Shortbow
- Thread starter tjwilson
- Start date
Caliper Mount Front Post
Picked up some coupling nuts that match the caliper mounting bolt thread. Notched the seat-stay/cantilever and welded in the front mount.
Picked up some coupling nuts that match the caliper mounting bolt thread. Notched the seat-stay/cantilever and welded in the front mount.
Caliper Mount Rear Post
Based on the rear post location and tight spacing I decided to mount the rear caliper post onto a tab. The tab mounts with the same bolt that holds the seat support clamp.
Got lucky and ended up with just enough space.
Reverse view
Side View
Based on the rear post location and tight spacing I decided to mount the rear caliper post onto a tab. The tab mounts with the same bolt that holds the seat support clamp.
Got lucky and ended up with just enough space.
Reverse view
Side View
Binky worthy bracket! ( I hope you get that!)
Loving the build so far, that seat is an absolute standout!
Loving the build so far, that seat is an absolute standout!
Pieces and Parts
Some odds and ends that needed attention. First up, the seat support clamps started to look a little too thick, the curve a little awkward to me. Did some reshaping and polishing.
Got the welds smoothed and everything polished on the seat support / sissy bar.
Finally put in a rear bridge between the cantilevers / seat stays.
Some odds and ends that needed attention. First up, the seat support clamps started to look a little too thick, the curve a little awkward to me. Did some reshaping and polishing.
Got the welds smoothed and everything polished on the seat support / sissy bar.
Finally put in a rear bridge between the cantilevers / seat stays.
Weld Smoothing
I've had a body solder (unleaded leading) kit from Eastwood for a while and have used it sparingly a couple times. With the top welds on this frame I decided to get serious and spend some time with it. Came out... okay. Despite attempting each joint about three to four times I just couldn't get rid of the small pinholes. I did figure out the best way to feather edges though. Unlike plastic filler were you need to delicately sand the edge, the body solder edges came out better with vigorous sanding.
Initial weld
Weld high spots ground down
Area tinned... the first step is to lay down a thin layer of solder. This comes in a paste, a mixture of fine metal and acid. The acid helps the tinning stick to the metal. The area is then washed down with a water and baking soda mixture to neutralize the acid.
The body solder comes in sticks. This image is after melting the solder over the tinning and doing some rough shaping with a wooden paddle.
Initial shaping with a file.
Final shaping and sanding.
I've had a body solder (unleaded leading) kit from Eastwood for a while and have used it sparingly a couple times. With the top welds on this frame I decided to get serious and spend some time with it. Came out... okay. Despite attempting each joint about three to four times I just couldn't get rid of the small pinholes. I did figure out the best way to feather edges though. Unlike plastic filler were you need to delicately sand the edge, the body solder edges came out better with vigorous sanding.
Initial weld
Weld high spots ground down
Area tinned... the first step is to lay down a thin layer of solder. This comes in a paste, a mixture of fine metal and acid. The acid helps the tinning stick to the metal. The area is then washed down with a water and baking soda mixture to neutralize the acid.
The body solder comes in sticks. This image is after melting the solder over the tinning and doing some rough shaping with a wooden paddle.
Initial shaping with a file.
Final shaping and sanding.
Bare Metal Frame
Soldered all the welds on the top of the frame. I only did some grinding and a little cleanup on the welds around the bottom bracket rather than completely smoothing. Didn't think the extra work would be worth the payoff. After sanding the entire frame I coated the bare metal with boiled linseed oil.
Soldered all the welds on the top of the frame. I only did some grinding and a little cleanup on the welds around the bottom bracket rather than completely smoothing. Didn't think the extra work would be worth the payoff. After sanding the entire frame I coated the bare metal with boiled linseed oil.
That's awesome! Never heard of the unleaded technique. I remember learning about lead sleds, watching videos of old dudes with their paddles scultping Mercs. I assumed the skillset of that particular dying art would be lost. Can it be done with aluminum frames too, or just steel?
Old dudes... Eastwood has an instructional video with Gene Winfield that’s fun to watch. Somewhere along the way I also remember seeing a video demonstration with Bill Hines. No mask or protective equipment, real lead, smoking a cigar the entire time!
