1 Thing ALL Home Bike Mechanics Should Know
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- čas přidán 16. 05. 2024
- A demonstration of how grip position on (some) torque wrenches matters. Good info for all home bicycle mechanics.
The math behind the phenomenon:
• Why GRIP Position on T...
2:55 Thx, @PeakTorque for the quick cameo
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www.thebikesauce.com/ - Zábava
Nerd alert!🚨 Just kidding. I actually appreciate you going down the rabbit hole a bit and explaining in layman’s terms how click type torque wrenches work.
This guy will find a way to use math in EVERYTHING.. i hate math
Props to going an extra mile for all the disbelievers!
One more counterargument for them might be "yes, torque is torque, but what the scale shows is not torque, but spring preload". I think this argument is a good gateway to concept of indirect measurements and basis of powermeter inaccuracy
for a beam style torque wrench it is absolutly crucial to hold the wrench in a specific spot. that's the reason why they have either a ball for a handle or a handle that is on a swivel. there are dial indicator torque wrenches where the moment arm doesn't matter, because the interals are indipendent from the externals.
the funny thing is, i tried to explain to one of my high school theachers that it does matter where you hold a click type torque wrench, but he coulnd't unterstand the concept of it. after about a 15 minutes discussion i gave up and said forget about it.
Yea you’re right about the ball handle on the beam style wrenches. It’s bc of the deflection profile in the beam yea?
I need to borrow that digital torque meter to calibrate my hand.
Another awesome video that provides an easily understandable explanation based on scientific principles. Kudos. And I love the flashing reference to Peak Torque. 😂😂
Great explanation and demonstration. Thanks.
Thanks. Your torque wrench videos have been very helpful.
I never knew this. Well explained, thank you!
Excellent, great information. Thank you!
great video. Thank you for presenting this information.
great video thank you
Please keep up the nerdy tech stuff! You are excellent at explaining these kind of things in a straightforward concise, yet entertaining manner!
God, I love these nerding out videos. Please keep them coming!!!
You make excellent videos. Thank you.
This is great. I always wondered about this with my torque wrench.
Hahaha peak torque, I’m glad you watch his videos or know who he is. I love his videos as a fellow engineer
Solid channel
Fascinating, Captain. Absolutely fascinating 😂
Excellent sir 👍
Well done!
Didn’t know that, thanks for the info!
Why I love your channel.
A lot of very good information in this video!…thanks for making it and sharing it with us!…😎
Whoa! Clear thinking. Clear speaking. You da man. You’re an outlier on YT - not to mention the planet. Your video production values are a treat. Thanks.
Good video, thanks!
great content, thanks!
Love the science videos.
Thanks for your info, I committed this mistake for a long time
Awesome explanation and it is great you are sharing this. I am an engineer and fully understand, also the readings can also be affected if you have an extension on the socket as well.
Cheers
As a professional bike mechanic and a CZcamsr, this is awesome! Great job!
Good info
Spat my coffee out with the pic of Peak Torque
😄 credit where due.
I knew, but totally forgot 😁
so thanks for the reminder!
You blinded me with science! :)
So use the handle I guess😊
Enjoyed the demonstration.
Now I understand why I torqued some bolts wrong to even snap. Thanks.
After watching your previous video, I bought the beam torque wrenches and called it a day.
My mind is blown, thank you
Nerds own torque wrenches. The ultimate nerd owns a torque meter lol
😆 I suppose you’re correct
Well done. Great hat too. I want one.
@skratchlabs is where I got mine 🙌
Thank you for the link and for taking time to reply.
this episode is good, I thought the shorter arm to the torque head will have lower force, but actually opposite. lmao, thankful I didn't damaged the carbon parts. I always use the left hand push the torque wrech haed to the screw and use the right hand hold the edge of the grip at the far side.
Great explanation! Physics wins again!
Hey, awesome videos on the science behind torque wrenches. Recently, I had to use a crowfoot attachment on a click-type torque wrench which extended the length from pivot point 33mm (center of the drive to center of the crowfoot wrench). I could not figure out, how to properly set the torque wrench to get desired torque on the bolt. I am still scratching my head, do you have any ideas how to calculate the proper set torque?
