Archive for the ‘Brazing’ Category.

Ivy-T progress


The most important bit of progress is that the bike is rideable, and I’ve been commuting on it for a week.  It isn’t done, it needs a front rack, stem, and tail light (all will be custom), but rideable is a huge step.

It is a nice compliment to Gifford, pretty much the only bike that I’ve been riding for a year.  Gifford is utilitarian, the station wagon of a bicycle fleet.  The Ivy-T is much sportier, currently weighing in around 23# with fenders, battery powered lights, and a frame fit pump.  If I can keep it near 23# with generator lighting and the front rack I’ll be very happy.

Ivy-T in rideable, but not yet finished, form

The Diacompe GC450 centerpull brakes work very well. They almost never squeal, do a fine job of stopping, and are light and nice looking. I'm surprised, but the 27 year old brake pads (never used) even work well.

Brandon Ives did a nice job brazing the lugs (with silver). My fork crown, done in brass, is a little messier.

Here are some photos showing some of the fork building steps.  I don’t have a photograph of the fork raking because I raked these fork blades months ago at Alistair Spence’s shop.  I don’t have a fork bending form yet.

First the crown was brazed to the steerer. This is done first so that I can turn the crown race down on my lathe (easier without the fork legs attached).

I remove the flux and clean up the crown by hand. The aluminum rod sticking out is a part of the fender mount, and works with an eye bolt to keep the fender in place. It will be cut trim at installation time.

Dropouts are brazed in and cleaned up. I made these dropouts myself on the CNC mill.

I use this fixture to check the frame angles and set the fork blade length. The fork blades are uncut and the front axle height is setup until the angles are correct. The difference between the front and rear axle height (142mm front, 150mm rear) tells me how much fork blade to remove (8mm in this case).

The fork blades are not yet brazed during this operation. A dummy headset (made by Alistair Spence) is in place.

seat tube angle

head tube angle

The fork and trimmed down blades are set into the fork fixture for brazing. This is my second generation fork fixture, I'm going to sell these as a kit later this winter.

The blades are brazed into the fork crown.

The flux is soaked off in hot water and everything is cleaned up. The top hole on the inside of the fork crown is open as a vent hole and will be used to run the wire for the front light.

The fork alignment is checked on my alignment table. I had to tweak one fork blade slightly. Rake was left at 63mm.

Finally, here is a photo of the fender mount in use.  I learned about this setup from Jan Heine.  The fork crown is drilled in the back, and there is a blind hole in the front.   A piece of aluminum rod (fender stay) is put into place.  The tension of the fender’s eyebolt holds it in place.  It looks very clean, it is light, and it was easier than making a threaded fitting in the bottom of the fork crown.

Really simple bending for a rack platform

I published a blog entry a long time ago with a “simple” way of bending tubing. It is far more complex than what I actually do today. I’ve been meaning to write a followup for over a year, but always forget to take photos when I’m bending up a rack deck. I’m going to just do it in words. Hopefully I’ll update this in the future with photos, but in the meantime this drawing will have to do.

The instructions here are for making a 10″ x 14″ rack deck using roughly 4′ of 5/16″ tubing and a bender that has a 15/16″ radius. The straight sections of the rack deck will be 12″ and 8″. The 15/16″ radius for each bend makes the rack about 2″ wider and 2″ longer than the straight sections in each of those directions.

I always make my bends to the right. There is no math in this method except for basic subtraction and dividing by 2″.

Bend 1:

  • Mark a line 6″ from the start of the tube.

  • Align that mark with the 0 on your bender.

  • Bend to 90 degrees and mark where the 90 is on the tube.

  • Check with a square to make sure that it is actually 90, tweak as necessary.

Bend 2:

  • Mark a line 8″ from the last mark (the start of the next straight section)

  • Align that with the 0 on your bender

  • Check that the bends are in the same plane. I do this by spotting down the bender to align the tube with the bending form.

  • Bend to 90 degrees and mark the 90

  • Check the 90 with a square. Check that the bends are in the same plane using a flat surface. Tweak as necessary.

