What's the purpose of this weld?

stillwelding
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stillwelding 6/12/2018 7:47pm
6/12/2018 7:47pm Edited Date/Time 6/12/2018 7:52pm
TXDirt wrote:
Sorry, I'm ignorant on this. It's a pic of the new Kawasaki. What is the purpose of this weld I've circled? Why couldn't it just be...
Sorry, I'm ignorant on this. It's a pic of the new Kawasaki. What is the purpose of this weld I've circled? Why couldn't it just be one piece. Appreciate any info. Just curious...

Besides all the other input, I’d say that that weld joint is a blade and slot arrangement, instead of the usual square plug to square tube. Makes the joint a lot more robust. Also, as you see on all welded aluminum frames, street and dirt, a lot of the welds are robotically welded for quality control. As for the manual welds ( or manual looking), they are there for cosmetic purposes only, IMO.
Awesome Johnson 6/12/2018 8:06pm
6/12/2018 8:06pm
Holy shit. I can’t believe you guys are discussing this. I mean, this is how sub frames on dirt bikes have been manufactured for the past 20 years.
milliebays
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milliebays 6/12/2018 9:52pm
6/12/2018 9:52pm
Squirrelings wrote:
Lightweight and durable. No need for anything else.
looks like a good old lotus frame dont it. speaking of, why do they use chromoly A-arms when the whoole tub is AlYouMINium
TXDirt
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TXDirt 6/13/2018 12:49am
6/13/2018 12:49am
Natester551v wrote:
because the extruded box tubing is light, very strong in flexural strength (i.e. "up and down", as in seat bouncing, etc.), but terrible in compression w/o...
because the extruded box tubing is light, very strong in flexural strength (i.e. "up and down", as in seat bouncing, etc.), but terrible in compression w/o a solid insert. Since the bolt going through the end attaching it to the main frame has to be in compression through the subframe (and the bolt is in shear during normal riding loads), they address both stress modes while keeping costs low by using this hybrid approach.
Thx. That makes sense.

Appreciate everyone’s feedback. I’m not a structural engineer and was just wondering why they weld those two pieces together.

Case closed. Smile

The Shop

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StartedTooLate 6/13/2018 1:01am
6/13/2018 1:01am Edited Date/Time 6/13/2018 1:03am
TXDirt wrote:
Why not mill a single piece or cast a single piece? What is the benefit of a standard piece welded to a milled piece? Seems like...
Why not mill a single piece or cast a single piece? What is the benefit of a standard piece welded to a milled piece? Seems like extra work for really no reason? I'm sure I'm wrong. Just want to know why.
Falcon wrote:
Because It would probably cost $100 to manufacture that entire assembly as one piece, instead of 69 cents to do it the way they did. There...
Because It would probably cost $100 to manufacture that entire assembly as one piece, instead of 69 cents to do it the way they did. There are probably similar compromises all over the motorcycle.
My numbers may be way off, but I can almost guarantee you they did it so your KXF450 doesn't cost $20,000.
Falcon is on the money here. This is by far the cheapest way to make framework fabs. The end pieces are all CNC machined, and they all bolt into a precise fixture which is set up before any welds. In between all these CNC pieces, in a fixture, are sections of std structural sections. They have a few people assembling everything on these fixtures, and the whole thing is on a line in a cell. The welder does no set up. He gets a complete fixture assembly, ready to weld. In 10 minutes he is done. The pop it out of the fixture, and send the fixture back to the set up techs, who assemlbe another set of pieces on it.
StartedTooLate 6/13/2018 1:07am
6/13/2018 1:07am
Jeremy Macbeth wrote:
Lighter, faster, stronger, cheaper: [img]https://i.pinimg.com/originals/14/a6/f0/14a6f05407d9a77c4816152ecb73c9db.jpg[/img]
Lighter, faster, stronger, cheaper:

How many are you going to sell. Injection mold tooling is not cheap. How many units are you going to amortize it over. The molds for something like that would probably be into 6 figures.
Texas Built
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Texas Built 6/13/2018 1:17am
6/13/2018 1:17am
Jeremy Macbeth wrote:
Lighter, faster, stronger, cheaper: [img]https://i.pinimg.com/originals/14/a6/f0/14a6f05407d9a77c4816152ecb73c9db.jpg[/img]
Lighter, faster, stronger, cheaper:

When they quit making them in a couple years and your breaks, then what? Your bike becomes a brick.
You-n-Gs-town born & bred 6/13/2018 11:21am
6/13/2018 11:21am
As far as the plastic going down that far........i had a brand new 2000 KX250 so all the plastic was fresh and nothing was bent or anything and at the time i was wearing AXO boots.

Quite regurlarly when i was returning to a more upright position after being leaned back like you would if you were riding some whoops the side panels would catch the top of my boots. I cannot tell you how annoying it was and i know some magazines mentioned it as well.

All the OEMs started migrating their side panels down towards the foot pegs so any edges were below the top of the boot line to prevent any snagging.

Im sure there might be other reasons but im pretty sure if you were to look at any OEM's side panels.... particularly the lower edges of them from maybe the 90s to current youll see their shape and location on the bike moving further rearward, downward and becoming more and more smaller & thinner (think number heigth) because it looks more sleek and modern but also to prevent boot snagging.

Pit Row

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