I doubt that properly tightened Campy pedals would ever come loose from a Campy crank, unless the cranks had previously been run with improperly tightened pedals. It has been my observation that there is very little allowance between the pedal and crank threads, but if someone had forgotten to tighten pedals in the crank in the past, the thread in the crank could have become enlarged. Once enlarged, you would probably have troubles ever afterward. You could try blue Loktite, but bring a wrench with you, just in case.
When I was a young mechanic, I often over tightened pedals, thinking that this would keep them from coming out. Unfortunately, this meant that sometimes they broke, instead. (Not Campys, of course.) Years later, I learned the importance of proper torque--that this was dependent on the materials, thread pitch, and diameter of the thread, as well as its application. There are some cases (head bolts on many modern engines, as an example) where the bolts are supposed to be discarded and replaced rather than reused. Some say that grade 8 fasteners should never be reused, if their full strength is necessary for the application. It seems that there is supposed to be a certain amount of stretch in the fastener when tightened, which is one of the factors in its staying tight.
All this brings up an interesting topic (NOT to revisit the greasing spindle flats issue again!) Just what are the proper torque specifications for the various treaded fasteners on our beloved old bike parts? Have these ever been published? Pedals would be easy to torque with a calibrated torque wrench and a crowsfoot socket. Such a list would be greatly appreciated and could save many an out-of-production part from damage. Though highly prized, my "feels right" skills, honed through years of wrenching experience, are a poor substitute for a true measure, and are not transferable.
Steve Barner, watching the snow melt in Bolton, Vermont
----- Original Message ----- > From: Roadgiant@cs.com
> Date: Sat, 14 Dec 2002 03:43:00 EST
> To: NortonMarg@aol.com, TheMaaslands@comcast.net,
> Subject: [CR]loose Campagnolo pedals- help!
> Hey everyone,
> Seems I have had two right side pedals fall off after a recent
> rebuild. Two separate Colnagos but the same scenario--both fell off while
> under load (up hill climbing, sprint). I put white lithium on both pedals
> (and everything really) before screwing them onto the crank arms.
> Any ideas why they would be unscrewing themselves? Am I doing
> something wrong? The only common denominator between these two bikes and
> pedals is myself with a wrench. Yikes, the implications are humbling.
> I've also lost a bit of thread from the crank arm. Can these be
> Scott Smith