Mtracer

I stumbled on this webpage from Park Tool. It has recommenced torque settings for all things bike. While I would always try to find specific manufacturer's specifications, sometimes that's just not possible. This seems to be quite a comprehensive list of torque specs. And some are manufacturer specific.

Park Tool Torque Specs

JoeTBM 

Should this be up in the Hint and Tricks sticky?

redshift1

While I like the inclusion of so many often hard to find torque figures for numerous fasteners, I find it strange that such an apparently authoritative article doesn't mention whether the torque values given are for dry or oiled or otherwise lubricated threads ( unless I missed it ).

Duragrouch

Thanks. I was just looking online yesterday for torque specs for bottom brackets and crank arm pinch bolts, still couldn't find, in past had to just do by feel. This was in regard to the thread regarding need for a torque wrench. Yeah I said, you can get by without it, but better if you can torque to spec.

Duragrouch

Good point, but I'm gonna guess clean and dry. I never use oil or grease, can result in overtorquing (harder bolt pull for the same torque value), however on all threads going into my steel, aluminum, and titanium frames, I use anti-seize; The consistency of grease, but has fine metal powder in it to try to keep the coefficient of friction near dry, I'm sure it's more slippery than that, but better than grease and keeps threaded fasters and bottom brackets from locking in place. Also prevents galling, which can be more common on stainless steel, and I use stainless bolts for everything on the bike. A thread on here years ago, a mechanic swore by using oil on bolt threads, was certain about it, would not entertain talk of anything different.

grumpus

Normally the torque is given for a dry thread, typically de-rate by 40% if it's lubricated.

Duragrouch

I did not know that, but it makes sense. Different de-rate for anti-seize? Because that's my go-to on all threads.

70sSanO

Lube or dry has had some debate over the years. I would think that a number of bicycle fasteners are dissimilar materials from the the component/frame and lube or anti-seize should be used.

I’m guessing that for a bicycle the torque range is for lubrucated/anti-sieze installation; although I’m not certain.

Personally, I use light coat/dab of Phil’s grease, or anti-seize if specified, on threads. I have not had a problem so far torquing to within the range.

John

grumpus

No idea - I think 40% is for a 30 weight oil, but obviously even that will vary depending on if it has EP additives.

Sy Reene

Not sure it makes sense. A delivered bike with a seatpost clamp that is marked eg. 6Nm, or stem clamp with some other value. Were the bike's seatpost clamp threads or stem bolts shipped dry or greased when you took delivery of the complete bike?

Mtracer

Concerning wet or dry, I too would like that information. But The generally accepted 40% derating when wet (lubed), while significant, isn't orders of magnitude. I tend to err on the low side of any range of specs given. So, if it is meant dry, then I'm not necessarily exceeding it if lubed, if it has a wide enough range. Or not exceeding it by much.

Also, many of the specs printed on bike parts are a maximum. So, I always tend to stay well below that. Basically I use a torque wrench but if the spec is 5 N-m Max., I'll use 4 N-m unless I have a reason not to. I can't think of anything that has ever become loose on my bikes. So, this approach has been working well for me. I ride mostly road, so might be a different story if I were riding a lot of MTB in rock gardens.

The only time I got bit was tightening some aluminum chain-ring bolts. The aluminum bolts snap VERY easily. The Shimano spec is 12-16 N-m (I know super high). I now know this is a dry number, but didn't at the time I snapped one. There's a lot of debate whether to lube or not lube chain-ring bolts. Many if not most opinions I saw people lubed them to avoid seizing issue later and to perhaps avoid noise. But they torqued to 8 N-m Max.

It also seems a lot of things on the bike are lubed. I try to find manufacturer's specs whenever possible. But sometimes I can't find anything. So, that where a table like the one I linked is way better than nothing.

Calsun

I helped out in a bike shop in the 1970's and a torque wrench was never used. The bike mechanics knew to use the correct size wrench when tightening anything. The length of the wrench handle limits the amount of torque that can be applied. People bringing their bikes with failed fasteners had used wrenches meant for use on automobiles and not small 8mm bolts on a bike.

