For anyone interested, this was the work-flow/process I’d have students use in my framebuilding class. It’s not a comprehensive guide to building a bike and many details are missing, but hopefully it’s helpful to someone. Note that a bunch of the framebuilding supply/info links are obsolete or broken at this point (and many new suppliers aren’t on there).
Syllabus.pdf (189.6 KB)
Most of what you’ll be learning you will learn by doing it yourself – but I’ve compiled some basic information (as well as an outline of the flow of work I use to build a frame) as a reference.
Please remember that the balance of your class fee is due on your first day!
These are all common items that should be available both locally and online. This is purely a list of consumables and small parts, however – I am assuming you have access to a TIG machine or are renting my 120V Miller Maxstar. If you do not have any welding equipment and need advice on what to purchase, please call me to discuss.
Remember: the more practice you get beforehand, the better the class will go. If you are struggling with the welding, you will struggle with the class. You have plenty of lead time - make it a goal to get in 20-30 hours of practice before you arrive!
If you need some mitered tubing scraps, let me know and I will make you a big box of them.
Please note that this outline does NOT include every step, or discuss in full every technique we will use. It is purely intended as an easy reference to help guide you through the basic process
Identify driveside of BB shell.
– Discuss varieties of shells, PF and BB30, T47, English, EBBs, etc.
Drill vent hole.
– 3/16” is sufficient. Very large vent holes will cause increased distortion of the BB shell post-weld.
–Vent holes are useful to let water drain, let rustproofing compounds in, and they make welding easier on thin wall tubes. You can also backpurge (mandatory on titanium).
– Larger holes for Di2 bikes.
Install BB shell in fixture (using appropriate spacers) and clean with nylon abrasive wheel.
– These are superior to wire wheels and inexpensive, but cannot remove deep rust/ scale.
– Chemical cleaning usually not needed with steel, except in cases of excessive oil/mill scale. Denatured alcohol recommended.
Find butt (or butts) on seat tube and choose where to miter.
– Butts are often not to spec! Always measure!
– Seat tubes can be configured many ways – lug/external sleeve, external butted, internally butted, fusion welded plug, etc.
Miter seat tube to BB shell.
– This miter can be offset to help make it easier to miter/weld chainstays, to increase tire/seat tube clearance, or both. Can cause problems with front derailleurs in some cases, however.
Deburr and clean seat tube.
– Generally a mechanical cleaning is sufficient. For very oily/greasy tubes a bottle brush and dish soap works great.
Center seat tube on shell, tighten seat tube cone, and test for fit (wiggle test). If further mitering is necessary, miter by hand to finish fit.
– Half round files are made to match SAE sized tubing. It’s a good idea to have a set of 8”-16” files for mitering.
– Centering can be easily accomplished by using a parallel or calipers.
Tack seat tube to BB shell at 1:30/4:30/7:30/10:30 in fixture.
– Check alignment after tacking – if alignment is problematic, you can still break the tacks and correct.
Weld seat tube to BB shell.
– Typical sequence is front/nondrive quarter, front/drive quarter, rear/nondrive quarter, rear/drive quarter.
Check seat tube alignment and adjust as needed.
– For smaller diameter tubes, cold setting can work.
– For larger diameter tubes, re-running a section of weld bead (no added rod) is usually the most practical solution.
– Alignment is mostly determined by good miters and weld sequence.
Drill relief hole in seat tube and slot using double hacksaw blade.
– Typically 3/16” relief hole, but larger is fine too.
– I prefer to slot the front of the seat tube.
– Discuss brazed-on binders vs. collars.
Cut head tube to length, install spacers/heat sinks if required, and install in fixture.
– Basic chop saw cut is suffient, no need to face head tube before welding.
– Discuss head tube/headset standards.
Set fixture to match BikeCAD drawing.
Locate butts on downtube and toptube, decide where to miter.
Miter downtube as per BikeCAD angles/lengths.
Fit downtube into fixture to locate head tube.
Miter toptube.
Install water bottle bosses (if required). Test fit bottles to double check locations.
– Ceeway in the UK is a great source for these.
– 6mm or ¼” drill bit works great.
– Remember that bottle cages are not standardized.
Clean brazing flux from bottle bosses with hot water and abrasive wheel.
Clean tubes and drill vent holes in BB shell and head tube.
