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The Street => The Lounge => Topic started by: Cellmember on February 17, 2015, 06:00:41 PM
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Hi Guys,
I've been in contact with a frame builder seeing about having a custom made up, from what I've been told about my design I wan't to know what you guys think of his way of building a frame.
I was told that A: a wishbone rear end is not a strong as a A or S bend stays and B that round tubing for the SS/CS bridges are weaker than a plate. O_o
Basically I'm just talking about the specs I was after which he was not interested in doing as he believed his way was better/stronger.
I've heard the opposite to what he has told me and have tried both so I have first hand experience with those options.
I'm dumbfounded by what I've been told as I can't see that being the case but then again, you learn something new every day.
Chime in.
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I would think single bend stays are stronger than S bend stays
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I would think single bend stays are stronger than S bend stays
Yeah due to less bends
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I would go with a tube brace. I dunno if they're stronger or not
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I would go with a tube brace. I dunno if they're stronger or not
My personal pref is tube bridge as well, I can't see a plate being stronger/stiffer.
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Laird?
I do know that some people break frames and some don't. And some folks always break a frame in the same spot (a friend of mine always broke his on the seat stays, near the top tube. another friend always broke his at the top tube/head tube)
Are you breaking a lot of frames?
I know Laird has some heavy hitters on his frames. (if that's who you're talking about)
I say buy one and try to break it.
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Laird?
I do know that some people break frames and some don't. And some folks always break a frame in the same spot (a friend of mine always broke his on the seat stays, near the top tube. another friend always broke his at the top tube/head tube)
Are you breaking a lot of frames?
I know Laird has some heavy hitters on his frames. (if that's who you're talking about)
I say buy one and try to break it.
I'm after a custom mainly due to not being able to find certain frames so It's just easier to have one made up, no I'm not breaking frames, I have had a lot of defected frames not none braking at crucial points mainly just brake bit snapping off *Cough* Fly.
If I'm getting a custom built up I want to have the spec's I'm after not what someone tells me I should have, plus that's not what I'm talking about here, I don't want to mention names that's not my thing, I just want people's opinions on my first post and even better if someone has a professional background on the matter.
Yeah I've seen a lot of "Pro's" on his frames, good to see.
I wonder why Buckworth isn't on his laird frame any more.
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So he is basically saying that some of the strongest frames over the last 15 years... are now the weakest? I'll take wishbones and tube bridges thank you very much.
Maybe you should find a new frame builder.
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(http://www.gsportbmx.co.uk/custom/G%27s_bike/frame%20only/tigerf%20diagonal.jpg)
???
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lairds got some nice welds going on but he seems like a bit of a tripper, especially if hes telling you plate bridges are stronger than tube ones.
i heard wishbones being more twisty is true though, but i guess it depends on the specific dimensions and stuff cos sunday frames
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i heard wishbones being more twisty is true though, but i guess it depends on the specific dimensions and stuff cos sunday frames
Bro, do you even Barcode? :D
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I was told that A: a wishbone rear end is not a strong as a A or S bend stays and B that round tubing for the SS/CS bridges are weaker than a plate. O_o
Whoever told you this, I would completely ignore in future
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I've heard from several reputable sources that wishbones greatly strengthen a frame. Not sure about the whole plate/tube argument but tube should take forces better and be lighter. If you want to build a strong and stiff frame, I'd opt for something with large diameter tubes, gussets, a wishbone (or two), and non-micro dropouts for more weld contact area. Basically build a sunday.
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i heard wishbones being more twisty is true though, but i guess it depends on the specific dimensions and stuff cos sunday frames
Bro, do you even Barcode? :D
nah brah, not trails enough. im awaiting delivery of an AOD though in all its wishboney goodness
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If Im not mistaken Mr. French made an article somewhere stating that wishbones are stronger.
I wonder if 3D printed frames could become a thing.
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lairds got some nice welds going on but he seems like a bit of a tripper, especially if hes telling you plate bridges are stronger than tube ones.
i heard wishbones being more twisty is true though, but i guess it depends on the specific dimensions and stuff cos sunday frames
Like I said I can't see a plate being better suited instead of tubing for the bridges.
Really, I wouldn't have imagined that, but it could be a possibility, I can definitely notice the difference between a wishbone rear end and a A and S bend, the wish bone feels much much stiffer.
I was told that A: a wishbone rear end is not a strong as a A or S bend stays and B that round tubing for the SS/CS bridges are weaker than a plate. O_o
Whoever told you this, I would completely ignore in future
Yeah I'll mostly pass on this particular builder as it looks like he's not interested in doing what I'm after any ways.
I've heard from several reputable sources that wishbones greatly strengthen a frame. Not sure about the whole plate/tube argument but tube should take forces better and be lighter. If you want to build a strong and stiff frame, I'd opt for something with large diameter tubes, gussets, a wishbone (or two), and non-micro dropouts for more weld contact area. Basically build a sunday.
For sure, that all makes sense, and is basically what I'm doing.
If Im not mistaken Mr. French made an article somewhere stating that wishbones are stronger.
I wonder if 3D printed frames could become a thing.
