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Torque Wrenchs - suggestions?(14 posts)

Torque Wrenchs - suggestions?outofthesaddle
Dec 11, 2003 12:24 PM
I'm doing a lot more of my own wrenching. Anyone have a good recommendation for a torque wrench for bicyle application?
Buy two, one for small stuff and one for the big stuffhudsonite
Dec 11, 2003 1:33 PM
I purchased my 'click' style torque wrenches from Sears. I always had good luck with Craftsman tools.

I use a 1/2" drive for the big stuff (Bottom Bracket, cranks and Cassettes) and a 3/8 inch drive for the small stuff (stems, brakes, derailleur).

The 1/2" adjustments are too 'big' for the small stuff and the small one is too small for torquing the heavier pieces.

I am sure some people use only one, but the way I see it, if you avoid messing up one stem, you paid for the second torque wrench.

YMMV
re: Torque Wrenchs - suggestions?seyboro
Dec 11, 2003 2:55 PM
I went with the Park wrench. Easy to read and use. I bought my 4,5,6 and 8 mm parts at Sears, as well as a socket to fit the Campy bottom bracket/cassette tool. Also while you're at it, check out the torque spec list on the Parktool website.
re: Torque Wrenchs - suggestions?Synchronicity
Dec 11, 2003 3:25 PM
Yeah don't get one!
For approximately 9 years I did my own guestimations. I rarely, no make that NEVER, have had anything come undone on either bicycle in all that time, but I periodically undo things to clean them, so the tightness is always rechecked.

Then I bought a torque wrench as I have the ITM The stem. I think torque specs have a tendancy to be too tight, and you are in more danger of stripping threads or braking boltheads off. This is because the handle is quite long, and you can't gauge the tightness yourself, only by tightening by hand first, then seeing how much further the bolt tightens. I won't be using mine, or I'll be lowering the suggested torque values a little, as I usually cringe when I'm approaching the final reccommended torque value.

For example, I used it on my motorcycle to tighten up the front discs, and sure enough, a bolt head snapped, leaving the thread remaining in the wheel. I knew instinctively it was too tight. It happened at about 2/3rds the reccommended torque value.

If you get one, you might also consider picking up a set of screw extractors!
A word of warning: if the screw keeps turning, and yet the torque value isn't rising proportionately (if at all), STOP!! - as something is about to give way.
re: Torque Wrenchs - suggestions?Synchronicity
Dec 11, 2003 3:32 PM
Further thoughts:

- yes I own two wrenches; big and small.

Ask yourself: if you've been hand tightening your bicycle fasteners, and you've never stripped a thread or had your stem mysteriously come undone midway through a ride, what do you need a torque wrench for?

I like the idea of being able to feeeel how tight something is. You get used to that. A torque wrench, in all its objective splendour, removes that feeling. At least the cheap park ones with the bendable rod mechanism do.

So basically what I'm saying is they're over-rated.
Agree, to a point....torquecal
Dec 11, 2003 6:31 PM
Torque wrenches are only as good as three things they ALL rely on:

1) The accuracy of the torque specifications provided by the manufacturer,
2) The skill of the user, and
3) The accuracy of the wrench.

The first is usually pretty good if you've got info straight from the manufacturer or manufacturer(s) (in the case of handlebars with a different make of stem, for example) involved. If you're taking general torque specs from a maintenance handbook you're probably close, but nowhere near needing a wrench to get it in the ballpark.

The second varies widely. Take the previous post for example; if the screw stops turning (to the nekkid eye) that doesn't necessarily mean that value added torque isn't being applied. Fastener manufacturers are normally pretty good about hiring the right kind of mechanical engineers to determine the optimum torque values for their products. Most of these values I've seen are usually past the point of visible rotation of the screw or nut you're tightening. Also, ALL torque wrench manufacturers in the USA say their wrenches are accurate ONLY after exercising them 6 times to max torque value prior to use. How many times have you seen a LBS mech exersize a torque wrench?

Finally, torque wrenches are notoriously fickle devices. Most are calibrated to +/-4% in a CW direction and +/-6% in a CCW direction (some deflecting beam type wrenches are spec'd +/- 2% in either direction). The click (aka snap action impulse feel) type wrenches always have to be stored at their lowest torque settings, else their springs gain unwanted metal memory and they lose accuracy. The beam types have to be stored protected so that their pointer beams don't get bent thru incidental contact.

Bottom line: torque wrenches are usually overrated - NOT because they aren't useful, but usually because they're used incorrectly.
Follow up ?outofthesaddle
Dec 12, 2003 11:35 AM
My primary area of concern is the bar/stem torque spec. With T. Coleman's bar snapping at DMD this year (Doug Sloan's case) I've become more sensitive to getting the bolts torqued correctly. Based on the errors introduced by the three considerations you've raised above, does the torque wrench really make much of a difference?
For bars and stems I like Torque wrenches...torquecal
Dec 12, 2003 2:24 PM
As long as youve got the manufacturer's specs for the torque values, maintain and store your wrench correctly, and use it correctly, then I think torque wrenches are great, especially for things like bars and stems!
Sears-$49....lyleseven
Dec 11, 2003 4:04 PM
Sears... you only need the 3/8 drive and then an adaptor to handle larger stuff like cassettes, etc. Buy the one rated for 25-250 lbs. They are on sale this week for $49!!!!
Left-hand thread factorDale Brigham
Dec 12, 2003 6:39 AM
English-threaded bottom brackets (what likely 95% or more of bikes in the U.S. have) have a LH (left-hand) thread on the drive (chainring) side and a "regular" RH thread on the non-drive side. Since properly torqueing the bottom bracket cups may save much grief later, I need a torque wrench that "goes both ways" (works both clockwise and counter-clockwise).

My old "click" (AKA breakaway) torque wrench only works on RH thread (clockwise). So, I'm asking Santa for a beam torque wrench from Sears for Xmas. I don't know of any "click" torque wrenches that work on both LH and RH directions (please inform me, if there are some out there), so I'm thinking that a beam torque wrench is the only way to go for LH threaded BBs. If you, too, have English-threaded bottom brackets on your bikes, it might be something to consider.

Dale
They aren't cheap...LactateIntolerant
Dec 12, 2003 8:49 AM
...but they're out there.

http://www.mcmaster.com/

go to catalog page 2615
Left-hand thread factortorquecal
Dec 12, 2003 2:22 PM
Snap on, Proto and Craftsman all make click type that work both CW and CCW. Beware though, they are all less accurate in the CCW direction than the CW direction. Proto's are my personal favorite but they ARE expensive, probably way too expensive unless you have a use for it every day.

The beam types are nice for CCW applications because most of them are the same rated accuracy either way.
Sears goes both waysKerry Irons
Dec 13, 2003 5:27 PM
My big Sears torque wrench works just like any ratchet - you just twist the head to reverse it.
Thanks for setting me straight on CCW (LH thread) torque wrenchDale Brigham
Dec 15, 2003 2:21 PM
It looks like my dad got me a Craftsman beam-type torque wrench for Xmas, so that will have to do!

Dale