Wednesday night I did not mount fenders. Instead the rider took the bike for a test spin. By the way, its the blue bike listing below under "Sneak Preview" Anyhow, she was extremely happy with the ride. Good on that.
Now I've hung the blue bike up for a few days. Tomorrow is our annual ride up the Des Plaines river trail to the Wisconsin border. This is fun, and often wet. While the trail isn't paved, much of it is cinder, so it doesn't require anything like a mountain bike. 30mm tires and fenders will do the job. Nonetheless, a number of folks will ride mountain bikes because their road bikes can handle wider tires.
For myself, I'll be riding my test hack - which is why I've put the blue bike aside. I had some nice Michelin 28s, which were really more of a 30 or 32mm tire. They weren't great on the road, but they were fine on the trail. Unfortunately, one of them wore out. They got replaced by a nice set of Hutchinson's with a folding bead. These are fast tires, with 80psi in front and 85psi in back. But, they're too narrow for wet weather on the trail. It's been raining this evening and some form of rain is being predicted for the morning.
I went scouting out wider tires, naturally looking for a deal. I found some Panaracer Pasellas (sp?) with a folding bead for less than $20 each in a 700x35c. These are pretty highly regarded tires, reasonably light and good rolling. The question was: could I mount them and fenders on the hack?
Meanwhile, on my last ride, the hack was slow and draggy. The culprit seemed to be the bottom bracket. The crankset is an FSA Gossamer compact double with external cup bearings.
So, BB, tires, fenders, have taken all my shop time since Wednesday.
I pulled the cranks, sure enough the left bearing was toast. I dug up a Truvativ crankset with external cup BB from inventory. I mounted the cups and tried to push the Gossamer through. Oppps, I pushed the press-fit bearing out of the left cup. It turns out that FSA and Truvativ use different specs. The Truvativ left bearing has a smaller hole for the axle, which necks down to fit. The FSA axle doesn't neck down. As best I can tell, Truvativ uses the same spec as Shimano, but apparently FSA doesn't.
Hopefully I haven't damaged the Truvativ BB, but I wasn't going to use this crankset (carbon arms) on the hack in the mud tomorrow. This lead to some thinking. I got out a nice old Stronglight 93. One of prettiest cranksets ever made. It's rather dirty, and has some oxidation - but its cool.
The Stronglight is a true low-tread (low Q) crankset. And it needs a longer axle than any of the BB I have in stock - so that means a trip to pick up a new BB. Also, with 10speeds on the back, It didn't make much sense to me to leave the the large (52t) chain ring on. Instead the small (47t) ring got moved to the outside, and mounted with track chain ring bolts. On this went a set of bright red Look Keo pedals.
The normal wheels on the hack are a set of Record 10 hubs laced to some MA3 rims. Smooth rolling and dependable. I also have a set of wheels that matches this except that the hubs are Chorus. I mounted the new tires to the Chorus wheel set - so we can easily switch between to the two tire sizes. Unfortunately, the Chorus wheels (an eBay find) had their own problem. In particular, the cassette lockring won't engage to thread onto the cassette carrier. I can see anything wrong with the cassette carrier, and tried three different (brands or) lockring with the same results. Eventually, I gave up for now and swapped tires on the Record rear hub. Along the way I cleaned all the grit and dirt out of the cassette - so it looks so much better now next to the Stronglight crank.
Both wheels fit on the bike. They need a little pop to get past the brake shoes, but not enough to interfere with the angle of the shoes. The rear tire has a good fit all the way around except the chain stays. I tried to get my crimper in there to make an adjustment but it just doesn't fit. The tire appears to be not quite true (the rim appears fine) for some reason. I pumped it up to 120psi, and then the trueness returned. This isn't a realistic riding pressure, but it does increase the diameter of the tire enough so that it drags on the front mounting screw for the rear fender.
After returning to normal pressure, the snakiness returned to the tire. Argh!! Anyhow, careful adjustment makes sure that the tire clears both stays without issue. If the mud were to get deep, however, it could cause a problem. But that should be an unlikely scenario on this trail.
With the additional traction provided by these tires, it became clear that the front brake needed a tweek. Tightening up its cable made a big difference in the front stopping power.
I pulled out an old set of hack fenders and started to mount the front. It was a little bit tighter than I like, but not too bad. Then I tried the rear. Nope, not a winning combo. The fender is too narrow and when combined with a being a bit close to the tire, it just isn't ago.
I have a set of Velo Orange brand aluminum fenders size appropriately for these tires, and pulled out the rear. A bit of fiddling, tweeking, cutting, filing, drilling, futsing, and so on later, and I had a workable rear fender. The fender line isn't perfect, but it's not bad.
So now the hack has a plastic front fender painted white, and an unpolished aluminum rear fender. Not a fashion statement, but definitely a look that stands out.
Hopefully everything is snug and will hold together for the ride. More on this later.