Great video as always, now let's dig deep and talk about how lubrication effect torque values, are stated torque values for bicycles meant to be dry or wet, most stem bolts, seat post collar bolts, seat clamp bolts, and brake caliper bolts that come on bikes are dry (maybe with some thread lock); Apparently using lubrication will reduce the required torque by 25-40% 🤔, can we have a video about this please ✌
🤔 interesting
It's always great, when you can prove something in an experiment.
I saw the "nerd-out" video a while ago and agreed with the math. Today I thought that something doesn't 'click' o-) If the the distance from pivot point to clutch is constant and the outer handle is rigid, it should not matter where you hold it. And it doesn't - for the clutch mechanism. In your experiment, we see a recorded maximum torque, so it gave me another idea. When the wrench clicks, the inner beam strikes into the outer handle. I had an idea, that when we put pressure on a wrench by hand, and then it slips (clutch disengages), the overall maximum torque at the moment of the inner beam striking the outer handle is greater than at the moment of "the click". And this impact would be bigger when we shorten the handle, use more force, and have less control. And also, with a longer handle and more control when using less force, the strike could not exceed the torque at the moment when the clutch disengages. This might be accounted for in the calibration process, for the correct handle length. That was my theory for why the recorded maximum torque value changes with the change in handle length. I still agree that the wrench needs to be held at the right length.
But then I did two things.
I watched the previous video again, and yep - you are completely right o-) You say that there is no difference for the clutch where you grab the wrench. But it is calibrated to take into account the distance from the pivot point and socket axis. Which could still be in line with my theory.
I watched the experiment at 0.25x speed to see that the torque value exceeded the setting BEFORE the clutch gave away. Making everything correspond with the math and busting my weird ideas. Good job.
I got a chuckle out of the “Science” hat. I was going to say that the last video in this was the scientific one and this was not. But wrong
You’ve just ventured from theoretical to experimental science 😂. Nice demo to make it real. The torque math video was actually how I discovered your channel. As much as I enjoy the channel (You’re on my ‘must see’ list when they come out), I’d love to see a bit more science content. Maybe on material use in bikes? Keep up the good work m
I find that the other potential issue I have with the Park Tool one is that its clicks aren't always very distinct. Have to admit I've been eyeing that expensive Wera SafeTorque just because it physically won't allow you to apply any force past the limit you set it to.
Very well done video!
What about my Effetto Mariposa Gusta Forza torque wrench?
Thanks, Dave
Yep, looks like it’s the same fundamental technology. The key is that pivot point that goes through the main shaft just below the head.
Absolute facts, thanks for the examples! This definetively will save a lot of carbon parts out there.
Can you do a video on good budget torque wrench.
Good idea
Great video. Is there going to be a test on this? If so, please send review materials.
😄 please review the course notes for specifics
Well damn, I knew there was a right place to hold them, I just thought it was at the very end. Mine doesn't have a clearly marked better location to hold. I'll have to see if there's a manual somewhere.
How about spokes?
What’s even going to throw you for a loop, the friction within a threaded interface is inherently nonlinear to where +/-25% is a reasonable estimation of the preload generated by a torquing operation.
Message received, but a digital torque wrench! 😁
Great video, thanks!
My digital torque wrench (Shimano PRO) uses a pivot like the click-style torque wrench. I was under the assumption that because of the pivot, it still requires the practice of applying force at the correct spot on the handle. Correct me if I'm wrong, as you stated it doesn't matter for digital torque wrenches.
Hmm, well the fact that there’s still an offset pivot suggests that maybe in this case it actually is length dependent
❤
can you compare dry vs wet torquing with the torque meter too?
Wet torquing sounds like it might get flagged by CZcams
Are the T-handle, preset torque wrenches length-dependent or independent? In tight spaces I tend to use my fingers on the end of the handle, and I'm worried that it might affect the torque applied.
