Originally Posted by
Dave Wolfe
Joejewler - it looks like you did this the best way possible but for those that might not know -- aluminum really doesnt like 500 degree f temperatures. It loses its heat treat and turns into weak soft butter. Dont throw an aluminum hub into the oven at 500 f!!!
Ok ill take off my engineering hat now and return to eating popcorn and watching threads about poop eh
I was worried about that,.....but i'm pretty sure the outside of the steel dura ace cog got the full temp (or close anyway),.....and the hub quite a bit less as it's much larger/thicker,....etc. Heating gold jewelery parts to solder them over 35 years gives you a pretty good feel. Aluminum is a great conductor of heat, and based on how hard it was to unthread the cog i probably never got it near full temp. That's what i was going for, anyway. Keeping the wheel on my lap kept the cog to the top, and heat rises as we all know,.....so further support to my feeling that the hub threads were less impacted.
By directing the flame into the cog toward the center of the hub (air space), i'm thinking the hub threads were nearer 400 degrees,....still not prefered,.. but this was on an old schwinn hub with mavic rim with not a great deal of value anyway. That's why i decided to NOT ty this on my dura ace HF-7261 hub!
With the newly applied red permatex and full curing (in another 6 hrs),.....the thread's temper hardness have less impact than if they were holding on a regular freewheel 'sans" locking compound. I'll run the wheel see what happens!
In any case,.....i think it's worthwhile to find out. I do wish i hadn't worried about including a lockring with the initial setup,......as i would have gotten the chainline perfect and had no need to remove the cog.
Practically speaking though,.......cogs wear out so EVENTUALLY you'll be faced with having to remove one. I hope my method of removal help others to do it with the least impact on spokes and hub.