B.T.O.

Been busy with the day job and building frames at night so I've missed a few blog days! Good progress has been made though, John's frame is starting to resemble a Bicycle Type Object! A little extra miter work here: double compound miters on the seat tube and down tube. Why? No good reason other than it looks neat inside the BB shell. A lot of folks will just put the extra cut in the seat tube, and that's fine, it just won't look as cool later. Although, the only people who will ever see it are me and Jogn, but still.........
Seat tube brazed in here and getting one of the 40-50 alignment checks a frame gets through the build process. Nice and square here!
View from inside the BB after the downtube is brazed in- it's the little things......
Top tube mitered and fitted. I like to be able to rotate the frame for this braze, so the frame is clamped in a workstand that allows me to turn it whichever way I need.
A trip to the Morroni jig to get the chainstays fitted up. I love this huge chuck of machined steel, there's only one other jig like this in use today. But I do know where another one is sitting and can be had for a song!

Starting the front triangle

Here's how I like to start the front triangle, the down tube to head tube connection. All the frame's geometry follows this angle, so it's important to get it right. A perfect fit, with no gaps in the miter is essential for maximum strength and alignment. For this frame, the angle has to be 58.5, a typical angle for a smallish frame and only half a degree off from the angle of the lug- just a tiny bit of tweaking and it will all go together perfectly. A light-tight fit done with only a hacksaw and a file.
All brazed up! It looks like hell with the flux still on it, but trust me, it's a nice braze!

Lining up the angle with the blue print- spot on! If it were off, I'd have to cold set it (read: bend) something I absolutely hate to do and something I haven't had to do since my first frame. If the miter is right and the proper brazing sequence is followed, it will be right every time.

You can also see the water bottle bosses have been brazed in too- this is another one of the little things you do to before the frame is together, it makes it easier to maintain alignment later on. Building frames comes down to the millimeter, so every little bit helps!

Saturday night blog down.....

Time to personalize this a bit before the big brazing is underway: Drawn on.
Drilled out.
Excess cut away- only broke two blades!
Approximately 3,476 file strokes later and the Dark Knight approves!

Subs

Getting the seat stays, chain stays, and fork blades sorted. The seatstays will have the traditional caps- made from scratch to give it the custom flair. Because, as you must know, every custom has to have the required amount of flair.

Here you see the initial cut out. It kinda makes the stay look like a big hypodermic needle, huh? A blurry pic of a scrap piece of seat stay brazed in place. I like to use this diameter because it gives the cap a more scalloped look.Excess tube cut away and a bit of file work later......and we have our cap!

Got to working and left the camera in the house for the chain stays and blades. Blades have been raked to 50mm, with a nice curve to them.

Also, you can see I've used two types of dropouts. The fronts are the plug-in type and the rears are attached by cutting a slot in the stay and then filling the gaps with brass. One thing I don't like is drops that don't match between the front and back, so I spent quite a bit of time blending in the rears to balance with the front. Once painted, thy will look like a matching set.

Next is lug prep, miters, and some real working shots of the greatest frame jig ever.

First Steps

Ah, here we are, on the eve of a new frame build....gotta love it! This will be John's fixed gear commuter/long ride/fun bike. Since John can't be around to see the progress first hand, I though a little on-line build chronicle was in order.
After all the dimensions and geometry is hashed out, I draw up a full size blueprint for the frame- no computer needed.
Then, all the tubes have to be cleaned inside and out and inspected. I look for any imperfections, mark the butt lengths, check the tubes for straightness (by the way, no tubeset is perfectly straight), and orient the bows in the tubing so that when the frame is built the bows won't affect the alignment. I'm using a Dedacciai tubeset here, and as is typical for this brand, everything is very nice and within 1mm of being true.

Laying the tubes against the blue print to balance the butted sections and make the marks for the rough cuts....looks like there's a rogue spider on there too!Checking the downtube lug angle. This lug will have to be adjusted a bit as this frame has a taller fork (fender clearance) coupled with a higher BB (pedal clearance) that puts the lug about a half degree out of spec- well within adjustment (read: bending to fit) limits though.

This is my first time using a Pacenti fork crown too, it is super nice!

Drop out mods underway.

Next: sub-assembly fabrication.

Short, but is it stupid short?

Here's the frame that didn't want to get built! Last year, I had some leftover tubing from making a curved TT that I thought might make a cool curved ST. So, I decided to make a "What if?" bike. As in "What if I built a frame with chainstays way shorter than most pro builders recommend"? I did the front triangle and then set it aside to build some other frame, then another frame, then another, until I had forgotten about this one. I unearthed it while attempting to clean the shop last month and figured it was about time to finish it.
So here it is:

Most agree the 370mm is too short for chainstays, this bike can run at 360. Head angle is 74 and the seat is an effective 73.

I also figured that since this is just a test frame, it should have some curved seatstays to see if they really help to smooth the ride.

The seatstay angle looked funny if they were to attach to the top of the seat tube, so I stuck them on the top tube in fine Hellenic fashion -named for 1920's bike builder Fred Hellens so, no, GT did not pioneer this design! They aren't attached to the seat tube at all in order to take full advantage of any compliance they might offer.
Bridge is a 16 tooth cog with requisite lightning bolt.

My favorite part of this bike is the segmented fork- my first one that narrows at the top. I expect that I'll be using this fork long after I'm done testing this frame.

Just have to pick a color now...I'm thinking bright green. What do you think?

Next up, a step by step build of John's fixed gear commuter.

"Riders on the gate......"

Yeah, BMX time baby! FINALLY had a break in our daily rains that allowed the track to dry up enough to let the first ever Live Wire BMX tear it up! It's amazing how much faster a kid is on a quality mini-BMX compared to their old 16" dept store bike.

First practice run with one of the "big" boys.

Jammin' down the start ramp- the coolest 5 year old out there! ;)

Lined up and ready for moto 1.

Riding alone after a pretty good crash at the end of moto 2- turns out the new bike is so much faster he's catching air in places he was just barely rolling over before. Still ended up with a 2nd place trophy on the day, not bad for the first time out on the new bike!

Next up, the curved seat tube fixed gear I mentioned a while back.