Advertise on Bikeforums.net



User Tag List

Results 1 to 7 of 7
  1. #1
    Senior Member vredstein's Avatar
    Join Date
    Aug 2008
    Location
    Tucson, Arizona
    My Bikes
    '02 Lemond Buenos Aires, '98 Fuji Touring w/ Shimano Nexus premium, '06 Jamis Nova 853 cross frame set up as commuter, '03 Fuji Roubaix Pro 853 back up training bike
    Posts
    701
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Rings on DA 7410 crank

    I picked up a 7410 crank set at a swap meet. I'm not sure if they have the original rings. The big ring is labeled "Shimano SG" and "B-53", all marked on the outer side of the ring and with a grove running around the circumference of the ring beneath the teeth. The inner ring is mounted with no markings on the outer side. On the inner side it is marked "Shimano SG", "TL", "B-39", and a "V" mark positioned right at the crank arm (3rd pic). The inner ring has a "shelf" on both sides running around the perimeter of the ring below the teeth (2nd pic). As mounted, the shelf on the on the inside is about 1/2 mm higher than the shelf on the outside. Is this the correct orientation? Are these original DA 7410 rings? IMO, the condition of these rings is excellent, but I'd appreciate a second opinion. Thanks.
    Edit-After removing the rings, I see the ring nut groove on the inside of the bolt holes of the small ring, so it was correct.
    Attached Images Attached Images
    Last edited by vredstein; 04-16-14 at 10:14 PM.
    "See, it's not that getting wet is a big deal. Really, it's what you're getting wet with.
    Fenders....because it's probably urine."
    Bike Snob NYC

  2. #2
    Senior Member
    Join Date
    Dec 2010
    Location
    Above ground, Walnut Creek, Ca
    My Bikes
    7 single speed road
    Posts
    3,977
    Mentioned
    4 Post(s)
    Tagged
    0 Thread(s)
    they don't look too bad, but IME, an opinion from looking at a pic is worthless. for me, either the chain skips or it doesn't. if it does, i buy a new chain and cogs, and if it STILL skips, i buy a new chainring. other's will have different opinions and no doubt you'll hear them.

  3. #3
    bike whisperer Kimmo's Avatar
    Join Date
    Dec 2009
    Location
    Melbourne, Oz
    My Bikes
    copy/paste links: http://velospace.org/node/36949 http://velospace.org/node/47746 http://velospace.org/node/47747
    Posts
    6,828
    Mentioned
    8 Post(s)
    Tagged
    0 Thread(s)
    Wow, they're pretty damn mint for 7400! Those are totally DA rings; look how smooth all the edges of the chainrings are. Pretty sure those surfaces are rough on a nice shiny tricolour chainring.

    I bet the cranks aren't even scuffed, huh? If they are, these rings would have to be replacements.

    Quote Originally Posted by hueyhoolihan View Post
    IME, an opinion from looking at a pic is worthless.
    Bah. Those chainrings are like 1/4 used, max.

  4. #4
    coprolite fietsbob's Avatar
    Join Date
    Jun 2010
    Location
    NW,Oregon Coast
    My Bikes
    7
    Posts
    529
    Mentioned
    31 Post(s)
    Tagged
    0 Thread(s)
    Many seem to see the way the engineers modified the tooth profiles to make it shift just a tiny bit quicker as if they are worn down ..

  5. #5
    Senior Member
    Join Date
    Aug 2005
    Location
    Pittsburgh, PA
    My Bikes
    '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
    Posts
    25,591
    Mentioned
    6 Post(s)
    Tagged
    0 Thread(s)
    The mounting orientation is correct and the chainrings are "matched". The corresponding "B" on both rings means they are made to work together. And yes, Shimano rings are mounted so the engraving faces outward on the big ring and inward on the smaller one.

  6. #6
    Senior Member vredstein's Avatar
    Join Date
    Aug 2008
    Location
    Tucson, Arizona
    My Bikes
    '02 Lemond Buenos Aires, '98 Fuji Touring w/ Shimano Nexus premium, '06 Jamis Nova 853 cross frame set up as commuter, '03 Fuji Roubaix Pro 853 back up training bike
    Posts
    701
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Kimmo View Post
    Wow, they're pretty damn mint for 7400! Those are totally DA rings; look how smooth all the edges of the chainrings are. Pretty sure those surfaces are rough on a nice shiny tricolour chainring.

    I bet the cranks aren't even scuffed, huh? If they are, these rings would have to be replacements.




    Bah. Those chainrings are like 1/4 used, max.
    Drive side arm is scuffed to a high gloss. I only picked them up because I needed a 172.5 mm, square taper set to replace my current Suntour Cyclone 170's. $40, probably cheaper than I'd get them on Ebay.
    "See, it's not that getting wet is a big deal. Really, it's what you're getting wet with.
    Fenders....because it's probably urine."
    Bike Snob NYC

  7. #7
    bike whisperer Kimmo's Avatar
    Join Date
    Dec 2009
    Location
    Melbourne, Oz
    My Bikes
    copy/paste links: http://velospace.org/node/36949 http://velospace.org/node/47746 http://velospace.org/node/47747
    Posts
    6,828
    Mentioned
    8 Post(s)
    Tagged
    0 Thread(s)
    These cranks were anodised rather than clearcoated like the 7700s, right?

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •