I worked at a shop once that had a table set up for this sort of repair. It was a series of wooden blocks some supportive and some with notches to hold and support tubes/frames. On your De Rosa, the downtube would be set parallel to the table top and the two ends of the DT supported by blocking. A series of wide notched blocks would then be placed on the top side of the DT and these would be held by long C-clamps. It would then be like removing a bend from a rim---slowly and sequentially the 3 or 4 C-clamps would be tightened and would gradually realign the tube. Obviously a slow and careful process to align and not over compensate. The method also puts little or no stress on other frame elements. The process and machinery were simple, inexpensive and could be duplicated with any long work bench etc.....if you were closer I'd say bring it on over and let's fix it up.
On Sat, Mar 1, 2008 at 11:48 PM, Steve Birmingham <
> I haven't the experience Dale has, but I also think the bend is
> I'd certainly trust it once it was fixed but maybe with regular
> But I'm not so sure the frame jack pushing along the downtube would work
> this bend.
> I picture it like trying to straighten a bent spoke by tightening it.
> get tension, but
> it will still be bent., and return to bent once the tension is off. I've
> actually tried it with dead soft mild steel,(and 304 stainless) and just
> pulling won't straighten a bend like that in the soft stuff.
> On the other hand, working it with some wooden blocks with grooves cut to
> give the tube proper support
> till it was straight should be easy.
> Steve Birmingham
> Lowell, Ma
> Date: Sat, 01 Mar 2008 21:47:37 -0500
> From: Dale Brown <firstname.lastname@example.org>
> To: email@example.com, firstname.lastname@example.org,
> Subject: [CR]de rosa vs pothole
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> Guys, in all my 36 years in the biz, I have never quite seen a down tube
> just bow like that!
> All the head on pile ups and smack into something or other crashes I have
> seen, have wrinkled that DT just below the lower head lug.
> That sort of long gradual curve is something you should be able to work
> with. I think it can be bent back.
> As Brad says, I might reach for the fork jack... Actually not exactly the
> FORK jack but I think Park or Bicycle Research had a tool with which you
> removed the fork (leave headset cups in) insert a steel rod in the head
> and then use the jack pushing against and away from the bb shell. It
> on the frame alone and would equal in the opposite direction, the force
> which caused the damage.
> Of course, you also need to check the fork too; looking at the pics, it is
> possible it got tweaked a little as well......
> Dale Brown
> cycles de ORO Bike Shop
> 1410 Mill Street
> Greensboro, North Carolina 27408 USA
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