Sunday, September 26, 2010

Greg Curnoe Bike's Fork

For the past week or so I've been working on the Curnoe bike's fork. It's been a bit of a pain. First, the steerer/crown joint was decidedly tricky. I decided to leave the cast-in lip in place on the underside of the crown, in order to line up the bottom of the crown with the water bottle boss I'd added to the bottom of the steerer as a fender mounting point. Unfortunately, this made adding silver tricky (since the silver needed to turn a 90 degree corner before beginning its journey to the other side of the joint.) I'm not entirely sure what kind of penetration I got in the joint, but it seems to be adequate.

Then, raking the blades and brazing in the dropouts was tricky. This was my first time using the fork bending mandrel, and it was a learning experience. My first blade came out pointing off about 15 degrees off-axis — one for the scrap heap. I thought I had the the next two matched in rake, but in the fork fixture it was clear they were off by a few millimetres. This resulted in one of my dropouts being cocked a bit, but I was able to clear that up with some creative filing.

The next step was brazing on the Mafac bosses, which went smoothly enough, and then brazing in the fork blades, which actually went very well (there's the fork in the jig, about to have the blades brazed in). I did a very slow preheat, and experimented with using different flame sizes for different parts of the joint, and this was very successful. I got a lot of silver in there!

Here's a close look at the crown post-brazing. Doing the bosses first makes a certain amount of sense, since trying to brass-braze them after doing the crown/blades would melt the silver and make a mess. Speaking of messes, you can see quite a bit of burnt flux around the brake hole. Filling these holes is a gigantic pain, since you need to get the steerer and crown up to brazing temperature, and they're both massive and slow to heat. I did manage to fill the front hole, but the rear simply wouldn't go. I'll get Noah to fill it with contrasting paint instead! For future reference, I will remember to fill these holes while brazing the crown/steerer joint, when everything is already up to temperature. Also visible in the picture is my fender mounting point at the bottom of the steerer.

Here is how the fork came out. That's Greg Curnoe Bike's front wheel, a radially-laced 32-hole Mavic SSC tubular rim with a Dugast 27mm tire. The crown is a Richard Sachs Newvex that I significantly reshaped. I really like the bend our incredibly simple wooden mandrel produces. (This fork has 51mm of rake.)

A close up at the "pool-style" dropout attachment. I would call it "French-style," but it seems that French builders filed in deeper radii than I did here. I like the way this looks, and it very closely resembles the style on the original Mariposa. (By the way: the hub is a polished Deore DX [cost, about $5], and the skewer is an old Camapgnolo. I love the conical nut, and want another matching one for the rear!)

Below you can see the cool triangle-accented top of the Newvex crown (the triangles will be painted in contrasting yellow to the fork's green colour), and a mounted brake. I'm going to use a NOS Competition on the finished bike, but these well-used ones confirmed that the bosses were mounted in correct alignment—no interference between the brake arms. I left quite a bit of clearance on this fork, since I'm going to mount fenders at least some of the time. Actually, this bike will be very versatile—you could even use it for cyclocross if you were so inclined!

Of course, the bike in the painting has neither fenders nor lots of clearance. There is quite a bit of compromise, in fact, in adapting a cool-looking painting-bike to a bike I will actually want to ride (and I'll ride it a lot, since my rides are increasingly fast and shortish, and this will be a sort of 'racing' bike). The Curnoe bike is a time trial bike; mine has two chainrings, clearance for fat tires and fenders, a wider crown, Mafac bosses, etc.

But I can justify most of my changes. For instance, the tires in the Curnoe painting are bright orange. Bright orange tires do not exist in the real world—but you can quite easily have fenders painted bright orange. Having (orange) fenders not only makes the bike look more like the painting, but also makes the bike more useful. I am going to do the fastback seatstay attachment, which might seem like a weird move for a bike with fenders. The main reason to do a fastback it is that it's probably the most distinctive feature of the bike in the painting. But it's also practical for this bike; the fastback puts the seat stays close together at the brake bridge area, which means I'll be able to mount my Mafac bosses on the centre of the stays instead of on the inside, which can be a bit precarious. There should still be plenty of clearance for the 37mm Velo Orange fenders (which will indeed be orange) I'm planning on using.

Thursday, September 23, 2010

Mike Barry's Greg Curnoe bike

While progress been underway on my own Curnoe bike (updates soon), Mike Barry has completed the first of two replicas of Greg Curnoe's famous "Close the 49th Parallel" Mariposa (see the story on Mike's blog). Mike was commissioned do do these replicas by Toronto artist Paul Butler. The finished product is, indeed, a work of art.

Here is Curnoe's painting of the yellow Mariposa:

And here are a bunch of pictures of the replica. The mustardy yellow colour is really wonderful—a colour you would never think of painting a bike today, but extremely distinctive. If only he could find a green freewheel! (Remember, though: this is a replica of the bike, not the bike in the painting...)

