Topic: downtube extension plugs questions

[hondachopproject]

Hello,
Still working on chop project.
I need to use downtube extension plugs as on this page: http://www.hondachopper.com/jim.project.html
So that engine will set level.
Has anyone done this?
Does anyone know the diameter of the down tubes on a 76 550? I had some of the same size tubing from where I hardtailed it and had plugs made, but it has since gone AWOL! Probably in a hurried clean up.
THanks,
Lee

[hondachopproject]

javascript:void(0);
EmbarrassedNevermind! I found the tubing.
But stil looking for any advice or ideas from those who have tried this.
Lee

[Bob Wessner]

javascript:void(0);

 

[cbjunkie]

is that some kind of moderator's humor 

[Bob Wessner]

No, actually I thought I was replying to what I believed was a bit of web developer humor on his part.

[Lumbee]

...hey Lee, I've done it...whats u'r questions?  I added about 4 inches to the down tubes on a 750 frame.  I cut the extentions about 6" so I had about an inch on either side when I slid the sleeve down over the frame.  I then welded at the seam, and plug welded each side.

...heres some pics...you can bearly see the extention to the downtubes in pic #4....

http://pg.photos.yahoo.com/ph/marklocklear/album?.dir=1602&.src=ph&store=&prodid=&.done=http%3a//pg.photos.yahoo.com/ph/marklocklear/my_photos

[dusterdude]

No, actually I thought I was replying to what I believed was a bit of web developer humor on his part.

well someone educate me on what that was supposed to be

[hondachopproject]

No, actually I thought I was replying to what I believed was a bit of web developer humor on his part.

No intended humor, Embarrassed smiley just didn't work

[hondachopproject]

...hey Lee, I've done it...whats u'r questions?  I added about 4 inches to the down tubes on a 750 frame.  I cut the extentions about 6" so I had about an inch on either side when I slid the sleeve down over the frame.  I then welded at the seam, and plug welded each side.

...heres some pics...you can bearly see the extention to the downtubes in pic #4....

http://pg.photos.yahoo.com/ph/marklocklear/album?.dir=1602&.src=ph&store=&prodid=&.done=http%3a//pg.photos.yahoo.com/ph/marklocklear/my_photos

Lumbee
Thanks for reply. Yes it is hard to see. We are talking about the front down tubes in front of engine, right.
Main questions deal with proper alignment  after welding, was this done with engine in place to maintain engine alignment.
Do you have any completed pics ?
What are you running for forks?
Lee

[Lumbee]

..ok, I see what your are asking.  Before I did mine there was a discussion about keeping the engine mounts inline and what not, and its simply not a problem.  After you cut the backbone and the down tubes, the frame (and engine mounts) will still maintain there place.  The area around the swingarm keeps the frame rails in place.  I took some measurments of the engine mounts before and after the mod, and everything held to its original position.  You do need to use some common sense on making sure everything is aligned and equal on both sides as you put the sleeves in place.  If I can remember I'll get some more pics this weekend of the frame, and some close ups of the sleeves.

...I havn't used the frame yet...when I find a motor thats where it will go.  So as far as forks goes, I don't know cuz I havn't mocked it up.  I'd guess only a couple inches over stock as I 4" to the downtubes, but did not change the rake...

[puppytrax]

I did a similar lowering project on a short-tracker back in the '70's; I wanted the engine lowered 2" in the frame so I made my plugs 4" long. 1" on each end was turned down to the ID of the downtube; the middle was the OD of the downtube. Made out of mild steel with a chamfer on the "step"; a similar chamfer on each edge of the downtube cut. TIG welded all around; several holes drilled in the downtube where the middle of the 1" insert of the plug fit were welded also. Afterward, ground/filed smooth and painted. I can't recall now if I hollowed the plugs out [drill] or not; but if I did, I would have left at least 1/8" of metal in the long end of the plug.

Worked fine; never cracked in two years of running. Having the centerline of the engine/trans 2" below the centerline of the F&R wheels & swingarkm pivot made for some weird handling, however...think of a pendulum effect when you threw it into a turn...   

[Lumbee]

...OK, heres a couple of pics...sorry, my camera doesn't handle closeups all that well.  I also updated pics at:

http://pg.photos.yahoo.com/ph/marklocklear/album?.dir=1602&.src=ph&store=&prodid=&.done=http%3a//pg.photos.yahoo.com/ph/marklocklear/my_photos