I'll have to do a quick search and find the article, I'd like to read up on that. Always interesting to see G's input.
I'd like to see a 3D printed frame definitely curious, one day...
So he is basically saying that some of the strongest frames over the last 15 years... are now the weakest? I'll take wishbones and tube bridges thank you very much.
Maybe you should find a new frame builder.
Yep, so would I.
That's what I'll be doing.
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Just get a custom AoD and be done. Cause wishbones
Or Dave at pedal driven he was pretty good to talk to before when I was looking at a custom from him
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i heard wishbones being more twisty is true though, but i guess it depends on the specific dimensions and stuff cos sunday frames
Bro, do you even Barcode? :D
nah brah, not trails enough. im awaiting delivery of an AOD though in all its wishboney goodness
I'll allow it. I love how the new AODs remind me of an S&M Bennett. Drooooollllll.....
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I've been curious what Laird's take was about wishbones and tube braces, now I know. That being said, I think that what he is doing looks really great.
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I just looked at this Laird guys site...
What I saw: Generic designs, decent quality (I've seen better), cheesy laser cut plate bridges, and welded seat clamps on everything. No thanks.
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But USA, bro!
In all seriousness, please stay away from this dude. As soon as I opened his site, I saw those god awful cutouts where the stays meet the dropout. You know, the ones that are identical to old federal frames that all cracked? My friend had an older lacey and it cracked in 8 places. 2 on each stay cutout.
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http://instagram.com/p/Y50zz-sObP/?modal=true (http://instagram.com/p/Y50zz-sObP/?modal=true)
8 Places!
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The devil is always in the detail, but generally speaking, comparing like with like, a wishbone is either going to be stronger for the same weight, or lighter for the same strength.
In terms of plate bridges, just no. They are a LOT easier to make though, so there's that...
:)
G.
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Just get a custom AoD and be done. Cause wishbones
Or Dave at pedal driven he was pretty good to talk to before when I was looking at a custom from him
That's awesome that Fbm are have brought back the AOD, definitely got a lot of people stoked.
Yeah I will be looking into him, thanks.
I've been curious what Laird's take was about wishbones and tube braces, now I know. That being said, I think that what he is doing looks really great.
I will admit he has very pretty welds !
http://instagram.com/p/Y50zz-sObP/?modal=true (http://instagram.com/p/Y50zz-sObP/?modal=true)
8 Places!
Holy shit, I've never seen that kind of crack in a place like that before, fack.
The devil is always in the detail, but generally speaking, comparing like with like, a wishbone is either going to be stronger for the same weight, or lighter for the same strength.
In terms of plate bridges, just no. They are a LOT easier to make though, so there's that...
:)
G.
I definitely noticed a difference when it came to wishbone vs A and S, makes sense to. Like I said I was shocked when I was told otherwise, haha.
I've never been a fan of plates for the bridge's mainly because I think it looks tacky and the obvious it wouldn't be that strong compared to a tube, but it looks like for this particular builder plates are strongest for him, and yeah you are most correct with it being cheaper to produce.
Nice to hear input from everyone, thanks all !
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I've been thinking about this, and intuitively, I think wishbones should be more rigid up and down (I.e., about and axis through the bb), and side to side (axis normal to the ground), but less rigid in twisting.
I could probably work out how to prove it, but my structures fu is not strong.
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One of my friends had a Barcode. I distinctly remember dropping into a quarter pipe on it and being surprised by how much stiffer than my non-wishbone frame it was.
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The cutouts look terrible on the stays and not a fan of the seatclamps. He can do standard seat tubes w/o a clamp
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One of my friends had a Barcode. I distinctly remember dropping into a quarter pipe on it and being surprised by how much stiffer than my non-wishbone frame it was.
That was definitely my impression the first time I pumped up a transition on my Barcode.
It was actually just a little scary at first.
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If your frame isn't breaking on you, isn't it strong as it needs to be?
Over the last 30 odd years I have seen every style of frame crack.
Personally I don't like a super stiff rear end. Hurts too much. Now, that don't mean I like flexy ass frames.
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T1 builds rule.
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One of my friends had a Barcode. I distinctly remember dropping into a quarter pipe on it and being surprised by how much stiffer than my non-wishbone frame it was.
Oh yeah, best feeling, makes the frame feel secure and trustworthy, no doubt.
The cutouts look terrible on the stays and not a fan of the seatclamps. He can do standard seat tubes w/o a clamp
That was the only thing the builder was willing to do. Probably because there's no welding required so it's quick and easy.
If your frame isn't breaking on you, isn't it strong as it needs to be?
Over the last 30 odd years I have seen every style of frame crack.
Personally I don't like a super stiff rear end. Hurts too much. Now, that don't mean I like flexy ass frames.
That's not really what I'm talking about on here but like I said in my original post, tube ss/cs vs plate ss/cs and wish bone etc, and the fact that I couldn't get what I wanted done on the frame is what bothered me.
Fair enough everyone to their own, I dig the solid rear end's personally.
T1 builds rule.
You Sir are correct, now If only I could have gotten my hands on one.
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lairds got some nice welds going on but he seems like a bit of a tripper
You dont say...
