I searched but didn't find any post about it....Im sure there are.
Whats your opinion on using torque wrench's ?

I'm new to bike maintenance and just wondering if I should invest in one...or get a couple of preset ones
I have a Cannondale Synapse Carbon Disc.

Thanks for any suggestions

I'm surprised a search didn't find anything since there have been dozens of threads on that very subject here.

Briefly, yes, a torque wrench is very valuable particularly for a novice mechanic and even more particularly when working on carbon components.

Ideally you will need two of them, a 1/4"-square drive for small fasteners requiring low torque values and a 3/8" or 1/2"-square drive for higher torque requirements. "Beam-type" wrenches are lower in cost and less likely to go out of calibration with out being noticed. "Click-type" are more convenient but more costly for good ones and have to have their calibration checked periodically. The preset type are much more limited to basically one job each.

I think that a torque wrench is a must for any carbon bike or carbon component. A torque wrench is the only way to be sure that you have the proper torque without "strong-arming" it. Torque wrenches come in all sizes and flavors, and if you are serious about it, Park Tool and other sources will give you a generalized list of torque values for any particular application, i.e. pedals, etc. IMHO, proper torquing of your bicycle assembly makes for a better bike.

You'll probably guess that I am a huge fan of Park Tools. They have any torque wrench to meet your needs, so no reason to look elsewhere. I say this, because their tools are tried and true. A chinese torque wrench may work okay, but I think its hit or miss on quality. Buy once - cry once is my motto.

Yeah, you ought to have one. And I'm not talking about a big one that you use on the car that torques starting at 5 foot-pounds up to 80 foot-pounds. You need a smaller one that measures well below that in inch-pounds (or Newton meters (Nm)). If you get the pre-set style I think you're kind of limiting yourself. With the adjustable torque handle you can use all the sockets and hex attachments that you already have. I think the most popular style is the "click" type. That's what I have. But I don't like it. Often times I can't hear/feel the "click" and don't know if I'm over-torquing. I keep telling myself that I'm going to invest in one with a digital readout, or perhaps even and old beam-type.

Dan

A torque wrench is a must when working on a bike.

https://www.amazon.com/dp/B01LX4ND65?psc=1

Carbon frame and components? Yeah, you're going to want a torque wrench to make sure you don't over-tighten a fastener and crack one of those expensive carbon fiber bits.

You don't need super fancy ones. Inexpensive beam-type torque wrenches will generally serve you just fine.

The most you'll need is 300 in-lbs.

When I went to bicycle mechanic school (yes, there is such a thing), we worked with both the beam and dial types. The beam type is better for bigger jobs but not always convenient to use because it's visual only. The dial type is more tactile, clicks when you get to desired torque, but it must be zeroed out between uses.

In the end, I went with an electronic transducer type, the Topeak d-torq. Digital display where you set the recommended torque. It beeps once when you reach the set torque and then beeps again if you exceed that torque, so it's pretty foolproof. Plus it doesn't need to be zeroed out between uses.

One other thing. Torque wrenches tend to most accurate in the middle of their range and less so at the extremes. There are two variants of the d-torq for different ranges, and I selected the one where the torque values I worked on most fell in the middle of the range for that wrench.

I just got this one on sale from Performance (who charges $34 more and puts "Spin Doctor" on it). I was putting carbon bars on my son's bike and decided to bite the bullet. I'm really glad I did, because 5Nm of torque is noticeably less torque than I thought. I used to just wing it, but no more. And btw, I considered one of those fixed 5Nm wrenches for considerably less, but when I was working on his bike I noticed his carbon seatpost requires 8Nm.


https://https://smile.amazon.com/VENZ...ue+wrench+5+nm

I've got a big torque wrench also, purchased for my motorcycle wrenching.
Question for you bike forum mechanics - how much torque should I use to tighten down the end bolt holding the crank arm to the spindle of a square taper crank? It's an 80's Peugeot, if that matters, and it keeps loosening on me. I'm planning on using Loctite this time around. I was going to use a huge breaker bar, but remembered the large torque wrench in my garage.

They're prudent for things which require little torque and break when too tight, most notably screws that clamp hollow carbon fiber parts like seat posts, handlebars, and fork steerers.

They're a good idea for things which need to be tight enough many people need some encouragement to pull harder. Cassette lock rings, crank bolts, finicky saddle clamps, etc.

Crank arms (even most splined ones) have tapers, and if you don't get them on tight enough they'll wobble, the hole will open up, and you won't be able to make them tight enough to stay on until you buy replacements.

Some saddle clamps are fickle and slip when not torqued disproportionally tight with assembly paste only helping a little. Some snap bolts perhaps due to torque. Having finished too many rides with my saddle in an uncomfortable position or detached I switched back to more reliable seatposts (Campagnolo C-Record posts stay put with a normal tug on a 6mm hex key, have no teeth limiting angle, and just work).

