A Father-Daughter Build Thread

[cblandford]

... I am more the type to leave it raw and rough and ride it till it brakes and move on to the next one, no patience for soaking flux and hand filling the fillets. I love the idea of practicing a joint a day I need to do it.

That's definitely the smarter way to go about it! When it's just a hobby and the point is spent time, the soaking and finishing is weirdly enjoyable, I think. (I'm probably different from most in that I like tinkering with bikes more than I like riding them.) I do envy your just-ride-the-damn-thing attitude, though!

Myself as well, thanks a lot for taking the time to share your process.

For sure. It's selfishly helpful, too... Knowing I'm going to have to explain things in detail is making me really stop and think about what I'm doing as I go along. Thanks for following the progress!

-Chris

[cblandford]

Moving forward. Steps for today:

…
12. Check Frame Alignment
13. (Align Frame if Necessary)
…

I only recently purchased my little alignment table. Up until my last couple frames, I’d been relying on my fixtures and the various string/straightedge/frame-alignment-gauge methods to check alignment. The classroom at UBI housed a full-size BB-tower style alignment table; in both of my courses it served as a very heavy coffee table.

I think the attitude there is that if you use good fixturing and processes, an alignment table isn’t really necessary. I think I understand the wisdom in that. One of my favorite walk-around-town activities is one-eyed-squinting at the rear ends of production bikes that I see locked up to racks. Yikes. At least in terms of alignment, the bar isn’t set very high. And really, I don’t know enough about bikes to know whether any of it matters or not. Especially for the types of bikes that I build and ride.

So, I “align” my frames to a level that my perfectionism will accept. Which--given that I’m new to making bicycles--is a pretty loose tolerance. I’ve put a couple of my scrapped frames on my little table and felt the amount of force that it takes to move a head tube even a half-millimeter. A triangle made out of tubular steel is shockingly strong. In essence, I’ve quasi-decided that: A. if something needs mild correction, it isn’t worth me yanking the hell out of my frame to correct it; and B. if something needs major correction, I should probably just start over. So--as of right now--“aligning” my frames is really just a way to gain a little feedback as I go along. I'll nudge dropouts, but that's about it. I use the alignment process as a tool for improving the work on my next frame, not as a way to correct my current incompetencies. I hope that makes sense.

With that said, here’s what I check and how I check it. (Note: I didn’t take photos of this until after I’d finished the fillets, but I checked the frame before I started filing. Nevermind the shine for now!)












First, I face the BB shell with my Park Tool facer. The Paragon shells are supplied .5mm long, which I’ve found to be about perfect for the amount of distortion I get at the BB while brazing. Taking off .25mm from either side results in a full, fresh cut around the BB.

Once faced, I re-scribe the BB centerline onto the bottom of the BB, using my calipers. Then I mount the frame onto the alignment table. I use a little surface gauge/scratch/probe/thing and set it to meet the centerline. Then I compare this height to the height of the axle center.
















Next, I set my previously-mentioned Compass gauge to the height of the surface scratcher. I use this gauge to check my head tube and seat tube ends.
On the table, I found that my head tube was off-center by about 1mm, to the drive side. My axle center was off about 1mm as well (but to the other side). The head tube showed no twist, though, and the seat tube was fine. I make mental notes.

Next, I take the frame off the table and clamp it in my vise. I throw some Park H-tools into the dropouts and check for parallelism. (I’ve never had even a slight problem here, for whatever reason.) Then I place a true wheel into the dropouts. I check (using a straightedge held against the head and seat tubes) the top of the rim for center (keeping in mind that my head tube is off-center and so this reading will be skewed). I also check the distance between both chainstays and the rim. And finally I check the dropout spacing. Everything here jived with the readings on my table. If they didn’t, I’d have to figure out what was off (other than what I already know to be off).









Finally, I step back and do the fling-the-wheel and one-eyed-squint thing. Better than most bikes I see on the street, which is good by me.

I make the conclusion that the dropouts need moving 1mm each, back to center. I’m going to leave the head tube alone for now, and check it again after I tack the mixte-style stays in place. Mostly out of curiosity.

With the dummy axle in place, I give the chain stays their 1mm… nudge.

Once more on to the table and then I call it good.

If you’re curious, I did put the little sample Cleary bike up on the table, too. Let’s just say that I’m happy with how my frame compares. Or that--more likely--none of this mattered. Like, at all. Especially on this little bike.

Like I said, feedback and perfectionism appeasement.

