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1968
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7/21/2011
Location
Galesburg, IL
US
Edited Date/Time
1/27/2012 3:37pm
Wanting to use my 2007 rm250 engine in a rmz250 af. The obvious question is how is this usually done to fit the pipe? On the af the frame down tube comes directly down and Y's out at a much lower point since the 4 strokes exhaust port is offset to one side. The 250t comes in centered on the frame which looks like the down tube will block. So, is the down tube cut up higher and the bottom rails lengthened to make the Y start higher near the radiators? This would open up some access to come directly into tge centered cylinder. any pictures would be great.
They are nuts about aluminum frame conversions. Even though they concentrate on Hondas, they would probably help you out after flaming you to death.
I have a buddy who is running a 2011 YZ250F chassis with the '94 YZ250 motor, loves it. He rides 250 "B" class and claims it handles better then the four stroke motor. He got 4th at the baja brawl on that bike.
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I didnt know that team trubble did that! Wow, that is some B.S., glad I didnt send him any money! Did you guys get any of that shit resolved then? I have done a few honda 250f's by cutting the weld and trimming back the down tube. Worked out real well.
BTW I am a Engineer but have been welding professionally for 17 years and am very critical of other peoples welds, espicially Mr. Retardo. I see you live in Ontario, you come over to our side much?
Actually I haven't been over there riding in a few years, and not because I don't want to. Just circumstances. I only live an hour and a half from Pt Huron. Have a good friend over there, Gordy Baird. You know him? Man, HE seems to know everyone! Used to come and race with him when I had the time. We are a couple of Vet Class retards. Used to do Baja and Log Road. Love that track. Did Florida and Georgia with him 2 separate years. Then I got married and then I got an ex-wife. You know what THAT does to the pocketbook. Hoping to change that next year.
Was actually at the Baja Brawl, just watching though. Was in Fairgrove Mi east of Saginaw partying for the weekend. Canoe trip down the river from Caro for a couple hours then home for a big bbq and some drunken stupidity. And I don't DRINK! Hung there 'til Sunday noon then hit Baja to hang with friends from home. Watch some racing and the Belly Flop contest. Too funny! I recall you and another fellow chatting here about the Baja thing and I looked for his number but didn't see it. Should have just talked to you then and found out where you were camped. Would have looked you up.
As far as I know Aliso Bob recovered ONE guys bike. Everyone else got fucked. Can only hope Karma comes back to bite that son-of-a-bitch and he dies a slow painful death bleeding to death in a car wreck after he swerved to miss a deer. Watches his shithole of a life run in front of his eyes while he approaches hi fate. And it's down, not up. Nice and warm. Fiery warm. I believe the fuckin' asshole actually ripped off an active service man in Afghanistan. He wanted a toy when he got back home. Nice eh?
yota, any chance you might want to sell your '83 XC125?
Styx - Too Much Time On My Hands by jpdc11
Pit Row
Just an observation worth checking in to.
Flesh, he is a angry little man that lives in his moms basement that doesnt ride dirt bikes.
I took my buddies 2009 rmz250 frame into work with me this weekend and layed it out using a coordinate measuring machine. I did some measuring on the engine and combined the information in Autocad Inventor to make a 3d drawing. I'm going to use the same material stock to mod my frame as what's already used in the frame.
After i did some stress-strain analysis with inventor, I found the junction where the small tubes come together was a potential weak area as there just isn't enough weldable surface there. I used weights taken from the engine and then ran some simulations using what I think are forces and pressures that might be seen on the frame through normal riding. I found that if I mill a 1" long plug to weld inside the tube, the weld joint then becomes plenty strong.
So, I have everything drawn out for the frame mod and engine mounts. I believe I found a donor 08 rmz250 from a buddy so it looks like i will have a nice winter project in the works!
Have you also considered the material degradation of the aluminium itself in the FEM analysis? Did you also consider frame torsional and lateral ridgidity?
And what is the type of aluminium used? Did you lab test it?
I simulated aersospace grade al that will match the wall thickness found on the factory frame. I was able to find some pretty good parameters for this material through our QC lab at work who had done some work with material similiar in the past. They had some record of rockwell testing, shear strength, torsional strength, and a few strain analysis tests.
As far as material degradation on a used frame, I wouldn't know how else to compare it to new stock other than cutting up a frame and having our QC lab run some tests on it. If you would like to donate a frame for testing I would be more than happy to report back with results
Torsional rigidity is a whole nother beast in itself. It would take some pretty serious equipment, math, and physics to figure out what kind of torsion the frame sees during riding. The tests i did were using forces perpendicular and parallel to the modification. I know more testing could be done, but i gurantee that some of these companies modifying frames aren't even going this deep into their development and they seem to be having good results. I'm glad i did it though because if I wouldn't have seen the y joint needs an inner plug, I probably would have learned a hard lesson the first time.
You still mad because I banged you mom?
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