Chainring torque specs

DWill · **Posted:** Mon Oct 01, 2012 10:22 am

Does anyone know the torque spec for the four bolts on a small (24t) chainring for a Shimano XT crank set.

I can't find them my search skills are very weak.

OhNooo · **Posted:** Mon Oct 01, 2012 10:45 am

I don't know the torque specs. But I do know that I will never reuse these chainring bolts again. I reused the 24t bolts when I replaced my rings after a few seasons. One of them sheared off in my crank under very little torque. I guess they fatigue after a while. Luckily these bolts are hollow so a 1/4-20 easy-out worked perfectly to extract the stub that was remaining in my cranks.

Dirtrider · **Posted:** Mon Oct 01, 2012 10:49 am

Tighten it until it snaps and then back off a 1/4 turn :lol:

From Park Tool:
Chainring bolt- steel 70-95
Chainring bolt aluminum 44-88
Both in Inch pounds

DWill · **Posted:** Mon Oct 01, 2012 11:19 am

Dirtrider wrote:

Tighten it until it snaps and then back off a 1/4 turn :lol:

From Park Tool:
Chainring bolt- steel 70-95
Chainring bolt aluminum 44-88
Both in Inch pounds

thank you, i forgot about the Park Tool site.

OldDogDan · **Posted:** Mon Oct 01, 2012 11:48 am

And don't put grease on them. Put blue Loctite on.

McLovin · **Posted:** Mon Oct 01, 2012 3:13 pm

OldDogDan wrote:

And don't put grease on them. Put blue Loctite on.

Really? That's exactly opposite to the advice I've been given before. :?:

DWill · **Posted:** Mon Oct 01, 2012 3:25 pm

McLovin wrote:

OldDogDan wrote:

And don't put grease on them. Put blue Loctite on.

Really? That's exactly opposite to the advice I've been given before. :?:

They had red locktite on them when I took them apart. Thankfully not on the tthrefs but on the flats at the end of the bolts.

OldDogDan · **Posted:** Mon Oct 01, 2012 8:16 pm

McLovin wrote:

OldDogDan wrote:

And don't put grease on them. Put blue Loctite on.

Really? That's exactly opposite to the advice I've been given before. :?:

Well, that's my opinion. Grease will definitely help you snap it off easier, or at least allow it to loosen sooner. Everyone's got an opinion, and there have been previous threads on this. Here's your post last year:

McLovin wrote:

From all of my past experience with automotive and motorcycle service manuals, it's usually assumed that unless otherwise noted, torque specs are for clean dry threads.

To which I replied in agreement:

OldDogDan wrote:

I'm definitely with McLovin on this. Torque specs assume clean & dry. Reduce the torque if it's been lubed for some reason -- such as anti-seize on dissimilar materials, or blue loctite on things you don't want to vibrate loose, or red loctite on things to stay together nearly permanently (I don't use red anywhere on a bicycle). I don't use grease on bolt threads -- either clean & dry, blue loctite or anti-seize.

McLovin · **Posted:** Mon Oct 01, 2012 9:23 pm

Yeah don't get me wrong, we're definitely on the same page for torque specs being stated assuming dry threads. I had just heard otherwise that locktite on chainring bolts would only bring pain and suffering later when you try to remove them. I've never had one go missing on me but then again I tend to check stuff relatively often.

Red Hot Sloth · **Posted:** Mon Oct 01, 2012 10:02 pm

I dont use a torque wrench on anything bicycle related, I do it all by feel.
I tighten those mutha britchers up, then back off a smidge.
The only thi g I use lock-tite on is rotor bolts and adaptor bolts, everything else get grease.

OldDogDan · **Posted:** Mon Oct 01, 2012 10:11 pm

McLovin wrote:

Yeah don't get me wrong, we're definitely on the same page for torque specs being stated assuming dry threads. I had just heard otherwise that locktite on chainring bolts would only bring pain and suffering later when you try to remove them. I've never had one go missing on me but then again I tend to check stuff relatively often.

It's the red that brings pain & suffering. It's for locking things in place pretty much permanently. The blue is easily removeable, but keeps things from vibrating loose.

http://www.pinkbike.com/news/Tech-Tuesday-Thread-locker-Basics-2011.html

OldDogDan · **Posted:** Mon Oct 01, 2012 10:43 pm

Red Hot Sloth wrote:

I dont use a torque wrench on anything bicycle related, I do it all by feel.
I tighten those mutha britchers up, then back off a smidge.
The only thi g I use lock-tite on is rotor bolts and adaptor bolts, everything else get grease.

Yeah, I have a torque wrench but use it only occasionally. You develop a feel over the years (...after you've broken a few bolts) which is good enough most of the time. But I disagree about tightening way up, then backing off. That works good for adjusting bearing sets and anything requiring very slight play, but not good for fasteners. It will actually make them more likely to loosen, because they've been stretched past the point you back them off to. Better to tighten up juuuusst tight enough, maybe a wee tad more, and leave it there. I do use grease on tight mating surfaces of the same material that might creak (stems, bottom brackets, seat posts). It's faster and less messy than anti-seize. But if the materials are dissimilar, use anti-seize (or the special carbon paste for carbon).

Red Hot Sloth · **Posted:** Mon Oct 01, 2012 10:48 pm

Your right Dan...
Im a ham-fisted neanderthal and usually break things, any mechanical advise given by me should be taken with 2 aspirins and a grain of salt.

And a sense of humor.

OldDogDan · **Posted:** Tue Oct 02, 2012 8:11 am

Well, they're all just opinions...my way works fine for me, and yours for you. And lots of bike shop mechanics swear by greasing everything, and it works for them. Easy to take apart. As long as we all spend more time riding than breaking bolts, we'll be happy.

OldDogDan · **Posted:** Tue Oct 02, 2012 8:23 am

Geez, I just can't shut up....okay, a caveat: if you are very frequently changing chainrings, say on your singlespeed, then you might not want to use the blue loctite. It will build up a residue in the threads after several uses. It's pretty easily cleaned off with a wire wheel or wire brush. But you would want to keep in mind that every time you cinch those tight, you are stretching and fatiguing them slightly more. So if you change chainrings a lot, put in new bolts fairly often, especially the aluminum ones.

Chainring torque specs

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