lb, some things to think about
:
1) Even for bikes (and definitely for cars), a single torque wrench won't cover the full range of torques. Remember that click-type torque wrenches are typically spec'd only for 20-100% of their max torque, so trying to go under 20% can cause problems.
2) Different types of torque wrenches vary greatly in their durability and ability to hold their calibration. In particular, the rotating-collar "micrometer-style" click wrenches need to be set back to their low end setting before storage, as otherwise an internal spring can become stretched, throwing off the calibration.
3) A number of items on bikes are reverse-threaded, so you'll want a torque wrench that works both clockwise and counterclockwise.
4) It's nice if the drive size of the torque wrench matches most of the sockets/drivers you'll be using it with, although adapters are fairly inexpensive.
I'd suggest looking at beam-type torque wrenches. Not only are they cheap to make and robust, but any miscalibration is easily spotted (the pointer doesn't indicate 0 at rest) and simply corrected (by bending the pointer to the correct position). Finally, they work equally well for clockwise and counterclockwise readings.
I'd suggest getting a pair of beam-type torque wrenches:
a) a 3/8" drive 0-600 inch pound (1-50 foot pound) model
b) a 0 to 100-200 inch pound model (probably 1/4" drive beam-type)
Sears has a 3/8" 1-75 foot pounder on sale today and tomorrow for $25:
http://www.sears.com/shc/s/p_10153_12605_00944690000P
Park has their TW-1, which is a bit on the expensive side and only goes up to 60 inch pounds/5 foot pounds. Thus, it doesn't overlap that well with the Sears torque wrench; it does better with the Park TW-2, which only goes up to 50 foot pounds.
Personally, I'd try for something used, like this Snap-On dial-type torque wrench (150 inch pounds max):
http://cgi.ebay.com/ebaymotors/Snap-...mZ220279256106