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  1. #1
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    Unusual Handlebar Stem

    I have constructed this Stem for a left field application.
    Unusual Handlebar Stem-img_0258-4-.jpg
    It uses a Specialized angle sleeve to adjust +/- height, rather than using spacers on the steerer tube.
    Unusual Handlebar Stem-img_0264.jpg
    The angle is 3 degrees, 1 1/8" steerer, 26mm h/bar, reach is 90mm and weighs 250grams.
    It was fun to knock up, but initially was unsure how it would look when I put its 'Warts' on.
    It looks good once it is mocked up with a bar and attached to a fork.

    Eric
    If I don't make an attempt, how will I know if it will work?

  2. #2
    Mtn Biker Machinist
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    Very interesting, care to share what it's for?

  3. #3
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    You might want to make those fillets a little bigger.

    -Joel
    NOTHING WORKS LIKE CLOCKWORK

    www.clockworkbikes.com

  4. #4
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    Well;

    I didn't really think of it when I first saw these a few days back, but I'd guess I agree with the larger fillets philosophically, at least at the steerer clamp. That is based on total hunch and gut. I have no real world experience to back that up. I know brazing has been holding bike frames and components together for ever and ever, but it still makes me a little nervous. I mean, it is essentially gluing steel together, not fusing the bits into one.

    The concept? Love it!
    Most people ply the Well Trodden Path. A few seek a different way, and leave a Trail behind.
    - John Hajny, a.k.a. TrailMaker

  5. #5
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    Those fillets looks frankly frightening - so tiny, which in and of itself is not necessarily a bad thing, but the erratic nature of the radius does not speak to a level of proficiency of the builder. I would never trust my life / face to that.

  6. #6
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    What, you don't like my brazing????

    On appearances, I fully accept your critique.

    So to explain that all is O/K, this is my method. I use silver. Silver has a wonderful quality whereby it capillaries through even tight mitres and back fills the joint whereas Brass will 'coat' and therefore requires bulk filleting to achieve its strength.

    I have drilled access at both ends of the stem to view each individual joint internally with torch light and I can asure you all that the Silver has formed a much tidier and fatter fillet than you can see on the surface.

    The silver will also flow around a bit with the flux and give a micron or 2 of over coat beyond the braze area. I used to fanatically clean this off for a 'perfect look' but these days I find this a bit of a folly and a time waster. It happens to be a good anti corrosion material.

    There is also a very large surface area of joint here - 36mm OD steerer tube clamp and the stems flow into the OD. This is quite alot more than you would have on a conventional stem. I have never had a joint break, but I have had 2 Tig joints break on me on 1 of my integrated H/Bar-stem combo's. Did not snap off, just wondered what a creaking noise was before discovering hair-line cracks.

    Eric
    If I don't make an attempt, how will I know if it will work?

  7. #7
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    Specifically, what was the type of silver that you used (alloy constituents, brand etc.)?

    Alistair.

  8. #8
    Nemophilist
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    As I would have expected;

    This was not done on a whim, nor executed on one either.
    Most people ply the Well Trodden Path. A few seek a different way, and leave a Trail behind.
    - John Hajny, a.k.a. TrailMaker

  9. #9
    Eric the Red
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    Quote Originally Posted by TrailMaker View Post
    As I would have expected;

    This was not done on a whim, nor executed on one either.
    Ah, so those pinholes were all part of your plan. Pro. Gotta love MTBR.

  10. #10
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    Alister

    I can only give you the % content. I live in New Zealand and there would appear to be wide variations around the world.

    The fillets themselves are 34% silver, the Warts are done with 45%.

    I am experimenting with the 34%, as I need to fillet more, and this one does quite a good job, though it can blob a bit. My experiments to date shows good back filling but a bit lumpy on the surface. I am limited on flux variety so I'm not sure if this can improve the finish.

    I only tried 34% due the high price of Silver recently and it deserved a trial to see how cost effective it would be and how it performed.

    Eric
    If I don't make an attempt, how will I know if it will work?

  11. #11
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    I dunno man, have you tested or ridden any joints like that? I'd be a pretty skeptical in the least.
    Last edited by adarn; 04-22-2013 at 10:09 PM.

  12. #12
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    Just one more (unsolicited) opinion: upon viewing the pictures I thought it looked like silver and said to myself, "I would've used brass for that." I'm guessing it'll hold for some amount of time but will fatigue and crack at some point. OTOH, if you've been building like this for awhile, maybe that some point is far enough in the future so as to be negligible.
    Last edited by Feldybikes; 04-22-2013 at 08:38 PM. Reason: misplaced punctuation

  13. #13
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    Unusual Handlebar Stem-img_0129_3.jpg
    Adarn, I have made a few of these stems and integrated bars, only problem I ever had was as mentioned above, a Tig weld, 2 cracks on 1 integrated bar.