Bends 3 and 4:

  • Repeat the same technique for bend 2 with distances of 12″ and 8″.

Closing the loop:

  • After bend 4 mark a line 6″ from the start of the last straight
    section. That should line up with the start of your rack deck. Cut
    off the excess tubing (a couple of inches) and splice.

If you want a different size of rack deck then just pick different numbers for the straight sections. Most of my recent racks have been 12″ x 11″ long, so I’m using 10″ and 9″ straight sections.

You can put the splice anywhere that seems good. I just tend to center it because it keeps the math simple.

Gifford: Powdercoat and Details

This color is hard to photograph. I’ve done my best at getting an accurate portrayal in these photographs. It is a brown with a lot of red in it. The Surly Karate Monkey comes in a similar color.

In this photo you can see how clean the fillets look with paint on them. You can also see the taillight cable getting hidden into the downtube:

The taillight wire comes out at the bottom of the downtube and runs under the chainstay to the light itself. The light is attached to the Rohloff shift box that is also under the left chainstay. In this photo you can also see the Rohloff cable guides (which I think look good now that they are painted) and the adjustment bolts for the eccentric bottom bracket.

I made a mount for the taillight using a stainless steel spoke. The wiring still needs to have the proper connectors crimped on and to be trimmed:

I built a new rack for this bike. It is probably the most nicely finished rack that I’ve built. It works with my Pass and Stow bag (which snaps to the rack) and my Acorn bag (which attaches with Ortlieb hooks to the front crossbar). It is designed to make the bicycle work well with Sportworks bus racks.The bus rack hook that holds down the front wheel can get right up to the fender.

The cable routing for the headlight on the fork was done so that the wiring can be removed without unsoldering the hub connector. The lighting is routed using pairs of hooks which are facing in opposing directions. You can turn the wire 90 degrees to remove it manually, but it won’t do so on it’s own. The hooks were made with 1mm diameter steel wire. There are two wires in this photo, one going from the hub to the headlight, and another going from the headlight to the taillight:

A final full bike shot:

There are some more photos on my smugmug site:

The todo list is getting very short and none of it prevents me from putting a lot of miles on this bike:

  • Custom stem
  • Build up my SON20 based front wheel. That one will be lighter than the current wheel.
  • Trim the wire for the tail light.
  • Make a fender guard so that I can remove the rear rack. It is only there to protect my rear fender from the spring loaded rear wheel hook on my employer’s bicycle shuttle.

This winter has been pretty mild and spring is coming fast. I expect the tone of the blog to change back from project statusto trip reports soon. I already have tenative plans for an overnight ride at the end of March if the weather is good.

Frame progress — finished up the rear triangle

I had planned on doing this in 2 or 3 blog entries, but I’m running behind. That means you get one mega entry.

The frame is pretty much done. It just needs cable routing brazeons and rear canti posts. This is what it looks like in profile:

A set of photos for making the seatstays (mostly the caps). Ifound this to be more challenging than I expected. Things that I learned for the next time are to cut the seatstay a little shorter than I did, and make the cap longer. I also should have used thicker caps, I used .4mm thick tubing. That didn’t leave me a lot of room for error. At the end of the series you’ll see a pool of brass on top of the cap, that was to thicken it up a bit.

I made an M5 seatpost binder on the lathe and made this cantilever brake cable hanger too. I like the twin wire design, but enhanced it a bit by wrapping the wire around the seatpost binder. It is very strong, but light and delicate looking.

I was a little worried about tire clearance when I wrote my last blog entry. In response I made a tool for denting the chainstays and went at them. The dents aren’t too elegant, but they gave me a couple of extra mm of clearance and that was all that I needed.

I want a good fenderline on this bike, so I carefully measured tire height with three different tires and a test wheel. I set the bridge 18mm above the tread of the tire that I expect to use with fenders. That still left me pretty good clearance with a knobby (for riding without fenders). The fixture holding the bridge in place is called a “bridge jack”. There was a blurry photo of one in the Patarek manual and I couldn’t find one anywhere else, so I just made what I thought would work. I can adjust it’s length then lock it into place. It worked well for getting the chainstay and seatstay bridges equidistant.