Saturday, September 11, 2010

Jos is Off, Back to Greg C

I dropped my Jocelyn Lovell bike off with Noah at Velocolour on Thursday. I brought my camera to capture the incredibleness of the Mariposa shop (where Noah paints)—but as usual, it was so very incredible that I forgot to take any pictures.

The best thing I saw was a replica of Greg Curnoe's Mariposa road bike that Mike Barry was recently commissioned to build. It was painted a truly beautiful and utterly un-fashionable mustard yellow colour. No one would even consider painting a bike that colour today. When I found out about this whole replica project, I was a bit surprised—since I had my own Greg Curnoe replica project in mind. But mine is a bit different—different bike, different "bike of a painting" concept.

Anyway, seeing that bike inspired me to get back to work on my Greg Curnoe bike, whose front triangle I've already finished. Time now for the rear triangle. It's pretty clear in the model-painting that the bike has "French-style" dropout attachments. I'd never done those before, but was looking forward to trying them, since if done right it seemed like they'd require almost no cleanup. At right is the dropout and the stay ready  to go. (I must say, I find this style of dropout attachment—and this picture—pretty gorgeous.)

As it generally has these days, brazing went well. I was able to fill the stay with perfectly even and smooth pools of brass, as this photo (with Curnoe's blurred out, self-portraited face in the background) shows:

But this photo, taken right after brazing shows something else.

In all my excitement to try out this new dropout style, I forgot to properly square my dropouts. You can see in this picture that the slots are not at all parallel. I did this yesterday and brooded over it all evening. Today, after a nice long ride out in the Goodwood area, I went in to the shop to fix it.

This too went pretty well. I put the non-drive dropout in the vise, heated up the joint (without fluxing it, since I didn't want my beautiful little pools to run out), and once it was red, just pushed the stay down. I checked it after cooling, and now it's pretty much right. This opened up a little gap on the top of the dropout/CS joint where I'd pulled down; I filled it with silver. This is a poorly lit picture, but it shows a now properly-squared dropout and some very nice silver-coated "pools."

I also did my trick of adding a fender-mounting boss to the underside of the steerer, and in fact got my fork crown/steerer joint tacked before realizing that Martin was closing the shop. It sits fluxed and tacked on the floor of the shop, waiting for my return on Tuesday to finish it off. Then I'll build the fork, then finish off the rear triangle (with its exciting fastback attachment!).

Sunday, September 5, 2010

Last Steps Before Paint

I did a bit more filing in the shop on Friday, and cut a drain hole in the BB. My attempt to put a serial number onto the underside of the BB was not particularly successful. Since we don't have numbers, I managed to write a very sloppy, uneven "AH TWO," and then added "SEP IO," using the letters "I" and "O" to indicate 2010. I had planned to write "Jocelyn Lovell Bike," but neither my skills nor space permitted.

I also did some "correcting" of my lug filing. I think I went a bit crazy with Niles's lug filing, but I'm beginning to worry I've not gone nuts enough on JL's lugs. They seem a bit lumpy, and tend to taper toward the edge. I think I'll go in and just clean up a few little spots, and then bring the frame to Noah at Velocolour on Tuesday or Wednesday.

Since then I've been finalizing my decal sizes and shapes. On Niles I used different head tube and seat tube decal shapes (indeed, I used a headbadge on Niles), but for this bike I'll just use a simplified shape, adding a slanting line (to suggest an A and an H) to the nautical symbol indicating "A Gale From the North" as used in the British writer and painter Wyndham Lewis's 1914 small magazine, BLAST. Here is my decal, next to the original.

(Speaking of Wyndham Lewis, I have an article about him in the current issue of The Walrus, Canada's answer to the New Yorker and Harper's. Buy a copy!)

I'm going to keep my downtube decal excatly the same. I'll put the logo on the head tube, seat tube, and on the painted pump also. I've experimented with scaling the logo to the tube it sits on, but it seems to look best if all the decals are the same size—except on the 7/8" pump tube, which does need a 10% smaller decal.

Other things: I brought my crankset and BB in to the shop on Friday to test that the clearance would be okay. I also "converted" the Nuovo Record strada cranks to pista by sawing off the tabs for the inner chainring. Unfortunately, after doing all this, I realized that the lovely old 48T chainring I'd purchased on eBay as a 1/8" ring, is actually 3/32".

I have a nice 1/8" cog for the back, and don't really want to switch to 3/32". So I thought about using this Stronglight/TA track setup. Then I thought about using the Dura Ace track setup currently on Niles.