    Feldy, I have posted elsewhere a frame I built over 30 years ago. A Road Bike that is Silver brazed. How old are we talking here before silver gives up?

    I find it amazing how some of you percieve what you see, focus on welds is not what bikes are about. Whilst a achievement, perfect welds a frame does not make. What makes a bike is the sum of all its parts blended together. I choose to experiment with the parts....more to come.

    Eric
    If I don't make an attempt, how will I know if it will work?

  14. #14
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    Another way I could've said what I said is that, while I wouldn't use silver for that joint personally, it's possible/likely that you have enough experience to know that this method can hold up for a long time when done properly. Sorry, I was trying to be funny with (not so) clever wording and that's not always clear over teh internetz.

  15. #15
    pvd
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    It's interesting, but those Specialized adjustable angle stems are junk. I wouldn't try to use that system. The first part of a Specialized that goes into the trash.
    It looks neet in theory. I'd have to see it in place to know more.

  16. #16
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    Quote Originally Posted by edoz View Post
    Ah, so those pinholes were all part of your plan. Pro. Gotta love MTBR.
    Edoz

    Am I to presume that if I were to purchase a frame off you for $US1750, that I would recieve a frame with pin holes in the brass covered over with 56% silver? Its just that I have a problem reconcilling with your Blog site EDOZ bicycles, where in August 2009, under the heading: Friday, you critique me for the very thing you do yourself.

    Eric
    If I don't make an attempt, how will I know if it will work?

  17. #17
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    Quote Originally Posted by pvd View Post
    It's interesting, but those Specialized adjustable angle stems are junk. I wouldn't try to use that system. The first part of a Specialized that goes into the trash.
    It looks neet in theory. I'd have to see it in place to know more.
    PVD

    Firstly, I am not using Specialized stems. Only the Sleeve, for a specialised application.
    Secondly, you are into reverse engineering. What fault can you allude to that makes this item 'junk'. The OD of the sleeve is 33mm, therefore the clamping sleeve has to be machined specifically to fit it. There is no fault in its squareness of manufacture.
    Thirdly, I use these creatively. Please present a piece that you think would better fullfill my design brief, as I'm sure my piece of junk and the theory behind it has been perhaps miss-guided.
    I just don't know how all my earlier integrated stem/bars worked so well.

    Eric
    If I don't make an attempt, how will I know if it will work?

  18. #18
    The cat's name is jake
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    Hi Eric,

    It's always nice when someone has a project that they are excited enough about to take photos and post them. Your stem reminds me of some of the 1980's era bullmoose stems - pretty cool.

    I can see you take issue with people's critique of your fabrication design. I'm in no way trying to pile on. I've seen other people's joints fail where there was more material, and I've seen people who use even less filler, believe it or not.

    Something to consider - feel free to ignore it, and you may know it already anyway.
    When mechanical engineers design static structures, they often calculate the expected loads, and then give at least a 3x safety factor, or even more if failure could mean human injury. While a structure may never see the forces that would cause it to fail, that backup is there to make sure that the structure is sound, even when the unexpected happens. A person could under engineer something (say with a 1.5x safety factor), and it might never fail because the expected load and life are never exceeded. In some cases though, that structure might see more forces than was expected, and then something bad can happen. When people are making bicycles, they rarely actually calculate the forces that a frame or other structure might undergo, and even then, since they are dynamic forces, it's pretty much futile to even try to figure the real numbers. However, there is something of a collective experiential understanding of what is required to achieve a reasonable safety factor, and it's worth taking note of, and ignoring when you understand the consequences. People might bring it up though.

    Some of the critique could be seen as a situation where engineers are advising someone about the potential for danger with the structure as built. I don't mean to imply that anyone here is even remotely qualified to be an engineer (unless you actually are, in which case ignore this sentence), but it's more of a metaphor. I personally know some people who put the weight of their bike or part above a "reasonable" safety factor, or simply don't understand the limitations of the materials that they are working with. I have seen failures because of this, and in some cases people have been hurt. The concerns, while not always stated thusly, could be taken to be a form of care for one's well-being - that others don't want to see you or someone else get hurt in the event that your structure undergoes some type of unexpected overloading.

    Just a thought - I'm not trying to beat up on you. You clearly have some creative ideas, and it's awesome that people like to share.