It's late and I need to pack, so we'll see you around.
Friday, October 26, 2007
Wednesday, October 24, 2007
Blu Bik
It's been a busy few days with lots going on in the day job.
Still, I've started the build on the blue bike. The rider tried drop bars but decided she wants to stick with upright ones, so that's how the frame was built - giving it a bit longer top tube.
The fork is mounted using a nice Tange Levin headset (very durable and classic looking). I first grabbed a Nitto Technomic stem, not really thinking. Put it in the steerer and push down. Whoops, it won't go very far. This is a small frame with a short steerer. The bottom of steerer tubes is butted (its where most of the stress gets concentrated), and a stem won't fit through the butt. Because this steerer is so short, the butt is nearly half the tube and a tall stem like a Technomic ends up sticking way up in the air like a flag.
I have a nice SR forged stem in stock, this has more traditional proportions. Substituting it in gives just the vertical fit I'm looking for. Into this I mounted a Nitto Albatross aluminum bar. This is a big wide bar which the rider likes, even though it's more than is really necessary for the size of loads she'll be carrying.
For the seatpost, we're using a NOS Sugino fluted one bolt. It has a classic look, but is a bit easier to adjust. The lug design looks nice against the front of the post. On top of this we selected a Velo ladies saddle. I can' t say much about this except that its supposed to be comfortable to the rider. She wasn't interested in trying to break in a Brooks.
Brakes are Cane Creek cantilevers, which are now mounted on front and back. With their tension spring adjustments, these are so much easier to balance than old fashioned brakes. I toyed with the idea of using a TT style lever mounted in the end of the bars. But we're using cork grips and I don't like the idea of carving them up to make passage for the brake cable. Instead, we're using a nice old set of Sun Tour MTB brake levers. The rear is connected, using a single long casing routed through a top tube tunnel. It looks like it will wrap nicely under the handle bar tape, routed along the front side of the handlebar. This will give the rider a couple of more hand positions for longer rides, including one that gets her down out of the airstream.
As you may assume, given that the rear brake is adjusted, the wheels are mounted. The rear wheel needs a little work, based on the test fits prior to paint. It is an old 120mm hub with a new longer axle, that is re-spaced to 130mm. The spacers need to be adjusted to move the hub further toward the non-drive side of the dropouts, otherwise the derailer can't move the chain over to the small ring. As part of this, the wheel needs to be redished. So mounting and adjusting the derailers needs to await this change.
Even with all that's left to do, this is starting to look like a real bike now. Tonight I'll pull the wheels and mount fenders, then connect the front brake and finish the handlebars.
Pix soon.
Still, I've started the build on the blue bike. The rider tried drop bars but decided she wants to stick with upright ones, so that's how the frame was built - giving it a bit longer top tube.
The fork is mounted using a nice Tange Levin headset (very durable and classic looking). I first grabbed a Nitto Technomic stem, not really thinking. Put it in the steerer and push down. Whoops, it won't go very far. This is a small frame with a short steerer. The bottom of steerer tubes is butted (its where most of the stress gets concentrated), and a stem won't fit through the butt. Because this steerer is so short, the butt is nearly half the tube and a tall stem like a Technomic ends up sticking way up in the air like a flag.
I have a nice SR forged stem in stock, this has more traditional proportions. Substituting it in gives just the vertical fit I'm looking for. Into this I mounted a Nitto Albatross aluminum bar. This is a big wide bar which the rider likes, even though it's more than is really necessary for the size of loads she'll be carrying.
For the seatpost, we're using a NOS Sugino fluted one bolt. It has a classic look, but is a bit easier to adjust. The lug design looks nice against the front of the post. On top of this we selected a Velo ladies saddle. I can' t say much about this except that its supposed to be comfortable to the rider. She wasn't interested in trying to break in a Brooks.
Brakes are Cane Creek cantilevers, which are now mounted on front and back. With their tension spring adjustments, these are so much easier to balance than old fashioned brakes. I toyed with the idea of using a TT style lever mounted in the end of the bars. But we're using cork grips and I don't like the idea of carving them up to make passage for the brake cable. Instead, we're using a nice old set of Sun Tour MTB brake levers. The rear is connected, using a single long casing routed through a top tube tunnel. It looks like it will wrap nicely under the handle bar tape, routed along the front side of the handlebar. This will give the rider a couple of more hand positions for longer rides, including one that gets her down out of the airstream.
As you may assume, given that the rear brake is adjusted, the wheels are mounted. The rear wheel needs a little work, based on the test fits prior to paint. It is an old 120mm hub with a new longer axle, that is re-spaced to 130mm. The spacers need to be adjusted to move the hub further toward the non-drive side of the dropouts, otherwise the derailer can't move the chain over to the small ring. As part of this, the wheel needs to be redished. So mounting and adjusting the derailers needs to await this change.
