Results 1 to 8 of 8
  1. #1
    mtbr member
    Reputation: Pollution Warrior's Avatar
    Join Date
    Apr 2010
    Posts
    385

    Need advice on strengthening Santa Cruz Blur frame

    I have a Santa Cruz Blur Classic, 2003, size L. I've recently learned that lots of these in this size and made during this year have the problem of cracking around the front der. See this thread for more info:

    Blur Classic Seat Tube Crack - Options?

    Mine is fine now, but obviously out of warranty. I'd really like to avoid this problem in the future, so here's my question:

    Could I strengthen this area of the frame by getting a 30.8mm seatpost, cutting it down to just a bare 6" post, and ramming it down into the seat tube as far as I can until it reaches the bottom? I'm pretty sure that with 10 years of oxidation and whatever that it would be quite a snug fit so nothing would be needed to hold it in place. Seems to me that this would help to spread out the forces place on the seat tube by the rear triangle via the pivot welded onto the seat tube (which I think is what applies the force that causes the break).

    I'm asking this here instead of the Santa Cruz forum because I want the opinion of people who know something about how frames are built, not just some Bubba spouting of nonsense. If there is anything else I could do please let me know.

  2. #2
    Moderator Moderator
    Reputation:
    Join Date
    Jan 2004
    Posts
    3,931
    It won't help, ride it until it dies. 10 years is a great lifetime for an aluminum FS bike, anything you get out of it at this point is gravy.

    -Walt
    Waltworks Custom Bicycles
    Park City, UT USA
    www.waltworks.com
    waltworks.blogspot.com

  3. #3
    Randomhead
    Reputation:
    Join Date
    Sep 2008
    Posts
    1,036
    they reinforced it there and so it breaks at the edge of the reinforcement. Just another data point that supports PVD's law of gussets

  4. #4
    mtbr member
    Reputation: smilinsteve's Avatar
    Join Date
    Jul 2009
    Posts
    6,422
    It seems like it might help reduce stress in that area if you can get the tube past the weld . If it doesn't help, it sure won't hurt either, and you won't notice it in there, so why not try it?

  5. #5
    mtbr member
    Reputation: Pollution Warrior's Avatar
    Join Date
    Apr 2010
    Posts
    385
    Quote Originally Posted by Walt View Post
    It won't help, ride it until it dies. 10 years is a great lifetime for an aluminum FS bike, anything you get out of it at this point is gravy.

    -Walt
    Why won't it help? Just curious.

    Seems not so good to ride it till it dies if I can easily prevent the dying. Especially if I'm going to have to walk 7 miles with it after it dies and then find another low-budget FS frame for a 6'2" rider. I'd really rather avoid all that. Too, I've ridden it very little since buying it. I'd like to get my money's worth out of the frame (all $175 of it).

  6. #6
    Randomhead
    Reputation:
    Join Date
    Sep 2008
    Posts
    1,036
    if you look for cracks occasionally, you can stop riding the bike when you see one and you will not have to walk. You don't have to monitor it between every ride, it's simply not going to break that fast.

  7. #7
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    193
    ^ Is this like texting your ex-wife you want her instead of your girlfriend?
    andy
    to the op, just ride it, the fix doesnt sound like it would help.

  8. #8
    mtbr member
    Reputation:
    Join Date
    Aug 2009
    Posts
    31
    I can think of a number of reasons this won't work.

    1. If the tube is straight gauge the ID is likely slightly under the seat tube diameter and reamed to size for a snug fit. Once you get past the reamed area that seat post won't go anywhere.

    2. If the tube is butted, it likely has a bigger ID in the middle and smaller ID at the bottom near the bottom bracket.

    3. If by some chance, the tube has the correct ID all the way to the bottom, at best you might have reinforced one area while creating a serious stress riser in another area where the unbonded seatpost segment interacts with the seat tube.

    WWS. Ride it till it dies

    Quote Originally Posted by smilinsteve View Post
    It seems like it might help reduce stress in that area if you can get the tube past the weld . If it doesn't help, it sure won't hurt either, and you won't notice it in there, so why not try it?

Similar Threads

  1. Santa Cruz Blur LT frame size
    By scottalej in forum Bike and Frame discussion
    Replies: 7
    Last Post: 04-12-2013, 07:25 AM
  2. Santa Cruz Blur LTc Frame weight
    By Bolty12 in forum Santa Cruz
    Replies: 9
    Last Post: 10-07-2011, 06:13 PM
  3. Replies: 48
    Last Post: 08-30-2011, 04:39 AM
  4. Want to buy Santa Cruz Blur LT frame...Question
    By VonMnt in forum Bike and Frame discussion
    Replies: 1
    Last Post: 06-23-2011, 01:06 PM
  5. Price of a Santa Cruz 2006 4X Blur frame only ???
    By Roger Serafin in forum Santa Cruz
    Replies: 3
    Last Post: 05-19-2011, 07:51 PM

Posting Permissions

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