Your question about aluminum got me curious. Never thought about it because I’ve only been focused on steel. Did a little searching around. Only thing I found was a Q&A at Eastwood. Answer was yes but. Yes, if you can get the tinning to stick to the aluminum. But, no guarantee on how it will hold up over time.
Just catching up on your build here, TJ. Love the tab mount for the rear caliper! Excited to follow through on other pages preceding this too. Great design and fabrication / engineering work as usual!
Front Caliper Mounting Bracket
Used the same type of coupling nuts as I did for the rear caliper to create a post mount bracket for the front caliper. I initially wanted to go with a 180mm disc up front but the clearance was too tight between the fork and disc and the disc rubbed intermittently during test rides. I swapped the 180mm out for a 160mm, same as the rear disc.
At this point I decided to change the way I planned to attach the bracket to the fork. One of the advantages of having a welder is that you actually can cut a piece twice to make it longer!
Used the same type of coupling nuts as I did for the rear caliper to create a post mount bracket for the front caliper. I initially wanted to go with a 180mm disc up front but the clearance was too tight between the fork and disc and the disc rubbed intermittently during test rides. I swapped the 180mm out for a 160mm, same as the rear disc.
At this point I decided to change the way I planned to attach the bracket to the fork. One of the advantages of having a welder is that you actually can cut a piece twice to make it longer!
Rear Reflector
I used 20ga sheet metal for the reflector base and attachment tab. The self adhesive reflector tape has a hexagon pattern to it. I trimmed the tape following that pattern, scribed the angles to the metal base as a guide, and attached the trimmed pieces. Because the reflector is recessed into the housing it's really hard to see that it isn't an actual reflector. Pretty happy with the way it came out.
I used 20ga sheet metal for the reflector base and attachment tab. The self adhesive reflector tape has a hexagon pattern to it. I trimmed the tape following that pattern, scribed the angles to the metal base as a guide, and attached the trimmed pieces. Because the reflector is recessed into the housing it's really hard to see that it isn't an actual reflector. Pretty happy with the way it came out.
Bullwhip Grips
Got the idea for this from a company that sells leather bullwhip handlebar wraps. I used the same vinyl that I covered the seat with. Slit a single piece so that there were four attached strips. These strips were then wrapped around the bars in a basket weave pattern. Next time I think I can come up with a better way to finish off the two ends. Maybe a metal band at the top and a cap that fits up and over the wrap at the end.
Got the idea for this from a company that sells leather bullwhip handlebar wraps. I used the same vinyl that I covered the seat with. Slit a single piece so that there were four attached strips. These strips were then wrapped around the bars in a basket weave pattern. Next time I think I can come up with a better way to finish off the two ends. Maybe a metal band at the top and a cap that fits up and over the wrap at the end.
Finished
Might have some additional photos at some point but calling it done for now. Thanks to everyone who offered input along the way. Really like the thumb shifter and hydraulic brakes. First time I've used either. The shifter and derailleur worked right out of the box with very little adjustment. The hydraulic brakes work great but were a mess to bleed. The bleed kit includes a syringe to fill the lines from the bottom up. I had the hose that connects it to the caliper pop off while squeezing the syringe a couple times and fluid sprayed all over. Luckily I bought more than enough. From the outset I wanted to try and match the performance and feel of the Schwinn Fastback that I spent most of last summer riding. Haven't spent much ride time with this bike yet but I think I succeeded. And, I managed to come in about a pound/.45kg lighter than the Fastback, even with the fat rear tire! Still may switch out to shorter cranks eventually but I can do that at anytime, after some miles.
Might have some additional photos at some point but calling it done for now. Thanks to everyone who offered input along the way. Really like the thumb shifter and hydraulic brakes. First time I've used either. The shifter and derailleur worked right out of the box with very little adjustment. The hydraulic brakes work great but were a mess to bleed. The bleed kit includes a syringe to fill the lines from the bottom up. I had the hose that connects it to the caliper pop off while squeezing the syringe a couple times and fluid sprayed all over. Luckily I bought more than enough. From the outset I wanted to try and match the performance and feel of the Schwinn Fastback that I spent most of last summer riding. Haven't spent much ride time with this bike yet but I think I succeeded. And, I managed to come in about a pound/.45kg lighter than the Fastback, even with the fat rear tire! Still may switch out to shorter cranks eventually but I can do that at anytime, after some miles.