Tuesday 6 December 2011

Local bicycle users group article on Keith's frame

Keith did a writeup on his frame, which made the front page of the Bikenorth (my local cycling club) newsletter.

Have a look:


Friday 25 November 2011

A brass headbadge

Here's a headbadge I knocked up from brass for my next frame.

The process was surprisingly simple. I started with an offcut of 1.6mm brass sheet. I polished the front surface with brasso, then cleaned it thoroughly and coated it in a thin layer of etch resist. I overlaid the black part of the little fish logo printed on clear transparency paper, and exposed the resist with ultraviolet light. Then I developed the resist to remove the unwanted stuff, put some tape across the back to protect the back, and bunged the whole thing in an etchant tank for about 30 minutes.

This setup is usually used to make circuit boards, and etch times are usually about 3-4 minutes.

Once I pulled it out of the etchant and washed the resist off, I had this:

I then rolled it to fit a headtube, cut it out, gave it a quick polish, and hey presto. The etching is remarkably deep. I confess I'm surprised at how well it turned out. It was done as a quick experiment during lunch, and I expected all the lettering to disappear.

All that remains is soldering it to the headtube and infilling the etched areas with colour.

Sunday 20 November 2011

A better dropout fixture

Up until now my jig has made use of a piece of threaded 10mm rod as the "axle" supporting the dropouts. This has been okay, but has been the most annoying thing about the jig.

So I figured I'd improve it. I noticed Alex Meade was selling dummy axles at quite reasonable prices, so figured I'd buy a couple and adapt them to my jig.

First thing I did was to turn up a sleeve to slide over the dummy axle. This is simply a piece of brass tube 50mm long, turned 19.05mm on the inside and 25mm on the outside. I made sure it was a nice accurate slip fit over Alex's axle. I used brass because it doesn't rust, is easy to work with, and is easy to soft solder.

Then I drilled and tapped a hole for an M6 grubscrew in the middle. Now the dummy axle can be held accurately in my brass tube.

I made a pair of flange pieces with 25mm holes in the middle, and 9mm holes to suit my 8020 extrusion. I used 3mm copper sheet because there was some in the scrap bin. Brass would have been fine here as well.

Then I jigged one flange piece on the axle, so it was accurately perpendicular, and soft soldered the two together. This is much like brazing, except that you use lead/tin filler and soft-solder flux. The solder melts at 180 degrees, so the pieces don't distort. Be careful to orient the tube on the flange to ensure the grub screw hole is accessible once it's all assembled.

Finally I bored a 26mm hole through the 8020 extrusion where the original 10mm hole was, and slipped the tube through. I then put the other flange on the other side of the extrusion to provide a bit more support.

If you have a thumping big bit of brass to hand, you could turn flange and tube out of one piece. I didn't, so made it out of what was kicking around.

Sunday 30 October 2011

A basic 8020 spine jig

One of the most common emails I get is "have you got drawings or plans for your jig?"

I haven't up until now, or at least not decent ones, as the jig I'm using just sort of happened, based on a series of discussions and trial-and-error between myself and a friend.

It's a fairly simple jig - it's nowhere near as user friendly as commercial ones, because there's no easy way to set angles and lengths in it. You cannot use it to design or lay out your frame. You must design the frame in CAD or similar first, then miter the tubes and set up the jig to fit the mitered tubes. Indeed pretty-much all it does do is hold the seat tube, head tube, and dropouts in plane while they're being pinned or tacked. This however is all you need to build a straight frame.

That said, it does so for not a lot of cost and not a lot of machining. There is still some machining required - you'll have to have access to a lathe, and a pedestal drill is pretty-much mandatory.

So the following picture shows the overall arrangement. Key to the design is a spine constructed from 120mm x 40mm 8020 extrusion. It's made in two pieces, with the bit at the back going down the center of the frame axis, and then the front section bolted to the side, so it's offset by 40mm.