(http://i.imgur.com/fIwPlq0.png)
(http://i.imgur.com/0tThv2K.jpg)
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lol. gyro tabs.
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Yeah that's a little too lazy but I'm guessing it could be stronger.
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He's probably buying prefabbed HT's, 0 of which these days would come with tabs
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welding on a stock detachable gyro tab looks super half arsed on a custom frame from a builder who places so much emphasis on the aesthetics of his work and his welds
maybe he couldnt get the lugs from anywhere else (welded gyro tabs arent exactly in high demand in bmx atm), but he surely could have come up with something a little better than that
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Maybe the rider asked for it like that. Not everyone has been riding long enough to remember welded on gyro tabs.
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Would take 15 minutes to make some tabs from scratch, bit lazy just banging some stock ones on.
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yeah, definitely a case of "fuck it" going on there
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Just bondo over the bolt hole. No one would ever know. :P
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Maybe the removable tabs provide more surface area to weld, thus making them stronger? I agree that it looks pretty tacky though.
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TBH, his welds have room for improvement...
(No, I couldn't do better but I have professionally inspected welds before)
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They are some of the nicest looking welds in BMX though.
Laird is an OG shredder as well.
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Guy looks like he knows what he's doing. I'd ride one if I had the desire for a custom. Sure the gyro tabs look a bit wack but if you're running a gyro I'd ridicule you anyway.
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Check out Daniel Dhers' new siq seatstay bridge on his #lairdframe
https://instagram.com/p/zK0P55IB5M
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Check out Daniel Dhers' new siq seatstay bridge on his #lairdframe
https://instagram.com/p/zK0P55IB5M
3.6lb lolol.
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Id get an F16 silhouette as a seat stay bridge in a heartbeat
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I'm not sure if I'd go with the the guy who build dhers' dream frame
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I've been thinking about this, and intuitively, I think wishbones should be more rigid up and down (I.e., about and axis through the bb), and side to side (axis normal to the ground), but less rigid in twisting.
I could probably work out how to prove it, but my structures fu is not strong.
If you can prove that then you should move on to prove that up is down and black is white. One big one will always beat two small ones...
:)
G.
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Check out Daniel Dhers' new siq seatstay bridge on his #lairdframe
https://instagram.com/p/zK0P55IB5M
3.6lb lolol.
I saw that, I can't see that frame lasting to long, then again Dher's only weighs about 30lbs
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I've been thinking about this, and intuitively, I think wishbones should be more rigid up and down (I.e., about and axis through the bb), and side to side (axis normal to the ground), but less rigid in twisting.
I could probably work out how to prove it, but my structures fu is not strong.
If you can prove that then you should move on to prove that up is down and black is white. One big one will always beat two small ones...
:)
G.
(https://pbs.twimg.com/media/BSbBkzoCMAAAvyH.jpg)
i want a 20.75 grim reaper
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hmmmm, which of these bridges is better?
(http://lucforsyth.com/wp-content/uploads/2011/10/overpass-weave-2.jpg)
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The lighter one, duh.
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I've been thinking about this, and intuitively, I think wishbones should be more rigid up and down (I.e., about and axis through the bb), and side to side (axis normal to the ground), but less rigid in twisting.
I could probably work out how to prove it, but my structures fu is not strong.
If you can prove that then you should move on to prove that up is down and black is white. One big one will always beat two small ones...
:)
G.
Even in Bukkake films?
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I've been thinking about this, and intuitively, I think wishbones should be more rigid up and down (I.e., about and axis through the bb), and side to side (axis normal to the ground), but less rigid in twisting.
I could probably work out how to prove it, but my structures fu is not strong.
If you can prove that then you should move on to prove that up is down and black is white. One big one will always beat two small ones...
:)
G.
First and foremost, It's been a long time since I've done any work like this, so I would certainly defer to your expertise.
However, what I was thinking is that trying to twist the rear wheel, (like imagine putting a bar through the dropouts and standing on one side), the lower wishbone would be in pure torsion, and there would be a bending moment at the top wishbone, with a moment arm length of something like standover height - BB rise.
On a standard rear triangle, the single bending moment would be replaced by two bending moments, one at each seat stay, and the moment arm would be marginally longer (the hypotenuse of a triangle with vertices at the center of the axle, the dropout and the center of each seat stay). Additionally you would replace the torsion about the lower wishbone with two bending moments, but I can't remember if that's a good thing or not, especially considering that lower wishbones are rarely circular.
So that’s where I stopped, because even if this line of though was accurate (I’m not sure it is), I’m pretty sure that if you held mass constant, you could plug in all the material properties and over some range of section dimensions, one would be better than the other, and over another range of section dimensions, the other might be better, and there is absolutely no guarantee that you could make a tire fit on any of the optimized solutions.
And ultimately, that’s not really a loading I think we care a whole lot about. I don’t think a little twisting on a peg stall, or landing with some sort of yaw is going to be noticeable. Obviously, that’s something I think I would be willing to compromise to make the structure stiffer when you apply a downward force to the bottom bracket.
One of these days I’ll dig my books out and prove myself wrong, in the meantime, hopefully I’m not sounding like too much of a muppet.