Dan Dubeau
Ultra Member
Damn, that's pretty impressive. I like your fixturing setup for the tube mitering. Well done!
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Xyphota's bicycle related projects
- Thread starter Xyphota
- Start date
Xyphota
Ultra Member
So I've been on a bit of a hiatus with my own frame for the last few weeks, mostly because I promised I'd get my buddy a frame by the start of June like 10 months ago, and like everything in life, everything takes longer than planned so I paused my frame progress to build his. His frame is a pure fixed gear bike, no brake mounts or anything. He even only wanted water bottle bosses on the seat tube, nothing on the down tube. My bike still needs a few fixtures made to hold brake fixtures, so I felt comfortable getting my frame to a good spot before pausing and working on his.
The start of the build is basically identical up to where my frame is currently at. I did make one additional fixture to help ensure the rear dummy axle is perpendicular to the seat tube. This stays in place while tacking in the seatstays to the seattube, and brazing the dropouts.
After finishing the seat stays, those get brazed in, and then I spent probably 4-5 hours filing them down. I really enjoy the brazing process and I like the finished look so If I build more bikes I'd like to do more brazing, but the filing is pretty tedious. I think the next shop tool is a large air compressor than can feed a finger belt sander.
After the dropouts, the last step is to slot the top of the seat tube so that it can deform slightly to pinch the seatpost when tightening the seatpost clamp. As this last operation on the bike, this was a bit scary, I'm not going to lie lol.
Here is me just after finishing the slotting and doing a bit of final alignment at 1:00am lol. Off to the powdercoaters at 8am the next morning.
The start of the build is basically identical up to where my frame is currently at. I did make one additional fixture to help ensure the rear dummy axle is perpendicular to the seat tube. This stays in place while tacking in the seatstays to the seattube, and brazing the dropouts.
After finishing the seat stays, those get brazed in, and then I spent probably 4-5 hours filing them down. I really enjoy the brazing process and I like the finished look so If I build more bikes I'd like to do more brazing, but the filing is pretty tedious. I think the next shop tool is a large air compressor than can feed a finger belt sander.
After the dropouts, the last step is to slot the top of the seat tube so that it can deform slightly to pinch the seatpost when tightening the seatpost clamp. As this last operation on the bike, this was a bit scary, I'm not going to lie lol.
Here is me just after finishing the slotting and doing a bit of final alignment at 1:00am lol. Off to the powdercoaters at 8am the next morning.
Dan Dubeau
Ultra Member
That looks great. Well done.
Can't wait to see the next one!
Can't wait to see the next one!
Xyphota
Ultra Member
Frame building updates:
I've finished a disc brake mount welding fixture, and I decided to change what dropouts I am going to use.
Brake mount welding fixture: This is a shameless re-creation of the this tool: https://farrframeworks.com/farr-tools/le-disco . Bicycles have a standards crisis every 3-5 years where a new wheel hub or brake mount standard is introduced, so to the tool is very modular to potentially accommodate any standard. This tool mounts to a dummy axle, and when paired with the correct 'arm' and the right holes, it will hold the disc brake posts at the right position relative to the dropouts. I've made two steel arms so far; one for a flat mount style disc brake on my frame, and one for a different standard of flat mount disc brake for the fork lol.
This dropout is an off-the-shelf part, but the brake posts needed to be welded to it.
Frame update: I was originally planning on using traditional quick release wheels and rim brakes, but after starting the build I couldn't find any rim brake compatible rims that I liked for 27.5" wheels, and I won't have the funds to purchase the rest of the bike before the snow starts falling anyways, so I've elected to change to disc brakes and 'through-axle' wheels so I can just rob all the parts off my other bike and I'll at least get to ride this in a couple weeks. I cut out the original dropouts and have spent the last couple of days reshaping the tubing and filing down the new dropouts to fit goodly. I just need to file the non-driveside seat stay dropout tab and then they'll be ready to be brazed in.
I've finished a disc brake mount welding fixture, and I decided to change what dropouts I am going to use.
Brake mount welding fixture: This is a shameless re-creation of the this tool: https://farrframeworks.com/farr-tools/le-disco . Bicycles have a standards crisis every 3-5 years where a new wheel hub or brake mount standard is introduced, so to the tool is very modular to potentially accommodate any standard. This tool mounts to a dummy axle, and when paired with the correct 'arm' and the right holes, it will hold the disc brake posts at the right position relative to the dropouts. I've made two steel arms so far; one for a flat mount style disc brake on my frame, and one for a different standard of flat mount disc brake for the fork lol.
This dropout is an off-the-shelf part, but the brake posts needed to be welded to it.
Frame update: I was originally planning on using traditional quick release wheels and rim brakes, but after starting the build I couldn't find any rim brake compatible rims that I liked for 27.5" wheels, and I won't have the funds to purchase the rest of the bike before the snow starts falling anyways, so I've elected to change to disc brakes and 'through-axle' wheels so I can just rob all the parts off my other bike and I'll at least get to ride this in a couple weeks. I cut out the original dropouts and have spent the last couple of days reshaping the tubing and filing down the new dropouts to fit goodly. I just need to file the non-driveside seat stay dropout tab and then they'll be ready to be brazed in.
Xyphota
Ultra Member
Alright I've essentially finished the frame! Pretty much all of my free time in the last month was finishing up the fabrication. I'll break the post up into a few posts.