Vertical pieces are attached to the spine for the head tube and seat tube, using simple angle brackets, which are standard 8020 parts. The verticals don't need to be at 90 degrees to the spine - they can rotate to pretty-much any angle you want, to accommodate whatever head and seat tube angle your heart desires. Onto these are mounted the bits that actually hold the frame; angle brackets and cones for the top of the seat tube and either end of the head tube, and a machined block upon which the bottom bracket fits.

The dropouts are held in place by a simple piece of 10mm threaded rod through the tail end of the spine.

So here's the parts you'll need from 8020. The distributor near us was happy to cut the extrusion accurately to length for a nominal fee. Note that it's all in metric. If you really desperately must use American fasteners etc., then you're going to have to work out how to do that yourself:

  • Spine rear piece: 360mm length of 8020 40-4012 profile extrusion.
  • Spine front piece: 860mm length of 8020 40-4012 profile extrusion.
  • Seat tube vertical: 780mm length of 8020 40-4080 profile extrusion.
  • Head tube vertical: 600mm length of 8020 40-4080 profile extrusion.
  • Small angle brackets: 4 x 40-4302 two hole 40 series inside corner brackets.
  • Large angle brackets: 3 x 40-4311 six hole center 40 series inside corner bracket.
  • T-nuts: 24 x 40-1981 economy offset t-nuts.

And stuff from any old hardware store:

  • Bolts for angle brackets: 20 x M8x1.25, 15mm bolts. Button headed capscrews are ideal. I bought hex headed bolts and have been complaining ever since.
  • Bolts for BB mounting block and head tube cones: M8x1.25, 25mm capscrews.
  • Dummy axle: 160mm length of M10 threaded rod, with six M10 nuts.
  • Bolt for seat post cone: M10 x 80mm bolt, with M10 nut. I actually used a length of M10 threaded rod here, with two nuts.
  • Bolts for holding spine together: 4 x M10 x 90mm bolts, with 4 x M10 nuts.

Here's the drilling needed for the spine:

Once that's done, just bolt the two pieces together using M10 bolts and nuts.

Here's details of the cones and BB support:

Make these pieces from mild steel. Note that two head tube cones are needed. These are sized for 31.75mm head tubes. If you're going to use other sizes, scale them proportionately or else make a cone that works with either.

The headtube cones are just bolted to the large angle pieces using M8 cap head screws. The seat tube cone is mounted using an M10 bolt, so you'll need to open the hole in the angle piece out to 10mm.

In use I find the best way to set up the jig is by laying it horizontally, loosening off the bolts holding the small angle pieces in, then sliding the verticals around to the right spot. Finally I use G clamps to pull the verticals hard up against the spine before doing up the bolts in the angle pieces - this way the verticals are held snug against the spine. Always measure the angles of the frame itself, not the jig.

Getting the vertical pieces set up just so can be a bit of a pain, but it beats the hell out of a piece of flat bar.

At the moment the dropout supports are simply a piece of 10mm threaded rod with some nuts on it. This is reasonably accurate, but I plan on making a cheek piece that I can use to bolt a proper dummy axle on with.

Wednesday 26 October 2011

Must see ad parody.

Here's a distillation of, well, every ad on telly.

Tuesday 18 October 2011

Et Voila (again)

I figured this frame was worth the effort of a decent photoshoot, so set up a background inside when the light was good (one of these days I'm going to buy some decent studio lights). Anyway, here's some finished photos of Keith's frame and forks.

Please do click on the pictures - each one brings up a huge version where you can study the detail.

Firstly an overall shot of the right side, showing the general decal layout and that gorgeous pearl blue paint.

An overall shot of the front, showing the headtube logo. The logo features our hero being chased by a bigger fish. Little fish have to swim fast, lest they be eaten by the big fish.

The head tube and fork crown, with stainless polished head lugs. The stainless is quite annoying to photograph well, as it catches all manner of reflections.

Another photo of the head lugs and crown, showing the cutout in the lower one, as well as the ergo adjusters. I'm very happy with the way the lug masking worked out.

More detail of that gorgeous lower headlug. I confess this is my favourite picture. I could look at it all day.