Tack downtube in at BB shell bottom to pull downtube down/into frame. Then tack at head tube and remaining points on downtube.
– Tack at 1:30/4:30/7:30/10:30 (approximately). Avoid the points of the DT/ST compound miter when tacking.
Do a very brief alignment check to make sure there isn’t a problem with the miters or tacking (pull top head tube cone up slightly to check for gaps).
Weld in the top of the downtube/head tube joint – easy access while the toptube is not in yet.
Tack the toptube in, using a sequence that holds it into the frame.
Perform another very quick alignment check.
Weld (in fixture if possible) bottom 2/3 of DT/BB joint, top and bottom of seat tube/ toptube, toptube/head tube, and downtube/head tube.
– Don’t weld the sides of the joints in the fixture as the back sides are very hard to reach – and we want to be alternating sides of the joints when finish welding.
Remove frame from fixture and weld in sequence the remaining joints.
– My personal sequence is downtube driveside, downtube nondrive, seat tube drive, seat tube nondrive, toptube drive, toptube nondrive, downtube drive, downtube nondrive.
– Everyone is a little different with weld sequence and you can experiment and see what works for you.
Frame back into fixture.
– No further alignment checks until chainstays are welded in – BB shell distortion will prevent accuracy.
Determine where chainstays, chainring, tire, cranks, and disc rotor/heels will need to clear and pick an appropriate chainstay.
– Discuss varieties of chainstay assembly – wishbone, yoke, prebent, asymmetric.
Dimple chainstays if required.
– Stays can be dimpled for tire, chainring, or both.
– Dimpling has hard limits, and always weakens the stay.
– Dimpling tools mostly consist of shaped wood or aluminum blocks, cradles, and some form of press.
Miter dropouts to chainstays (there are a variety of ways to do this) and tack in place.
– 3 tacks is generally sufficient. You can partially weld the dropouts in if desired.
Load stays into chainstay fixture and miter to BB shell
– Miter offcenter if needed to maximize clearance for welding around seat tube area.
Check that stays are same length/aligned.
– This will sometimes require hand filing a bit.
– For modern/through axle bikes it is important to get the stays very even! On older QR dropouts, dropout slots can be filed (to some extent) in the event of an alignment problem.
– In some cases the stays can be pushed slightly inboard, then released – if they come to center, you’re good!
Set fixture to ~1/2 degree more drop than needed, stays will tend to pull down.
Tack stays to BB shell in 3 places on each side (top, bottom, center/inside)
Weld chainstays in sequence.
– I prefer inside/nondrive, inside/drive, outside/drive, outside/nondrive.
Face shell.
Reinstall frame in fixture and check front end alignment. Fix as needed.
– With oversize tubes, best way to do this is by reheating/rerunning bead to pull frame.
Check chainstay alignment. These can mostly be coercing into position by hand, but you can use more heat if you have to as well.
Bend seatstays.
– There are a variety of ways to do this. Discuss/demonstrate.
– Prebent stays can work in some cases, but not as often as for chainstays.
– Avoid very thin walls/heat treated tubes.
Miter seatstays to seat tube.
– We will build a fastback style stay frame, but we will discuss other methods (wishbone, brazed/capped, etc).
Miter seatstays to dropouts (variety of ways to do this).
Tack seatstays, check alignment again. This is your last chance to fix a problem!
Weld in seatstays.
– Leave a gap/vent hole somewhere at the dropout end. You can seal this after finishing other welds.
– Sequence is relatively unimportant here, but it’s still good to alternate sides.
– Generally most difficult welding on the frame.
– Remember that you can extend your tungsten WAY out in the tight spots!
– If it’s just too tight, you can fill tight spots with silver rather than a full TIG joint.
Construct seatstay/chainstay bridges, if needed.
– Demonstrate how to make bridges (straight) on the mill.
– Curved bridges require hand mitering (which we will do just to get a taste of how it works).
– Bridges are relatively unimportant structurally but important for fender/brake/ kickstand mounting, and for aesthetics.
Weld or braze in bridges.
– Totally safe to silver braze or fillet braze if TIG is too difficult to do – bridges can be a real pain.
– You can use plate, old disc rotors, etc – no need to use tubing if you don’t want to.
Weld or braze on cable guides/stops (and pump pegs, derailleur mounts, etc).
