Well it’s day 3 and things are really happening now. At this stage of the build I’m doing lots of small things that alone don’t take very long but once grouped take a long time.

First things first – it’s time to chase the threads and face the BB. This is a very important step as all alignment is based on those two faces of the BB being dead parallel. The frame will be held by the BB on the plate and it’s these faces that it holds onto and if they are off it’s like building a house with a level that doesn’t work. I face the BB to a tolerance of .001” and then it’s ready to put on the plate.

With the BB done I put the frame on the plate and set the dropout spacing to be even from centerline but wide at 132 mm. This will allow me to braze the chainstay bridge in and this should shrink the spacing down to 130 mm where we want it. You may wonder why I haven’t put the c-stay bridge in yet. This is left out until the end for two reasons. The first is that I want to be able to set the spacing as I need it to be and once the bridge is in it becomes much more difficult. The second reason is that it makes it much easier for my big hands to get in and do the BB fillet clean up work without the bridge being in the way. So I’ll be putting it in later.

The spacing is set and it’s time to clean up the BB fillets. The method is the same as before with a rough shaping, a rough sanding, a first sanding and then last a polish with the wheel. This part of the fillet work is by far the most time consuming. It will take about an hour to go from raw c-stay fillets to the fully polished and ready to paint fillets here. That may not sound like a long time but stand bent over sanding in a tiny area and it will give you a new appreciation of how long an hour is.

With the BB finish work in the rear view mirror it’s time to move onto 100 different little things. The first of which is mitering and brazing the c-stay bridge. I also install all the braze-ons and head tube rings at this point. Note the fancy tooling holding the braze-ons in place for brazing. High tech stuff here. Once the flux is soaked off it’s time for the final machining operations. I face the head tube and clean out all the threads.

Now it’s time for the final alignment. From here on out the methods are the same as they would be with a lugged or TIG welded frame and not fillet specific. The frame gets put on the plate and checked relative to the plate to be sure that the BB, head tube, seat tube and rear dropouts are all set to the centerline of the BB. This assures that the bike will track straight and true and that you’ll be able to take your vest off while riding no-handed without ending up in the ditch.

Once everything is checked to the centerline I use “H” tools to be sure that the dropouts are concentric and parallel to one another. This is to be sure that the rear axle isn’t loaded up when you tighten the quick release skewer which will let the rear wheel spin as it should and not wear the bearings due to misalignment.

Now it’s a matter of putting a calibrated wheel into the frame and checking that the wheel is vertical and pointed dead straight ahead. With that done the last step in the alignment is to use a dropout hanger tool to check that it is straight relative to the wheel and will place the derailleur properly.

The alignment now done it’s time to do the final bit of finish work. You may have noticed that the seat tube was left long during most of the build. There is a very good reason for this. When you braze the top tube and seat stays to the seat tube the heat can distort the top of the seat tube so that it becomes oval shaped – not good. But by leaving it long the extra tube supports itself and helps keep things round. At this point of the build I cut the extra off and shape it into my style of point.

Next I check the fit of the seat post and ream it out for a good fit to the seat post and then the binder gets slotted. For slotting I make two parallel cuts with the hacksaw and voila! I have a slot. Some final shaping of the top of the seat tube and deburring and the frame is done and ready for paint.

I hope it’s obvious that I have skipped more than a few steps. I did not include everything lest you get bored and I get tired of typing – but this should give you an idea of how I build a fillet frame.

The next and final installment will be the building of the fork and some good photos of the whole deal taken in the studio. Look for that next.

Thanks again for reading.

Dave

P.S. in my last post I used the word ‘ass’ a number of times. I forgot my Mom reads the blog so sorry Mom!

This entry was posted on Friday, January 28th, 2011 at 11:33 am and is filed under Uncategorized. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.