Moving now to the seatlug, showing the view from the back including the brake bridge.

A side shot of the seat lug, showing the seat stay attachment and a name decal for Keith. It's a bit thicker than I'd have liked ideally. Next time I think I'll organise a spray mask and paint it on with my airbrush.

I just love the way the stays worked out. Thanks to Anderson custom bikes for the inspiration.

The ultra sexy Sachs front derailleur hanger and bottom bracket.

And more detail of the rear of the bottom bracket, showing the scalloped chainstay bridge. The paint is just so blue.

Finally a shot of the rear dropouts, in nice sensible stainless, so the skewers don't bite into paint.

This frame has surpassed all my expectations. It came together really well. Keith is over the moon. I was concerned that all the stainless would look over the top, so I deliberately kept the cutouts and carving to a minimum. Note also that some of my more tongue in cheek decals (the "handmade in straya" and "keepum fingers" ones) didn't make it. Again, I was conscious of adding too much detail. I think in other colours it could look terrible, but the blue just sets off the stainless perfectly.

Each of my frames has been a little better than the last, but I really don't know how I'm going to better this one, to be frank.

Monday 17 October 2011


So after a day to let the colour coats set up nice and hard, I added the decals, masked the stainless bits again (taking care not to mask all the way to the edge of the lug - the clear on the edges gets removed with a scalpel when I unmask after clearing), then set the frame up in the booth again for clearcoating.

This is the frame after the initial two coats. I put on a really light misting coat first, then wait about 10 minutes for it to start to set up, then put on a full-gloss coat. Reducing with about 20% reducer ensures that I get a gloss coat without excessive buildup - it also makes the paint flow nicely with my 0.5mm nozzle airbrush, which is really a little small for this task - I resemble a whirling dervish when putting the gloss coats on.

I then left it to sit for a couple of hours, mixed up more clear (same 20% reducer) and did another two coats. In this case the first coat was almost glossing, then a wait of 10 minutes, then a full gloss second coat. By doing it like this I get gloss faster on the second coat, so there's much less chance of overspray dulling the finish.

Here's some detail of the masking - note I only mask up to a millimetre or two from the lug edge. A quick wipe with the scalpel once the paint has set up and I've removed the masking gives me a much better lug line than I could get with the masking tape alone. An exception is the top of the seat stays. I masked right up to the colour coat edge here as the geometry of the lug doesn't guide my scalpel.

Here's our hero, courtesy of the decal printing services of Cyclomondo. No, I don't make my own decals any more.

The little fish downtube logo, in a nice white and red. Red and Blue goes together terribly well.

The Columbus Spirit decal. I like Spirit for lugs. It's really nice tubing to work with. I think I'll default to this stuff in future unless there's a compelling reason to choose something different.

If you look closely at the rear brake cable port, you can see how the lug definition is maintained. This is after twelve coats of paint; 1 primer, three base coat, 4 colour coats, and 4 clear coats. The trick is to make each coat super thin.

The fork.

And finally the stem, taken outside to show how it looks in sunlight, rather than the fluorescent light of my booth.

Saturday 15 October 2011


After spending a couple of evenings masking the lugs, and then waiting for good weather, I started painting Keith's bike today.

First coat is a nice thin coat of epoxy primer. I add about 25% reducer to the primer to ensure it doesn't destroy all the detail. I prefer not to sand the primer unless I have to - much better to get the metal underneath nice and smooth before the painting starts.

Next are one misting, then two light coats of Auto Air black sealer. The sealer goes on really thin - it's there to provide a nice even tone for the colour coat.

Then four light coats of Auto Air pearl blue. This stuff only takes ten minutes or so between coats to set up, so four light coats only takes an hour or two. As with the sealer, it's incredibly thin, so doesn't hide any detail.

I've just removed the masking. I'll touch up the lug lines with a ruling pen and then add the decals tonight. I plan on starting the clear coats in a day or two.

The pearl blue looks really good in sunlight, and sets off the shiny polished lugs quite well. This isn't Keith's stem - it's one I've done for myself. I thought I'd paint it along with Keith's bike and use it for the photo shoot.