It's a bit "modern"-looking, but it's still nice. I'll probably use it. And hey, according to this picture, Jocelyn Lovell used (two!) Dura Ace track cranks:

I had been planning on using these Campagnolo Triomphe brake levers—

—but now that I'm not planning on using the Campagnolo cranks, I think I'll use my Shimano 105 BL-1050 non-aero levers instead:

The question, now, is how many brake levers to use, and what to do with the second one if I do use it. I came across this incredible picture of Mike Barry on his son's blog:

That's Mike going hard in a 1950s time trial in Britain. He's on a bike almost exactly like the one I just made: one brake, rear-facing track ends, etc. He's only got one brake lever (on the right side!). I'm definitely tempted to use this bike for a road time trial or two next year (imagine going up against awful modern time trial bikes!). But I also want to use the bike for a hill-climbing training ride I do fairly often. This photo from the British Hill Climb Championships shows someone on a fixed gear bike with two levers, though the blade is taken off one of them:

But I often find that bladeless levers both look odd and feel odd when you're pulling on them out of the saddle—I like to wrap my fingers around the blade. So what I think I'll do is find a way of fixing the blade in place—so that it won't rattle when going over bumps—rather than removing it. Olivier and I took the first steps toward making something like this today:

On the left is the housing stop that sits in the BL-1050 brakes. On the right is a highly technical illustration of something that would sit in the same place—but instead of acting as a housing stop, would just pinch the brake cable and prevent the blade from moving. (It also fairly closely resembles my logo...)

That's it for now. I'll bring it in for paint soon!

Thursday, September 2, 2010

Filing, Day One

I took care of most of it today—just a bit of cleaning up here and there. Here's how he's looking today.

The seat cluster, all cleaned up. I'm really happy with how this all came out...

The fork with brazed-on Mafac bosses. Huge head tube!

Slotless front dropouts.

Crown and lower headlug.

From above. (There's some waviness to take out of that lower headlug...)

And now, some lovely hand-drawn colour scheme mockups. (Those are fork crowns seen from the top on the left, obviously.) I'm currently leaning toward the bottom one:

Update: I finished everything off today — it's ready for paint now! Also mounted the cranks to make sure clearance was okay. It is—but the NOS Nuovo Record 48T track chainring I bought for this bike... is not a track chainring! It's a 3/32". I can't believe I didn't notice!

Anyway, here are my latest thoughts on colour scheme, including a painted Silca pump:

Wednesday, September 1, 2010

It's All Over But the Filing

Today was another long, hot day in the shop—but I completed all the actual brazing for my second frame, a track-like fixed gear I'm now thinking of as "Jocelyn Lovell Bike."

Toronto is suffering through a three-day late-August heat wave, and today felt to me like the hottest of them. I was planning on doing some lug filing, but I don't have the patience when it's this hot. And it didn't really have time, either. Mitering the seatstay bridge, brazing it in place, filling all my vent holes, and brazing in a pair of watter bottle bosses took almost all day. I just had a bit of time to work on the seatstay/dropout finishing.

The photo at right was taken after I brazed in the water bottle bosses. It looks like a frog with a fire in its belly. It also accurately describes what it was like to be in my small, non-air conditioned shop on a 33 degree day with a torch in my hand.

The first thing I did today was miter and locate the seatstay bridge. This is a reasonably tricky, since the two miters need to be in phase with one another, and the angle needs to be right. I scribed a line on the 5/16" tube to orient the miters to one another; and my smallest half-round file just happened to have a curve corresponding to the diameter of the 14mm stays. With a little bit of work, I had it right. Brazing went exceptionally well; the fillet is very small and clean. Unfortunately the stay came out very slightly crooked; but probably not by enough for anyone but me to notice. (The good news is that the wheel sits perfectly straight in the completed rear triangle.) Here's the bridge, after the flux came off (no cleanup):

In that picture you can see the second thing I worked on: filling vent holes. This is a very fun activity—you drill the vent holes so that they correspond to the diameter of brass rod, and then to fill them you stick the rod in and silver-braze it in place. It's a fun challenge to see if you can braze the rod in without bending it excessively (it weakens as it heats up.) It's a good exercise in heat control.

This one, as you can see, bent a lot! This is a fat 3/32" rod, and it was very long and heavy. (I like this picture!)

Next up were the water bottle bosses. I only decided to put these in at the last moment. I wanted to keep things as "clean" as possible on this bike—but then I thought it was a bit stupid to deliberately limit my options distance-wise by not putting on bosses. I decided to use star reinforcers for these bosses—and let me tell you, it's a massive pain enlarging the holes in them to accept the bosses. They're tiny and thin and extremely hard to hold in a vise. (I ended up using rubber soft jaws, which worked acceptably.) My brazing was again pretty perfect—I'm having a good run!

It will take a day or two to get everything perfectly filed (I'll try not to go too nuts.) Then comes the all-important matter of finalizing the colour scheme!