Markings for Quasi-Moto (Q),Hetre,and Trimline tires.  The very top line is where the bridge will go.

Clearance with the Quasi-Moto is a little tight for a mountain bike, but decent.

This bike is being designed for a Rohloff internal hub. The Rohloff has three different options for a reaction arm to keep the hub from rotating. Lee Williams described how R&E used the OEM2 one (normally designed for disk brakes) with a hidden bolt inside the seatstay. My seatstays are very thin, so I added this bridge instead. I like how it looks, it is a lot more elegant than the normal Rohloff reaction arm (photo from an old bike at the bottom). The boss for the bolt head was made on the lathe. It is like a blind water bottle boss, but sized for an M6 bolt. The boss goes all the way through the bridge for extra strength.

The ugly black arm with holes is the normal alternative. I’d say that mysolution looks nicer.

A detail shot of how the eccentric works. I think that this is a little nicer than the normally fully slotted bottom bracket, and much nicer than using set screws:

A couple of blog entries ago I talked about alignment. Brandon Ives saw my photos and suggested making this tool instead of using a square. I call it a vertical dummy axle, and have to agree with him that it works well. The dummy axle just threads into the base. Right now I just have a dummy axle that is 10mm for rear dropouts, but when I make my fork I’ll also make a 9mm dummy axle for front dropouts.

Stainless Cycle Truck Rack

John Speare has my old Cycle Truck now (giving me room in the basement to make a new one). As part of the deal I wanted to make a new rack for that bike. The original rack is long and narrow (20″ long, 16″ wide) and after riding that bike a lot I came to the conclusion that a short and wide rack would be better. This will encourage keeping the loads closer to the head tube, which is the key to carrying heavy loads and having good handling with that bike.

In addition to the size differences the new rack has also gained a U-lock holder behind the backstop and some cleats for holding die down ropes. I copied the cleats from Joseph Ahearne’s lovely cycle truck that was shown at the OBCA show a couple of weeks ago.

The old rack will be going on my next cargo bike, which will look a lot like the Cycle Truck except that the front wheel will be under the rack instead of behind it. It could look something like this:

The new rack is made out of stainless steel (316) and was my first rack made with the material. It is challenging to work with, mostly because brazing it is trickier. The bronze filler that I normally use doesn’t work with stainless. I tried three different fillers (Harris 45% silver, Cycle Design’s Fillet Pro, and Nickel Silver from Gasflux). In the end I used the Harris 45% silver on the joints which wouldn’t see high loads and nickel silver on the ones that would. The Fillet Pro was the nicest of the three to work with, but I have limited quantities of it and wanted to save it for my framebuilding projects. Nickel silver is very strong, but melts at a higher temperature and was harder to use. The fillets also don’t clean up as nicely. 45% silver is the weakest of the three, but easy to work with on stainless steel.

In the photos shown here the rack is just about finished. I have some cleanup work to do around the brazed joints (that will remove the smoky color near some of the joints).

The underside of the rack. You can see the 4 cleats as well as the 4 mounting points that hold the rack to the bike.

A closeup of one of thecleats. The rack has stainless water bottle bosses as mounting points, and the cleats screw into those.

An early photo of the lock holder. The final one has a second loop on the middle rail of the rack:

I’m delivering the rack to John a few days after Thanksgiving and will take some photos of it installed on the bike then.

It's starting to look like a bicycle frame…

I brazed the front triangle of my first frame this weekend.

Things went pretty well. I did have one mistake which has made a fairly minor change to the geometry. My brazing order around the downtube, seattube, bottom bracket area should have brazed the front of the downtube and the back of the seat tube first before any of the crotch in between them. The fillet in the crotch pulled them them together, which made the seat tube angle a bit tighter. I think that this is all okay, I’ll just build the bike with a 72.5 HTA and a 73 STA instead of the opposite as I had planned. The seat tube is 56cm C-T and the top tube is 56cm C-C (giving me a virtual of around 57cm because it has a sloping top tube). The top tube slopes at roughly 4 degrees. This is a learning frame, so I’m okay with a few little mistakes.

