Good morning gentlemen. I had a couple quick questions. Like most other newbies, I'm interested in building a steel road/commuter bike but I need to get some practice under my belt before attempting a build. I work in a shop that builds/restores vintage race cars, so I already have tools and space to do a bike build however our roll cage tubing would make a rather heavy bike. I have an account at an industrial metal supply and they have a great scrap section. From what I have read here 4130 is what most suggest to practice with? What size/wall thickness tubing should I look in to? Another question I had was what is the ID of a head tube that would fit most modern headsets? I'm sure these are way to common questions, but my searches haven't pulled anything for whatever reason.

-Long time newbie lurker

I just buy head tube stock from the usual suspects, list of suppliers is HERE. Nova, Bringeheli, and Henry James are the easiest for me to order from. If you want to roll your own head tube, Cane Creek has everything you need to know in this PDF document HERE

.035 should work for most frame tubes, but I would consider the cheaper tubes from Henry James or Nova depending on what you are doing with them

I'll add to Eric's good reply that a mock (or real...) lug/sleeve can be made with two tubes very easily. The outer tube (the one which is the "lug") needs to be 1/8" larger in diameter then the inner tube (the "frame tube") and have a .058" wall. This results in a near perfect sliding fit suitible for both brass and Silver practice. So a "frame tube" of 1" diameter would need a "lug" tube of 1 1/8" x .058" wall. Here's a link to Aircraft Spruce, a source for said stuff. Andy.

https://www.aircraftspruce.com/catalo...tubing_un1.php

Sean- Forgot to add that I have a bunch of photos on my Flicker Site with a lot of building processes, many using home made tooling. Andy.

https://www.flickr.com/photos/73195587@N00/

Awesome, thanks for the tips guys =) What would be suitable OD's for the different tubes?

I swear, aside from the few bamboo bikes I've made, the idea of framebuilding is like crack... always in the back of my head.

seat stays 5/8"
chain stays, 7/8" -- will probably require bending and definitely require crimping so standard bike tubes might be better
Top tube, 1 1/8"
Seat tube, 1 1/8" (get some 1 1/4" .058 wall for a sleeve at the seat cluster)
Down tube, 1 1/4"

The top tube and down tube can go up or down 1/8" depending on what you want the bike to look like. Bigger will be stiffer/heavier
Probably best to go with 1 1/8" seat tube for seat post compatibility, although you can go up 1/8" and sleeve for the seatpost

Thank you unter and Andrew for the info.......and not heckling the new guy =)

Please excuse the most likely stupid question, but what direction does the STI stop go? One side is flush and the other side has grooves in it.. THIS is what I have.

grooves go towards the head tube, i.e. in the direction of the shift levers. The grooves are stops for the adjusters as you twist them

does this mean you built a frame?

Thanks Unterhausen, that is what I thought but wanted to double check you guys. Yes I built a frame....I have learned quite a bit...especially things not to do hah. I haven't been very good at taking photo's as I went along but I will snap some here soon. I have a small time frame to work on the bike which is usually about an hour a day (4 month old). Andy S has been a HUGE help as well answering all of my dumb questions via email. Between the two of you, beers are owed =)

So here is the finished product. Again, thank you Andy for helping me along the way and answering all of my dumb newbie questions via email and Unterhausen for all of your helpful suggestions. So far everything rides nice, smooth, and stiff but I still havent taken it on a long ride (just built it up today). I have already started planning for my next frame. One thing that was a huge pain in the ass was the amount of distortion on my head tube and seat tube...not twist, but ovalizing. Being that I am still new to this, I did make a couple of passes on most of my joints to fill in the pinholes etc, so that is something that practice will help with and I assume that there will be minimal distortion with less exposure to heat. Anyways, thanks again fellas.

Nice!

Sean- Looks great! How far into this build did you say to your self "I'm going to do this THAT way on the next one" ? Andy.

ha, the second I made my first tack. I already have ideas for at least 3 more bikes.....like I needed another hobby =)

So I'm working on another frame, what can I say, I have the bug. I'm progressively getting better at clean fillets. Seeing how I'm still a newb at this, I still am getting pinholes/low spots/etc. I read a post on Vsalon by Eric @ Winter giving advice to get rid of said pinholes which I will mess with on a practice piece. I made a second pass this morning and I couldn't get the existing brass to wet out. That said, when I went to add more rod to the joint to fill in spots, it just sat on the old material and never wet out. I experimented with different amounts of heat, from very little to very hot and all it did was turn the new brass red without wetting.I assume I already cooked the first pass, so does that make the second run impossible to build up? My obvious goal is to make a nice fillet in one pass, but I am obviously still a ways off from that. any tips? Thanks.

it takes more heat to remelt filler than it does to melt it in the first place. I have never had any trouble adding filler, other than the classic, "oops, fillet collapsed" moments.

Wow, how much more heat are we talking? I had the original riller, at least I thought, pretty damn hot...glowing red

I haven't experienced trouble adding filler to an existing fillet. I find the extra heat needed comes from the larger thermal mass of the joint + fillet. Usually using the same tip size with a bit more flow works... I'm not sure why it doesn't work with you... flux?

it may seem like it's not melting until, "oops, fillet collapsed." (Is there an echo in here?)

