# How much do I tighten a mid-80's Campagnolo Crank Arm 15mm bolt?



## Mark McInerney (Mar 3, 2018)

I am restoring a mid-80's Patelli Professional.  It has a Campy Victory crank arm set with 15mm bolts.  How much do I tighten it?  How many newton meters on the torque wrench?  Or, do I tighten it with a socket wrench?  If so, how tight is "tight"?  Also, do I apply grease, or not?  My old school brain tells me that these bolts went in dry, without grease.  However, opinions and info, change over time.  So, what is correct?
Thanks everybody!  Mark


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## pedal4416 (Mar 3, 2018)

Lube it, I do have a torque value somewhere I’ll look it up. I alway use a campy peanut butter wrench and get it good and tight.


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## bulldog1935 (Mar 3, 2018)

310 lb-in


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## Mark McInerney (Mar 4, 2018)

pedal4416 said:


> Lube it, I do have a torque value somewhere I’ll look it up. I alway use a campy peanut butter wrench and get it good and tight.
> 
> View attachment 763067



Is Park Tool PPL-1 poly grease okay to use?  Or, do I need something different?  Thanks,  Mark


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## bulldog1935 (Mar 4, 2018)

any grease will do  main thing is to grease the square tapers so they don't bind crooked
I always use a wood block to tap the crank arms onto the square taper before tightening


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## Mark McInerney (Mar 4, 2018)

bulldog1935 said:


> any grease will do  main thing is to grease the square tapers so they don't bind crooked
> I always use a wood block to tap the crank arms onto the square taper before tightening



Thanks, Bulldog.  Do I also grease the threads of the bolt, or does that go in dry.  I bring up "dry" because my old school brain tells me that Campy originally installed the bolts dry...but, like I said earlier...things change, and wisdom is gained.   So, a little grease on the bolts...or not?


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## pedal4416 (Mar 4, 2018)

Only lubebthe bolt, not the square tapered spindle. Lube will cause the crank arm to slide too far down the spindle. And only use campy spindles with campy cranks. The taper is different than shimano/others.


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## Mark McInerney (Mar 4, 2018)

pedal4416 said:


> Lube it, I do have a torque value somewhere I’ll look it up. I alway use a campy peanut butter wrench and get it good and tight.
> 
> View attachment 763067



I have noticed that the Campy crank arm bolts that came with this Patelli DO NOT have washers with them.  When I look up these bolts on Ebay they always come with washers.  Do you know if back-in-the-day the washers were not used for some reason?  I would assume that washers would be needed, and probably required, to assure a good tightening.  However, it appears that the cranks were tightened without washers.  Should I get some Campy washers?


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## pedal4416 (Mar 4, 2018)

Definitely use washers, campy washers are not important as long as they are the right size to stop the bolt head from binding into the crank. If I remember correctly the campy bolts and washers are fairly expensive.


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## bulldog1935 (Mar 4, 2018)

you'll hear every permutation of this, but I grease the tapers and not the threads - I use loctite on the threads, and an indexing torque wrench

for about 60,000 miles

I'm also a licensed professional engineer


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## pedal4416 (Mar 4, 2018)

I used to alway lube tapers but these days manufacturers don’t want you too so I don’t anymore to keep up with warranty issues and I also go. Y what ever shop I’m working at’s preference.


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## 100bikes (Mar 6, 2018)

OK, so I am old school.

Clean the tapers well(Citrus degreaser) , both the spindle and the arm .

Let them dry.

Dry mount.

Tap - read that tap them into position, tighten the bolt with nothing longer than 
the peanut butter wrench(6"+-) and tap again.

Tighten and ride.

Precision mounting with these surfaces.

My thought is that lube does just that - lube the surfaces. That works both ways.
Never getting things quite tight and then, letting things loosen up.

Another opinion.


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## fattyre (May 7, 2018)

Regardless of ones technique, I always try to remove square taper crank arms as little as possible.  Every time you tighten cranks down, your smashing them against steel.  Can't tell you how many square taper Campy cranks I have seen where the washers or just the bolt bottoms out on the spindle and the cranks still creek when you ride them, greased up or not.


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## bikemonkey (May 16, 2018)

Here is my approach - remove one arm and mark the spindle so you know which way the arm was originally mounted. When replacing the crank arms, mount them the same way they were before you removed them.

Oil or grease cannot be compressed so if you have any lube on the taper (spindle or crank arm), the crank arm does not fit as securely because there can a small degree of "float" and it can work loose later as the grease migrates out under load. I have never had any issues pulling cranks from dry tapers if the extractor threads were good.

However, the crank bolt threads must be lubed and the surface of the bolt head and/or washer as you want minimum friction in order to get the bolt tight and not have a false torque value.

I don't think lube on the tapers will cause the crank arm to move too far up the spindle - that is caused by a wallowed out crank arm that was ridden loose. Everything I can recall in the industry recommended the taper and crank taper be clean and dry.

Of course, that is just me and here are two articles with an opposing opinion.

Jobst Brandt

Jan Heine


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## bulldog1935 (May 16, 2018)

as far as grease on the tapers, it should be the thinnest film you can leave behind, and it's just to prevent friction from binding/misaligning the taper during installation.

The actual goal of tightening bolts is to stretch them to 90% of their elastic limit.
Torque is an approximation, and assumes a friction factor of dry threads.  If the threads are lubricated, that friction factor changes, and tightening to recommended torque on your torque wrench reading can permanently stretch your bolts beyond their elastic limit and lead to bolt fatigue down the road.  Too tight is the same as too loose.
So that is my engineering approach to the problem.


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