Torquing the pedals on -- what special tool is needed?

xtinctionRebeller

xtinctionRebeller

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I have a bit of history of pedals coming loose while riding and getting stripped. The manual of my latest bike states (page 14) that the pedals need 37 +/-3 NM of torque. I'd like to get this right so I don't continue to have problems.

How do you install pedals at a measured torque? Obviously a pedal wrench is useless. I'm thinking I need something like this:

th


but the attachment cannot be that thick.. it has to be thin enough to fit between the pedal and the crank arm. I'm also not sure if I can trust the torque setting with that kind of attachment (edit: yes but must be 90 degrees). Also, I think the torque wrench needs to work in both directions, correct? Although I can probably change cranking direction on the pedals just by flipping sides on the reverse threaded left-hand pedal, that trick wouldn't work when torquing the crank arms.

Anyone know where to get the proper tool?
 
Simply attach the Tork-Grip to the pedal wrench https://sheldonbrown.com/tork-grip.html
 
You don't need to actually measure the torque for pedals you just need to put them on tight enough. There is a decent range of torque between tight enough and stripping the threads. Stop using the wrench like a girl!
 
I was 10-12 when I was getting the pedals on and off just fine. Short handled wrenches at that. 37 foot pounds ain't much.

Out of curiosity is it both pedals that come loose, or always the same side? The thread direction reverses for the opposite sides, they should both be tightening as you pedal. This is a curious situation indeed, I don't recall anyone having pedals come off the crank completely.
 
you don't need a torque wrench for this but you do need a good quality pedal wrench.. grease the pedal threads and tighten your pedals as tight as possible using a long pedal wrench.. then use the rear wheel as a lever and tighten them some more (they may even dig into the crank alum a bit) .. in other words position the wrench, hold firm and then turn the rear wheel backwards and the pedals will tighten via the chain with this added leverage.. recheck crank and pedal tightness after first few rides..
 
I found this video:

http://mfqczy4mysscub2s.onion/watch?v=LFbSBG7jMzY

It shows the pedal wrench technique and also shows that those [strike]open wrench socket mahoochies[/strike] "crow foot wrenches" work. He says the adequate torque results from 10 inches of turn once it's finger tight (I think). I'm tempted to buy a torque wrench anyway, for tightening the crank arms and also for the lug nuts on a motorcycle. So I may try to track down some open wrench sockets that are thin but not too thin. (edit: found one).

I'm also looking to buy a bike tool kit (budget ~$250). They all have inadequate torque wrenches. This kit has the best torque wrench after an extensive search, and it's limited to 24 NM.

This thread has several people telling someone not to torque their pedals on, but I'll be scrapping that advice. Replacing stripped out crank arms (or rethreading them) isn't cheap.

Dauntless said:
37 foot pounds ain't much.
Click to expand...
It's 37 newton meters actually.

Dauntless said:
Out of curiosity is it both pedals that come loose, or always the same side? The thread direction reverses for the opposite sides, they should both be tightening as you pedal. This is a curious situation indeed, I don't recall anyone having pedals come off the crank completely.
Click to expand...
It's always the right-side pedal that comes loose for me. Note as well that it was always a pro bike shop that installed the pedals, not me. I've also seen other cyclists pedals fall off when riding in a Critical Mass event.

@efMX - thanks for the tip. I was half tempted to grab this kit but now that you mention it the pedal wrench looks like junk.
This looks better.
 
I had the problem of wheels coming loose even when I tightened them and put grease on. I have a few threads posted. I just use blue loc-tite now and tighten them a lot by feel. I know everyone will say use grease or lube, but blue loc-tite is actually working for me. I have broken a half dozen crank arms due to the pedal coming loose, making the whole 1pc. crank useless and the arm useless. Blue loc-tite I havent had one issue at all. I have even taken the pedal off easy enough, I had it on through winter, then taken it off, was easy.
 
using the rear wheel as leverage to tighten the pedals on (with the bike in the stand) is key.. not sure if you understand it but the pedals need to fully bottom into the crank threads, that's not easy to do without grease, a long pedal wrench, AND the rear wheel used as leverage all together.. unless your arnold schwarzenegger;)..
 
xtinctionRebeller said:
markz said:
I have broken a half dozen crank arms due to the pedal coming loose, making the whole 1pc. crank useless and the arm useless.
Click to expand...
Perhaps it'd be worth it for you to get one of these tap and die bushing kits. (procedure)
Click to expand...

I have broken mostly used gear, I bought a box of used cranks, arms, and gears about 2 yrs ago. I did break Cyclone freewheel arms, and new Shimano Tourney 1pc 3 gear crank (some have bolt on gears), the rest are old, used components.

Tapping the old holes would make them larger, good for the smaller pedal thread.
Most pedals have 9/16" x 20 tpi threads.
Pedals for one-piece cranks are 1/2" x 20 tpi.
I have one or two single, not paired 1/2" but the rest of mine are 9/16.
 
efMX Trials Electric Freeride said:
using the rear wheel as leverage to tighten the pedals on (with the bike in the stand) is key.. not sure if you understand it but the pedals need to fully bottom into the crank threads, that's not easy to do without grease, a long pedal wrench, AND the rear wheel used as leverage all together.. unless your arnold schwarzenegger;)..
Click to expand...