Even with all that's left to do, this is starting to look like a real bike now. Tonight I'll pull the wheels and mount fenders, then connect the front brake and finish the handlebars.
Pix soon.
Sunday, October 21, 2007
Wednesday, October 17, 2007
Late breaking news
Just heard from Duane at Chester Cycles. I'll have two frames back from paint on Sunday. Pix Soon!
New Rule!
New Rule: Never say you're getting into a rhythm. It's only tempting fate.
Since the last posting, work's dumped on me. That said, I did a little more work last night.
The front and back dropouts on the Surprise Bike are traditional Campy forged. No fancy stainless steel, just good strong dropouts. Because of the horizontal slot on the rear, the bike will be a good candidate for a fixed conversion - which is another factor in choosing these DOs. Also, they are very classic and this will be a classic looking frame. So Campy it is.
Last night I brazed the rear DOs to the chain stays. I wanted to do these with brass filler. 1) there is a lot of space to fill and brass is way cheaper than silver; 2) when the seat stays are mounted, the temperature will be too low to bother the filler in the chain stay joint. The latter is important because with a high-mass DO like the Campy, much of the heat gets directed to it rather than the stay. If you over do it (without burning flux or anything) it carries this heat some distance and can cause silly problems. Therefore, it's brass on the first joint with the DO and Silver on the second.
I was low on flux and tried to pick some up at the local welding supply. I asked for Gasflux blue paste, but they didn't have any. Instead they offered me another brand, saying that all blue fluxes are the same. I should have just ordered some more from Henry James.
So, it turns out the new flux isn't paste. Its a dry powder. Powder may be an exaggeration. The grains are about like course sand. Anyhow, I tried mixing some with water. Nope, its just like wet sand in a bucket of water. It doesn't absorb the water no matter how much I mix it. Adding more flux doesn't help. So I set this aside. Fifteen minutes later, it was one solid mass. Hmmm??? Maybe with some heat it will melt and can be applied like paste flux.
The can says to dip a heated stick of filler into the can and then braze with the fluxed filler. That doesn't sound good enough for me. So, I dipped the parts into some degreaser and then dipped them in the can. This seems to work to get a decent coating on everything.
So, the parts go together and the chain stay gets mounted DO-end up in the vice. Then I heat the filler and dip it in flux and get to work.
One thing I'll say about this flux, it covers the work pretty well. Sometimes, a flux can drip off of a small area of the parts being heated and that area gets a burn mark. Not so for this stuff.
Moreover, the dipping process makes it pretty easy to add flux as desired to the hot parts. Adding a paste flux to hot parts is a no-no. As the water boils off, the temperature of the parts plummets which can affect their temper.
From here, the brazing went pretty well: plenty of penetration in the joint, not too much excess brass for later clean up. The same went for the second chain stay. I let things cool, and over dinner the stays went into the washtub with hot (too hot for me to put my hands in) water. Usually, if no flux is burned, this (about 45 mins) is plenty of time for the flux to wash off. Not so with this stuff.
After another 30 mins of soaking, there was still a lot of excess flux hardened onto the parts. Maybe an overnight soaking would have worked better. Anyhow, I tried taking them back into the shop and chipping the flux off with a welders hammer. This often works easily after the flux has soaked for a while. Not with this stuff. It's tenacious. They should probably use it to coat the ceramic tiles on the Space Shuttle.
Using a combination of a sanding drum, the welders hammer, and an old bastard file got most of the remnants off. Then it was off to clean up brass.
I've been working on some ideas for a signature style for finishing off the ends of stays. I haven't seen any examples that I can remember of the style that most appeals to me - perhaps because it's a lot of work.
After slotting the stays, I file the ends in a semicircle with the slot being the equator of the semicircle. This differs from a traditional bullet end, where the profile as seen from the side & the top is similar. With my style, the tubing is not bent inwards on the end. When viewed from above, the surface of the tube forms a straight line all the way to it's end. Whereas on the bullet style, the end of the tube is hammered inward, so that even from above it looks like a semi-circle.
Once this is brazed up, I file off the excess so that this semicircle presents a square face to the world. Pictures will be clearer, so here they are (Click to Enlarge):
The reason that these are time consuming is that the further the edge of the tube is from the dropout, the more slumping/lumping the final filler will do in that space. With this style, there is a large open area between end of the stay and the DO. So, there is lots of post braze filing.
Next I have to prep the BB Shell so we can start to assemble the main triangle.
By the way, I hope everyone loves this little composition of pictures. Formating pix to page is a real PIA with
blogger!
Since the last posting, work's dumped on me. That said, I did a little more work last night.
The front and back dropouts on the Surprise Bike are traditional Campy forged. No fancy stainless steel, just good strong dropouts. Because of the horizontal slot on the rear, the bike will be a good candidate for a fixed conversion - which is another factor in choosing these DOs. Also, they are very classic and this will be a classic looking frame. So Campy it is.
