Torque Wrench Choice?

[CyclinYooper]

Well, now that I have a carbon frame bike, I'd like to invest in a torque wrench.

Can anyone tell the pros/cons of the two types available?
Classic style: http://www.parktool.com/product/torque-wrench-tw-1
Ratcheting style: http://www.parktool.com/product/ratcheting-click-type-torque-wrench-tw-5

A basic Park TW-1 for ~$35 looks pretty good and simple, but curious to see what folks think. Classic wrenches can be on the long side, and I wasn't sure it would always fit where you need it?

Typically, it looks like ratcheting style are more expensive (and it looks like price can vary greatly between brands). Is there a type that maintains calibration longer? Is it a waste of money to buy a "bike specific" one? Many non-bike ones have only inch-pounds ... but I"m quite sure I can do the conversion.

Scott

 

[alienator]

Well, now that I have a carbon frame bike, I'd like to invest in a torque wrench.
Can anyone tell the pros/cons of the two types available?
Classic style: http://www.parktool.com/product/torque-wrench-tw-1
Ratcheting style: http://www.parktool.com/product/ratcheting-click-type-torque-wrench-tw-5
A basic Park TW-1 for ~$35 looks pretty good and simple, but curious to see what folks think. Classic wrenches can be on the long side, and I wasn't sure it would always fit where you need it?
Typically, it looks like ratcheting style are more expensive (and it looks like price can vary greatly between brands). Is there a type that maintains calibration longer? Is it a waste of money to buy a "bike specific" one? Many non-bike ones have only inch-pounds ... but I"m quite sure I can do the conversion.
Scott

The beam type--"classic" in your terminology--tend to be more accurate but less user friendly or readable. Parallax can change the reading, and of course vision issues can change the reading. They can be recalibrated by just bending the needle to re-zero it. Click types are more convenient but need occasional recalibration. If they're not reset to zero after each use, they can go out of calibration more quickly. As often as a torque wrench is needed on a bike by a home mechanic, either works as well as the other. Here is the mac-daddy of torque wrenches for bikes. It's available in quite a few place and under a different name or two. When I worked in government lab, one group was working to see how much torque they could generate. I don't know why they were doing it (other than it was an awesome geek project) as it was likely a poor expenditure of tax dollars........still....They were using hydraulic rams to flex a stainless steel beam that was (if memory serves correctly) several meters long and on the order of 30 or more centimeters thick. I think they generated something on the order of giga- or teranewton-meters of torque.

 

[davereo]

Originally Posted by CyclinYooper .

Well, now that I have a carbon frame bike, I'd like to invest in a torque wrench.

Can anyone tell the pros/cons of the two types available?
Classic style: http://www.parktool.com/product/torque-wrench-tw-1
Ratcheting style: http://www.parktool.com/product/ratcheting-click-type-torque-wrench-tw-5

A basic Park TW-1 for ~$35 looks pretty good and simple, but curious to see what folks think. Classic wrenches can be on the long side, and I wasn't sure it would always fit where you need it?

Typically, it looks like ratcheting style are more expensive (and it looks like price can vary greatly between brands). Is there a type that maintains calibration longer? Is it a waste of money to buy a "bike specific" one? Many non-bike ones have only inch-pounds ... but I"m quite sure I can do the conversion.

Scott

I have the TW-1. If I was to buy again I would go with the TW-5. The TW-1 only goes up to 7nm the TW-5 goes to 15 or 16 nm. It covers a wider range of fastenening requirements in one tool. You would need to get the TW-2 and TW-1 together to get the same range making the TW-5 a much better value.

 

[swampy1970]

Spend a few minutes figuring out the torque of all the fasteners on the bike. Chances are that most will be within a similar range. Get a torque wrench when that value is somewhere in the middle of the wrenches specifiied torque range. Most will be in the 4 to 9 Nm range - especially stuff like stems, seatpost binder bolts and front mech clamps. Personally, I use a torque wrench on the brake caliper bolts too. It'd be a pisser if the fork crown just happened to split due to massive overtorquing of that bolt. They only build it a certain amount of "idiot proofing" into stuff and it's way too easy to generate some serious clamping force when tightening a fine pitched threaded bolt.

For ***** 'n giggles I tested my little 1/4" dirt cheap harbor freight wrench against a friends Mac Tools 3/8" torque wrench that was very expensive. The Harbor Freight wrench was gave very similar reading to the Mac Tools depsite costing only $12 rather than the near $200 for the bling bling, heavy duty and will last for years under severe car mechanics use, Mac. Then again, you'll probably swing a torque wrench on a bike a dozen of so times a year...

... if you already have some Park Tools, their little beam wrench would keep the collection the same and won't break the bank.

 

[AlanG]

Originally Posted by swampy1970 .

Spend a few minutes figuring out the torque of all the fasteners on the bike.

This is a good idea but where do you find all of these values? I have a torque wrench and some things are marked, but I don't know where to look for other values. And I have several bikes, old and new.

 

[alienator]

 
This is a good idea but where do you find all of these values? I have a torque wrench and some things are marked, but I don't know where to look for other values. And I have several bikes, old and new.
 

That's a fun question. Well, all the group components--derailleurs, shifters, brakes--will have spec sheets on their manufacturer websites. Get thee to those and inspect. As Swampy said, most of the torque values are going to be in the ball park of 5N-m. It could 5, 6,7,8 or summat. The torque on pedals is not large. In fact, unless there's an issue with bearings seizing, most pedals will tighten themselves a bit on the crank. Still, the manufacturer instruction sheet should specify that torque. The biggest torques are typically associated with the crank.....like the bolt tightening the hirth joint on Campy, Lightning, and Specialized cranks. Then there's the odd torque: on my Look 595 the biggest torque is on the seat rail clamp, 22 N-m. Sometimes stems and handlebars have torque printed on 'em. Another large torque item is the cassette lock ring. It usually has the torque printed on it. In short, you're gonna have to do some inspection and some searching online. If you can't find something, you can always post here and ask. It should be emphasized that if you're going to work on your bike, you really need to know these torques or have them readily available. In fact, there's no excuse, if you're working on your own bike, for not having these values. If something breaks, manufacturer analysis can reveal the point of failure and the likely cause. That means they can, if they put enough energy into it, find that something likely failed because it was over-torqued. That is of course only the case if you want the manufacturer to replace something.

 

[CyclinYooper]

Originally Posted by AlanG .


This is a good idea but where do you find all of these values? I have a torque wrench and some things are marked, but I don't know where to look for other values. And I have several bikes, old and new.

Cervelo has torque specs contained in their online manual. Looks like any wrench with 3-9 N-m range would be adequate.

Scott

 

[CyclinYooper]

Thanks everyone for the advice on this.

Originally Posted by CyclinYooper .


Cervelo has torque specs contained in their online manual. Looks like any wrench with 3-9 N-m range would be adequate.

Scott

Looks like, if I want to get a single wrench that covers that entire range, I'd really have to get a ratcheting type. I haven't seen a beam-type that has that versatile of a range. Many small ratcheting ones seem to be in the 3-15 N-m range, however.

 

[AlanG]

I just found a big list of torque values at the Park Tool Blog.

http://www.parktool.com/blog/repair-help/torque-specifications-and-concepts