Is this crank arm toast
 

Hadn't ridden this bike in nearly a year. When I did there was creaking while pedaling. So I lubed the pedal bearings, creak remained. Then I tightened the pedals and crank arm bolt...creak was gone, but only for a few miles.

When it returned I removed the arm. It does look a little misshapen. Is it done? https://cimg2.ibsrv.net/gimg/bikefor...a7510af7fa.jpg

You tightened the cranks....you did get them up to 40Nm, right?

Used crank puller.

Does a clean bottom bracket shell effect the fit of the arm on the spindle?

I got them as tight as I have in the past.as far as I know. But I don't have torque wrench

That makes sense. I guess it could be coincidence that the creak was gone for a little while after tightening the crank arm bolt

Did you happen to clean and lube the pedal and crank threads when you tightened the pedals? The fact that tightening them made the problem go away for a while could indicate that you are at the source of the problem. I would thoroughly clean and grease both the pedals and crank threads and reassemble or better yet substitute in a known-quiet pair; I use a stainless pedal washer as well.

Get one. 40Nm is much tighter than many people suspect doing it blind.

That the arm came loose after riding after being tightened an unknown amount...means damage may have taken place from inadequate torque. Only way to know is to start by properly torquing the fastener.

The photo shows no obvious tapered hole rounding out. It does show what I think is surface galling (not sure that's the best term) in the middle of the taper surface. IME this isn't yet a reason to replace the arm. Andy

Thanks Andrew.

I'll try to get a hold of s torque wrench, clean and grease the threads, and get it on tight

One of my hybrids kept developing an intermittent creak that I chased around for a couple of weeks before redoing the entire BB.

I'd already retightened the new cassette, figuring maybe the lock ring wasn't quite snugged down -- I don't have a torque wrench anymore and was just guessing. Seemed to help... for a couple of days.

Then I tightened the crank arms. Seemed to help... for a couple of days.

Then I tightened the BB lock ring. Even bought a proper forged Hozan "rock ring" wrench when the cheap stamped metal wrenches kept slipping. Seemed to help... for a couple of days.

But the creaking kept coming back. So a few nights ago I redid the entire bottom bracket. It seemed fine to begin with. But what the heck.

Test ride -- still creaking.

Turned out to be the stupid plastic dork disc. I'd forgotten about it after installing a new 12-32 cassette that covered up the dork disc. It was clipped onto the spokes with four plastic fingers. The disc was slightly warped and rubbed the chain intermittently *only* when in the 32T cog. Which I rarely used. Which explained why it seemed to come and go, mostly on one particular short, steep climb that I usually take very slowly en route to casual group rides.

Removed dork disc. Problem solved.

D'oh.

I'm not discounting the importance of a torque wrench. I had and used one for years, until injuries from a 2001 wreck persuaded me I'd never ride a bicycle or motorcycle again. Got rid of most of my tools by 2004. I should have kept them, including the torque wrench. Never give away or sell tools. Never say never about something we used to enjoy doing.

Creaks can be maddening, while you are searching for a torque wrench I would suggest tightening everything you can get a wrench on near the sound, it can be something as seemingly innocuous as a chainring bolt.

I agree that sounds can travel from their true source and seem to come from some other spot. Much like water leaking from a upstairs bathroom on one side of the house is seen dripping from the ceiling in another spot below. Andy

That's a good story and now I wish there was a dork dish to take off. There are plenty of other parts I recently installed..fenders, chain, freewheel, rear tire and tube. The crank arm is relatively new too.

When I solve it I'll report back. Thanks everybody.

Oh, your post reminds me... I'd forgotten about the fenders. Yup, I reinstalled an old set of Bluemels I had in the closet. For a week I thought the fenders were creaking. Redid every bolt, tried various nuts, lock washers and shims. No help. It was the dratted dork disc all along. I just overlooked it because it was smaller than the diameter of the new, larger cassette.

Now that it's solved, on to the next maddening problem. Dunno what it is yet, but it's bound to turn up.

Yes, creaks in the bottom bracket/crank area are maddening. Long ago I overhauled and re-overhauled the BB on one bike but it still made noise. I finally removed the pedals, regreased the threads, and reinstalled. No more creak.

Also grease the taper on the spindle. https://www.sheldonbrown.com/brandt/...ng-cranks.html

very slightly if any..

(there are disagreements there ... 60 years I never have )

update: I cleaned the spindle off , though there was still likely some grease residue inside the square hole of the arm.

then I looked up what 40nm is and did my best job of cranking the crank arm on nice and tight. I didnt jump on the wrench or anything but I think i got it to the correct amount maybe a little more. i've ridden the bike 12 miles since with zero creaks heard.

I would declare success but that would guarantee the creaks return on my ride home today. so we'll see if the silence lasts

thanks again

40Nm is about 30 ft/lbs. Imagine a 30 pound weight hanging off the end of a foot long wrench. If you are using a 6" long Allen key to tighten your crank arms, I'd be willing to bet you're not getting them to 30 ft/lbs. That's a quite common problem, by the way.

:) :) :)

And?