It's been a while since someone has posted about actually building a bike so, thought I would do one.
The Backstory:
There is a velodrome in Redmond, near Seattle, and they want to add to their fleet of rental bikes for their Junior program. After talking with my accountant, insurance agent and forming an LLC, I will be building these framesets and donating them to the velodrome. This sort of sets me up to also start a business making framesets so, I've created Draper Cycles LLC. I'll go more into the expectations of that later.
A local shop is giving build kits with wheels, bars, cranks etc. and Seattle Powdercoating is giving a deal on finishing. I have had all my frames finished there and they do great work even on lugs on other details where powdercoating can obscure the details. Prices are very good and they are fast.
My previous 9 bikes have been built at a rate of about 2 per year so, now I need to ramp up to 4 framesets completed by the first week of April. At least track frames are fairly simple as there aren't braze on bits. I am having fun with the challenge of 'production-izing' my process and thinking about how to do things more consistently.
Progress so far:
The first step was a design obviously. I use RattleCAD and print out on extra large paper. I wish I could print out full sized but, I don't have a printer that large.
These bikes are for kids from 9-14 years old. The current bikes were built about 15 years ago and have horizontal top tubes which limits the sizing on the lower end. They also have 650c wheels. They want steep-ish sloping top tubes and more standard 700c wheels. The bikes will be fillet brazed as I won't have time to manipulate a bunch of lugs. I've attached the preliminary drawing. I started from other production track bike geometry and tweaked slightly to shorten them up a bit without creating too much toe overlap or making them too twitchy etc. I will be visiting the velodrome storage shed tomorrow to take measurements from their current bikes - although the current bikes are 650c wheels so, really I will only be looking at the reach and stack dimensions as well as wear patterns on dropouts and that sort of thing. From these measurements, I will finalized the drawings and may tweak other details.
I'm using Vari-wall tubing in 1" top tube and 1-1/8" downtube with fairly thick walls so they are dent resistant. These bikes will take a beating over the years.
I wanted them to be somewhat traditional track frames so, I am using track crown and round blades from Nova and round stays and cast fork ends in the back.
[/url]
I didn't think I would have time to make and braze stainless faces on each fork end so, I found some thick fork ends that should work fine.
These bikes will have a separate serial number sequence. These are brazed to the left side of the seattube 5-6cm above the BB shell. They get polished up and are not coated over.
The first thing I do when I receive in materials is to 'play' with them. This includes filing off any casting marks or surface imperfections. I measure butts and just generally make sure they are what I ordered and they work together as expected or I understand what manipulations will need to happen. The first real step is to 'blueprint' the BB shell. I made a little bar that allows me to measure the insides of the shell sockets so I can identify the centerline of the frame. I scribe a mark on the outside and center punch the shell to give a reference for when the triangle eventually goes back on the alignment table. I verify the angles of the sockets. At this time I clean up shorelines and drill drain holes and add any carvings that are required.
Then I do the same with the fork crown and then I build the fork.
4 forks matched up and ready to be prepped and brazed.
Stay tuned.