    -Peter

  19. #19
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    Peter

    Thanks for your thoughts. Yes I do have structure knowledge. Its part of my day job.

    It was my hope that a constructive dialogue of why, design benefits, pro/cons type of thing may have ensued.

    I do appreciate the concerns for my health, but I have hurt myself more from breaking chains than any other event.

    I call out snarcky comments as they are counter productive. Sadly, the opportunity to discuss has been lost.

    Eric
    If I don't make an attempt, how will I know if it will work?

  20. #20
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    Actually, I think structurally it's fine - you've got pretty much double the contact patch of a standard stem, and with two tubes side by side you've got half the load on the top of the join.

    I'd probably have made bigger fillets, but for aesthetic reasons ;-)

  21. #21
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    An up-date, Silver brazing head-ache.

    Unusual Handlebar Stem-img_266-stem.jpg

    The re-done stem. I am now happy with the finish and build-up of fillet.

    The under-lying problem encountered here was indeed a flux issue. I am used to silver as a lug filler and small parts brazing filler. As such, I was a user of 56 & 45% silver. Due to a variety of reasons, I am restricted to the use of low temperature fillers. I experimented with 34% for the first time here, but found it flowed differently. I also discovered that even the small ammount of extra heat created a new challenge.

    What was happening was that I applied standard silver flux as a paste, heated, and the flux changed into liquid and flowed around in the usual way. When the silver was added at a slightly higher temperature, the flux washed away, leaving the joint 'dry'. I was getting good back fill fillets as the flux carried through to other other side of the joint, but the surface was quite frankly - crap.

    I went on a Google search to see if I was missing something and got tired of data sheets with specifications. It was not explaining anything, so I went onto Google images and found a you-tube snippet with an older guy doing a joint and explaining the mixing of fluxes. Turns out that adding a drop of detergent does wonders to the flux in keeping it in place. So..........I tried this bit of chemistry.

    The result is what you see, bigger fillets, smooth finish.

    The mix I used was about 10:1 flux to detergent. I used dish wash liquid. On cleaning up in hot water, the flux cleaned off easier.
    In heating up the joints, the flux did not flow off when reaching its upper limits, boiled nicely, and the silver flowed under the flux and solidified to the finish you see here. The joint was hot water cleaned then sand blasted, nothing is touched up.

    This is a break through moment for me, as I was beginning to dispair on this jointing method.

    Eric
    Last edited by Eric Malcolm; 05-07-2013 at 02:24 AM.
    If I don't make an attempt, how will I know if it will work?

  22. #22
    Nemophilist
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    How Cool!

    Those old timers... they really know some neat tricks. It pays so greatly to find people like this and hang with them. Unfortunately, the most skilled generations - those used to finding creative solutions to issues like this, working with the most rudimentary tools, when there WAS no technology explosion - are passing beyond us, and it seems there are fewer and fewer to take their place and carry on with what they've learned. We'll be there before we know it. Take what you have learned and Pay it Forward!

    I aint no scientist, but my guess is the soap raises the boiling point of the flux, and/or also decreases surface tension to improve flow. I'm wondering if all soaps would work the same? Probably not....
    Most people ply the Well Trodden Path. A few seek a different way, and leave a Trail behind.
    - John Hajny, a.k.a. TrailMaker

  23. #23
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    Funny you shake off ppls critique.. then take it.

    We are all here to help each other. Cool project!

  24. #24
    Nemophilist
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    Quote Originally Posted by DEFCON4130 View Post
    Funny you shake off ppls critique.. then take it. We are all here to help each other. Cool project!
    Well...

    Constructive critique is generally welcomed by most people here, if they are in the right frame of mind, and if it is offered in the spirit suggested in your second statement. Taking pot shots (not from you) is another matter. We are all defensive of our ideas and the bits that result from them, to some extent. That there is often much more going on in many projects than the viewers realize when forming their critiques is just part and parcel of this medium.

    The obtuse would throw up a defensive wall and look no further than the end of their own torch. I give him credit for taking the nugget of truth in the opinions offered, being objective & inquisitive, searching for different ideas, and in the end drawing out an old time notion that still has relevance today, right here, for everyone to learn from.

    I wonder if the internal fillets - that no one can see - grew or shrank, or changed at all?
    Most people ply the Well Trodden Path. A few seek a different way, and leave a Trail behind.
    - John Hajny, a.k.a. TrailMaker

  25. #25
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    Thanks for sharing the detergent tip! Sounds pretty interesting, would you have the you-tube link still?
    Good job on your project!
    cheers
    andy walker

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