Last night I brazed the rear DOs to the chain stays. I wanted to do these with brass filler. 1) there is a lot of space to fill and brass is way cheaper than silver; 2) when the seat stays are mounted, the temperature will be too low to bother the filler in the chain stay joint. The latter is important because with a high-mass DO like the Campy, much of the heat gets directed to it rather than the stay. If you over do it (without burning flux or anything) it carries this heat some distance and can cause silly problems. Therefore, it's brass on the first joint with the DO and Silver on the second.
I was low on flux and tried to pick some up at the local welding supply. I asked for Gasflux blue paste, but they didn't have any. Instead they offered me another brand, saying that all blue fluxes are the same. I should have just ordered some more from Henry James.
So, it turns out the new flux isn't paste. Its a dry powder. Powder may be an exaggeration. The grains are about like course sand. Anyhow, I tried mixing some with water. Nope, its just like wet sand in a bucket of water. It doesn't absorb the water no matter how much I mix it. Adding more flux doesn't help. So I set this aside. Fifteen minutes later, it was one solid mass. Hmmm??? Maybe with some heat it will melt and can be applied like paste flux.
The can says to dip a heated stick of filler into the can and then braze with the fluxed filler. That doesn't sound good enough for me. So, I dipped the parts into some degreaser and then dipped them in the can. This seems to work to get a decent coating on everything.
So, the parts go together and the chain stay gets mounted DO-end up in the vice. Then I heat the filler and dip it in flux and get to work.
One thing I'll say about this flux, it covers the work pretty well. Sometimes, a flux can drip off of a small area of the parts being heated and that area gets a burn mark. Not so for this stuff.
Moreover, the dipping process makes it pretty easy to add flux as desired to the hot parts. Adding a paste flux to hot parts is a no-no. As the water boils off, the temperature of the parts plummets which can affect their temper.
From here, the brazing went pretty well: plenty of penetration in the joint, not too much excess brass for later clean up. The same went for the second chain stay. I let things cool, and over dinner the stays went into the washtub with hot (too hot for me to put my hands in) water. Usually, if no flux is burned, this (about 45 mins) is plenty of time for the flux to wash off. Not so with this stuff.
After another 30 mins of soaking, there was still a lot of excess flux hardened onto the parts. Maybe an overnight soaking would have worked better. Anyhow, I tried taking them back into the shop and chipping the flux off with a welders hammer. This often works easily after the flux has soaked for a while. Not with this stuff. It's tenacious. They should probably use it to coat the ceramic tiles on the Space Shuttle.
Using a combination of a sanding drum, the welders hammer, and an old bastard file got most of the remnants off. Then it was off to clean up brass.
I've been working on some ideas for a signature style for finishing off the ends of stays. I haven't seen any examples that I can remember of the style that most appeals to me - perhaps because it's a lot of work.
After slotting the stays, I file the ends in a semicircle with the slot being the equator of the semicircle. This differs from a traditional bullet end, where the profile as seen from the side & the top is similar. With my style, the tubing is not bent inwards on the end. When viewed from above, the surface of the tube forms a straight line all the way to it's end. Whereas on the bullet style, the end of the tube is hammered inward, so that even from above it looks like a semi-circle.
Once this is brazed up, I file off the excess so that this semicircle presents a square face to the world. Pictures will be clearer, so here they are (Click to Enlarge):
The reason that these are time consuming is that the further the edge of the tube is from the dropout, the more slumping/lumping the final filler will do in that space. With this style, there is a large open area between end of the stay and the DO. So, there is lots of post braze filing.Next I have to prep the BB Shell so we can start to assemble the main triangle.
By the way, I hope everyone loves this little composition of pictures. Formating pix to page is a real PIA with
blogger!
Tuesday, October 09, 2007
Tuesday
Not building frames full time, it can sometimes be hard to get into a rhythm of work. Lately, however, thats coming easier - leading to more progress, faster.
No pix yet, but tonight I finished the penultimate miter in the main triangle. After fitting up in the jig, I'll miter the bottom of the down tube. The rest are all done based on measurements from BikeCad and either miter templates provided by same, or scribing the profile of the inside of a lug. Anyhow, a test fit up looks good so we're almost ready to jig.
After the miters, it's important to take care of any fittings that go on the tubes. In this case, that means H2O mounts on the seat and down tubes, and a brake casing tunnel in the bottom of the top tube. The H2O mounts are pretty simple. Measure, mark, drill a pilot hole, drill out one size larger, then drill the final hole. A little clean up with a deburer, file and sandpaper and they're ready to prep for brazing.
The tunnel is a bit more work. First a mark the tube where I want to entrance and exit to be. These are approximate locations. Then its a similar process to the H2O mounts to drill holes - only this time there are more bits involved because the holes are bigger. Then its time to cut a length of brake line - this needs to be longer than the distance between the holes. Using a tube bender, I tilt each end about 45 degrees. The bends are slightly closer together than the holes in the top tube - so that the tunnel will stand away from the walls of the top tube once its brazed in place.