The seat tube to top tube junction was one that I spent a lot of time thinking about. I wanted to put a sleeve here to keep heat distortion down and I don’t like brass brazing long sleeves. Mark Bulgier had the best suggestion for handling this area, but I didn’t have the right materials on hand. My solution (a pretty common one) was to sleeve out of 1 1/4″ x 0.058″ (which sleeves perfectly over a 1 1/8″ seat tube). The top tube was brazed to the sleeve first with brass, then the sleeve was brazed to the seat tube using silver. The silver inside the joint will melt a bit when I braze on the seat stays, but the sleeve is so long that the top and bottom will stay solid and the silver won’t be able to go anywhere. That is the theory anyway, we’ll see if it is true in a few weeks. My biggest concern is that I probably don’t have good silver penetration between the sleeve and seat tube behind the top tube fillet. I’m not worried about the lack of strength there, but I hope that it doesn’t create a good area for rust.

I used a pin through the sleeve to align the vent hole in the top tube with the one in the sleeve.

Everything came out fairly straight when I checked it on my alignment setup. The head tube has a very slight twist when compared to the seat tube. I might try to cold set it out of there, but I’m not too worried about it.

I mitered everything on my milling machine. My setup for this was really simple,but seemed pretty effective. I used two of Alex Meade’s clamping blocks and clamped the tube into the milling machine. I set the angle using the machine’s head (I don’t really have a good angle table to adjust the angle of the tube itself). To keep the miters in phase I always kept one block locked onto the tube at a time when I moved the blocks from one end of the tube to the other. The final miters came out nicely. I only touched up one miter witha file,and that was the top tube to seat tube miter because the top tube length shortened a bit when my ST/DT angle tightened up.

If you aren’t bored with this project by now you can see tons of other photos in my smugmug gallery.

Seasons Speeding Tikit Porteur

I’ve finished my most recent round of hacking on my Bike Friday Tikit.

Side view with lots of visual clutter, making it hard to see the bike.

I callit the Seasons SpeedingTikit Porteur. Seasons because that is what Bike Friday calls the Tikit with an internal hub. Speeding because that is what they call it when you put on drop bars. Porteur because it has a (mini) porteur rack up front.

i9 hub, new dropouts

The new rear hub is a SRAM i-Motion 9 (or i9). The i9 conversion benefited from some brazing of the bike’s rear triangle. I switched the dropouts to the pivoting dropouts that Bike Friday makes. I also had to move the rear canti studs a bit. I made a photo essay of swapping out the dropouts. The i9 seems to work well and has a nice gear range. I had originally planned on building a custom bar-end shifter, but gave up on that project. The rear triangle will get fresh powdercoat soon.

The drop bars make the quick fold a bit wide, but remove the stem and it gets narrower than a stock tikit. I don’t need a compact quick fold very often, so this is a good compromise for me. I can ride on drop bars all day long, but flat bars hurt my hands after 20 miles or so. I really love the Tikit fold, it is very fast and all of the dirty bits on the bike get folded to the inside.

I made the mini-porteur rack a long time ago and it continues to function well. It looks really dressed up with the black powder coat.

The Tektro V-brake drop-bar levers are a lot more comfortable than the Diacompe 287-V option. They seem to work pretty well on the front, but the rear is a bit spongy from the long cable run. The levers work better if your V-brakes have shoes at the top of the slot than at the bottom.

I hacked up my favorite MKS Grip King pedals to have a quick release MKS EZ axle. This lets them pop off of the bike in an instant to make the fold smaller. Taking axles out of $60 pedals and putting them into $50 pedals is an expensive solution, I wish MKS just offered these with the quick release axle as stock.

I’m taking the bike on a train ride with me soon and looking forward to giving it a real test.

A quiet blog doesn't mean I'm idle

A minor pre-note… Iignored the comments for a while, but I just moderated them and went and answered any questions in them. If you were waiting for an answer you should find one there now.

I’ve been mulling over stuff to write about, but none of it seems like it is worth of a whole blog entry. This is going to seem like a random mis-mash of stuff. I’ll split it into electronics and bike.


