bonnie & jason

Finished the front quadrilateral

Well, it’s not pretty. And some of the joints don’t seem 100% filled in. But it’s together and actually feels rock solid. I’ll probably go back and try to redo the parts where I can see gaps. I think I’m getting better at the whole brazing thing but I might just be getting lucky too.

The geometry didn’t quite come out as I had calculated. The top tube is almost 1/2″ longer than I expected probably due to the cumulative effects of measurement and cut errors along the way. Plus, some of the angles are off a hair here and there. This bike building thing really is half art, half science. Overall, I’m pretty happy with how it turned out given I’m doing it without a proper jig.

Second braze attempt – Down tube to Head tube

I *think* my braze yesterday was good so I moved on to the second braze which connects the down tube to the head tube. I believe this one turned out better. To get some feedback, though, I took some video to show my fraternity brother, Marc, who has been my bike building mentor of late. I’m thinking most of you will simply use this as another way to make fun of me, but that’s never stopped me before, so here it is:

Braze attempt #2 – headtube to downtube from Jason Wang on Vimeo.

Grizzly tube notcher fix and first braze attempt

I managed an easy fix to the offset tube notcher problem. I’m not really happy that it needs a fix to begin with but maybe Grizzly will come through with a solution. In any case, the solution I found was to just use a file I had as a spacer to shift the tube up the millimeter or two necessary. Here’s a pic:

I also took my first attempt at brazing. I tried getting a couple scrap pieces together first.

I don’t think I did a good job… I was afraid of getting the tubes too hot. After a couple tries, I figured I might as well just go for it, so I put the seat tube and the bottom bracket together:

Before brazing (note the tube is inserted too far for illustration purposes):

And after brazing:

Again, I’m not sure I did a good job. It’s not very pretty, that’s for sure. But I tried pulling them apart as hard as I could and they didn’t budge. So there’s at least a little silver in there sticking them together. The other bonus is that I didn’t burn the house down. Next, I have to cut and miter the down tube and braze it to the head tube. Hopefully, the little experience I have now will mean a better braze there.

Bike build part deux – tube notcher

There are going to be lots of bike build posts in the future so for those of you looking for Alissa pictures, feel free to gloss over these. On to the topic of the day! I got the bench grinder bolted to the work bench and bought some c-clamps and other hardware to make the Grizzly tube notcher work. This tube notcher is a cheapo version of the “Ol’ Joint Jigger” and it shows in the quality. I had to clean up and grease the saw shaft because it was kinda rusty and did not twist freely in the bushings. Also, the degree scale is pretty much worthless because 1) there is no arrow pointing at the scale to begin with and 2) the hole saw shaft isn’t really square to the tube fixture. I made it work by making my own arrow and calibrating the shaft to the fixture. Finally, the adapter that connects the shaft to larger hole saws was drilled eccentrically so that the saw would wobble when rotated. To Grizzly’s credit, they’re sending me a new one gratis. In the meantime, I was able to use the adapter that came with my Rigid Hole Saw kit.

The other thing I wanted to be careful about was the tube fixture. It’s not defective, but given bicycle tubing is pretty thin, I didn’t want to dent it by tightening down on the clamp too hard. So I just cut a couple pieces of angle iron and used them in between the fixture and the tube to distribute the holding force across a larger area.

Anyway, after I got the notcher ready to rumble, I clamped it to the work bench, tightened up the 1/2″ drill to the shaft, and went to town on a test cut.

Here’s the result:

All in all, it did a pretty good job. It only took 30 seconds to do and this was slow since I was experimenting with how hard to push. I did notice that the tube seems to be sitting a bit low compared to the saw so the cut is offset a couple millimeters. That might be because of the angle iron I used to support the tube. I need to dig into this a little more before I make the actual “money” cut. Otherwise, the cut is pretty clean. If it wasn’t for the offset issue, a few minutes with a hand file and this tube would be ready for brazing. All in all, I’m pretty happy with the purchase. Without this, I’d probably have to spend quite a few hours calculating, rough cutting, filing, and cursing all the miters I’d need for the bike. Now, those hours will likely be turned into minutes. Yay tools!