Next comes a large (12" I think) bastard cut round file. I use this holding it with two hands and cutting with the last 6" or less of the file. Using this I can elongate the hole s in the top tube. With a bit of back and forth to test fitting, the holes get finished off and the ends of the tunnel shortened until I can just pop it into place. Then it's time to pop it out of place so we can prep for brazing.
All three tubes spent some time in hot water with Wisk to remove any cutting oil left over from drilling holes. Then a dip in a degreaser just to make sure all is well. After this, I check that the edges of the holes are clean of burrs. Finally, the tubes get sanded with 80 grit on the inside and outside. The inside can be a bit of a trick to sand. I ended up making a flap sander for this purpose,. It's a piece of copper tube about 3/8" in diameter. One end has a slit cut in with a hacksaw. Then this was squeezed part way closed. Into the slit go pieces of sandpaper. Usually, I pull a 3" strip off a roll of 2" wide paper. This piece gets split lengthwise, and the to pieces are placed back to back - then shoved into the slit. The back to back thing makes sure that a rough side always faces the tube, no matter how the paper is put into the tube.
Anyhow, this gets chucked into my portable drill and shoved up the tube. Zing! The inside gets clean.
Then its time to flux everything up. I used Freddy's Stainless Light tonight. It was a little dry, so water was added before zapping in the microwave. The heat usually makes it easier to spread onto the tubes, and have it stick. I like the flux to have the consistency of slightly loose mashed potatoes. Done right, not to much falls off in the application process - and what stays there drys onto the tube if its allowed to sit for a little while. This makes it easier to keep the flux where I want it once the torch starts heating the tubes.
The H2O mounts are surrounded by decorative reinforcers. I try to get these straight before the flux drys. Its much easier this way than trying to poke them into position after things are heated up. Using a small tip and a soft but medium to large flame, I warm the area until the flux starts melting. As the flux gets clear, its time to add silver. I start by pointing at the actual threaded mount, and applying silver to the edge of its flange on top of the reinforcer. I point the tip of the flame into the threads (which have been fluxed) to draw this silver around the mount and down into the tube.
I don't like to apply too much filler here, because its easy to leave a glob on top of the reinforcer while pulling silver around the bottom. So I then apply filler first to the edge of one end of the reinforcer, and then to the other end. The end of the filler wire gets touched up against the edge of the reinforcer that is closet to me, while I direct the flame the other side of the reinforcer. This pulls the silver from the point of contact, under the reinforcer, to the far side. A little waving of the torch makes sure that silver is making it to the side points of the reinforcer. The same process is used at the other, end, but less filler is necessary because the first step filled more than half of the reinforcer. At this point, its important to look to see if there are gaps, globs, or other issues than can be best cleaned up now while the joint is hot. On both tubes, things looked great, so it was time to move on.
For the H2O mounts, I used a 56% Silver alloy. This gets very wet when heated and fits into small places well. For the brake casing tunnel, I use something called Filet Pro, which is a special formulation (I think high nickel content) for making silver based filets. It will wet out and I can pull it into tight places, but this takes work. On the other hand, it has a relatively wide band of temperatures at which it is plastic. And if the tubes aren't over heated, its possible to set a 3/8-1/2 inch length down and melt it a bit at a time by moving the flame around. Where the fit is tight, more heat pulls the filler through. Where a filet is needed, less heat is applied to the filler. But, where the filler needs to pull up on to the exiting tunnel, heat on the tunnel with an occasional dip onto the filler (to soften it up) pulls the edge right up. The net of this is the filler can vary from internal to filet and back as it works around the tunnel.
Don't get me wrong, file work will be necessary tomorrow to dress up the tunnel to tube transition - but it will be much easier than if there was a large filet all the way around.
Well, that's all I got done today. Well the above and soaking the flux off the tubes. So tomorrow I'll inspect my work and do any necessary filing. Then it will be time to get out the jig. The breathing holes need to be drilled in the head and seat tubes. Then test the fit up of tubes and lugs in the jig. If all is well, the tubes can be preped and fluxed and then it will be on to brazing. So there should be lots to report on in the next few days.
Cheers!
No pix yet, but tonight I finished the penultimate miter in the main triangle. After fitting up in the jig, I'll miter the bottom of the down tube. The rest are all done based on measurements from BikeCad and either miter templates provided by same, or scribing the profile of the inside of a lug. Anyhow, a test fit up looks good so we're almost ready to jig.
After the miters, it's important to take care of any fittings that go on the tubes. In this case, that means H2O mounts on the seat and down tubes, and a brake casing tunnel in the bottom of the top tube. The H2O mounts are pretty simple. Measure, mark, drill a pilot hole, drill out one size larger, then drill the final hole. A little clean up with a deburer, file and sandpaper and they're ready to prep for brazing.