Preset torque keys are independent. You just keep tightening until it clicks or slips. They're great if you're dealing with just one torque spec or if you deal with said torque spec frequently.
That's why I got my 5 Nm Prestacycle Pro TorqKey (clicks then springs back upon reaching torque spec). That, and I'm also lazy to keep whipping out my 1/4-inch torque wrench whenever I'm doing cockpit refinement work as I don't want to keep winding it up and down.
Do we know they’re independent? Probably depends on the mechanism they use.
No need to be a nerd, just read the documentation. I typically use bestool kanon japanese torque wrenches, they have a ring on the handle that you put your finger on to torque it accurately within 3%.
Ever use a T-handle type? wonder how it would compare in your fancy machine
Funny you mention that. Fergus from Ritchey gave me one to test out because he was curious too. I’ll report back
Also, I believe, that the actual force applied to the joint also depends on whether the bolt being tightened has been greased or not. If it hasn’t, then a portion of the applied torque is applied within the bolt itself rather than the joint. That reduces the amount of force actually applied to the joint.
its the friction coefficient that changes within the thread. the lower the friction coefficient the lower the force needed to loosen the bolt. using grease the applied torque has to be higher. therefore grease does not affect the applied torque.
I have a B.S.M.E. and am licensed professional engineer. This topic of torque was a problem we explored and tested in college.
I will begin in general and then provide actual engineering to discuss in more details of what is actually happening.
When you torque a fastener, you are applying a "clamping force". The bolt stretches and maintains the tension when torqued to the correct specification. This tension locks it in place. On one hand, failure to use grease will increase friction and make it less likely to loosen, however, on the other hand failure to use a lubricant may prevent you from actually achieving the desired amount of clamping force. The proper amount of clamping force will allow that fastener to work as it was designed to perform. Too much clamping force applied will cause the fastener to not work as it was designed to perform and the fastener will be rendered useless.
Both clamping force from bolt stretch as well as friction will help prevent loosening but clamping force is more predictable and thus the standard used. If you want to increase friction you wouldn't remove the grease and run the fasteners bare, you'd instead use a thread locker of your choice which increases the contact/surface area between the threads and allows the clamping force to maintain.
Now the actual engineering to discuss in more details of what is actually happening.
This can best be explained by the following videos:
czcams.com/video/kTwpA2yJ81o/video.html
czcams.com/video/fN9b3ByRh7A/video.html
czcams.com/video/Jq38Oe6lMEg/video.html
czcams.com/video/g_CdH3RJc04/video.html
czcams.com/video/i9SJbCCoACg/video.html
From my experience, I tend to used grease on fasteners that are 5mm or larger. I ONLY add grease to the lower threads (yes it spreads to the upper threads) and do NOT apply to the base of the fastener head since that friction is also required to keep the fastener in place. I use thread locker on fasteners that are 4 mm or smaller. Your results may vary.
Probably way more than you want to know, however, you asked and I answered.
-Larry
200nm Torque Wrench!!! What the hell do you use that for!? 😅
The awesome part: there’s a special instrument just for measuring a torque wrench’s torque.
But what calibrates the machine..?
I love it, Wera rules!!!!!!!
The bad thing about Wera torque wrenches is that they can only go 1 way! Some other brands do this also, but you can’t torque counter clockwise. It doesnt matter all the time, but doing something like installing a UDH is not possible. Love Wera and own their stuff, but I don’t like their torque wrenches. The Unior digital ones are the best I’ve used
Oh..I actually take my new torque wrenches (simple ones) apart, and using weights on string, clamp the wrenches into a vice and calibrate them myself...using a known weight at a known distance from the center of rotation, not the trip mechanism offset point, wrench held level in the vice, weight gradually applied till the weight hangs free. Loosen or tighten the spring till the torque reading is close to what the math says it should be. Seems to work...
But it only works if your string is tied in the correct place around the handle.
Do your new wrenches arrive uncalibrated?
