Dan Burkhart 

Correct. Especially essential with aluminum freehub bodies. I see it too often in the shop when a lock ring comes off easier than it should and you have to pry the sprockets out of the bite marks they left in the freehub.

xroadcharlie

Funny you you should ask. When checking reviews of the SunRun 7 speed cassette I had installed on my comfort bike last week, Most reviews where pretty much what I expected. While it works fine out of the box, durability is questionable.

But there where some complaints about it malfunctioning, and falling apart. Perhaps they simply didn't torque it down enough. Hopefully the shop I had the work done at didn't make the same mistake. This is probably a freewheel so it might not be the same effect for a cassette.

zandoval 

I just tighten the cassettes down by hand. Never had a problem. I do though use a Torque wrench on a few other things. I definitely use a torque wrench on my Crank Arms. I am using the torque wrench more often now that I am loosing strength in my hands and arms due to age.

I think that with modern bikes transitioning into exotic materials using a torque wrench more often will become necessary. It's more then just Steel to Aluminum as we now look at Carbon, Titanium, and Chinesium alloy material combinations. Do note that you do not need a fancy Torque Wrench. A 20 USD Torque will do provided you check its calibration. Torque specs on a bicycle are ball park figures. I usually go just to, or slightly under, the recommended torque.

I recently compared my 50 year old Sears analog torque wrench to my neighbors new digital and found it amazingly Spot On!



Sears 70s Vintage

Also note that finding proper torque specs on a new bike might be very hard. Here is a list of possible torque specs I put together a few years ago. The table is scavenged from multiple sources on the net. It applies to older bikes with Steel to Steel and Steel to Aluminum. Hope this helps.

Basic Bike Torque Specs

Kontact

No, you just misunderstood:

YOU were assuming that the ring wasn't tight enough and suggested tightening it a little more in your post. And I'm saying that the ring needs to be at full torque from the get-go, and that adding "a little" might not get it there if you seriously undertightened it in the first place.

And I'm not saying you have to use a torque wrench, I was using torque values to illustrate that Not Tight + A Little More = Too Little Torque.


Unlike washing your hair, bike parts get damaged when not assembled correctly the first time - so I don't know why trial and error would ever be considered an acceptable methodology for tightening drivetrain components. Loose lockrings, loose pedals, loose QRs, loose crank bolts and loose BB cups lead to often expensive damage.

Iride01 

Still in no way did I say something should be tightened less than what it needs to be. And that won't always be the specified torque which many times it just the maximum torque that should be applied or else exceeding that means you are risking damage, deformation and breakage.

However, my advice was for what one should do if they find something loose. And I would think that if one tightened it too loose the first time, then they haven't achieved the level of experience to sense when things are tight enough and about to risk that damage, deformation or breakage. So tightening more than before will give them the experience to continue leaning.

While you make the good point that there will be some damage to the free hub, it isn't life threatening, nor will it necessarily require immediate replacement of the free hub body. It's mainly an ugliness that might make it difficult to remove the cassette and I suppose some rings might clock to a slightly less than perfect position for the optimum shifting that the mfr. built into them.

If I was to use your method of tightening them tight as I could get them without any previous experience of what tight was for a nut or bolt of a particular size, then I'd be breaking the item I'm tightening or the wrench. I've broken more that a few breaker bars. But not on a bicycle.

Kontact

I have never seen a freehub body stripped out or otherwise destroyed by overtightening the lockring. It is certainly possible, but not much of a danger considering that cassette spacers are plastic.

Some torque numbers are limits - like stem bolts on a carbon steerer. Others are recommendations to make sure you get in that range. A little above doesn't matter.


Yes, some people have no feel for the tools they are using. They can either learn from someone else, use their own deductions based on the length of the wrench handle supplied, or use a torque wrench. Bicycle mechanics aren't egalitarian - some people are going to screw it up if they have no prior knowledge or aptitude.

squirtdad

that is about right and 40nm is way more than you think it would IME I use a beam type torque wrench for this

as for everyone saying don't bother with a torque or get it tight enough, there is a reason a manufacturer specifies the torque needed, so why not follow it?

even small bolts like cable clamps take more forces than I had been using by feel.

Kontact

Mainly because there is so little danger of over torque. If you make an honest attempt to get the lockring real damn tight with a 1 foot wrench, chances are that you did it right. It might be 37nM of 49nM, but it will hold correctly and not be damaged.

Torque wrenches were never much of a thing in cycling until carbon steerers and bars came along.. You'll even note that many crank/BB torque specs are actually huge ranges rather than a specific target.

If you have a question about how tight and you already own a torque wrench - why not use it. But if you have an adequate idea of what is required and you don't already own a $50 tool, why are you failing to install your cassette? Grease it and firmly tighten it down. Just like pedals.

Mr. 66

I guess there are houses built screws, most studs are installed with nails.

Kontact

And the same principle applies: The boards are locked together by the tension in the nail. If the nails were loose they would shear off.