The bike construction has moved on again. I have made some good progress, and some not so good.. but I want to tell everything as it is and not how I want it to be..
The not so good first. ‘The Bad’
After practicing my first ever TIG welding on some scraps of tube, I now felt confident enough to have a go at tacking the bottom bracket to the down tube and seat tube. However.. given the number of factors that come into play, it proved to be more tricky than anticipated. TIG welding requires Argon gas (an inert gas, which helps the weld quality and restrict damage to the metal) However unless you sign up to a replaceable large cylinder rental scheme, you typically need to purchase small disposable cylinders.
These cylinders are consumed very quickly with TIG, and to cut a long story short, I blew a hole in the down tube, at the mitre. (It was a bad feeling! I guess anyone that has any experience at welding, knows how quickly something like this can happen)
I decided to cut my losses and re-trim the mitre, in effect making the tube shorter. (Something I don’t want to happen too many times, as the bike will be more suited to a rider the size of a 5 year old!
Anyway.. re-trim complete, I managed to tack the tubes in place on the BB (still keeping my options open as to whether I make some lugs to catch the chain stays, or whether I attempt to fillet braze them.
And so, the rest of the front part of the frame, Down tube to Steerer tube and top tube to steerer tube and seat tube, are to be held in place with Lugs, which are brazed into place with silver solder.
After acquiring the solder, and flux, I set to work brazing these in place. This part of the build seems to have gone very well, and has been very enjoyable to too. (It certainly won’t earn prizes for presentation, but seems to be a very strong part of the job) Looking down and across the frame, from all angles, I can’t see any twist either, which is also a plus! I was going to make a jig, to facilitate alignment, but using lugs for the construction seems to have aided this considerably.
You will see in the photo’s how the
has progressed. It will almost be a shame to paint it (if I get that far! And hopefully not yellow!)
Well, I guess that’s me, and hopefully not the bike!
To sum up, I still think I am on course with the build and hopefully not too many ‘set backs’ to come, but no doubt there will still be issues that arise, that this wannabe bike builder has not yet thought of.
In the final photo you will see a prediction of how the bike will look. I have decided to let the seat stays run past and onto the top tube. (GT bikes are often constructed in this manner, and I guess I like the look)
Next time, I hope to cover, assembling the rear triangle and silver brazing the horizontal dropouts, and with a bit of luck, fixing to the bottom bracket (either by fillet braizing or by welded and brazed home-made lugs)
Hopefully see some of you at the Christmas meal out at the weekend..
Safe riding in the mean time!