Cracked dura ace crank?
01-12-10, 09:12 PM
#1
Senior Member
Thread Starter
Join Date: Mar 2009
Location: Colorado
Posts: 9,458
Bikes: Something Canadian, something Italian, something American, and something German
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 64 Post(s)
Likes: 0
Liked 14 Times
in
8 Posts
Cracked dura ace crank?
I just picked this up used then realized this:
The green I think is supposed to be there, the red not so sure. Pictured is where the crank arm enters the spider. It is kind of raised, so is it just forging?
The green I think is supposed to be there, the red not so sure. Pictured is where the crank arm enters the spider. It is kind of raised, so is it just forging?
__________________
Originally Posted by rjones28
Are they talking about spectators feeding the cyclists? You know, like don't feed the bears?
Last edited by mzeffex; 01-12-10 at 09:57 PM.
01-12-10, 10:01 PM
#2
Senior Member
Join Date: Oct 2009
Location: Northern/Central VA
Posts: 212
Bikes: Specialized Sirrus, Univega Activa ST Hybrid, 70's Schwinn Traveler, Giant Innova, Nishiki Mixte
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Get your money back if you can.
Assuming you have some $$$ tied up in this, if you can't get your money back and want to be sure, run it by a machine shop and have them do a penetrating dye test.
Assuming you have some $$$ tied up in this, if you can't get your money back and want to be sure, run it by a machine shop and have them do a penetrating dye test.
01-12-10, 10:21 PM
#3
Senior Member
Join Date: Feb 2006
Location: Medford, OR
Posts: 325
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
I had a stronglight that came apart right there, it was on my fixed and I almost hit a car. Good thing I still had a break, it just took me a second to remember it was there, and to stop wondering why I was coasting. Mine didn't fall apart though, it just spins like a free wheel now. lol
01-13-10, 06:26 AM
#4
Senior Member
Thread Starter
Join Date: Mar 2009
Location: Colorado
Posts: 9,458
Bikes: Something Canadian, something Italian, something American, and something German
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 64 Post(s)
Likes: 0
Liked 14 Times
in
8 Posts
It's not cracked. It's part of the manufacturing process.
__________________
Originally Posted by rjones28
Are they talking about spectators feeding the cyclists? You know, like don't feed the bears?
01-13-10, 07:49 AM
#5
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 35,964
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Mentioned: 125 Post(s)
Tagged: 1 Thread(s)
Quoted: 4372 Post(s)
Likes: 0
Liked 50 Times
in
44 Posts
It looks more like flash then a crack. Flash is raised metal whereas a crack would not be. It's a normal result of the manufacturing process, resulting from a gap in the edge of the production tooling which allows excess metal to flow out a bit. Usually it's broken, polished or machined off later, but not always, especially in non-critical places or where they don't expect it to be visible in the finished assembly, like the back of a crank arm. Don't sweat it, enjoy your new cranks.
01-13-10, 08:09 AM
#6
Senior Member
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 33,294
Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!
Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 1839 Post(s)
Likes: 0
Liked 777 Times
in
565 Posts
Originally Posted by mzeffex
It's not cracked. It's part of the manufacturing process.
I can't believe a Dura Ace crank would be less finely finished than these are so I have to believe yours is cracked.
Don't use it.
01-13-10, 11:22 AM
#7
Horse Categorie
Join Date: Sep 2007
Location: Carlsbad, CA
Posts: 6,205
Bikes: '09 Felt F55, '84 Masi Cran Criterium, (2)'86 Schwinn Pelotons, '86 Look Equippe Hinault, '09 Globe Live 3 (dogtaxi), '94 Greg Lemond, '99 GT Pulse Kinesis
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 235 Post(s)
Liked 66 Times
in
40 Posts
Originally Posted by HillRider
I don't agree, I think it's broken. I don't have a Dura Ace crank but I just inspected two 9-speed Ultegra cranks, two 8-speed 105's and a couple of old SR and Suguino cranks and NONE of these have any molding flash, forging marks or similar parting lines on either side of the spider/hub junction. The hub to spider transitions on all of these are completely smooth.
I can't believe a Dura Ace crank would be less finely finished than these are so I have to believe yours is cracked.
Don't use it.
I can't believe a Dura Ace crank would be less finely finished than these are so I have to believe yours is cracked.
Don't use it.
01-13-10, 11:40 AM
#8
Senior Member
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 33,294
Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!
Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 1839 Post(s)
Likes: 0
Liked 777 Times
in
565 Posts
Originally Posted by calamarichris
I disagree completely. The new Dura Ace (Hollowtech) is made with a different process than those earlier, solid cranks you're comparing it to. The crank is fine. Mine had it when brand-new. Shimano puts it on the nearly-invisible underside of the crank. True, the underside is not as pretty as those earlier cranks, but overall it's much, much (& much-much) lighter and stiffer.
01-13-10, 04:35 PM
#9
Senior Member
Join Date: Mar 2007
Location: Louisville, KY
Posts: 469
Bikes: Trek Madone 5.5, Klein Q Pro Elite, Surley LHT
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
The green areas look like casting marks. The red area looks like a crack. Get a 10x magnifying glass and look at the area. If it is a crack you will not be able to see the bottom of the area. Flashing or casting marks will be very obvious.
