Spreading an Ally rear triangle, in the real world?

Spreading an Ally rear triangle, in the real world?

Post by A . L » Tue, 25 Jan 2000 04:00:00


I know many people say it cannot be satisfactorily done, but has anyone
'spread' their rear dropouts fron 126mm to 130mm, in an aluminium frame
(7005), and got a good result, (or even bad one) ?
I have measured the space on mine and it is just below 125mm, so each
side will need to be bent out around 2mm.Personally I dont think it will
do any harm to the frame if I do it.
The frame is not a super light expensive frame, it was 80 ukpounds
($120) so was quite cheap.It has quite thick tubing, is tig welded and
the dropouts are about 8mm thick.
If there is any chance of cracks developing,would they happen at the
bottom bracket joint?
Thanks for any replies.
Alan lee
 
 
 

Spreading an Ally rear triangle, in the real world?

Post by Roge » Tue, 25 Jan 2000 04:00:00

Quote:

> I know many people say it cannot be satisfactorily done, but has anyone
> 'spread' their rear dropouts fron 126mm to 130mm, in an aluminium frame
> (7005), and got a good result, (or even bad one) ?
> I have measured the space on mine and it is just below 125mm, so each
> side will need to be bent out around 2mm.Personally I dont think it will
> do any harm to the frame if I do it.
> The frame is not a super light expensive frame, it was 80 ukpounds
> ($120) so was quite cheap.It has quite thick tubing, is tig welded and
> the dropouts are about 8mm thick.
> If there is any chance of cracks developing,would they happen at the
> bottom bracket joint?

I would rely on the natural spring of the frame rather than trying to
cold-set it (you'd have to bend it a lot further than 2mm to get a
permanent deformation of this size).  This isn't the advice I'd give for
steel, BTW, which can and should be permanently cold-set.

I'd expect it to fail at the chainstay bridge first if it decides to
go.  It really depends on what the welds are like - it could also go at
the 'brake' bridge or the dropouts themselves could break off.
--
Roger

Web: http://freespace.***.net/roger.cantwell
ICQ: 40038278
*** Please remove 'filler' from the Reply address ***

 
 
 

Spreading an Ally rear triangle, in the real world?

Post by BRM » Tue, 25 Jan 2000 04:00:00

Back when I used to assemble a lot of Kleins they claimed alignment
tolerence of plus or minus 1mm.  I guess nobody else checked.  I often found
them to be out as much as 4mm with unsquare drop outs.  I put the Campy
alignment tools on them and cold set into place.  No failures and no
returns.  That being said, if it breaks, I never reccomended you try it!
Quote:

>I know many people say it cannot be satisfactorily done, but has anyone
>'spread' their rear dropouts fron 126mm to 130mm, in an aluminium frame
>(7005), and got a good result, (or even bad one) ?
>I have measured the space on mine and it is just below 125mm, so each
>side will need to be bent out around 2mm.Personally I dont think it will
>do any harm to the frame if I do it.
>The frame is not a super light expensive frame, it was 80 ukpounds
>($120) so was quite cheap.It has quite thick tubing, is tig welded and
>the dropouts are about 8mm thick.
>If there is any chance of cracks developing,would they happen at the
>bottom bracket joint?
>Thanks for any replies.
>Alan lee