That’s it. Next I’ll finish the main fillets and begin working on the seat stays.

-Chris

[cblandford]

Onward.

…
14. Finish Main Fillets
…


To finish my fillets, I follow the method described in these two links:

Steve Garro: Polishing Fillet Brazes
Dave Kirk: Fillet Show Bike

I start with round files, moving from larger to smaller. The largest file takes out all of my little bronze-dime edges; the medium and small smooth everything out. The smaller the file, the closer I get to the edge of the fillet, and the lighter I press. I avoid filing on the tube itself--I (try to) only file the fillet. There’s a thread in this forum where Doug Fattic describes the filing stroke itself. I’ll have to dig it up--very helpful. Basically, I work in a short, almost side-to-side pushing motion as I file.











Next, I use a piece of vinyl hose (with a wooden dowel shoved into the center for rigidity) wrapped with 80-grit emery cloth to blend everything together. Here again, I avoid sanding on the tubes as much as I can.

To finish up, I go back over everything with my smallest round file, hitting any spots that need touching up. And finally, I use strips of 80-grit emery cloth for a final polish and to blend the edges into the tubes.

As I work through the steps, a periodic swipe with some red Scotchbrite flattens everything out and helps reveal areas that need working on. On the BB, I’ll sometimes use my Dremel equipped with a little sanding drum (the same one that I used on my dropouts, earlier) to work on the nooks where filing is almost impossible.













And that’s that. I know some people dislike filing fillets. I love it. Blast the newest album and have at it. My favorite evening of any build, by far.

-Chris

[rwsaunders]

Good stuff...I’ve always liked making things for and with my kids. I believe that when they observe you “making/building/fixing” things; whether it’s woodwork, artwork, cooking, sewing, mechanical repairs, etc., that they will more likely not be apprehensive about exploring and trying to “make” things by themselves as well.

[cblandford]

... I believe that when they observe you “making/building/fixing” things... that they will more likely not be apprehensive about exploring and trying to “make” things by themselves as well.

That's the hope! This morning before we headed off to school, I threw a wheel into the frame and held it on the ground for my daughter to stand over. She observed that it was "Bigger than my purple bike! Because I'm growing?", which was pretty cool.

-Chris

[cblandford]

Here’s how things stand:







I’m calling this one 33% done. Makes sense in my head. Main frame... then seatstays, bridges, braze-ons... then fork & stem.

A couple things I’ve been meaning to mention:

1. I’ve left the seat tube long for now for two reasons. First, my jig only goes so short! And second, I’m not entirely sure what I’m doing for a binder/slot/collar on this bike yet. (Normally, I would have brazed the binder and at least drilled the pucker hole before connecting everything.)

2. I ended up going with a 68mm BB shell, 120mm rear spacing, and 16" (305 BSD) wheels. I wish I knew more about BMX parts, but I think I can make this work. Brakes are still up in the air a bit.

3. I did in fact use the aforementioned “seat stays” as chainstays. I also found a shorty 9-6-9 double-butted top tube to use as the down tube. Nice and light so far. Thanks to Jon in that Mentor thread for his advice.

My next step is the seat stays / top tubes. I’ve been pondering these (along with brake mounting, bridges, etc.) the entire time I’ve been working on this little frame. I think I’ve got a plan.

Definitely not going to finish both the Daughter and Father bikes before the New Year. That’s ok. As long as Mathilda’s is painted by mid-February. The other bike can come later.

Back soon,
Chris

[john swan]

Really enjoying this thread. I appreciate the detail and general quality of the posts. I have a daughter in the same age-group and would love the ability to do something like this, (my daughter got to pick her first bike at the shop, but this is a different level!). Looking forward to future updates/conclusion.

John

[cblandford]

Really enjoying this thread. I appreciate the detail and general quality of the posts. I have a daughter in the same age-group and would love the ability to do something like this, (my daughter got to pick her first bike at the shop, but this is a different level!). Looking forward to future updates/conclusion.

John

Thanks John! If I can learn to make a little bicycle frame, anybody can--that's for certain. Someday the daughters will appreciate the efforts.
I've got a couple updates to post... Getting closer on this one. Back soon.

-Chris

[cblandford]

Phew! What a couple weeks. I had a last-minute, year-end project come up right before the holidays and--as such--set this aside. Things are back to normal now, though, so I'm stealing hours in the studio again.

Anyway, back at it:


...
15. Top tubes / Seat stays!
...