Monday 10 October 2011

Seven and Eight

Numbers seven and eight have been started. They're a matching pair of track bikes - one for myself and one for Kristyn.

Here's mine - very standard geometry. It's about a cm smaller in many dimensions than my usual roadie. I've increased the head angle to 73.5 degrees, and increased the seat tube angle to 74 degrees. The goal is for a frame that's good for training on the track through winter, so not extremely twitchy - something to do longer events on.

I've already discussed the geometry of Kristyn's. We're using 650c wheels to get the bars down nicely - otherwise it's surprisingly conventional.

Both frames are to be built with Henry James oversize lugs, Keith Anderson dropouts, and mainly Columbus Spirit for lugs tubes. An exception is the chainstays - I'll use True Temper OX Platinum 28 x 20mm ones rather than the more usual 30 x 16mm ones. This should provide a bit more lateral stiffness.

Now to get ordering parts - I already have most of the lugs, but need to get a few from Henry James (a bottom bracket and seat lug), and need to buy the tubes as well.

And the nice bit. No stainless!

Our new place

So since we moved out of our awful little flat to a proper house (enabling more frame building with it's lovely large garage), I've settled into a bit of a morning routine. Perry and I get up around 6:30 (having been woken by the cat), I make coffee while he feeds the cat, then we pop some fresh food and water in the rabbit's bowl and put her outside for the day (she stays inside overnight to protect her from neighbourhood cats). Perry usually has brekky out, so I drop him off at the station, then come home and spend an hour or so working on bike stuff before getting ready for work myself.

This has come to be one of my favourite times of the day. The house is nice and quiet because Kristyn is yet to wake, so I sit at the computer, or clean lugs, or whatever, while our cat sits on whatever I'm doing.

Just now there was a bit of a racket outside. I looked up and saw one of our neighbourhood possums wandering along the fence. All is right with the world.

Monday 3 October 2011

Number six ready for paint.

Keith's new frame is polished up and ready for paint-prep. It's built with Columbus Spirit for lugs tubes in OS size, with traditional level top tube. It measures 56.5cm long by 53cm high, to suit Keith's relatively short legs and long torso.

The frame is built for road racing, with 73 degree seat tube and 72.5 degree head tube. Lugs are Llewellyn's custodian, in stainless, with substantial modification and customisation.

Firstly some non-stainless content. Here's the only plain steel lug on the bike - the bottom bracket shell. It's an Everest part, which originally had a cast-in chainstay bridge. Given that Keith is a pretty powerful guy, I removed the standard bridge and put a much beefier one in, using a section of seat stay.

I wanted to put it as aft as possible for maximum rigidity, so I scooped out a section using a file to provide a bit more tyre clearance, and filled it in with a down-tube offcut, brazed in with brass so that it didn't fall to pieces when silver brazing the chainstay bridge to the frame. It should be really stiff.

The front derailleur tab is a Richard Sachs one, again in stainless. These things are just so cool it's incredible.

Here's that seat lug, polished to a mirror finish. I know I said previously that I wouldn't do another, but I'm already plotting my next one. Will I ever learn?

The hardest bit to polish was between and under the seat stays, as I couldn't get a polishing mop in there. I did this by hand, using strips of cloth and Brasso.

The head lugs look really classy, I think. I put Bocama-esque cutouts in all the lugs, to make them look a little less heavy. I took a huge amount of material out of the top head lug around the front to lighten it, and removed the ergo cable stops from the lower head lug. I used Llewellyn's downtube-mount cable stops instead, which both look much cooler and ensure there's no interference between front brake and gear cables.

Of course it's all polished to a mirror finish, to showcase my obsessive compulsive disorder.

The dropouts are Llewellyn stainless, to match the fork. Again, polished to a mirror finish.

This is actually the second brake bridge on this frame - I wasn't happy with my first go, so cut it off and tried a second one.

This frame has been quite a bit of work, but I think the results are really worth it.