– Discuss how to locate, plusses/minuses of various configurations, types of guide/stop.
Cap/finish stay/dropout joints
Ream seat tube to size.
Remove heat sinks.
Check and adjust rear axle spacing.
Prep for powdercoat (check for flux/pinholes/other potential issues and correct as needed).
– Reaming/chasing/facing of the frame is best done after powdercoat to avoid contaminating the frame with cutting fluids and making things hard for the powdercoater.
Boom. You’re done!
Commonly requested sources for some of the small tools and information we used in class:
SRAM tech docs/frame fit specs: https://www.servicearchive.sram.com/service
RattleCAD: rattleCAD download | SourceForge.net
BikeCAD: https://www.bikecad.ca/
Linkage (full suspension): https://bikechecker.com/
ISU Westlake Insurance: https://www.isuwestlake.com/
Tubing magnets: https://www.amazon.com/Strong-Tools-MVDF44-Adjustable-Magnetic/dp/B00JXDSVA6/ref=pd_bxgy_469_2/144-4294448-1524100?th=1
Seat tube reamer: https://www.mscdirect.com/product/details/02239093
Nyalox cleaning wheel: https://www.amazon.com/Dico-7200048-Medium-Nyalox-Wheel/dp/B002YDJU98/ref=asc_df_B002YDJU98/?
Stainless Cable guides: Housing/Cable Guides – Framebuilder Supply products/stainless-hydro-guide-10-pack
Note that this list is not comprehensive – but it does include most of the extant sources for framebuilding supplies and tubing.
Aerospace & Commercial Metals UK. Aluminium UK. Stainless Steel UK . Alloy UK.
Hi-Temp UK . Low Cost Aluminium
UK source of plain gauge 4130 and T45. Very helpful, willing to sell by the foot rather than full lengths, huge stock and reasonably priced.
Pilot Supplies, Avionics, and Homebuilt Aircraft Parts from Aircraft Spruce and Specialty Co.
4130 cromoly (non-butted) in lots of shapes and sizes.
Alex Meade Bikeworks
Fixtures, dummy axles, other framebuilding tools.
Anvil Bikeworks: Professional tools for the professional bike builder The nicest fixtures on earth. Be the envy of your framebuilding friends!
BRINGHELI
Tubing, tools, lugs, etc.
Bike Fab Supply www.bikefabsupply.com Small parts, lugs, tubes
Kirk Pacenti’s beautiful lugs and small parts
Framebuilding Bicycles. Tubing, Parts, and Tools
Tubing, brazeons and small parts, tapping/reaming/facing tools. Located in the UK.
Composite Product Design and Manufacturing | Composite Resources Composite frame tubing for the carbon fiber set!
Call 319-367-2282 - website no longer exists, but they’re still making stuff. Brazeons/small parts only. Very inexpensive and American made!
Sadly, now out of business.
http://edgecomponents.com/BuyOnline.aspx?catid=1&page=1 Manufacturer of carbon frame tubing, also forks/rims/bars/etc.
Fairing Industrial Inc.-frame builder,aluminum tubes,cr-mo tubes,bicycle tubing,bottom bracket,cable stops,rahmenbauern,Aluminiumrohre,cr-mo rohre,Fahrrad-rohre,Innenlager Kabel-Stationen,framebouwers,aluminium buizen,cr-mo-buizen,fiets buizen,trapas
Steel frame tubing and a distributor for Reynolds in the US.
Henry James investment cast steel lugs
Tubing, small parts, tools, jigs/fixtures, consumables.
KVA STAINLESS: MS3 Stainless Steel Custom Bicycle Tubing Supplier of stainless bicycle tubing, made in the USA!
MSC Industrial Supply Co. | Find Power Tools, Hand Tools, Machine Tools & More
A huge range of industrial supplies. Framebuilders can find cutters of all kinds, machine tools and parts, shop supplies, and more.
Cycle Frame Tubing :: Nova Cycles Supply Inc. :: The Framebuilder’s Source" is the dominant supplier of cycle frame building materials in North America
Tubing, brazeons and small parts, consumables, some fixturing equipment and tools
Home
Dropouts, brazeons, some tools (purge equipment, arbors, etc)
Suppliers of the ARCTOS frame building system
Solid Bikes
Suppliers of Integrated head-tubes and BB shells for BMX.