The wrench I bought wasn't very $$ and was for lower torque values. I wrapped the string holding the weight (which I had calibrated at a supermarket!)at the very end of the handle, clamped the wrench socket holding pivot point in a vice with the wrench end at about 80 degrees from the vertical then gradually allowed the weight to hang free such that the "tripping" juuuust ocurred when the weight wasfully applied. Moving the string closer to the pivot point resulted in the same weight NOT tripping the wrench. Must be close to being adusted correctly!! Better than it was "out of the box" (I hope).!Wrench is a Lowe's Kobalt 1/4" torque wrench.@@iliinsky
Yes, you have experimentally verified that where you apply pressure matters. That is entirely compatible with the point of this video that is that force position on the handle matters and you will get different applied torque at the same click rating depending on where you put the pressure on the handle. A better process would be to hang the weight from the intended pressure point in the middle of the handle.
Most torque wrenches are spec’d to around 4% accuracy or better at the factory. I’d be curious if yours remain that close after your recalibration.
Haha! Peak Torque!
This is a great video, but you picked the wrong title IMO. This video is much more interesting to tool lovers, or just DIY'ers in general, not just home bike mechanics. I'd have titled it differently. Something like "Here is why a Torque Wrench Is Not Always Accurate" or similar. It's catchy, and it's aimed at a wider audience. Not really a criticism though, more so advice as your video is super helpful to everyone, and I really enjoyed it. Great video though. Thank you!
Thx! I considered the audience as well. I intentionally niched down to bike mechanics bc similar vids exist in the general / automotive space
@@TheBikeSauce Fair enough. You nailed the video though. Great job!
This is interesting but in what scenario are you ever going to hold the wrench in any other place than the designated handle?
There’s a long standing debate about using extensions. Also this same concept applies to using a crows foot. Should be basically 90 degrees so you don’t affect the pivot to axis of rotation length
One of my ex-colleagues chokes the torque wrench. Worse yet, he spam-torques. Worst of all, this torque wrench's calibration is already off, only a few months after it started seeing use. Nobody resets it back to the lowest setting when it's not in use other than me, but because I already have my own (still in-calibration to this day), I could care less about the shop's. Their problem, not mine.
The torque wrench in question, is an Effetto Mariposa Giustaforza 2 - 16 Nm torque wrench (no ratcheting head).
What about the double click people do.. or when you turn the torque wrench with too much speed and or force if that makes sense.. im only saying that because im a diesel mechanic.. and those I've heard and seen that give you an inaccurate torque..
Unless youre doing headbolts or something, double clicking really doesn't matter. Might over torque stuff but its so minimal i would say it doesn't matter if youre only changing wheels oil pans or something. If you use too much force/leverage/speed whatever, youre gonna over torque or just break the torque wrench lol
What about the length of the socket/bit?
That post doesn’t contribute to the applied torque, so you don’t need to consider it
Digital Topeak torque wrenches are length dependent.
Interesting. Do they have an offset pivot?
Yeah? But what is a Nooten?
😆😆
a bit lower won't damage the parts at least, a 'bit' higher will.
Yes! It does seem that way. The math in our previous video agrees with that finding as well
Park Tool weighs in: czcams.com/video/nc6fqnF5T2A/video.htmlsi=nKfcFDtADJVpfccn
Ha! Funny that video was just released. Wish they’d link my derivation / explainer vid 😄
Torque, shmork.
I’ve never used a torque wrench on a bicycle.
🤯🤯🤯
So much pain to own a carbon frame...
I was ready to call it BS until you slapped me with the real torque meter. I don't like this loss at all.
😄
After some amount of experience, you learn how to torque your fasteners by feel, disregarding your torque wrench. Probably not for head bolts, but certainly for most fasteners... and certainly for all fasteners on a bicycle.
This is the long explanation o why I always use the old German spec on my bike and cars - guudentite
This is not your forte, try something like 🤷🏼♂️
& with that pissy little vice on your wobbly looking workbench, I should trust anything you say?
😂😂
I know, I know, we all have ADHD; but jeez man, maybe ease up on the edit breaks.