Lots of considerations for these top tubes/seat stays. Before I started this bike, I knew I wanted these tubes to be swoopy-curvy. So, I impulse-purchased a Harbor Freight tubing roller and some small-diameter dies from Swag Offroad. When I got the roller home, I ran a couple test pieces. I’d never rolled tubes before. Super fun. I’m definitely going to use this in the future, for a variety of things.

I wasn’t able to find any definitive information on how to achieve this style of mixte-esque stay, so I had to wing it a bit. I began by rolling the tubes (went with .5”) across their entire length, holding them up to the frame to check the radius as I went. I rolled little by little until I was satisfied. No drawing here, just building in space.









Next, I compared the curved-to-my-liking tubes to my drawing. I determined that if I raked the ends of the tubes on my fork blade bender (using a 5” radius die), the dropout tabs would line up nicely. So, I raked the ends.

Next came the tricky part. I knew I wanted the stays to pinch in towards the seat tube (for little-kid-inner-thigh clearance), as opposed to running in straight (wide) lines from dropouts to head tube. But, I was unsure how to put that kink/bend in the middle of (and opposed to) my long, swoopy bend. In addition, I thought it would be nice if the seat stay portions of these tubes were “twisted” inward a bit (for brake stud spacing and aesthetics purposes). I thought about just putting a slit on the outside of the stays and nudging everything inward, but in the end decided to split the long tubes entirely in half and miter the four different sections individually. (My fall-back plan was to just throw a single top tube in the frame, and side-tack the seat stays.)











Once split, I tabbed, slotted, and mitered everything up. As I normally do with seat stays, I started with the dropout tabs, then slotted the seat stays (using my drawing, just like the chain stays). Then I mitered the seat tube ends of the seat stays. Finally, I mitered the two little top tubes. All of these miters were done the same way as the chainstays-to-BB miters, using BikeCAD’s paper templates.

This all took two full evenings. Definitely the trickiest mitering I’ve done.

Once mitered, I was left with (anticipated) little half-butt joints on either side of the seat tube. I’m guessing this could be addressed differently on a welded frame, but I decided that--since I was brazing this all together--I’d use an internal splice to connect everything back together and avoid having two tube ends running right into one another. I’ve spliced the ends of rack decks together like this, but I had/have no idea if this is a kosher way of doing this here (so certainly don’t copy me!). The end result, though, is essentially a solid-ish plug of steel and bronze, about an inch long, right at the side of the seat tube. (These spots are also going to get little reinforcement bridges/plates ala Retrotec in my next installment.) If I’m an idiot and should not have done this, feel free to tell me so.







Speaking of, if there’s a better way to execute--in general--these types of top tube/seat stays, I’d love to know what it is! It seems achieving multiple bends in a single plane (?) is pretty simple… But putting multiple bends in two different planes is tricky. I’ll give this some additional thought for the Father version of this frame…











Anyway, I next drilled vent holes at the "tops" and "bottoms" of each of the four tubes. Cleaned everything up and tacked everything together, in the jig. At UBI, we tacked seat stays in place out of the jig. However, I’ve found that--as long as the frame goes back in the jig easily--the “universal tube holder” that my Anvil came with is really helpful for holding seatstays in place for tacking. Once tacked, I removed the frame from the jig and brazed all six joints in my Park stand. Same tips and fillers and methods described previously. Once brazed, I let everything cool, soaked off the flux, and finished all of the joints. Again, all as described previously. A quick check on the alignment table told me that everything stayed put, for better or worse.







Bridges, reinforcements, and braze-ons next. Fork after that. Need to move quickly now… Might even take a day off of work-work to get the fork built. In any case, back soon!

-Chris

[Paul van der Zwaard]

newbe here.
Beautiful work. Learned a bunch from it. Did you put the pin on seat stay so gravity wouldn't,t do its thing with the piece of metal inside the tube?

[cblandford]

newbe here.
Beautiful work. Learned a bunch from it. Did you put the pin on seat stay so gravity wouldn't,t do its thing with the piece of metal inside the tube?

Yes, that is why I put the pin in there. I've done that previously with rack deck splices, and applied it here. That said, don't assume I know what I'm doing! This seemed like a low-risk situation for that whole seat stay experiment, but I'm not sure I'd do it this way again. In any case, glad you're enjoying the thread.

-Chris

[Andrew R Stewart]

A pin is a nice and easy solution to gravity or a lack of clamps. Andy

[cblandford]

A pin is a nice and easy solution to gravity or a lack of clamps. Andy

I really like my high-temperature (alnico?) magnets, too, when nothing else will do.

