But you'll twist it more when riding hard than hardly riding.

Yeah, I'm just going to assume that you're being unusually obtuse in a bizarre effort to save face. Unless you'd like me to assume that this isn't an act?

You know what happens when you assume.

From working on cars I live with specific values.

Yes, you keep drumming home that you work on cars. Yippee. Do you need to be reminded again that bikes have neither internal combustion engines nor parts that spin at 1000s of RPMs and that even your own bike parts don't have 'specific values'?

Just that "tight enough but not too tight" is not very exact.

Why have a spec at all then?

The answer seems obvious - not sure why you're even posing the question, but anyway .............
Over-torquing with carbon and aluminum can have catastrophic results. An experience mechanic will likely know what tight enough is by feel. I don't and prefer not to crack a seat post, down tube or handlebars by giving that extra twist.

NSS, this is what we're trying to tell you and why a wrench with +/-.05% accuracy is not necessary.

For ham-fists and lawyers.


Anywho, at this point, I'm going to bow out of this, because your well of... whatever... runs too deep for me. Have fun being wrong.

Speak for yourself.

OK... tight but not too tight.

In other words, don't exceed the specified number, but tight enough that it doesn't come loose when you're riding.

Then there's always this: http://www.bontrager.com/model/08370

It came with my bike.

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Hi Sy Reene,

Did you read the first review for that wrench on Amazon (at your link)? If you did, then you'd see that it can be way out of calibration. The reviewer (A.D.) broke a suspension bolt on his mountain bike using it because it was so far off. I think the Venzo Bicycle Torque Wrench would be a very BAD choice.

And, like a comment to A.D.'s Amazon review of this wrench pointed out, even the Park Tool click-type torque wrenches are sometimes not calibrated very well from the factory.

Unless you plan to spend a lot of money on a professional-quality torque wrench, the "safest" thing for a part-time bike mechanic or hobbyist is to get the older spring type (also called "beam type") torque wrench. The Park Tool TW1 and TW2 are two affordable examples. They aren't as "pretty" and may lack the "cool factor" of the click-type. But, in my experience (which includes lots of automotive torque wrenches of all types), the "safest" and most affordable route to go for bicycle maintenance is with a spring or beam-type torque wrench.

Kind regards, RoadLight

Hi Vicegrip,

Excellent post! You're absolutely right that all of us who have replied so far have overlooked this important principle. But the question posed in the OP was not how to torque. Rather, it was a question about which torque wrench to buy and it was posed because the OP has just purchased a bike with a carbon frame. So I think we can be forgiven for omitting your valuable advice because it strays a bit off topic.

And, while on your topic, I'd like to respectfully suggest that a focus on fastener load is too narrow-minded. When working with carbon parts, the load on the parts, themselves, is the primary focus---NOT the fastener. Sure, you can include the fastener in your load considerations---and certainly the condition of the faster (dry/wet, clean/dirty) is vital to accuracy. But with carbon parts, the focus is on the load we're putting on the carbon parts we're fastening---not the fasteners, themselves. In many cases, each fastener will safely handle a greater load than the carbon parts they're fastening.

Kind regards, RoadLight

Whoa, my friend. Speak for yourself. MY CRANKS spin at 1000s of RPMs. Or maybe it just seems that way.

EDIT: Just saw that I was late on the uptake. Oh well.

It wasn't the first review, it was one of a number of highlighted reviews -- and one out of 233 total reviews.

:notamused:

Same here. I check with a torque wrench but find that tightening things so they stay put is generally well below spec.

Is anyone else using the simple 5Nm tool from Ritchey? That's all I use. This pretty much covers my stem and seatpost, which are the only spots that are carbon clamping areas. I suppose you would need more selections if you use carbon bars, saddle rails, etc...

Yes; just got the 6-bit version which turned out well since I didn't realize my groupset has half of the bolts needing a Torx head. Works great.. for those things asking for 5nm.

You are spot on. I too don't focus on the fastener load too much with respect to bikes. That is a simple calculation of bolt material and size in most cases. My point was I see this same "Which brand of T wrench is the best?" when the proper use of said tool is all over the map real world. This is not a cycling thing I see this same argument in other venues.

Fastener load is directly related to what is important, clamping force. Clamping force is the "just enough" to make what is intended to no move not move. The "not too much" part is the fastener or threaded receptacle / substrate or part failure point. In most cases we cannot measure the clamping force in ways that produce a numerical metric so we use a related method to try and get things in a reproducible range. Torque values can be used to produce proper clamping forces in reproducible ranges if the many variables are taken into consideration and controlled. (Variables such as wet or dry threads and the like) This is my point. I see people spending too much time babbling about brand and not enough time on methods. The Horrible Fright T wrench in capable hands will blow the $nap-On away in standard hands with regards to targeted results.
The load limits we are most often considering on the carbon parts with a threaded insert is fastener pull out load. This would be things like bottle cages and other bolt to the frame items. Other non insert things run the gamut from CF stems to integrated seat clamps. Too much clamping force on that form of CF device risks failure not of the bolt but of the component itself.

Clamping force is the Goal. Torque is the indirect metric used to get there.

In other venues such as automotive race motors fasteners are often the critical failure point. con rod big ends opening up, a split case block shuffling under load of head studs letting compression lift the head is bad news. In those cases the bolt is being elongated like a spring. With bikes the bolt tends to pull out or snap. We humans are just not all that strong a motor and thermal stresses after assembly are not a consideration in cycling.

Thanks for all the replies. I picked up one of these today. (Amazon.com: CDI Torque Wrench Tool with Bits: Sports & Outdoors) and plan to buy one of the Park spring torque bars in the next week or so. That should cover me for just about every need.

Exactly!

Add a drop of locktite, a dab of grease a cad plated bolt or even just spit on it and you'll change the torquing characteristics of the fastener more than the difference between the NASA spec $1,000 wrench and the $15.00 one

Yes, it was! The "Most Helpful Customer Reviews" section is always listed underneath the product description on an Amazon product page. Simply scroll down the product webpage and you'll see the reviews immediately after the rating summary bar graph. A.D.'s review is listed first because most shoppers thought it was "most helpful". I just checked again and it is still the first review.

If, on the other hand, you click on the link to view more reviews, you will go to a different webpage and the reviews may be listed in a different order. But most shoppers check the "Most Helpful Customer Reviews" section first for obvious reasons. They are the first reviews that they'll see in the main section of the webpage (not a sidebar section) as they scroll down the page.

But why are your quibbling over which review is first? If you want to buy that torque wrench---go ahead---it's your money.

RoadLight

lies, damn lies, and statistics..
Actually that first review had 6% of respondents who indicated it was an unhelpful review.
The following 3 five-star reviews had between a 3-5% unfavorable rating, which means they are reviews of higher quality, right? :)

So we've digressed into discussing the quality of the quality of the reviews of the quality of the tool? That's a little too meta even for the 41 :)

No, we are discussing the quality of the reviews of the reviews of the quality of the tool.

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