Frame Number 2 - A Fast Tourer
This is my second frame; a fast-tourer,
which will be my main commute bike, and will also be the bike I use for
training and long Audax style rides. It's built using many of the same lugs
as the track frame, but with Columbus Zona tubing (higher zoot factor than
Thron and a little lighter) and with utterly gorgeous Henry James dropouts.
I used AutoCAD to design the frame. It's 55cm square, with a 73 degree seat tube angle and 72.5 degree head tube angle. The head angle provides 57mm of trail with a 45mm fork offset (Look HS3). It was also useful to check that my cranks would clear the chainstays. Click on the drawing for a .pdf version.
I've taken a few pictures as I construct it, which I thought might be of
interest.
Firstly, the bottom bracket. The bottom bracket soldering on my first frame
wasn't very well done. I didn't get particularly good penetration, and I
fried the poor filler. This was caused mainly by using too small a tip on my
torch, and by concentrating heat too much. It works a hell of a lot better
when you use a big tip, run the gas through nice and slow, to keep the flame
temperature down, and heat the whole lug slowly and evenly. Cleaning things
so they're nice and shiny beforehand is imperative, too. The first pic is
after I'd just attached the chainstays, with flux still covering everything.
Note that there's heaps of flux, and that it's not badly charred. The second
is after some clean-up. It's by no means perfect (indeed not good enough - the seat tube socket penetration still wasn't adequate - see
the next frame), but it's better than
the first go, and it is a learning exercise, after all:
 
Here's one of my head lugs. I find head lugs and seat lugs are a lot easier to do than bottom brackets, as they have much less mass, so come up to temperature at a similar rate to the tubes. When you take your time with the preparation and
get everything clean, then there's much less clean-up to be done afterwards,
and the lugs retain their nice crisp shape. Takes lots less time to clean
things before soldering than after:
 
Next is something that I'm very proud of; a derailleur tab that I patiently filed, sanded, and polished, before mounting it to the frame. This part is stainless. Stainless is a bugger to get to wet, but if you're thorough with your preparation, it can be very rewarding. Again, reasonably large tip, slow gas flow, broad flame, heaps of flux, and scrub everything within an inch of it's life with 120 grit emery before you even think of lighting the torch. Afterwards, I simply soaked in boiling water to remove the flux, then cleaned up the edges with 400 grit emery, followed by 800, 1200, and finally Brasso:
My dropouts. These are Henry James ones, which are cast in stainless steel. To put them on the end of the chainstay, I first filed the inside of the chainstay and outside of the plug to get them to fit, then put a little spring of 56 percent silver rod up the chainstay, with a big gob of white flux, more flux on the outside, then heated gently until the filler came out the gap. This way I know there's solid filler the whole depth of the join:
 
After a quick wipe with 120 grit emery, there's just a thin gold line to indicate the join:
The seatstay plug was much the same, though because it was smaller in diameter than the inside of the stays, I first made a sleeve to fit it, soldered this on the plug, then repeated the same exercise as with the chainstays. A final touch was to add a stainless boss for a pannier rack. This is 8mm long, and tapped M5 all the way through:
I also made a chainstay bridge, from a length of cutoff seat-stay. This was mitred to fit the chainstays, then cross-drilled. I put a piece of 10mm diameter stainless rod through the hole, which I drilled and tapped M5. This will be useful for fitting mudguards, in the unlikely event that it ever rains in Sydney:
The brake bridge uses a pair of neat little diamond reinforcement thingies, which I bought along with the brake bridge. I found my 6" half round file is the same diameter as the seat stays, so made mitering a snap. I also put more of my stainless rack bosses on, this time inserted through the stays so I can mount a rack from either side. This is most definitely a touring bike:
A picture of the whole thing. I've put nice retro-grouch downtube gear levers on, to satisfy Hippy.
And again painted, with Imron red and clear-coat. I bought myself an Iwata HP-BCS airbrush for this frame, which uses a 0.5mm nozzle, so is heaps more controllable than the generic "touch-up" gun I'd used previously, with its 1.2mm nozzle. No decals, as the decals I'd done previously (predominately blue) didn't look so great on red. I may make some more decals, but have to work up the enthusiasm first.
Here's a nice pic of the rear end, showing off the dropouts and rack mounts. There was a lot of masking to be done.
A couple of little stainless pads (polished of course) are soldered in position to keep the Zefal HPX pump from marring the paint. The other end of the pump is located with a small stainless peg.
And a sexy polished stainless stem, painted red to match the frame. The stem was bought as a kit from Ceeway, composing cast stainless lugs and stainless tube. I filed the casting irregularities out of the lugs, then sanded them with progressively finer grades of emery, supported with balsa sanding blocks. Finally, I cut the tube to length, mitred it, and brazed it together with 56% silver, before polishing and painting. This serves as a good prelude for the sort of construction that my next couple of frames will employ; polished stainless lugs with painted tubes.
A few pictures of the whole thing, built up with Campy Chorus and Record parts. It's really comfortable, and handles beautifully. One of those bikes that encourages you to ride along no-hands. This geometry is just right for eating up the miles. Just the ticket for those long Audax rides. It also climbs and descends really well. The relatively long wheelbase (100cm) makes it nice and stable at high speed, while the 57mm (neutral) trail allows me to push it into corners with a minimum of body english, unlike my Colnago, which corners like a cow. Amazing how quickly you get used to using down-tube shifters again, too. Alas, all good things eventually come to an end (sometimes prematurely) as we'll see in the next installment.
And finally, me and my bike, looking slightly worn, dismounting at the end of my first 400, at the
Great Southern Randonee, held along the Great Ocean Road in Victoria, in
October 2004. The bike fared a lot better than I did. At this point I was having a little difficulty walking,
but I'm sure my bike would have happily done another 400 :)
Go on to Frame number 3, a replacement
for this one when it broke after 10,000km.
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