-Chris

[enieleni]

What a brilliant thread. Thanks for sharing this!

[cblandford]

All right, moving on. For today:

…
16. "Bridges"
…


I've only ever made bridges out of round tubing, but I thought I’d try something different on this little bike. I like the look of the plate reinforcements I’ve seen on a few different mixte-style bikes. So, I decided to ditch regular, round bridges all together and purchased some 4130 sheet steel from Aircraft Spruce.

I started with poster board (actually, this was a manilla folder that was within arm’s reach). I traced and trimmed until I had the pieces and shapes that I was satisfied with. Then I transferred the shapes on to the steel and cut them out with a cutting wheel, cleaning them up with files and checking that they fit well.











Next, I (blue) fluxed and (bronze) brazed the plates in place. I tried to be mindful about the already-finished fillets around the seat stays/top tubes. I think I’ve read, here, that remelting bronze--already on a frame--takes a little more heat than initially melting it. That matches my experience in this instance. (Also, note the little makeshift magnet-slash-clamp-slash-vise-grip fixture. Much to my surprise this worked pretty-ok, unlike some of my previous slapped-together holding techniques.)

Once all of my little plates were brazed in, I soaked and cleaned them up in the usual fashion. I also added a little bridge between the top tubes, about halfway between head tube and seat tube.













Overall, while I do like how these look, they definitely give the little frame a wicked/sharp/brutal personality. I'm not sure they compliment the curves of the stays as well as I'd thought they would. They certainly don't scream "Pink Giraffe". Oh well... It was something new to try. Mathilda thought they were neat when I shared my progress, so that makes me feel good. (And yah, about that one asymmetrical plate... I have a plan for that down the road.)

Next up are some head tube reinforcement rings and a seat tube collar. Then it’s on to the fork.

Back soon,
Chris

[cblandford]

For today:

…
17. Make and braze on head tube reinforcement rings
18. Make and braze on seat tube collar/binder
19. Slot seat tube
…

I was planning on using a cast seat tube collar on this frame. When I went digging for the one I thought I had on hand, however, I discovered that it was the wrong size. So, I decided to make my own out of a Paragon binder and some .058” tubing (to slip fit the seat tube).

I began by mitering the binder to fit the tubing. Then I put a small slot on the opposing side of the binder. I need to figure out a better way to fixture these while brazing, but a slot and one of my usually-used-for-cable-stops Sputnik clamps works ok. Then I (bronze) brazed the binder to the tube.









Next, I soaked, cut, and cleaned up the binder, squaring off the top and bottom on my belt sander. I also drilled the binder and seat tube for a pin. The pin will help me keep the collar straight while brazing. This was just done by eye.

Once the collar was made, I set in on cutting a couple of head tube rings (also out of .058” tubing, to slip fit the head tube). I’m using a regular 1mm-walled head tube on this bike, meant for use with lugs (as I understand). As such, I need reinforcement rings on the ends so that reaming the head tube doesn’t leave the walls too thin and prone to cracking around the press-fit headset. To make these, I first squared up the end of the .058” tube on the belt sander. Then I hacksawed the ring to length, and repeated for the second one. When I go to braze these on, I’ll make sure the square sides of the rings face “in”. The less-than-square hacksawed edge will get squared up when I face the top and bottom of the head tube.









Next I cleaned up the rings, collar, seat tube, and head tube with 80-grit and isopropyl. Then I fluxed all the bits, clamped the frame in my Park stand, and silver (56%) brazed them to the frame. (More about the silver brazing once I get to the fork...) Once cool, I soaked off the flux and cleaned everything up. Small files and emery, once again. Finally, I machined the head tube with my Park head tube reamer/facer.

I should mention that I’d love to learn how to use a lathe, if only for little bits like this. I’d like to be able to make these types of things more unique… tapered, perhaps... or something. For now, however, simple, chunky little rings and collars are what I can do. Maybe down the road.









Lastly, I slotted the seat tube. I enjoy every part of making a bicycle frame, except for this part. Even in my short time of doing this, I’ve learned to despise this task! On my most recent (adult) bikes, I’ve drilled the little pucker hole as part of making the seat tube sub-assembly. Even still, I never manage to get it exactly centered. In this instance, the hole--again--ended up a touch off center. Cursing to myself, I cut the slot with my Dremel cutting wheel (I usually use a hacksaw but didn’t have access on this little frame, which was anticipated) and then set in on getting it cleaned up with progressively-larger slotting files. When I was done, it just looked… off. Per usual. So, I “fixed” it as I’ve done a couple times before: by brazing on a “reinforcement” washer around the hole, and making sure it was good-and-center. Call it a feature.











That’s it for braze-ons at the moment. I’m still undecided about brakes on this bike. So, after I finish the fork I’ll need to add either brake studs or a plate for a coaster hub. And of course there’s the headbadge. But that always happens last. No matter what.

Here’s where we stand:







Fork tomorrow.

-Chris

[cblandford]

I built my daughter a bicycle. The first of many, I hope.









(Sorry for jumping ahead. Retroactive fork, brake, and stem posts coming soon.)

-Chris

[Ras72]

^^ That last photo is the shit! Perfect way to depict the end of the build.

[cblandford]

^^ That last photo is the shit! Perfect way to depict the end of the build.

Glad you like that one! It felt appropriate, for the build and for the day.

-Chris

[cblandford]

Moving on to the fork. I built this last week; sorry for the delay in posting photos!

Fork steps:

1. Fit and braze steerer to crown
2. Shape crown, if desired
…


I begin by fitting and brazing the steerer tube to the crown. The crowns I’ve worked with are nicely machined post-cast; to this point, they haven’t required much fiddling to fit nicely around the steerer. (I was taught that the steerer-crown interface should have no play, but should be loose enough to allow the crown to slide down the steerer under gravity.) In this case, I merely cleaned up the outside of the steerer and the inside of the crown with 80-grit emery. (I was also taught to orient the emery "scratch marks" in the direction one wants the silver to flow while brazing. So, I do that with everything I silver braze, as shown here.)


Once cleaned up, I drill a hole for a pin that will hold the crown to the steerer while brazing. I use regular hardware store nails for the pinning, tapering them slightly on my belt sander so that they fit tightly when I tap them into the assembly-to-be-brazed. Also worth noting is that I allow just a small lip of the steerer to protrude past the bottom of the crown. When I go to braze, I’ll do so “upside down”. Having a little lip there allows easier feeding of the silver filler.

Finally, I drill vent holes if appropriate. This crown is hollow in the shoulders. I vent fork blades top and bottom, so these holes will allow the blades to be vented directly through the steerer. Some crowns I’ve used don’t allow this; those forks’ blades just get a simple hole, somewhere up near the crown.













Once everything is ready, I clean with isopropyl, flux the steerer/crown/pin, assemble, and then apply more flux. Ready to braze.

Because silver brazing requires lower temperatures than bronze brazing, I--previously--associated silver brazing with smaller torch tips and smaller flames. Made sense, I thought. I have since found (and read, here, many times over), however, that using a larger tip and a bigger, broader flame is actually more appropriate for lugged joints. The temperature control--as I’m now starting to grasp--is handled by the movements of the user, not the size of the flame. As such, I now braze these joints with my largest torch tip, a Smith 207 (and 56% silver filler).

As mentioned, I braze this joint upside down. I also braze it out of any jig. Hence the pin. At UBI, we were taught to braze the steerer and blades to the crown in one shot. Even the slightest imperfection in the fit up of all those (four) parts, however, can result in the steerer/crown being under (even a tiny bit of) tension. I've found that this little bit of tension can make brazing this joint, in particular, difficult. So, I now braze lugged forks in two steps. Attaching the steerer to the crown first also makes carving/cleaning up the crown easier. It’s an extra heat cycle, yes, but it’s a tradeoff I know some well-respected builders make. Good enough for me.

I fire up the torch. I use a big, rumbling, 2-3x reducing flame. I preheat the entire circumference of the steerer. I feed silver into the “lip”, and draw it through to the race seat. Finally, I don’t skimp on filler. I make sure these silver-brazed joints are good and full. Eventually I’ll get the hang of how much silver fills a given joint; for now I just overshoot the hell out of it. “Shorelines”--or whatever--be damned.












Once brazed, I allow the assembly to cool completely. Then I soak off the flux, trim the pin, and shape the crown. In this case, I simply rounded off the sharp corners and also removed the brake mount... things (nubs? faces?). I thought this would look nice with the dropout treatment and swoopy curves of the frame. Finally, I touch up the blade sockets’ edges with a file. (I don’t bother with all the casting marks just yet; I’ll take care of those after the fork is done.)

That’s it for now. Blades next!

-Chris