Removing Cable Stops

swallow

Hi all - didnt know where to put this thread, so here it is....

I am just starting putting together a new townie bike project (mtb based of course )

having bought a cheapie mongoose tyax frame from ebay (£3.20!) I have just spent a happy two hours with the nitromors and it is now bare. The project is based around an internal hub gear, and hydraulic discs, so I have no need for the cable stops that are welded on, nor for that matter the canti bosses.
I was planning to get the Dremmel out and grind them all flush but I need to know...

....would the welds have weakened the frame? I can see how they wouldnt weaken the frame whilst the stops/bosses are still there as material has been added. But if I grind them all off so the tube profiles are smooth, will I then be left with a much weakened frame?

also I was thinking of routing hoses inside the frame "a la Klein" as this is a heavyish alloy frame, would it stand a little drilling?

Any tips/pointers etc MUCH appreciated

snotty badger

I carefully ground the cable stops of my DMR, you have nothing to worry about as you won't be putting a great ammount of heat into the frame.

If it does worry you do a little at a time.


My cablestops were brazed on but the canti/v bosses were welded.

snotty badger

Oh and its easier to remove material than to add it so don't go nuts and gouge the frame!

nicklouse

be aware that some of the stops might be needed.

before cutting do a part build as once they are cut they are gone.

dave_hill

swallow wrote:

would the welds have weakened the frame? I can see how they wouldnt weaken the frame whilst the stops/bosses are still there as material has been added. But if I grind them all off so the tube profiles are smooth, will I then be left with a much weakened frame?

You shouldn't have any problems removing bosses. Aluminium frames are heat treated after welded to normalise the crystalline structure - in effect the weld becomes part of the frame. You could say that all aluminium frames are actually monocoque construction!

Proceed carefully with the Dremel and leave plenty of material on the frame. Finish off with a file and/or a rotary wire brush to blend the remains into the frame. Judicious use of body filler and wet-and-dry paper will remove any final scores or marks.

swallow wrote:

also I was thinking of routing hoses inside the frame "a la Klein" as this is a heavyish alloy frame, would it stand a little drilling?

Absolutely not. DO NOT be tempted to drill any holes in the frame - this would set up stress risers and possibly lead to cracking.

swallow

thanks all - looks like I'll take off the canti bosses and front derailleur cable stop. It has two sets of triple cable stops on top of the top tube which I think I will just modify into hose guides for the hub cable and back hose.

I won't drill any holes then but I want to remove the two sets of bottle bosses - these are steel or some other metal inserts - Would I be ok to drill these out and fill with something nice and strong like JBWeld?

dave_hill

swallow wrote:

Would I be ok to drill these out and fill with something nice and strong like JBWeld?

No.

If you drill them out then you'll end up with holes in the frame!!! JB Weld is about as strong as a damp tissue in comparison to the rest of the frame, it's an epoxy plastic!

If you're really that bothered, (carefully) file the bosses flush with the rest of the frame then fill the holes with body filler like Isopon P38. Then sand it smooth and paint over.