The tunnel is a bit more work. First a mark the tube where I want to entrance and exit to be. These are approximate locations. Then its a similar process to the H2O mounts to drill holes - only this time there are more bits involved because the holes are bigger. Then its time to cut a length of brake line - this needs to be longer than the distance between the holes. Using a tube bender, I tilt each end about 45 degrees. The bends are slightly closer together than the holes in the top tube - so that the tunnel will stand away from the walls of the top tube once its brazed in place.
Next comes a large (12" I think) bastard cut round file. I use this holding it with two hands and cutting with the last 6" or less of the file. Using this I can elongate the hole s in the top tube. With a bit of back and forth to test fitting, the holes get finished off and the ends of the tunnel shortened until I can just pop it into place. Then it's time to pop it out of place so we can prep for brazing.
All three tubes spent some time in hot water with Wisk to remove any cutting oil left over from drilling holes. Then a dip in a degreaser just to make sure all is well. After this, I check that the edges of the holes are clean of burrs. Finally, the tubes get sanded with 80 grit on the inside and outside. The inside can be a bit of a trick to sand. I ended up making a flap sander for this purpose,. It's a piece of copper tube about 3/8" in diameter. One end has a slit cut in with a hacksaw. Then this was squeezed part way closed. Into the slit go pieces of sandpaper. Usually, I pull a 3" strip off a roll of 2" wide paper. This piece gets split lengthwise, and the to pieces are placed back to back - then shoved into the slit. The back to back thing makes sure that a rough side always faces the tube, no matter how the paper is put into the tube.
Anyhow, this gets chucked into my portable drill and shoved up the tube. Zing! The inside gets clean.
Then its time to flux everything up. I used Freddy's Stainless Light tonight. It was a little dry, so water was added before zapping in the microwave. The heat usually makes it easier to spread onto the tubes, and have it stick. I like the flux to have the consistency of slightly loose mashed potatoes. Done right, not to much falls off in the application process - and what stays there drys onto the tube if its allowed to sit for a little while. This makes it easier to keep the flux where I want it once the torch starts heating the tubes.
The H2O mounts are surrounded by decorative reinforcers. I try to get these straight before the flux drys. Its much easier this way than trying to poke them into position after things are heated up. Using a small tip and a soft but medium to large flame, I warm the area until the flux starts melting. As the flux gets clear, its time to add silver. I start by pointing at the actual threaded mount, and applying silver to the edge of its flange on top of the reinforcer. I point the tip of the flame into the threads (which have been fluxed) to draw this silver around the mount and down into the tube.
I don't like to apply too much filler here, because its easy to leave a glob on top of the reinforcer while pulling silver around the bottom. So I then apply filler first to the edge of one end of the reinforcer, and then to the other end. The end of the filler wire gets touched up against the edge of the reinforcer that is closet to me, while I direct the flame the other side of the reinforcer. This pulls the silver from the point of contact, under the reinforcer, to the far side. A little waving of the torch makes sure that silver is making it to the side points of the reinforcer. The same process is used at the other, end, but less filler is necessary because the first step filled more than half of the reinforcer. At this point, its important to look to see if there are gaps, globs, or other issues than can be best cleaned up now while the joint is hot. On both tubes, things looked great, so it was time to move on.
For the H2O mounts, I used a 56% Silver alloy. This gets very wet when heated and fits into small places well. For the brake casing tunnel, I use something called Filet Pro, which is a special formulation (I think high nickel content) for making silver based filets. It will wet out and I can pull it into tight places, but this takes work. On the other hand, it has a relatively wide band of temperatures at which it is plastic. And if the tubes aren't over heated, its possible to set a 3/8-1/2 inch length down and melt it a bit at a time by moving the flame around. Where the fit is tight, more heat pulls the filler through. Where a filet is needed, less heat is applied to the filler. But, where the filler needs to pull up on to the exiting tunnel, heat on the tunnel with an occasional dip onto the filler (to soften it up) pulls the edge right up. The net of this is the filler can vary from internal to filet and back as it works around the tunnel.
Don't get me wrong, file work will be necessary tomorrow to dress up the tunnel to tube transition - but it will be much easier than if there was a large filet all the way around.
Well, that's all I got done today. Well the above and soaking the flux off the tubes. So tomorrow I'll inspect my work and do any necessary filing. Then it will be time to get out the jig. The breathing holes need to be drilled in the head and seat tubes. Then test the fit up of tubes and lugs in the jig. If all is well, the tubes can be preped and fluxed and then it will be on to brazing. So there should be lots to report on in the next few days.
Cheers!
Monday, October 08, 2007
New Efforts
Well, two frames are being painted and should be back and built up in the next week or two, and the Path Racer is ready to go into the paint shop when I pick up the others. So its time for a new project.