Next on the list of things to do is to fix the offset problem, make the “money” cut, and try my first braze of the seat tube to the bottom bracket. (As soon as my silver, flux, and welding goggles arrive.)

Bike geometry spreadsheet

In preparation for the bike build, I’ve been doing some research on bike sizing and how geometry influences handling. Unfortunately, I couldn’t find anything that really told you how long to make certain parts of the bike, particularly the chain stays and seat stays. So I put together my own spreadsheet based on basic 10th grade geometry.

Here’s the graphic:

And the calculations:

Here’s a link to the file itself for those of you who might want to use it for your own bike build.

Clearly, I’m a geek, but hey… the world needs geeks!

EDIT: A had a problem with one of my calculations that determine the downtube length. I still haven’t figured it out yet, but fellow Dork (yes, that’s Dork with a capital “D”), and Cornell Mech E, Pete, laid it out for me in Inventor and did away with all that silly trigonometry to provide the right answer:

I owe Pete a beer next time I see him. Plus, at his suggestion, I’m downloading Inventor LT so I can replace all that spreadsheet dorkiness with some modern CAD dorkiness.

New project – the beginning of Jason Wang Bicycles

With the bike done, I find myself craving another project. Not that I don’t have enough to do around here as it is with Alissa, Bonnie on bedrest, and some photography stuff here and there. I guess maybe I just need a diversion from all the adult responsibilities that come with a growing family. And since I can’t afford a Lotus, I figure I’ll expand on the bike theme. But instead of just building up a bike frame, this time, I’m going to build a bike from scratch. Crazy you say? Crazy like a fox! =)

It’s actually not that big a deal although I admit that the scope has grown. How? Here’s the evolution:

1. The last bike project aggravated the lumbar radiculopathy that hasn’t bothered me for the last two years so I need a proper work bench.
2. Work benches are expensive though, so I’m going to build my own.
3. To build a proper work bench, I need a compound miter saw. (Ok, I don’t absolutely need one, but any self-respecting DIY homeowner should have one.)
4. While I’m at Home Depot, I might as well get the closet rod that Bonnie wants me to add.
5. Yet to be identified projects that will be born from here.

And of course, to build the bike itself, I need some other tools that I don’t already have (bench grinder, hole saws, hand files, vice, gas torch, etc.)

So anyway, no post is really complete without pictures, so here are a few quick ones.

Here’s the bench holding up the mitre saw I used to build it:

It has wheels so I can put it in the middle of the garage when I’m using it and then roll it against the wall when I’m done.
I got the miter saw for $60 off at Sears.

Here are the bike pieces:

I got them from Nova Cycle Supply. Many of the parts are from their November special.

Here’s about how they’ll go together:

Of course, I still need the chain, wheels, saddle, seat post, handlebars, stem, pedals, and brake lever. I already got a crankset, freewheel, and brake caliper.

So, hopefully, before too long, all these parts will turn into a ridable, safe, and cool bike that fits me perfectly.

Public service announcement

Here’s a funny video that I thought was worth sharing since I’m riding my bike quite a bit these days.

Finished the bike

These were the final hurdles I had to overcome to finish the bike:

1. I got an old seat post to work by using cut up pieces of a tennis ball canister for shims. (free!)
2. I abandoned the modern brake that I had bought and used an old style side pull brake instead. As a result, I had to move the brake to the right side so the cable routing was cleaner. ($8)
3. I had to readjust the headset and bottom bracket after a short test ride.
4. I had to get another rear wheel since I couldn’t get the free one with the bent axle to work ($20). I re-spaced that wheel so the chainline was straighter (more a nice to do than a must do.) That wheel also had a couple spokes break so I had to replace those as well. ($1)
5. I got some short stack bolts so I could just use the small chain ring. ($5)
6. A quick wipe down and wax and she’s good as new!