Duragrouch

I have personally seen, a 1" diameter, grade 8 bolt, that was necked from being overtorqued. I was told that some things are designed as large as they are, not for function, but to withstand a mechanic torquing on them with an 8' cheater bar. That was almost 50 years ago, hopefully use of torque wrenches has increased to prevent overdesign that way.

MudPie

The Park torque spec is my go-to reference, unless otherwise stated on the component. I've always assumed the Park table was for lubricated threads and I always grease threads. In general, I never liked the idea of wasting energy to overcome friction in the thread and would rather have the energy develop clamping force.

Let me send Park a question about dry v lubed threads and their table. In the past, they've replied to my queries pretty quickly. I'll let you all know what they say.

Mtracer

Great! Thanks for doing this. I hope you get a response soon.

As for greased or not, while you get more tension in the fastener with less applied torque when using grease, I think there may be advantages to un-greased in terms of a bolt loosening. But, I too, tend to grease unless specifically instructed not to do so or it is obvious for some reason to avoid grease (around disc brake rotors for example).

70sSanO

Thanks for taking the initiative. I had thought about sending a question off, but didn’t follow through.

It’s their table, although they might have a mfg’s fallback response which would be tough to track down each specific torque to a prep recommendation.

John

Bike Gremlin

These are my notes - the torques that work well for me, with anti-seize paste (what I always use):

https://bike.bikegremlin.com/14694/b...ening-torques/

Sy Reene

I'm not sure how any table can be reliable. Unless you know for certain that X brand only always uses Y-sized bolts that are made out of Z material. Aren't torque specs at least partially (if not mostly) contingent on the bolt size? And then sometimes torque spec might be also partly contingent on what the part is that is being clamped and not what the clamp and its bolt itself can withstand.

The Park Table, isn't it really out of date?
This is the clamping force table for tightening your saddle rails down in the seatpost's clamp? Any of these brands really still in play on any newish bikes? Ranges by brand from 6-34Nm .. seems really wide spread.

MudPie

John, you're correct, Pete from Park customer service did respond within a few hours, which they tend to do with my questions to them. Here is their response:

"Those are taken from the manufacturer as opposed to being generic like "for a 5x0.8 thread bolt, the max torque is...". So in the manufacturer specified specs you will want to defer to the manufacturer. But you point is valid, we could make a note of that in the chart, otherwise what is the point if you have to go look it up anyway. One note is that there is an assumption that the bolt was prepped from the factory and unless someone did something to the threads (which does happen) to modify the factory prep, if you are servicing the bike post initial assembly, then most people just check the torque, they don't remove the bolt, re-prep it and then reinstall it. Anyway, I will pass this question/suggestion on."

As a side note, on the Park site, https://www.parktool.com/en-us/blog/...hread-concepts, section 4 recommends greasing threaded fasteners unless the manufacturer advises dry threads.

MudPie

Your post sparked a debate whether the Park torque values referenced dry or lubricated threads. I sent a query to Park asking for clarification and Pete from customer service replied in a few hours. Here is their reply:

Those are taken from the manufacturer as opposed to being generic like "for a 5x0.8 thread bolt, the max torque is...". So in the manufacturer specified specs you will want to defer to the manufacturer. But you point is valid, we could make a note of that in the chart, otherwise what is the point if you have to go look it up anyway. One note is that there is an assumption that the bolt was prepped from the factory and unless someone did something to the threads (which does happen) to modify the factory prep, if you are servicing the bike post initial assembly, then most people just check the torque, they don't remove the bolt, re-prep it and then reinstall it. Anyway, I will pass this

Mtracer

Thanks for posting their reply. And let's see if they do update that table. Seems like a lot of work for them, but then again, the table is not very helpful if you still have to go digging for wet or dry from the manufacturer.

grumpus

Presumably that said "I will pass this on to our technical people ..."