My friends Lee and Andrewspent some time here the last month or so working on some racks. I think they are both very cool. Click the photos to see the whole slideshow (both link to the same thing).

Lee’s rack is built around a Seattle street sign (Seattle sells old ones for $5) and is sized to fit a case of beer or a pile of firewood.

Andrew’s rack is pretty similar to a lot of the ones that I’ve built. I think it came out very nicely.

I like teaching people how tobuild these things. Maybe at a later point in life I’ll be able to teach classes on it or something. For now it remains a hobby.


I’ve been working on the jig for my framebuilding. It’s coming along. I think it’s kind of boring for most readers of my blog, so I haven’t been posting about it here (but I have been posting away on the framebuilders list). Some friends disagree and think I should be posting here anyway. I update this gallery often with new drawings and photos, so just bookmark it if you are interested.


Around the holidays at work we got in a batch of new Windows Mobile phone. I got to play with the HTC Diamond Touch, HTC Touch Pro, HTC Diamond HD, and Palm Pro (I used all of them for at least4 days). All run Windows Mobile 6.1. Here are my brief thoughts:

  • HTC Touch Diamond — This is a primarily touch phone with a couple of hard buttons on the side and bottom. The form factor is really nice, it is exactly the same size as a Motorola RAZR when the RAZR is folded. Sound quality is good. I’m not so good at typing on touch keyboards, but this one wasn’t too bad. TouchFlo 3D is kind of gimmicky and yet kind of nice. If you like Windows Mobile and browse more than writing email then it’s a good option. The HTC Touch Pro is the same phone with a fold out keyboard and twice as thick. That makes it uncomfortably big in my opinion.
  • HTC Touch HD — It’s the same size as an iPhone with a much sharper display (800×480 pixels vs 480×320 pixels). It has almost no hard buttons. The lack of hard buttons is it’s big downside, Windows Mobile just isn’t designed for that. As an example you can’t switch between emails in Pocket Outlook without closing the message, moving to another,and opening that one. In contrast any other Windows Mobile phone lets you move between messages with the left and right buttons. The on-screen keyboard is larger and better than the Touch Diamond.
  • Palm Treo Pro– This is the phone that I originally ordered and the one that I liked the best. It is like the T-Mobile Dash with a touch screen. The phone is pretty small,battery life is great (3 days with constant email syncing), and the touch screen provides a better browsing experience than the T-Mobile Dash. It’s the least sexy of these 4 phones, but also the most usable hardware of any Windows Mobile phone that I’ve used.

At the same time that I was playing with all of these phones I bought a used iPod Touch from a friend. The iPod Touch is an iPhone minus the phone (if that makes sense). It still has wifi and all of the features such as the app store, email access, web browsing, facebook, etc. I still can’t type on it as well as I can on a real keyboard (like the one on the Palm Treo Pro), but it’s not as bad as I expected. The App Store is cool and makes finding apps easy. Framebuilders/gadget freaks note — there are some digital level software packages for the iPod Touch which are accurate to .1 degrees and the best one costs around $3. That almost paid for the phone since I had been considering buying a $100 one from Enco.

If T-Mobile had the iPhone it would be a no brainer and I think I’d just switch to it. As long as they are locked to AT&T (which would make our monthly bill much much higher) I’m going to have to be happy with my Palm Pro.


That’s 5 years of personal and work laptops in a pile. The one on top is the newest, and it’s awesome. It is a Dell E4200, weighs just over 2lbs, is plenty fast, has a sharp screen, and a great keyboard. The one just below it is the previous model, the Dell D430 (that’s been my personal laptop for the last 2 years, and what most of these blog entries have been written on). It is also a nice machine, but a 50% heavier and with less battery life.

It’s so much nicer to commute with a little computer like this than the huge beast at the bottom.