Maybe you overheated and the skin on top is more oxidized than normal and doesn't want to move. But if something isn't wetting out the only two things can be heat and oxidation

Yea, I'm not sure why it isn't wetting or collapsing for that matter. I had the heat on there for a long time....Probably too long on my second pass...Didn't budge. Prior, it was filed and cleaned to the best I could. I was directing all my heat to the brass and it was hot enough to start making the surrounding tubes red. Structurally I'm sure it is fine, just looks like crap in a couple areas. I had a similar issue with my first frame and it seems to be in the same spot, at the ST/DT junction to the bottom bracket shell. It's in that funny little crevice where I can't get a good angle for the file. I saw a post on Vsalon where Steve Garro had a bent rounded file that seems to be right for that area. Made one this morning and had a little better angle to clean up that area.

Way cool frame, you make it hard for me to sit waiting to get going on my own. Do you have a plan for lugs or just TIG and fillet?

[Partial QUOTE=seankanary;15427241]... One thing that was a huge pain in the ass was the amount of distortion on my head tube and seat tube...not twist, but ovalizing. Being that I am still new to this, I did make a couple of passes on most of my joints to fill in the pinholes etc, so that is something that practice will help with and I assume that there will be minimal distortion with less exposure to heat. Anyways, thanks again fellas. [/QUOTE]

Sean; I would like to poke at three issues you noted in hopes that some of the more skillful and higher volume builders (Andy, Frank, etc.) will add their wisdom and experience to steer you better or more completely;

Re Pinholes; From my experience I don't see that a few pinholes are a major issue on a fillet frame. I get one or more on most builds... After the basic clean up to inspect a joint for any major flaws, I poke at any pinholes with a probe; often just a selection from my tube of straightened out paper clips and slide a needle nose plier down until it hits brass, clamp on it and pull it back out for measuring to see how deep they are. To see if the pinhole opens up to a larger diameter below the surface, I pick a probe that is about the size of the opening, stick in it and wiggle it around to see if I can angle it off significantly indicating a widening below the surface that isn't obvious to the eye). I would like to hear what others think/do, but generally I will not reheat a joint to fix any pinhole that doesn't doesn't go deep enough to enter the bottom half of the fillets' thickness nor for any that are not larger than 1/16" diameter. I reexamine them again after final filing, but generally if they aren't found to be worse than initially examination, I handle them during the prep/prime/paint phase with a bit of "pin hole filler" the auto paint stores sell in small tubes for that purpose. Exceptions: The underside of the HT/DT joint and the DT, ST, and CS joints at the BB. Those have to be pretty close to spotless or else. Qualifier; I just don't build anything lightweight, thin tubed, or of marginal strength, so I always have some extra grunt available in the joints which may make my approach inadequate for others. Any others have ideas/comments?

Re the distortion; I have to suspect that: 1) Your basic process at this stage of development is keeping the joints under heat for too long of a time, which will generally improve with experience and time; 2) Your pinhole chasing is adding a lot of time to #1 and you may be able to reduce that with more experience and/or by reassessing the importance of fixing them as I suggested above; 3) Your basic process and the pinhole chasing together may be causing what I believe is called "captured stress/distortion by real builders. As I understand it, this occurs when heat from one joint expands the tubes that are already captured by other finished joints and the tubes have no where to go, so it basically pushes into or against the joint current being heated causing bad things as that metal is softened by the heat. I would suggest probing the better builders for what they recommend for the best order of assembly, etc.

Re the rewetting problem; As others have posted, suspect this is almost entirely a problem with the existing brass basically insulating the tubes from your subsequent heating attempt(s) and that the joint once initially brazed is acting as a giant heatsink foiling your attempt to put enough heat at the specific point you want it. I remember way back with early practice joints (really ugly for quite a while) that these issues were why I begin to avoid going back to an existing joint for non-critical touch-ups, such as pinholes or to smooth a wavy fillet. Mentor would bark at me..."what are you still do'in throwing more heat on it, that torch aint no damned paint brush yea know!! I pushed forward eventually by just ensuring that the flux is really at the right state, the brass was wetting out to the steel nicely, and then quickly building up a fillet that was a bit thicker and wider than needed. Then as soon as possible to get the torch away from the joint. I am sure that I still spend too much time in cleanup and filing stage as a result, but for my occasional hobby building, it seems to work out ok.

So there it is. Hopefully real builders of note will add or correct my suggestions.

/K

Thanks for the response K. I think that only practice/experience will help me correct the issues of distortion and pin holes. Once I get more comfortable and figure out a nice workflow (along with lots of practice) I have a feeling these issues will resolve over time. Thanks again for your feedback =)

"What I lack in talent, I make up in enthusiasm."

@Alan
Thanks, I think I'm going to stick with fillet for a while. I suppose I should try and get good with one thing before jumping to the next method.

did you clean the rod before you used it? Always run sandpaper or scotchbrite over the rod before use. I find I rarely get pinholes with Cycle Design or Gasflux rod. In fact, I don't remember ever getting any with either of these brands. The crap from the LWS was not as good in that respect, but sanding it definitely helps. I wouldn't have thought it was a result of technique, but who knows.

I actually gave the rod a bit of scotchbrite this morning while doing up my chainstays and it did seem to work much better! Next time I pick up flux from cycledesign, I will give there rod a shot. I've heard it is real nice.