Re: [CR] Was Velo-Mine polishing - Now crank arm breakage

(Example: Framebuilding:Restoration)

References: <687965.30702.qm@web82305.mail.mud.yahoo.com>
Date: Thu, 1 Apr 2010 16:21:33 -0700 (PDT)
From: "Anthony Taylor" <ajft1942@yahoo.com>
To: David Patrick <patrick-ajdb@sbcglobal.net>, classicrendezvous@bikelist.org, loudeeter@aol.com
In-Reply-To: <687965.30702.qm@web82305.mail.mud.yahoo.com>
Subject: Re: [CR] Was Velo-Mine polishing - Now crank arm breakage


All,

Buffing, amongst other metal removing processes, such as grinding, machining, etc., does in fact smear metal, potentially hiding surface discontiuities that might propogate. One of the most common, and useful, tests for cracks emanating from the surface of a test part is "Liquid Penetrant Testing". This involves covering the test surface with a penetrating dye for some pre-determined period of time, then gently removing the surplus from the surface. A "developer" is then flowed over the surface which draws any of the dye from surface openings. Cracks can readily be detected visually. back in the steam railroad days this was called the "oil and whiting" test, and was performed on locomotive wheels prior to the days run. In many sensitive industrial applications it is mandated to lightly etch the surface of the test part in order to remove any smeared metal that might cover over the surface opening.

I'm not close to suggesting everybody should rush out and have their cranks tested, but just wish to point out buffing smears metal.

In all my years of riding (50+) I have only ever heard of one crank failure - it was on my nephews bike, last year - and it failed when he was out of the saddle climbing. Ouch!!! This was one of the modern Campagnolo cranks.

Campagnolo Record cranks are known to develop cracks at the junction of the spider and the crank arm. We should all add this check to our spring pre-season preparation.

Now that I have thrown more gasoline on the fire........

Tony Taylor Manchester, NH

________________________________ From: David Patrick <patrick-ajdb@sbcglobal.net> To: classicrendezvous@bikelist.org; loudeeter@aol.com Sent: Thu, April 1, 2010 4:34:04 PM Subject: Re: [CR] Was Velo-Mine polishing - Now crank arm breakage

I appreciate your comments, Lou.  What you're saying is 100% valid as far as other areas of a bike, but I was talking only about cranks   Mike's comments definitely singled out cranks and in this case buyer beware of what?  I just don't think crank arm breakage is an issue and we're talking predominately Campy here.  Yeah, you should give the spider area a good look over for any really bad cracks near the arm, right? And buffing isn't going to hide those.  Maybe I'm blowing smoke. It's been known to happen before...

Dave Patrick

Chelsea, Michigan USA


--- On Thu, 4/1/10, loudeeter@aol.com wrote:


From: loudeeter@aol.com <loudeeter@aol.com> Subject: Re: [CR] Was Velo-Mine polishing - Now crank arm breakage To: patrick-ajdb@sbcglobal.net, classicrendezvous@bikelist.org Date: Thursday, April 1, 2010, 4:01 PM

Dave, I take Mike's comments as a buyer beware kind of warning for parts that have been polished.  There must have been a reason why they were polished in the first place, right?  I don't see it specific just to cranksets.  It is a little like a frame that is offered without the fork or with a replacement fork.  You have to wonder what happened to the original, right?  You might even take that to question why a bike was refinished.  Did it have rust?  Was it damaged and repaired?  Was damage covered over with new paint?  Lou Deeter Orlando FL USA

-----Original Message-----

From: David Patrick <patrick-ajdb@sbcglobal.net>

To: classicrendezvous@bikelist.org

Sent: Thu, Apr 1, 2010 3:41 pm

Subject: [CR] Was Velo-Mine polishing - Now crank arm breakage

I am a bit unsettled by Mike's comments on crankarm breakage, as I believe the CR list addressed the specific issue of crankarm breakage some years ago at the instigation of Greg Parker of Bicycle Classics and the number of actual cases of crank arm breakage by CR list members was almost non-existent.  As I recall,  2-3 actual cases were reported from a CR list membership of 1000+ at that time. Also keep in mind that the typical CR member owns multiple bikes and thus multiple Campy crank sets.  It seems that this informal "call for actual cases" indicated that the history of Campy crank arm breakage had turned into some sort of urban myth that has taken on a life of it's own.  Now, I'm recalling this from my memory, but a more adventurous CR member can go back and check the archives.  I guess it seems as if Mike's post makes it seem as if the problem is greater than it really is and that those "in the know" would never touch a polished crank arm, which I don't think is true.  Or am I barking up the wrong tree?  Or all of the above?  Reply on list please. 

Dave Patrick
Chelsea, Michigan USA


--- On Thu, 4/1/10, hersefan@comcast.net wrote:


From: hersefan@comcast.net <hersefan@comcast.net> Subject: Re: [CR] Velo-Mine polishing aluminum campagnolo vintage record components March 2010 To: "Charles Nighbor" <cnighbor1@comcast.net> Cc: ben@velomine.com, classicrendezvous@bikelist.org Date: Thursday, April 1, 2010, 10:51 AM

These services generally sound great, but for a few items, notably crankarms, it makes me a tad nervous.

A rough but in no way exact way of judging use of a crank is to look at its cosmetic condition.  Lots of toe strap rub, nicks, and the scrapes help tell a story.

Campy NR/SR cranks do break on occasion, and miles of use is very closely related to the likelihood.  Again, not an exact means, as some folks could break new ones, and typical folks may never break one.  But if one spiffs up a well worn crank and makes it look gorgeous, it makes one usure as to its history.  Of course, those "in the know" generally shy away from components that should be annodized but for some reason were polished.  But those unaware of this issue can get a false sense of security.  So I suppose it is great to do on ones own bike.  But folks should be aware of why an item was polished if it shows up on the second hand market.

Mike Kone
Rene Herse Bicycles Inc. / Boulder Bicycle
Boulder, CO USA
http://www.renehersebicycles.com
reneherse@comcast.net


----- Original Message -----
From: Charles Nighbor
To: classicrendezvous@bikelist.org
Cc: ben@velomine.com, Charles F Nighbor
Sent: Wednesday, March 31, 2010 9:38:09 AM GMT -07:00 US/Canada Mountain
Subject: [CR] Velo-Mine polishing aluminum campagnolo vintage record components


March 2010

Here is an interesting service by Velo-Mine

We can bring the life back to your scratched up & worn components!

Cranks,stems, brake levers, calipers and rear derailleurs require anodize stripping before polishing, which is included in the rates below.

Polishing rates:

$60 Crankarms

$20 per chainring

$35 seatpost

$30 headset

$50 pair hubs - includes new bearings and Phil grease

$50 brake calipers

$40 brake levers

$10 shifters

$25 stem

$60 rear derailleur - service only available on certain models

$60 pedals - service only available on certain models

Call me at 217.827.1173 or inquire by e-mail ben@velomine.com Ben Cole

http://www.velomine.com/index.php?main_page=index&cPath9_28

Not related Charles Nighbor Architect and Proffessional bicycle rider Walnut Creek, CA USA