I'd like to start on the bike for the winner of this years MS ride, but I'm still looking for the machinist who will turn down some lug spigots for that build. So, it's on a short hold.
As a consequence, I've started on a surprise bike. It has somewhat odd dimensions (one of the bene's of a custom build) - by memory they are 59 c-c seat tube & 57 c-c top tube. It's for someone long-legged.
This frame is using a set of lugs left over from when the Match frame shop closed. At one time they produced the Schwinn Paramount, and these are the lugs used on the Paramount.
I thought (memory is a tricky thing) that these used three main tubes all of 28.6mm diameter. Usually, either the top tube is a smaller diameter than the rest, or the down tube is a larger diameter than the rest. Which would make these lugs even more unique.
Alas, my memory is bad. These use a standard 1Xoversize tube set (31.7 dt, 28.6 st, 28.6 tt). Which is fine, I have the necessary tubes in stock, including a stainless head tube. When polished up, a stainless head tube really stands out + it really shows off lugs with fancy shapes and these Paramount lugs are definitely fancy.
Mostly this will be a pretty straight forward design. It's designed for a 700cX28 tire, although a 30 or 32 will probably fit as well. The chain stays are a medium length at 415mm. Not short, but not long either. I would have made them longer but with this rider, the weight tends to sit forward and I didn't want too much weight shifted to the front wheel.
Angles are 73 degrees parallel with about 51mm trail. This is a traditional racing trail from back in the days when they used wider tires, like the ones that will be used on this bike. It should be able to handle a front bag, but probably not more then 5 lbs or so in the bag.
With the 28mm tires, fenders will fit, so it will come with mounting points.
Naturally it will be set up for two water bottles and a pump, and it's going to look something like this. Click to enlarge the picture. Two cautions: 1) don't pay too much attention to the numbers. They don't always represent the measurement that you would assume. 2) Colors haven't been selected by the client yet - these colors were just to give me something other than black & white to look at.
At the end of the day, this should be a pretty good road bike, but it will have the edges softened just a little to make it more flexible in use.
This picture gives a hint at what the head lugs are like. Note the head tube still needs a lot polishing.
See ya next time!
I'd like to start on the bike for the winner of this years MS ride, but I'm still looking for the machinist who will turn down some lug spigots for that build. So, it's on a short hold.
As a consequence, I've started on a surprise bike. It has somewhat odd dimensions (one of the bene's of a custom build) - by memory they are 59 c-c seat tube & 57 c-c top tube. It's for someone long-legged.
This frame is using a set of lugs left over from when the Match frame shop closed. At one time they produced the Schwinn Paramount, and these are the lugs used on the Paramount.
I thought (memory is a tricky thing) that these used three main tubes all of 28.6mm diameter. Usually, either the top tube is a smaller diameter than the rest, or the down tube is a larger diameter than the rest. Which would make these lugs even more unique.
Alas, my memory is bad. These use a standard 1Xoversize tube set (31.7 dt, 28.6 st, 28.6 tt). Which is fine, I have the necessary tubes in stock, including a stainless head tube. When polished up, a stainless head tube really stands out + it really shows off lugs with fancy shapes and these Paramount lugs are definitely fancy.
Mostly this will be a pretty straight forward design. It's designed for a 700cX28 tire, although a 30 or 32 will probably fit as well. The chain stays are a medium length at 415mm. Not short, but not long either. I would have made them longer but with this rider, the weight tends to sit forward and I didn't want too much weight shifted to the front wheel.
Angles are 73 degrees parallel with about 51mm trail. This is a traditional racing trail from back in the days when they used wider tires, like the ones that will be used on this bike. It should be able to handle a front bag, but probably not more then 5 lbs or so in the bag.
With the 28mm tires, fenders will fit, so it will come with mounting points.
Naturally it will be set up for two water bottles and a pump, and it's going to look something like this. Click to enlarge the picture. Two cautions: 1) don't pay too much attention to the numbers. They don't always represent the measurement that you would assume. 2) Colors haven't been selected by the client yet - these colors were just to give me something other than black & white to look at.At the end of the day, this should be a pretty good road bike, but it will have the edges softened just a little to make it more flexible in use.
This picture gives a hint at what the head lugs are like. Note the head tube still needs a lot polishing.
See ya next time!
Wednesday, October 03, 2007
Details details
Updated Oct 6
Back to work this evening. Yesterday I built fillets up on the head tube lugs similar to the seat cluster as seen in prior posts. I'm sorry, but you'll have to wait until tomorrow for pix. Anyhow, these will show how the raw filler looks after washing off the flux. The trick is to melt the filler enough to flow and bond, but not enough to 'wet out' and want to fall with gravity or the pull of heat. So the raw filler looks kinda smooth and lumpy.
