stem tubing- apologies if this has been covered and i just didn't find it

[adashner]

have scraps and binders laying around, and somebody who wants a filleted stem. any minimum thickness/material issues/etc i should consider when fabbing this stem? there seems to be a dearth of good info through google or my other usual channels- might speak more to my study habits than anything else.

any thoughts are appreciated, especially those of the non-sequitur variety.

[Andrew R Stewart]

.035 is getting thin for stem extentions. .049 better. Andy.

[Alistair]

have scraps and binders laying around, and somebody who wants a filleted stem. any minimum thickness/material issues/etc i should consider when fabbing this stem? there seems to be a dearth of good info through google or my other usual channels- might speak more to my study habits than anything else.

any thoughts are appreciated, especially those of the non-sequitur variety.

This subject was discussed a fair amount back on the old (pre Google groups) frame builders email list. You can search the archives here, bikelist.org mailing list archives

Alistair.

[EricKeller]

when I saw this thread, I remembered a list of tubing sizes posted on the framebuilders list by Drew Guldalian. Couldn't find it in the archives. The document I made from it is on a hard drive I don't have hooked up right now or I would look it up

[Rody]

The choice of material is much more about your ability to design and construct a safe component than the diameter or wall thickness of the pieces that make the whole.

Unlike a frame, smaller integral items like forks and stems have less area of margin for error, requiring higher levels of fabrication experience.

The fact that you are querying others for imput tells me that you have not yet had the opportunity to begin to learn and feel this for yourself, so start with the basics. Focus on excellent miters, solid brazing with controlled heat and minimum HAZ, and utilize heavier materials that you think you need. As your skill progresses, so too can your choice of available materials to dial in the performance and feel of the part.

Have fun and be sure to report back with your progress.

cheers,

rody

[Willie1]

... on the other hand, I think getting a good starting point is important. Even with good technique, using too light duty materials is dangerous. This is not something that need to be trial and error, and is the purpose of a forum like this.

[steve garro]

any issues i should consider when fabbing this stem?

Fabrication experience?
- Garro.

[adashner]

thanks for all the response. and in hindsight i suppose i should have clarified more- was speaking specifically to the steerer clamp and the bar clamp. ended up going with 1.0 stainless i had in short pieces- made lugs 1. because that's what the guy ended up wanting and 2. wanted to play with nickel silver some more.

as for fab experience... 8 frames now. still learning on the fly. i have a bunch of metal fab experience, not so much with bikes specifically. but i quit my office gig of 10 years a couple months ago and am just going all in for now, either until i can get people to actually pay for these things or until the better half decides she's done paying all the bills.

none of this is particularly frightening to me, and i'm willing to experiment a bit, just curious as to what others tend to do. unfortunately there aren't many guys left in this neck of the woods doing steel bikes anymore. i'd much rather being going about all this as a grunt in somebody else's shop for a couple of years, but there aren't any... or, i should say, the couple of guys i know of are in the same boat as i.

otherwise, i've got 3 at the painter right now. i'll post some pics when i get 'em back.

thanks again,
abe

[jaredjerome]

thanks for all the response. and in hindsight i suppose i should have clarified more- was speaking specifically to the steerer clamp and the bar clamp. ended up going with 1.0 stainless i had in short pieces- made lugs 1. because that's what the guy ended up wanting and 2. wanted to play with nickel silver some more.

I go 1/8" up from what you're clamping to with an 0.058" wall. That's a little less than a total of 1/8", so it fights tight, but there's enough of a gap to slide it on/off.
So for a 1" steerer (or bar) I use 1 1/8" tube with a 0.058" wall. For 26mm I use the same OD but with a 0.049" wall.

[steve garro]

none of this is particularly frightening to me

I honestly don't know what to say.
It's scary as hell - you can kill people, their life is literally in your hands.
- Garro.

[adashner]

I honestly don't know what to say.
It's scary as hell - you can kill people, their life is literally in your hands.
- Garro.

i understand this, and am not attempting to be flippant. i'm confident in my joinery at this point (between aforementioned previous experience and cutting a ton of stuff apart), just not so much with materials. i know that everything i've done to this point has been overbuilt, and i'm not anywhere near trying to cheat physics. in fact, if anything i've found out in the past couple of weeks (via various photo galleries and videos of some of y'all and others <said without tone of indictment>) that i've likely been way light-handed and overly anxious to this point. like i said, i just was trying to get a general jumping off point, and appreciate the guidance.

[Rody]

Abe,

Thanks for checking in. The fine folks here at V-salon will always assist where we can.

If I may, the sentiment that Steve and I are trying to politely communicate is this...

With eight frames completed, three of which are at the painters, it conveys a perspective that your career is in it's infancy. This is a time that you SHOULD NOT be providing frames or components to other, either as finished product or testing material.

If you strive to be a professional in this small niche, you need to adopt a plan that allows you time to acheive success; liability insurance, education, practice, repetition, refinement, attaining a solid fundamental skill set, designing a structured financial business plan, then hang out the shingle.

How long will this take? Each individual is unique, but it will not be something you will achieve in an abbreviated period.

