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Why you need a torque wrench
#1
I was on a ride a few weeks ago and I could feel/hear something funky going on. Kind of sounded and felt like like a finger tapping on my bike frame, making a dull pinging noise. It took another 1/2 hour of riding to figure out what it was... The front of my left knee started to hurt all of a sudden because my seat post was ever so slowly sliding back into my frame. I raised it back up a little, tightened it, and thought about it no more.

Tonight I was sliding the seat post out of the frame so I could clamp it to my workstand, and when I tightened it back up I heard a loud "pop". Fearing the worst, I backed out the seatpost clamp bolt, and got a little surprise. The thing on the left is all the stripped threads from the seat post clamp Smile Came out as a nice smooth cylinder. I've never used the torque wrench on this bolt, so I must've been tightening the snot out of it.

Anyway, always listen to your bike because if it's making noise it probably is trying to tell you something, and always use a torque wrench Big Grin
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#2
Ouch!

Steve
Junkyard Tools rescued from the junkyard!
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#3
Wow! Never seen that happen before
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#4
Yep, you certainly tightened the snoot out of it. Live and learn, its the school of hard knocks. Good thing you did not get hurt.

BTDT. When I first started wrenching:-))

AS per using torque wrench, yes thats good but always put brain in gear first. If it feels tight stop and see whats going on. Use your fingertips lightly and short wrenches. Its not as tight as you can get it, its snug and maybe 1/4-1/2 turn more.
Torque wrenches can stick and clickers need warming up before use by Using them lightly and going through some clicks to make sure they are loose. Also always return them to zero for storage,
Beams are a bit more forgiving if not as accurate.
Never Give Up!!!
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#5
Geez, that's one of those things that people guess does not happen. Glad you caught it before anything dangerous occurred!
Good maintenance to your Bike, can make it like the wheels are, true and smooth!
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#6
One of the things that I wondered when they cross threaded and overtightened my pedals, causing me to replace my crankset on a new bike, was why it was never torqued to the manufacturer's specs. Then I went to Park's web site and noticed that none of their pedal wrenches have a way to connect a torque wrench. You have to guess and hope that what you are tightening is done to specs, which in most cases it isn't. I noticed this on other specialty tools for parts that require specific torque specs and there isn't any way to use those tools where you know just how tight the part is when you put it on the bike. Just saying.....
HCFR Cycling Team
Ride Safe...Ride Hard...Ride Daily
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#7
Yes thats true thats why you are the first line of defense against stripped and overtightened bolts. Be gentle, develop a feel for tightness.

There are special open end short wrenches that fit on torque wrenches. However calculations need to be done to account for their longer length. Usually torque wrench directions will have this formula.
Never Give Up!!!
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#8
I have a set of Craftsman crows-foot wrenches in SAE and Metric. These would be idea for replacing pedals with a torque wrench except that the thickness of the wrench is thicker than the bolt surface on the pedal. If you aren't familiar with crows-foot wrenches, they look like an one end of an open-end wrench without a handle and have an opening where you connect your socket handle or torque wrench. They may have an official name other than crows-foot wrench, but that is all I have known them by.

For the hex head bolts, there are plenty of manufactures of hex bit sockets, so they aren't a problem. I use them to tighten all of my hex bolts that need to be torqued.
HCFR Cycling Team
Ride Safe...Ride Hard...Ride Daily
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#9
(01-27-2011, 03:24 PM)JohnV Wrote:  I have a set of Craftsman crows-foot wrenches in SAE and Metric. These would be idea for replacing pedals with a torque wrench except that the thickness of the wrench is thicker than the bolt surface on the pedal. If you aren't familiar with crows-foot wrenches, they look like an one end of an open-end wrench without a handle and have an opening where you connect your socket handle or torque wrench. They may have an official name other than crows-foot wrench, but that is all I have known them by.

For the hex head bolts, there are plenty of manufactures of hex bit sockets, so they aren't a problem. I use them to tighten all of my hex bolts that need to be torqued.

I call them crow's foot extensions too Big Grin .Doesn't the math change when you add an adapter or extension?
Good maintenance to your Bike, can make it like the wheels are, true and smooth!
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#10
To be honest you don't need a torque wrench for pedals anyway, just remember this:

spin the spanner round the axle using a couple of fingers until you meet resistance. Provided you have clean threads you'll find the point the pedal is fully in by feel (it'll be like you've just hit a solid object). Heck, if you've got small enough fingers you can almost do it by hand!

You don't need to take them any further, as the directions of the threads mean they will torque themselves up properly anyway if you've underdone it a bit. There's no danger of them falling off this way, I torque my Downhill pedals up this way and given the abuse they take, if they won't fall off mid-ride nothing will.
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#11
Any time you add an extension to the torque wrench, it'll change the torque applied to the fitting relative to the reading if the effective length changes.
One way to avoid the problem is to mount the crow's foot at a 90 degree angle to the wrench, so the effective lever arm hasn't changed.

I had to use these frequently to torque propeller mounting bolts on small airplanes. Real lifesaver, these.
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#12
The only problem I have with this advice is that torque wrenches are bloody expensive!

: (
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#13
This is the one I use. Finding 1/4" drive bits was a problem, but finally found a decent priced set on amazon

http://www.pricepoint.com/detail/15340-325_SETTQ6-2-Accessories-42-Tools/Sette-Torx-ST-617-Torque-Wrench.htm
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#14
(04-04-2011, 05:06 AM)Dalton2250 Wrote:  The only problem I have with this advice is that torque wrenches are bloody expensive!

: (
And bike parts are inexpensive?
Wheelies don't pop themselves. (from a QBP fortune cookie)
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#15
I was going to say that, too. What finally made me take the plunge was having to buy a new wheelset for my mtb after stripping the disc rotor mounting bolt holes on one of my wheels. Curse my heavy hands and brute strength!!
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#16
(04-04-2011, 10:04 PM)RobAR Wrote:  
(04-04-2011, 05:06 AM)Dalton2250 Wrote:  The only problem I have with this advice is that torque wrenches are bloody expensive!

: (
And bike parts are inexpensive?

No, obviously not. Thanks for your friendliness!
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#17
(04-06-2011, 06:34 AM)Dalton2250 Wrote:  No, obviously not. Thanks for your friendliness!
Dalton, sorry if that sounded bad, buddy! I was being realistic.
Wheelies don't pop themselves. (from a QBP fortune cookie)
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#18
(04-06-2011, 08:31 PM)RobAR Wrote:  
(04-06-2011, 06:34 AM)Dalton2250 Wrote:  No, obviously not. Thanks for your friendliness!
Dalton, sorry if that sounded bad, buddy! I was being realistic.

Aah, thank goodness for that. I was preparing for a fall out! haha

No worries mate.

Personally for me, I wish I had enough money to buy everything I want/need to maintain my bike. It gets very frustrating!!

The only reason I said that really was because I wasn't aware torque wrenches were absolutely necessary, I assumed if something needs to be tight you just need to turn it with all your might. Shows how much I know about bikes!

; p
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