40-50 NM for cassette lock rings and bottom brackets is 350-450 inch-lbs.

450-550 kgf-cm for crank bolts is 400-500 inch-lbs.

Usually you end up with two for bikes - one for small screws (like 5 NM handlebar clamp screws) and another for big parts.

1/4" drive is for the small stuff , mostly you will take the thread out of the Composite or aluminum,
before the steel bolt goes
fancy pre sets will set you back quite a few Euros..

Torque spec for external bearing BB is another story 3/8 " beam torque wench
Tight, its the top of it's scale ..

I have a Harbor Freight for higher torques like pedals and a Pedro's Demi for smaller parts' 2-14 nm needs. Some places sell the same one as a Pedro's but for a lot less--compare pics/specs. I also use a couple pre-set torque keys for 4 and 5 nm for convenience. I've tested the keys against the Pedro's and they match up.

This^^^

I started using a torque wrench for crank bolts and bottom brackets when I became aware of the frequency of people having the left crank arm fall off of their square taper bottom brackets. Most of those take around 30 ft/lbs. That's quite a bit more than I'd use if left to my own judgement.

At some point I became aware of folks ruining expensive high end aluminum and carbon fiber stems by over torqueing the bolts. I was surprised at how little torque is specified for those components. Left to my own judgement, I'd over torque them.

I've usually went by a Pain index hand on the handle of the 'Peanut Butter wrench' on my old Campag cranks 15mm head bolt..

the torque wrench is a bit more professional.. and most importantly "how tight" IS A STANDARD UNIT OF MEASURE .

1/2" drive gets used to get the cylinder head tight enough on engine overhauls

Yes... I have been humbled... Several times I have checked the tightness of a part and found the tightness to be way off (My Bad)...

The "ChiCom Outlet Harbor Freight Torque Wrench" works just fine on steel but I am not sure on Carbon...

Here is a table I extracted for torque specs on older steel bikes. Its a compilation of several tables...

https://www.bikeforums.net/classic-vi...que-specs.html

Also note, after many years I finally got a spoke tension meter and was humbled again...

A few answers here:
https://www.google.com/search?q=site...e+wrench&cad=h

I rarely use them. When I do, I am sure to use torque grease. I hook my hanging scale on a wrench and pull to the desired value. No need to spend money on another tool.

I suggest that the OP have an experienced mechanic show him the basics of how to use and care for a torque wrench.

It can be highly inaccurate if used incorrectly and can easily be knocked out of calibration.

protip: for click type wrenches always lay them down with the socket side up and loosen the tension (set to zero) when you store it.


-Tim-

Same here, but were did you find a 15mm socket to fit that bolt ? A standard socket won't go into the cavity.

Thanks KB

There's a couple different types of Torque wrenches you need to consider... First off your avg Torque Wrench you see is usually rated for 20-100 Ft/lbs which is slightly overkill on a bicycle. What you need is a torque wrench that measures in "Inch Pounds" notice I said Inch and not Foot Pounds. This will take care of small things like stem bolts.

The two main inexpensive types of wrenches you will encounter are.

First off the old fashioned "Beam Wrench"
Pro's: CHEAP!
Cons: There is actually special techniques you need to know in order to use it. so it doesn't give a false reading.

2nd and your best bet: "Click Wrench"
Pro's: 100% easier to use then a Beam wrench.
Con's: More expensive, and can loose calibration over time
(What ever you do never loosen or break loose a bolt with a click wrench, it can really mess up the calibration.)

There are other Torque wrenches like digital, dial, or split beam. etc But these are usually quite expensive.

I have a Snap-On click type torque wrench that I have been using on bikes since the '70s. The Snap-On tool truck has a device they can use to test the torque wrench for accuracy (but they have to send them off for actual repair or calibration). My wrench has always checked out OK on the truck test.

At a job I had in industrial maintenance, we used torque wrenches made by Precision Instruments and found them to be of top quality. (I have heard that is who makes the ones for Snap-On). We had to send them out yearly for calibration and we used a company called Team Torque who had reasonable prices and quick turnaround time.

When it comes to tools, paying a little extra for quality pays off in the long run.

So this would be a decent wrench? I need one myself..

That much? Holy smokes! I was only going by pedals. Honestly, in my new torquing endeavors I have not reached the point of bottom brackets yet. I usually refer to the Park Tool website to find out how much torque I need for a given application. Anyhow, thanks for the correction.

Haha! Pain Index - I havent heard that in a long time. I was an aircraft mechanic in the USAF. EVERYTHING had to be torqued. We used the term "Pain Threshold," when we were to lazy to go back to the tool crib and check out a torque wrench.

There are instances where Park and the manufacturer don't agree on the spec.

I always go with what the manufacturer says if they make specs available.


-Tim-