As a professional, your first priority is the safety of your customers. We are just trying to insure that you allow yourself time to achieve this.

cheers,

rody

[steve garro]

Abe,

As a professional, your first priority is the safety of your customers. We are just trying to insure that you allow yourself time to achieve this.

cheers,

rody

Thanks, Rody.
You always say everything better then I.
- Garro.

[adashner]

i appreciate all of that. numbers 6-8 should round out the bike fleet for myself, the better half, two brothers, and a couple of friends- completely at my expense. i'm building out of a pedicab fab shop, so i do have some ears to bend here- they just don't tend to be as concerned with form as they are function. and for a little further background, for what it's worth- i did do the ubi brazing frame course 2 years ago. as i said, if i had my druthers i'd be working under somebody else at this point, but the only guys in town anymore are crumpton and kirklee, and i don't really have any desire to deal with carbon. wes is still around, but by all indications has zero desire (or availability, at the very least) to hold my hand for the next year or more.

admittedly this isn't ideal, but after trying for 18 months to get in the shop at night, on the weekends, or whenever i could squeeze time in off a 40+ hour work week- it just wasn't happening. and i had to get out of the office for the sake of my sanity.

i have no desire to put anybody in harm's way- in case that needs to be stated- and would rather build functional, rock solid basic bikes and worry more about getting fancy as time goes on. i just... i gotta start recouping some dinero at some level. the kids gotta eat. and i'm fully aware that means this "out of the frying pan, into the fire" course of action may mean i have to get another paying gig sometime sooner rather than later. but we're managing right now, and as long as i can i'm just gonna keep cranking these things out, giving them away if i have to, until whatever lightbulb goes off or some burning bush tells me to start putting dollar signs on these things.

[adashner]

while i'm giving my thumb a break (and catching some lunch), here's #9: my daughter's next birthday present. sorry for the image quality, the old blackberry is in its dying days.

and really- thanks for all the input.

IMG-20130213-00789.jpgIMG-20130213-00792.jpgIMG-20130213-00793.jpgIMG-20130213-00795.jpg

[cardinal-creative]

Along the same lines of constructive criticism, the top tube intersection at the seat tube appears way low.

[Andrew R Stewart]

Abe- Welcome to this activity. From the finished views your work looks fine. But we know it's what's "inside" that counts and with a lot of filing and sanding the outside can look REAL nice regardless of the prior conditions. The main issue I see is that you are already "selling" your frames. It's not the transfer of money that controls liability (or the likelihood of a problem creating a liability) but the use of the product by any one other then the builder. Even still, if your use of the product caused another an issue you could be found liable for that (indirect as it is). So building for your friends is just the same as selling to a customer.

You speak well of your experience and seem to not be taking undo chances with designs and methods, that's not the question some here might have. It's the effect on others when you're found to be human and overlook something. How to control this possibility (many will say "likelihood") is part of the plan you need to have in place. I'll let others talk about the QC methods and manufacturing processes to reduce failures. Certainly lots of practice and testing is a large part of this.

I will say something about the personal exposure and social obligation you have when making stuff for others. Some think that insurance is to limit your (the builder) hit when the s--t hits the car/pavement. To me thismisplacedaced. The insurance is there to make good (as much as $ can do so for a human tragedy) your customer after they suffer the worst case incident. Those who feel the former is why insurance is needed might also feel that if they have a shallow pocketassistsests to speak of, this will limit some lawyer going after them. No one seems to talk about this idea but I'm sure I have read between the lines of some people's posts and see this in practice, whether consciencely knowingly or not. For some reason there seems to be the thought that because the builder is a good guy who has all the best motives in starting a frame business that iOKs Ok to not have insurance. Certainly the cost of insurance is prohibitive for many. But this is the cost of doing business. It's like owning a car. There are reasons that insurance is required (at least in the state I live in) before you are allowed to register the car. We all know some one who has driven w/o insurance and if we ever got into an incident with that person we'd think thdecisionsion to go w/o was wrong. Now having theftcollisionsion coverage is a fair persojudgmentment but liability, NO.

My reason to mention this insurance need so greatly is that you don't mention it indescriptionsptions of your situation. The shop you work out of (hopefully) has their coverage but does it cover your stuff that's not being sold by the shop? I doubt it. When i was younger i felt differently about this topic. But having gone through the wrongful death claim thing before, my view has changed and I don't build for others because I don't have coverage. When i worked for frame shops i was covered under their policies, when i had my own bike shop I was told I was covered, but not now so no commercial frame building. Andy.

[afwalker]

You may have seen this topic on liability insurance, if not it was helpful.
http://www.velocipedesalon.com/forum...ion-28244.html
cheers
andy walker

I'm just at 8 bikes myself, about to start selling, but am going to a tig welding class soon and got my liability insurance.
You work looks fine! Keep on plugging away.

[Mr_Rafi]

I think it's worth adding here that the OP is likely going to make some stems whether or not anyone thinks it's a great idea. So while the discussion I think is critical, the fact stands that if he's going to make stems, better to know what is safe / recommended in terms of the stem stock.

Personally, for extensions, I like 1" and 1 1/8" 4130 with a wall thickness of .065". I go heavier - given how long the extension is, it makes no sense to shave grams as far as I'm concerned.