Bike From Scratch

Day 10, already, really? It feels like the pace has been picking up the last few days. I went from a pile of unconnected tubes on Sunday to a almost complete looking bike today. I had two missions today, a binder bolt for my bike, and getting my chain stays installed. Both were a success.

The day started out pretty slow going. I think all of us are feeling the lack of sleep and missing our families. The mood in the shop is jovial though and we are enjoying the time we have remaining. If you end up taking Doug’s class and staying in his parents place, the coffee pot is a gift from the class of Feb 2010, use it wisely.

This morning I got to work on getting my binder attached to the top of my seat tube. We propped it up against the bike using some square blocks on the alignment table. Then I tacked it in place using brass. After I was satisfied that it was straight and looked good I headed off to do a fillet braze for the bolt. This braze was a bit more fun that the main tube brazes because I got to do more shaping. The underside of the binder has to be kept smaller so my stays can attach underneath it. The top needs to be filled out more to avoid a really harsh edge. I’m trying to avoid any harsh edges / sharp corners up where at the top of the triangle. The braze went swimmingly, Herbie was around for the assist if I needed it and to provide instructions / advise on the look of the joint.

Binder attached, just needs some finish filing.

The next major task of the day was to attach the seat stays. I was offered the choice of using the Anvil fixture or using Doug’s method that he learned in England when he was studying there. Doug’s method is longer but involves little in the way of extra tools (in fact I’m building the tool I need to repeat this process at home while I’m here). The process involves a lot of measuring, and being paranoid I was triple or quadruple checking everything. After all was said and done I came out with rear dropouts that put the wheel about .5mm off of center. I can fix this with a bit of filing on one of the drop outs (or I could leave it alone as this is a perfectly reasonable amount I suppose). I suspect I’ll file it as it will bug me if I don’t fix it. I’m really bothered that I didn’t get the rear end exactly correct.

Since we had some trouble with this method the class members and I have been brainstorming about possible causes. The current theory is that when we tack in the second stay something shrinks or expands and contracts and “sucks” the stay in a bit further. We found out after the fact that Doug does a bit of adjustment during the tacking phase that we didn’t do…. More info for the next bike I guess.

Attaching seat stays

I ended the evening with a bit of filing on my head tube to top tube fillet and making sure that I was all set to go for seat stays tomorrow. First I’ll need to cut the seat post slot, and then I’ll get to mitering for the attachment to the binder. I suspect I’ll also be adding some braze ons as well. I need a derailleur hanger and a few water bottle bosses. Hopefully these will be pretty quick and drama free. The other big task for tomorrow is getting my fork converted from 1 inch to 1 1/8 inch steerer. I detect lots of filing in my future for this.