I had done servicing, repairing and modifying bicycle in my younger days but my skill and knowledge were just about that, the common bike that I had so my knowledge was quite limited. I did it through intuition and by trial and error.
More than a month ago, I bought a new mountain bike and I tried to acquire some used parts for my old neglected mountain bike. I was shocked by the questions they put to me, “How many holes? 32, 36, 7 speed, 8 speed, 9 speed?” And many more. Needless to say when I reached home I started to educate myself through the internet. Thanks to all those gurus on YouTube, I am more wiser now, know some finer points and have the knowledge on how to lace and truing a bicycle wheel. This is the part of the skill that I have yet to experience and manage to do it myself.
The intention to get my long neglected mountain bike rebuild had changed, I decided to build a cyclo-cross instead. Not exactly like it but at least in the intended usage. Only the frame, pedals and the cycle stand of the old mountain bike were used, the rest of the parts were either bought locally or through Ebay. The plan was for a disc brake version and by that I would have to make and weld a rear disc brake mount to the frame. Arc welding was out of the question, local hardware stores did not keep stock on aluminium welding rods because of the price and storage factors. Another consideration was brazing, but low temperature aluminium brazing rod was unavailable locally too. I could get it through Ebay, but the price and postage were not cheap. Apparently I was left with the last choice.
I had done brazing but not gas welding, it was new to me. After some videos on the howtos and safety factors, I was ready for it. I did some dry run on small pieces of aluminium tubes and it seemed to work well. On the other hand, working on a bigger piece was a different matter. I was reminded about heat loss effect and my lack of experience and skill. It was a struggle. In the end I managed to weld it plus melting some part of the mount and blowing a hole on the tube that I somehow managed to patch it albeit not in a neat way.
The cyclo-cross is now complete. I had learnt how to lace and truing a bicycle wheel and that complete my skill on assembling a bicycle from scratch parts. Also, I gained some knowledge and experience in gas welding aluminium pieces.