All told, I spent about $100 in parts but $40 of that was the brake that I didn’t end up using. I’ll probably keep it around for another project. I also spent $20 for the bike stand and maybe another $20 in special bike tools but I won’t count those against this project.

It was pretty fun to do actually. I’m going to start looking for another project bike to rehab. This time, I’ll get something that already has parts that might just require a little maintenance and minor upgrading.

Here are the pictures from start to finish.

DIY bike work stand

I’ve been getting tired hunching down to work on the bike, so I decided I needed a bike stand. Unfortunately, all the decent ones commercially available are pretty pricey, so off to the great google I went in search of a DIY solution. The first result is this page which lists eight different solutions but I ultimately decided on this super simple one.

I followed the directions almost entirely. The only real differences were that I used a shorter length pipe (12″) since I didn’t feel I needed as much clearance from the wall and that I just threaded said pipe directly into the PVC t-section. In the end, for about $20, I got a super beefy stand that takes 10 seconds to take apart and put away.

Otherwise, notice that I pulled the large chain ring off and got the seat on. I also tried to make the rear wheel work, but there’s something wrong with the spacing so I may end up needing a new rear wheel after all. Grr… oh well… at least the front wheel is good.

Bike rebuild progress

I’ve made some good progress on the bike rebuild.

1. Dennis helped me score some free wheels from a guy on sffixed.com. They’re old 27 inchers which is the correct size for this bike. They even had tires, tubes, and a cog (even though the cog is a “suicide” cog in that it’s just loc-tited on there.) I just cleaned them up, rebuilt the hubs, and pumped up the tires. The rear wheel axle is a little bent but I’m hoping I can position so that it doesn’t make the wheel cockeyed in the frame. At least not by too much anyway.
2. I got a set of handlebars for free from a guy on craigslist. He also threw in some bar tape and some pedal clips. I wasn’t a fan of the red at first, but they were free and it’s actually growing on me a bit. The handlebars I flipped and chopped into bullhorn bars.

3. Dennis had an old stem that he gave me (CONTROLTECH!). The bars were a little big for the stem, but I wedged them in there and I think they’ll work fine.
4. I got an old Sakae crankset on ebay for $20. The bigger chain ring is a bit worn, but the inner one, which is the one I’ll use, is in pretty good shape.

5. I ordered a brake from bikeisland.com but they don’t reach the brake surface. I’m going to need to find a longer reach brake. I also need to figure out how to attach them to the fork since they are a newer recessed nut style vs. the original double nutted style.
6. I got a cheap chain from bikeisland.com as well. Should be fine.
7. I bought some tools (cone wrench, bottom bracket tool, waterproof grease, degreaser) from The Bike Nook which is the local bike store on Taraval. Len has been pretty helpful and their prices aren’t bad. It’s a really small store though, so they don’t have a ton of stuff in stock, but they’re helpful with advice and can order whatever you want. I like to support the local stores when I can as well so go visit them if you’re in the neighborhood.

So what’s left to do?
1. Well, I’m not sure if the chain line is going to work so once I get the bottom bracket rebuilt and the rear hub tightened up, I’ll figure out if I’m good or if I need to be creative or if I still need a new rear wheel.
2. I still need a 25.8mm (I think) seatpost. It’s an odd size for modern bikes so I’ll probably have to order one. (EDIT: I used a tennis ball canister to make some shims for the seatpost. It seems like it’s going to work fine.)
3. I may need a new saddle. I have a cheapy plastic one (another freebie from Craigslist) but that may not be very tushy friendly.
4. If the chainline works and I want to remove the bigger chain ring, I’ll need some short chain ring bolts or chain ring spacers.
5. Still need to figure out the brake thing I mentioned above.

I think that’s about it. So far, I’ve just been working on it for 30 minutes here or there after Alissa goes to bed. Typically, I’d be much more impatient about it but wanting to do it on a budget means waiting for cheap (or free) parts. But I have enjoyed getting my hands dirty again. Without the motorcycle/sports car/go kart around for me to turn wrenches on, the bike has been a welcome outlet.