Cycle Truck Finished

This facade reminded me a photo that David Wilson has of his Borracho cargo bike in the doorway of a brick building in Georgetown

I did some finish work on the Cycle Truck and sent it off to be powder coated a couple of weeks ago. It was coated by Seattle Powder Coat in Ballard. They did a nice job at a reasonable price and with a very quick turnaround. The paint is red to pay homage to the donor frame and fork that were used to build the new one (both were also red). The rack is a silver/grey. I modifed this pizza delivery bag (thanks to James Black for telling me where to get one cheaply) to fit onto the rack. The bag is 20×20x12 inches and fits perfectly.

In this photo I’m carrying a roughly 50lb load of bird seed, cat food, and random bits from the hardware store. I think this bike works well for bulky loads (better than a porteur) and okay for heavy loads (the closer they are place to the headtube the better). I don’t think it does great for loads which are both large and heavy. It isn’t good if there is a lot of weight too far forward of the front wheel. If I build another one of these I may put the front wheel about a foot forward. It would complicate the frame and it would no longer fit on standard car/bus racks, but it wouldn’t increase the bike’s overall length and I think it would improve the handling with some loads.

Finishing Details

The rack support rails have been closed off and snaps were added for holding the pizza bag:

The a downtube shift boss was added which connects to the original U-brake. That makes a very nice parking brake. V-brakes mounted on the seatstays provide the main rear braking.

The back of the cargo tube was sealed with a little bit of steel plate. This area ended up being fairly complex. Next time I might try ovalizing the cargo tube where it joins the seattube to avoid this extra work.

Here are a couple of other shots of the final bike:

Fork Fixture V-block

This weekend I also did my first major project with the new milling machine. I made a V-block for clamping a fork steerer tube. This will be the basis of my fork building jig and my fork alignment system. If you are interested in how I made it then click on the picture to see a gallery with more info. The new mill is working out very nicely.

Made A Cycle Truck Rack

I had a little bonus free time on Friday so I built the rack for the Cycle Truck. It is 18 by 20 inchesand made of 1/2 inchdiameter cromoly tubing with a 0.035″ wall thickness.

The rack itself is very basic and didn’t require much tricky work. It is a 2 dimensional rectangle and doesn’t have any stays or back stop (a back stop is not necessary since the head tube acts as one).

The connection between the rack and frame was the hardest part of the project. The frame has two support bars brazed to the cargo tube. These are made from 5/8″ square tubing and are mitered to fit around the cargo tube. I was careful to make sure that these were square to the cargo tube and head tube in the horizontal and vertical planes.

The support bars have 6mm holes at each end that the rack mounting bolts run through. The bolt, support bar, and rack look like this when connected together. The bolt goes into a threaded pillow block that I made on the lathe. The pillow blocks are brazed onto the rack. I thought about just brazing the rack directly to the frame, but wanted it to be removable so that I could easily replace it (if it gets damaged) or exchange it for a cargo box if I end up making one of those.

The hardest part was getting everything to line up well. There is no tolerance for error in the fitting of the pillow blocks to the support bars, the distance between bolt holes and the threaded part of the pillow block needs to be exact. What worked best (after some bumps along the way) was to braze the rear support bar to the frame, then thread bolts through the pillow blocks. The rear pillow blocks were tacked to the rack, then I placed the front support bar on the cargo tube and did the same thing there. Since all of the bolts were in place during the brazing everything was perfectly aligned.

I’ve done some load testing around the neighborhood with a 40lb load and the rack and bike handled well. I’ll be doing more rigourous testing and with higher loads later to see if I’ll need structure tying the rack to the frame. I expect that I’ll be adding two more stays that go from the rear support bar to the top of the head tube. This will both add some rigidity and will give me a nice place to mount water bottles. My goal is for the bike to ride nicely with loads in the 50-75lb range.

On Sunday I used it to carry this bulky but fairly light load. This is the kind of stuff that is really a bit too big for a normal porteur rack but small enough that I don’t like having to pull my trailer out for it. The Cycle Truck fits that niche between trailer and porteur nicely and I think I’ll be using it quite a bit.

I’m reorganizing the Cycle Truck photos into a new galleryto try and make it easier to understand the whole process without having a lot of extra photos. My only regret in this project is that I often got too involved and forgot to pick up the camera and take a helpful photo or two.