Sputnik Tool
Tooling for framebuilding
Strawberry Bicycle Strawberry Cyclesport Inc. Cutters and framebuilding tools
Custom Titanium Tubing North America - Titanium Joe
Titanium tubing (not bike specific, if you don’t know exactly what you need, this isn’t the best place to get tubing)
TiLite
Suppliers of titanium tubes in both round and custom shaped forms
No longer in business.
United Bicycle Institute
Steel and ti frame tubing and parts
The current sole supplier of domestically made frame tubing. https://shop.vari-wall.com/
Welcome to Ventana Mountain Bikes USA
Suppliers of pre made single pivot suspension systems and kits for builders.
Wicks Aircraft Supply
4130 steel (non-butted) tubing in an amazing variety of sizes and thicknesses.
Thanks @anon91558591 this is a great read. I hope you don’t mind, I convereted the PDF to forum markdown format to allow it to be searchable. Lots of little tidbits of information that im sure even experience framebuilders can use. One bit I learned was:
- Reinstall frame in fixture and check front end alignment. Fix as needed.
– With oversize tubes, best way to do this is by reheating/rerunning bead to pull frame.
One day (in a long future and a galxay far far away) when I finish my Phd, I want to teach a framebuilding class coupled with engineering princples.
I would like to know why is the ST usually the first to be attached to the BB and the DT is usually notched around both the BB and ST. Especially in fillet brazed frames, the fit of the notched DT over the existing ST-BB fillet isn’t perfect. The DT being more stressed compared to the ST, wouldn’t it be better if the DT were attached to the BB first?
I’ve made and ridden fillet brazed frames where I notched ST to the DT, and also the DT to ST. When I was starting out, I had some sloppy fits, but never broke a fillet brazed frame, and I’m 6’9", 260 lbs and was building single speeds at that point. It’s definitely possible to braze ST to BB and still get a good tight fit for the DT, especially if you file away excess bronze after a tinning pass around the ST/BB, but honestly I don’t think it really matters all that much if you dump a lot of bronze on the whole cluster and tie everything together.
It’s just the way I usually do it. You don’t have to do the BB/ST joint first, and in fact in some cases where you’re offsetting the seat tube a lot it’s mandatory to do the DT/BB first.
For alignment check purposes it’s often easiest to start with the seat tube and make at least a token effort to get it straight before continuing, but again, it’s not mandatory to do it that way.
Both will work fine and unless you do a truly terrible job joining, that area of the frame is not going to break regardless, so do whatever you prefer!
-Walt
Thanks for the insight!
I think 44 Kris Henry does the CS / BB / dropout assembly first. So I’m going to try that way first and use the CS / SS mitering jig I’m building also as a welding jig for the CS / BB / and dropouts. So it’s probably fine to do that first, then front triangle.
Seems like the consensus is that the Seat stays are always last.
Once you install seat stays you can’t fix alignment problems anymore, so those go last regardless of your sequence for the rest of the frame.
-Walt
This is great Walt!
Can you explain item #34 a bit more in detail? Are you referring to the BB drop?
Thanks.
Brandon
So in general in the classes (and for most of the frames I build) the chainstays are mitered offset on the bottom bracket shell. This is just to allow more space for fitting the torch through/seeing what’s going on when welding near the seat tube.
Since there’s more welding on the bottom of the stay, they tend to pull the dropouts downwards from their intended position. So in anticipation of that (on my ancient fixture) I set the chainstay angle to an extra 1/2 degree of drop. That translates to 3-4mm of drop on most frames, if you’re using a fixture that measures the drop directly.
-Walt
Thank you for the explanation. It’s interesting for sure and not something I’d thought too much about. For the most part, I also offset my CS on the BB shell. I suppose I should check a few frames to see if there was any change in the drop at the drop outs.
Thank you so much for sharing this! To your wonderful list of sites I’d add Torch and File - torchandfile.com - It’s the only place I’ve been able to find new Reynolds tubing online, and they have a few lugs and bottom brackets I haven’t been able to find anywhere else either.
Tony, this is an obsolete (very obsolete) document I used to use for my framebuilding class. I have no plans to update the suppliers list, so I’d suggest you have Daniel create a resource here that can collect links/information about suppliers.
-Walt
Does anyone still offer bulk tubing scraps? Beginner looking to practice!
Shoot me an email.
Walt