I have a hoist for storing the bike, but it may not take much extra pressure. I might try your technique with the bike upside down.. if I don't end up getting the crow foot. I'll have to wing it since none of the videos I've seen make use of the wheel for leverage.
 
xtinctionRebeller said:
efMX Trials Electric Freeride said:
using the rear wheel as leverage to tighten the pedals on (with the bike in the stand) is key.. not sure if you understand it but the pedals need to fully bottom into the crank threads, that's not easy to do without grease, a long pedal wrench, AND the rear wheel used as leverage all together.. unless your arnold schwarzenegger;)..
Click to expand...

I have a hoist for storing the bike, but it may not take much extra pressure. I might try your technique with the bike upside down.. if I don't end up getting the crow foot. I'll have to wing it since none of the videos I've seen make use of the wheel for leverage.
Click to expand...

Yeah you just rotate crank until the direction of the pedal tightening counteracts the direction of the wheel, so the wheel is locked when you pull on the wrench to tighten it or loosen it. Can also throw in a steel bar so the arm hits the metal thats resting on the chain stay. Lots of ways to skin the cat bro.
 
it's from decades of bike shop work.. when you assemble hundreds or even thousands you don't want them coming back stripped out.. cranks are easy to over-tighten (without torque wrench) pedals are not.. bc threads need proper bottom to tension as opposed to press fit cranks which need specific torque.. upside down bike should work, report your results when done..
 
aroundqube said:
Simply attach the Tork-Grip to the pedal wrench https://sheldonbrown.com/tork-grip.html
Click to expand...

That's an interesting hack, though I don't have much confidence in vice grips. I'd prefer this hack if it weren't absurdly overpriced.

main_2126257842_20170816032307.jpg


what is a "one way" torque wrench, and how can we avoid it?

I was under the assumption that torque wrenches were like rachet wrenches in the sense that you can pivot a switch to crank in either direction. But then I discovered some torque wrenches are described as "one way". What does that mean? It seems to suggest that it can only tighten clockwise, which would make it useless for tightening reverse-threaded bolts like that of the right (drive-side) crank arm. Yet when I look at a torque wrench marked 1-way, it still has the switch on it:
J2yCTTY.png

What is that switch for if the torque wrench is "1-way"?

So I'm a bit concerned that I could order a torque wrench that is not labeled as "1-way" or "2-way", since most are not labelled as such, and end up with one that is only 1-way.
 
efMX Trials Electric Freeride said:
that's a two-way, non rachet torque wrench..
Click to expand...
I assume you're talking about the one in the picture. The one I linked must be a rachet.. otherwise what purpose would the switch have? BTW, this one looks like another exceptional 2-way racheting torque wrench, which the seller calls "reversible" (which unfortunately means I have to search for "reversible" and "two way").
 
efMX Trials Electric Freeride said:
the pedro's is a nice tool.. two way torque :thumb:
Click to expand...

Indeed it looks good but my motorcycle lug nuts need 108 NM and I'd rather not buy two torque wrenches.

I noticed this pedal wrench has a square hole apparently to attach a torque wrench to, but they don't tell us how big the hole is.. so we can't be sure what it's there for. Many of the Park Tools pedal wrenches cut a tear drop hole for no apparent reason.

main_2126249700_20170210033612.jpg
 
efMX Trials Electric Freeride said:
motorcycle stuff tends to be larger diameter, higher torque fasteners than pedal bikes.. thus different tool for different job..
Click to expand...

Why would I need two different torque wrenches? Certainly there are adapters from 1/2 inch to 3/8. This one is two-way and covers the torques needed for bicycle crank arms and motorcycle lug nuts. My only issue with it is it's not quite low enough in the torque range for pedals.. but maybe I'll use your approach on the pedals without torquing them.

Note as well that I'm struggling to trust some tools that are designed for bikes. E.g. this VENZO Bicycle Torque Wrench is part of some bike tool kits, and yet it's apparently 1-way and can't be used on the reverse threaded bolts that we encounter on bikes. And the torque range misses the pedal and crank arm torques. This Icetoolz torque wrench also hopes to cater for bicycle maintenance; it has the right torque range but still doesn't handle reverse threaded bolts.
 
CDI, I found my mid sized wrench "like new" used on ebay for not much more than the cheap ones! New, around $130. Treat yourself. Went without and used the cheap beam type for years that suck unless you can get in a good position to pull comfortable and see the scale with any accuracy. CDI provides tolerance spec. for both directions.

Even one well used is better than the cheapo breako types. https://www.ebay.com/itm/CDI-TORQUE-PRODUCTS-752MFRMH-3-8-Drive-Micrometer-Torque-Wrench-5-75-LB-FT/164145510761?hash=item2637d5b969:g:N4wAAOSwIexecHGY

The smaller size. https://www.ebay.com/itm/3-8-Drive-30-250-in-lbs-Metal-Kurled-Handle-Torque-Wrench-CDI-2502MRMH-USA/324120318736?hash=item4b77139310:g:XoEAAOSwWnhegltu

No going back!

As far as the crows foot not fitting the flats, just grind it thinner. Slowly, quench often. Keep it under kitchen oven temperatures.
 
I appreciate the suggestion speedmd. I'm with you.. I prefer quality used things over cheap new. But ATM Craigslist is down and I would never use eBay-Paypal or anything tied to Peter Thiel.
 
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