Just a little buzz box.

 

[QUOTE=I bought a chunk of 10 gauge metal and after making a template I used my grinder and zip discs to cut out the shape and I drilled out the holes.

Just wondering why you chose 10 gauge rather then a larger guage?

 

Ten gauge was the lightest size and still strong enough to do the job.

 

O.K sounds good, I'm preparing to strenghten my subframe. This i will be doing besides a gusset. Do you have any words of wisdom? Anything that could have done better, if anything?

 

Not really, I think that there are ways that you could do it that would make it even stronger, using gussets but would add more weight. I carry about 30 lbs tops.

 

Don't hold back ...lol . What ways are you thinking of. My plan so far is what you did and what Neil did.

klxforum.suncup.net • View topic - Broken subframe!

Also i noticed in the pics you did'nt drill the holes for the mounting bolts that hold the Fender rear flap. Was there a reason for that or did you drill them later.

 

From an engineering standpoint, the most beneficial addition you can make to support the rear rack with a heavy load is to run a tubular support from the rack area down to the lower frame area near the swing arm pivot. Anything hanging out back beyond the last good support simply has a "springboard" effect, flexing a bit over every bump, thus the cracking usually behind the subframe down tube. Although I've seen a few frame failures in front of that area, which is usually attributable to poor gusset design from the OEM.

I don't know if the stock frame has any bolt on areas there, maybe the passenger peg bracket or such, but a simple ear welded on in the right place on the back of the frame could give the proper mount for a support tube to the rear rack and possibly provide all the extra support needed. Make it detachable if you don't want it on all the time. That sort of support can be incorporated into a set of softbag support framework outside the number plates if you run panniers (side bags). That kind of support will take away the springboard effect I mentioned above.

 

I've seen people cut the tubing and insert an additional tube inside the original tube, and tack it in place. Is this overkill, or appropriate?

 

klx678 is right, and the cracks that appeared on my sub frame cross members were a product of the springboard effect of eight hours of whoops acting on the added weight. The cross member was the pivot point where the rack bolted on.

 

I bought a rack from TCI that bolts on the frame at 3 spots:

1. Subframe where the stock toolbag would mount
2. Rear seat mount holes
3. Passenger foot peg lugs on the mainframe

One the final tightening of all the bolts is done, the system is very solid. Still wouldn't want to try and put way too much weight back there, though...