kirk build part numbers anyone

[jimo746]

Re:

I've not ridden the Kirk i recently picked up, still a few small jobs to do on it.
the previous one though (a black 400 model) I thought rode "OK", nothing special, it felt a bit dull or rather there was a lack of liveliness to the ride quality, didn't stop me fitting a set of Bombers and ragging it around the red/black routes at a local trail centre though :twisted:

 

[Justonemorebike]

Re:

Thanks for the website link jimo746

From the sectional cutaway pictures from there and examination of my own frame and another a friend appeared with tonight i can see where the flex on some frames probably comes /came from. Assuming you were lucky and got a good casting the lower 4 sided box beam is only 4 sided because of a glued in insert. The inserts glue bond appears to partially fail along the middle section so you effectivly have an I beam top and a 3 sided box beam below joining the seat tube to the steering tube. I guess if you use it like this eventually the frame will crack even if it was a good casting. I guess other people have spotted this anyone got a good way of regluing the glued insert? Separating the bond at each end without damaging anything seems to be a potential problem.

 

[jimo746]

Re:

Yeah the x-rays of the frames are quite revealing :shock:
With regards to the bonded areas... If it ain't broke....
But if it is broke, I imagine a high strength structural resin would work, or have a word with Dan Chambers on here.

 

[focomat 1c]

Re:

You make a good comment regarding the bonded in panels on the Kirk frame

There are two major panels that when correctly fitted/bonded convert the seat 'tube'
and down 'tube' from relatively weak channel sections to much stronger box sections

If the bond fails , and this is not easily spotted , then the torsional stiffness of the frame
will be compromised leading to the many adverse comments regarding ride quality

Apart from the poor ride quality , the easiest test for problems is to use a penetrant dye crack
detection kit on the edges of the two panel joints

In the event that you find any sign of separation , the only realistic long term repair would
involve heating the resin bonded panels to the point where the adhesive is weakened and
the panels can be separated from the frame . You would then have to remove all traces of the
old resin and then re-assemble the panels using a two pack adhesive such as Devcon

This type of adhesive is capable of operation in the mid 100's C without loss of strength
( varies with manufacturer ) so you would need to achieve around 175 C to weaken the bond

This is also important to note should anyone decide to powder coat a Kirk frame , as the
around 200 C required for the powder coat process will seriously degrade the adhesive ,
and the bond strength will not be recovered as it cools to room temperature