This smooth and lumpy filler needs to be made into a finished joint, which is what I was doing tonight. 3 sizes of half round files, 5 sizes of full round files (including regular and chainsaw), plus a few other odd files and various sandpaper are the tools for this project. First, any odd nodules need to be 'knocked' off. A heavy work glove on
the left hand allows it to be used as a guide for the bastard (course) files used here. Then a large half round comes in handy to begin shaping the contours.
In an ideal world, filler gets laid down perfectly symmetrically on the joint. But in reality, some of the shaping is to find the lowest common denominator. At the center, the lug spreads the farthest as does the filler, at the sides the lug is narrow and fairly flat, so filler isn't needed. In between, the size of the concave face of the filler varies infinitely - so the contour has to vary infinitely in shape from side to side. And, the shapes should be pleasing to the eye, without abrupt changes. Net net, there is a lot of eyeballing going on. Even when the shape looks good, and I've sanded it smooth, I'll find problems and have to go back to filing. This often happens 5 or 6 times on a fillet.
But patience is rewarded with a nice looking fillet that will redefine how the lug looks under paint.
I'd like to say that the joints are all done. They are for tonight. But probably, by tomorrow, I'll decide that they need a little extra work.
I also brazed the rear fender mount tonight. This is a piece of stainless tubing with water bottle mount brazed to the end. The tube has bent with a nice arc near the end. At first the
plan was to mount this to a chain stay, but tonight, the right solution presented itself. I trimmed off most of the straight portion and mitered the end to fit the seat tube. Mounting it about an inch above the point of the BB socket leads to having the fitting perfectly positioned for the fender. And the profile is of a graceful arc coming out of the seat tube, ending just above the chain stays.
Most of the flux came off with a wet rag. The rest is soaking should be gone by tomorrow.
At present, I'm thinking that this frame needs a pump peg. Several options present themselves: a) mount it just above the fender mount on the seat tube; b) mount it high on the left-side seat stay, allowing the bottom of the pump to rest on the track fork. The more that I think about it, the more I am leaning toward this latter option, but tomorrow will tell for sure.
Well I tried fitting the pump in between the left track fork and the seat cluster. Guess what? It fits in place beautifully without a peg of any kind.
That's all for tonight. Pictures tomorrow.
Back to work this evening. Yesterday I built fillets up on the head tube lugs similar to the seat cluster as seen in prior posts. I'm sorry, but you'll have to wait until tomorrow for pix. Anyhow, these will show how the raw filler looks after washing off the flux. The trick is to melt the filler enough to flow and bond, but not enough to 'wet out' and want to fall with gravity or the pull of heat. So the raw filler looks kinda smooth and lumpy.
This smooth and lumpy filler needs to be made into a finished joint, which is what I was doing tonight. 3 sizes of half round files, 5 sizes of full round files (including regular and chainsaw), plus a few other odd files and various sandpaper are the tools for this project. First, any odd nodules need to be 'knocked' off. A heavy work glove on
the left hand allows it to be used as a guide for the bastard (course) files used here. Then a large half round comes in handy to begin shaping the contours. In an ideal world, filler gets laid down perfectly symmetrically on the joint. But in reality, some of the shaping is to find the lowest common denominator. At the center, the lug spreads the farthest as does the filler, at the sides the lug is narrow and fairly flat, so filler isn't needed. In between, the size of the concave face of the filler varies infinitely - so the contour has to vary infinitely in shape from side to side. And, the shapes should be pleasing to the eye, without abrupt changes. Net net, there is a lot of eyeballing going on. Even when the shape looks good, and I've sanded it smooth, I'll find problems and have to go back to filing. This often happens 5 or 6 times on a fillet.
But patience is rewarded with a nice looking fillet that will redefine how the lug looks under paint.I'd like to say that the joints are all done. They are for tonight. But probably, by tomorrow, I'll decide that they need a little extra work.
I also brazed the rear fender mount tonight. This is a piece of stainless tubing with water bottle mount brazed to the end. The tube has bent with a nice arc near the end. At first the
plan was to mount this to a chain stay, but tonight, the right solution presented itself. I trimmed off most of the straight portion and mitered the end to fit the seat tube. Mounting it about an inch above the point of the BB socket leads to having the fitting perfectly positioned for the fender. And the profile is of a graceful arc coming out of the seat tube, ending just above the chain stays.Most of the flux came off with a wet rag. The rest is soaking should be gone by tomorrow.
At present, I'm thinking that this frame needs a pump peg. Several options present themselves: a) mount it just above the fender mount on the seat tube; b) mount it high on the left-side seat stay, allowing the bottom of the pump to rest on the track fork. The more that I think about it, the more I am leaning toward this latter option, but tomorrow will tell for sure.
Well I tried fitting the pump in between the left track fork and the seat cluster. Guess what? It fits in place beautifully without a peg of any kind.
That's all for tonight. Pictures tomorrow.
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