cars
The other sears one has both measurements, although it’s a kind of complicated and less accurate system for the metric. As you twist the handle it moves up and down the shaft (it’s less sexy than it sounds) and the indicator lines kind of meet at a T and the X axis gives you standard, the y axis gives you metric. That’s not a very good job of explaining but if you look at it in action it’ll make sense. i went with 3/8. don’t buy the 1/4 unless you’re sure that you can find the allen wrench adapters, they were hard enough to find for the 3/8.
-charles
QR - I’ve got a nifty little program called ‘‘convert.exe’’ that does conversions for all sorts of things (mass, torque, volume, concentration, density, force, etc.). It’s a shareware freebie, so no copyright violations. If you’d like, I can shoot it to you - just PM me an e-mail address to send it to.
Mike
Sears has a dial torque wrench that me and most of my buddies, and the local shop uses, use too. I think it was about $60 and then another $4 or so for each socket type wrench size. I got a 4mm, 5mm, and 6mm and that covers most of the bike. One of the real keys in using the wrench is to properly grease the bolts you are torquing.