Bent dropput/hanger

Well, autoduel beat me to it, 4130 is heat treated, thats how you get 4130. No matter how you shake it, if you heat the metal, your going to soften it, which depending on the application will weaken, possibly strengthen it.

As far as steel breaking, U have seen steel break plenty of times. I am more suprised how much life you can get out aluminum, the life of steel has never been a suprise to me. Ive seen steel bikes last ten plus years, I have also seen steel bikes last less than a year.



I would very much like topoint out though the deformation that everyone should be able to see on the drop out. If the hanger was not part of the frame, and was a replaceable alloy unit, the drop out would not have deformed like that, it would have just been in need of a new hanger. I dont see that the added stiffness of a solid steel dropout/hanger assembly is that much of a difference in steel to make it worth not having a replaceable hanger. That may just be my opinion as well.

 

I think there are much better steel drop outs available than what is on the frame in question. These may not be a good representation.

I see where you are comming from with the replaceable hanger argument. I don't totally dissagree, but I do see merit to the other side of the argument too. I was refering to the stiffness of the hanger which can be more difficult to bend, and in some comparisons yield crisper shifting. Not all replaceable hangers are created eqaully either though. Some are very stiff and durable.

I feel really good about welding steel, and riding it with no final heat treat. I like the repairability.

I would suspect that in most all cases, this is taking place pre-welding.

 

On the note of hangers....... My last two bikes hangers Sucked hardcore ass.....KHS fr2000....... hanger bent if yo usneezed, never did that bike shift right after a shuttle or even falling over.......05 dirtbag.... not quite as bad, at least if I shifted to the low gear it would pull the derailer up and save it for the shuttle run, but never could I crash and have it be straight afterwords. The blindside has been great so far. Oh, the KHS, I paid the local fab guy to make me one out of Cromo and score it so it could still break, but it was way stiffer and wouldnt tweak from just dropping the bike.



Yes, the carbon treatment is prewelding, at the same time a bike should be heattreated post welding to give it a uniform hardness to eliminate softspots from the heat.


I was actually referring to heating the drop out to hammer it back into shape. That type of heat will most defenetly soften the metal,which"should" be re heat treated post repair.






Oh, and just to add, since we are on teh subject..... A quick ghetto heat treating you can do at home..... if you have an oven big enough......Dig a hole in the ground, put in a layer of playsand, heat the peice that has been repaired so it has a uniform heat, then put in in the hole ontop of the layer of sand, and burry it with more sand so it can cool uniformly. Leave it overnight, life isnt excellent..... but it is much inproved over no heat treating.

 

So crash replacement will cost prob wha i paid new, getting new drop outs and having the bike heat treated will be expensive, plus it will need some sort of finish after its done, (but i do like it alot). Was thinking of just buying a closeout jamis parker frame but i think i wil be back to having a crappy climbing bike. I wish I had money i would just buy a path spcial ventana and be done with it.

 

Heating an metal normally shrinks it a little, lose the strenth.. I am fabricator for off road racing prerunners. I have relaized using torch on chromoly later brings gnarly cracks.. So my old boss taught me one thing about heating chromoly.. it breaks down into tiny tiny holes inside those wall. So I recommend not to heat treat it! unless you want to add some funny looking gussets, adding more weight..

 

Well, heat treating is different than heating it alone. Heat treating is wher a metal gets its hardness from, specific heat levels, and a specific cooling rate, thats how steel gets its true strength. If you just heat it up, to whatever temp, and let it cool however... you changed the tensile strength of the metal. When I was still in the trucking ind, frame repair ont he trucks was done one of two ways. First off, its way easier than one would think to remove the frame from a big rig, not easy, but not at hard as you would think. So method number one of repairing a steel BR frame. Remove frame, make neccesary Tig welds and fill ;ossibly plate as needed to keep frame straight............ send it for heat treating....or it WILL cack at your welds...... Method two<The absolute more common way because its mad faster> Fishplating..... take some steel plates, cold cut them to shape to cover the crack..... very important to keep them from getting hot while shaping and drilling, buff the area to be repaired, lite coat of primer where you just buffed<Both sides by the way will get a plate> then drill both plates, and frame to match, coat the sides of the plates that will be mated to the frame with some sleeve retainer, bolt it on. Your done.


Oh missed one step, drill each side of the crack, that will keep it from spreading

 

You dont heat and stress relieve the welds of your cages???? Twang

 

only minium properly.. if its too hot, it can crack easy during pressure load. thats why we (tig welders) know what color to look out for while welding.. blue=too cold, orange/goldish= too hot.. we also look out where the heat goes.. so its difficult sometime on very thin wall tubing.. I mainly work on .120, .090, .060 wall 4130, and DOM steel. like someone said, heating makes the metal softer.. so if its softer, its crush like can easier. BUt as for the hanger, its thick.. I wouldnt risk, possible crack above the notch part for the rear axle.

 

update, on-one is sending me a crash replacement, 50% off . IWth shipping right now form the uk its not the greatest deal but I really like the frame, need to come up with an option to keep the hanger alive now