I had to make another fork which was pretty similar to the previous one, although this one has mounts for disc brakes. The brake posts need to be located relative to the axle, and the posts are just cylindrical blocks that get welded in so I just made some holes with an end mill.
My disc brake fixture from a previous post makes another appearance. The posts get held in place while they are welded into place.
I had to make another fork which was pretty similar to the previous one, although this one has mounts for disc brakes. The brake posts need to be located relative to the axle, and the posts are just cylindrical blocks that get welded in so I just made some holes with an end mill.
My disc brake fixture from a previous post makes another appearance. The posts get held in place while they are welded into place.
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Xyphota
Ultra Member
Towards the end of the build my brazing skills had improved quite drastically and I was no longer happy with how the water bottle bosses looked which were the very first thing I brazed and I cooked the sh*t out of them (pictured below). I decided to drill them out.
After drilling the heads off, the bodies of the bosses were stuck in the down tube. To get them out, I could grab them with needle nose and bring them to the surface of this internal cable routing hole (that I definitely did not need to shape this way for the express purpose of getting the bosses out
) and then I could very carefully cut them in half with the dremel so they could come out of the hole LOL.
Here is a pic of the new set of bosses brazed in, which look waaay better if I must say so my self
After drilling the heads off, the bodies of the bosses were stuck in the down tube. To get them out, I could grab them with needle nose and bring them to the surface of this internal cable routing hole (that I definitely did not need to shape this way for the express purpose of getting the bosses out
) and then I could very carefully cut them in half with the dremel so they could come out of the hole LOL.Here is a pic of the new set of bosses brazed in, which look waaay better if I must say so my self
Xyphota
Ultra Member
The crankset I've elected to use can only be purchased with 'single-speed' chainrings. Single-speed chains have wider rollers, so that the accompanying sprockets have wider teeth which makes them last longer. Multi-speed bikes have much narrower sprockets and use narrower chains. To use this crankset with a multi-speed drivetrain I need narrower chainring teeth so I just turned them down on the lathe. Fortunately, the proprietary chainrings that this crankset uses have a nice perfect circle in the center, almost like they are begging to be mounted up in a lathe.
There are several reasons why this is really not a good idea so I would not recommend anyone do this, but as my long term plan is to use a bigger chainring which will require an adapter, I am ok running this modified chainring for a few weeks.
There are several reasons why this is really not a good idea so I would not recommend anyone do this, but as my long term plan is to use a bigger chainring which will require an adapter, I am ok running this modified chainring for a few weeks.
Xyphota
Ultra Member
There were a few other steps I missed taking pictures of, but my frame is essentially done and I could throw it together! For now I've robbed all the parts off my other bike while I wait for the rest of my parts to arrive. I'm going to ride with these borrowed parts until everything else is in, then I'll strip it down and send it out for powder coating.
Couple pics of the internal routing:
Couple pics of the internal routing:
Xyphota
Ultra Member
I made a handlebar! This style of bar is called a bullmoose bar, and is sort of neat because it is integrated into the stem. I missed pics of a couple steps. The bar material is 7/8" x 0.049" 4130 from McMaster-Carr. It ended up being cheaper to buy from mcmaster even with shipping then it was to buy from spruce aircraft.
First I bent the bar and then coped and welded on the truss bits, and then coped the ends simultaneously for the steerer tube end. I wasted several hours trying to cope both ends of these truss tubes and get a good fit up because I did not want to remove my vice and un-tram my mill lol. I should have just did this in the first place.
I prepared the binder clamp pieces on the lathe and brazed them to the steerer clamp portion, then slotted it so it could do it's pinching action. I mounted it to the end of my fork and then put the whole fork in my tube clamp setup, and then positioned that above a 1:1 scale drawing of the bar for fitup. I tacked it in place and then welded it together.
Its about 780mm wide right now. I think I'm going to ride it for a bit but I'll probably end up trimming it down to 740mm wide.
First I bent the bar and then coped and welded on the truss bits, and then coped the ends simultaneously for the steerer tube end. I wasted several hours trying to cope both ends of these truss tubes and get a good fit up because I did not want to remove my vice and un-tram my mill lol. I should have just did this in the first place.
I prepared the binder clamp pieces on the lathe and brazed them to the steerer clamp portion, then slotted it so it could do it's pinching action. I mounted it to the end of my fork and then put the whole fork in my tube clamp setup, and then positioned that above a 1:1 scale drawing of the bar for fitup. I tacked it in place and then welded it together.
Its about 780mm wide right now. I think I'm going to ride it for a bit but I'll probably end up trimming it down to 740mm wide.
A trick I've used from time to time is to mount satelite vises (typically machinists vises) beside (or even in) my main vise. Sometimes that requires a bit of spacing but it beats losing tram.
Then again, checking and fine tuning tram is something I don't do as often as I should.
Your bike looks fantastic, nicely done! I too like how you’ve dealt with the cable exits/entrances.
How do you decide when to use TIG welding and brazing on parts like the dropouts?
Xyphota
Ultra Member
Thank you! There are a couple factors, but for me I wanted to try brazing and I like the look of brazed dropouts so that was it really for me haha. Brazing also lets you use thinner walled tubes, so my chain & seatstay tubes are only ~0.024" [0.6mm] wall thickness at the dropout end, and its easier to make the transition from the thick dropout to the thin walled tube with brazing.
You can get dropouts that are designed around tig welding like these ones: