I’ve got two or three bikes I want to build over the winter, so I figured I’d start a new thread to log my progress now that I’ve ordered the tubing and stuff.
This will be slow because I’m slow.
First, I made a send cut send order a while ago and threw 4 of these little stainless steel bottle reinforcements on to test out the idea. I used .03" 304 stainless steel.
Meanwhile I 3D printed a small die to clamp in the vice and shape them to a 34.9mm tube. Here’s a photo of the bottom half.
Thanks! I hope that I can figure out how to polish them up well and make them really shine. That might help if I make sure to mask off the eye and nose holes so they are the color of the painted tube underneath. We’ll have to see.
I meant to put it into the first post,( and I’ll edit it) but I used .03" 304 stainless steel. I like the idea of a themed reinforcement. The hole for the bottle boss is a little tight after the bending step, so I’ll have to adjust that for future projects.
Some parts started rolling in today. More to come over the next week. I thought it proper to add some of the design process, so here’s my CAD model for wide tire road bikes (gravel?)
I’m still nailing down the geometry based on what I plan on doing with this bike. My idea is kind of a modern randonneuring bike. It’ll have clearance for 40mm tires, maybe more. Fenders will be mounted full time and hopefully paint matched. I’ve never had a Dynamo hub, but I’d like one for this build. I picked up a 1x11 apex groupset from a friend that I’ll use along with some TRP Spyres. The goal is to have a bike that is always ready to be ridden whenever, wherever and for however long I want. No batteries to charge, brakes to bleed, fenders to mount. It’ll have some basic wheels. No need for carbon on this build. I’d like a frame mounted bike pump, any recommendations?
I’m kinda excited that these rear dropouts aren’t too expensive and look pretty nice.
Loving the skulls. I did something like that for a head badge. Cut the stainless out of an old microwave.
I had them powder coat right over it and then I carefully sanded the powder off and polished it up afterwards. Used lots of masking tape to protect the surrounding coating, but looked good when I was done.
I’m excited to see the end result.
That’s kinda what I was thinking I’d do. I do want to paint match the fenders on this bike, so it might not be powder coated, unless they can powder coat the fenders too? I’ll do some research and asking around. There is a pretty good powder coating place a 2 hour drive from home that some friends have used that can do some really fantastic paint jobs.
I’m working on my BMX a little bit first though. I haven’t decided on Geo for the road bike completely, so I’m gonna build the BMX while I ponder geometry choices.
So here is the top tube to seat tube miter. as well as the plan for the seat stays. I’m fillet brazing this bike, so my plan is to blend the seat stays into the top tube.
I left the ears of the top tube a little long so that I can cut them to whatever shape is going to be easiest. Which I’ll figure out when I get there. I don’t usually finish my fillets, but I think for this bike I will. It seems a little counter intuitive, but I like the idea of a nicely finished thing that gets used and abused.
It‘s a good idea to close the gap of the top tube with the seat stays, and I think when you finish the fillets nicely and then powdercoat the frame it will look really good.
When I made a few bmx frames, I copied what Solid and SandM did at their ST/TT junction…Make multiple notches with your holesaw on the TT. Start notching your TT at the hole saws widest diameter at the edge of the TT and repeatedly notch your way up to your desired TT length. This bores out the length of your miter, allowing you to wrap your TT around the ST easier. This technique also tucks the excess under the SS’s. Just a little file work on the SS after the SS mitering. S&M has factory Fridays on the gram and they have some real good bmx hacks on their posts.
That’s some really great advice. I love seeing how others approach frame building.
I’m a little basic though and only have hacksaws, files, a hand drill and a grinder.
I noticed recently that my jig doesn’t have Bottom Bracket pucks to hold a MID bottom bracket so I’m on hold until I can figure out a solution. I don’t really want to sacrifice some bearings, but if anyone has any suggestions or solutions I’m all ears. For context, I’m using a Bringheli JIG.
Easiest option, sacrifice some mid bb bearings. Best option, have someone turn you 2 allow cups to your specifications. There’s a lot of builders on here with a lathe and stock. I personally don’t. Worth drawing up some specs and asking around.
I’m probably gonna just sacrifice some bb bearings. I could probably have someone make me something. I’ve got a friend close by with a lathe. But I think I would rather hold out for a better reason to ask a favor. Just gotta check to make sure the bearings fit over the BB holder shaft.
Personnaly I don’t like the idea of seatstays overlaying the toptube on bmx frames, that’s where I’ve seen the most failure.
Also, and that’s an aesthetics preference,I don’t like the look of a bigger diameter toptube not fully wrapped around the seat tube.
My way (and many others) around that…give the toptube a little squish, ovalize it and they will not interfere .
I 100% agree here.
Overlapping the stays onto the ends of the TT miter means that the stays are welded/brazed to a thinner tube than it would be if welding or brazing straight to the seat tube since the walls of the ST will likely be thicker than the TT.
I’d personally prefer to do it the other way around - tuck the ends of the seatstay miters in under the “ears” of the TT miter. That’s if you insist on any overlap at all.
For the same reason I do not like seat tubes that are so pushed forward that they mostly or wholly join onto the down tube (not a BMX thing, but some MTB’s get made that way). Have no real data or anecdote that it’s bad. It just gives me that feeling it’s less than ideal.
[Edit: My post in the BMX appreciation thread shows how I did it on the two fillet brazed BMX frames I’ve built. Stays tucked as close to the TT miter as possible without actually overlapping.]
