Tweeking a bent steering head

[chuck hahn]

So you dont have a press or frame shop close and your project bike had been wrecked by the PO ( I was aware of this fact when i bought it ). But you didnt know just how bad it was till its torn down and looked over. Mine wasnt crushed back or any down tubes bent..just seemed someone walked up and twisted it counterclockwise about 3/16 inch...as your standing in front of the head.

So now, the task is how are you gonna get enough torque and be able to twist the head back in line and check for plumb?? Well I didnt take pics of the first stage of how i stabilized the bike and made my rig so I will try and describe that part as well as I can.

How to get the bike locked down so you can apply twist to the head.....simple. You set the bike against the rear wheel of a Ford 8N tractor and chain the frame right behind the head to the rear axle. And then you use a come along around the swing arm and ratchet the bike tight up to the wheel. Bike solidly locked to the rear wheel I needed to begin to twist the head back..but with what???

To twist the head I drove the top bearing race of the head and stuck a bent fork down the hole. next went a pair of vice grips on the tube about a foot above the top of the steering head. This was a stop for the chain.

Next was to wrap a chain around the fork sticking up, set an 8 foot 4x4 landscaping timber ( one with the rounded edges) against the bottom edge of the head. Now wrap the rest of the chain around the 4x4 and get at twisting the head. Now I dont know exactly how much pressure it takes to snap one of those timbers but I broke this one twice....but i got enough twist to get it darn close by eyeballing it.


Posb two will be on making a tool to read the center line of the lower triple to check for left to right plumb.

 

[chuck hahn]

MAKING A TOOL TO CHECK PLUMB...

Theres a 1/4 inch hole in the center of the tubes lower plug thing. I had to get a way to center the rod down the bore of the tube so I simply wrapped it with painter tape till it fit snuggly into the bore of the triple tube. next was just lay a level on the left and right sides of the rod to see if the bore of the lower triple was true.

 

[salty_monk]

How to get the bike locked down so you can apply twist to the head.....simple. You set the bike against the rear wheel of a Ford 8N tractor and chain the frame right behind the head to the rear axle. And then you use a come along around the swing arm and ratchet the bike tight up to the wheel. Bike solidly locked to the rear wheel I needed to begin to twist the head back..but with what???

To twist the head I drove the top bearing race of the head and stuck a bent fork down the hole. next went a pair of vice grips on the tube about a foot above the top of the steering head. This was a stop for the chain.

Next was to wrap a chain around the fork sticking up, set an 8 foot 4x4 landscaping timber ( one with the rounded edges) against the bottom edge of the head. Now wrap the rest of the chain around the 4x4 and get at twisting the head. Now I dont know exactly how much pressure it takes to snap one of those timbers but I broke this one twice....but i got enough twist to get it darn close by eyeballing it.

Absolutely useless without pics Chuck

Seriously be good to see some "grass roots" engineering in action

 

[bwringer]

After my Big Bambi Bash in 2013, I did something similar to verify whether my KLR's frame was straight. I used two of the discs from a set of tapered bearing drivers so that they would self-center, and drilled out the hole in the tapered discs to match the length of threaded rod.

Much to my astonishment, the headstock was still straight -- I was able to measure to within about 1 or 2mm referenced to the swingarm pivot point. The front end and rear subframe were demolished, but the basic frame structure was OK. The radiator was bent but not leaking and the crash bars were bent but fixable.

I ended up rebuilding the bike (thanks, eBay!) and it tracks perfectly true. I've put about 20,000+ miles on it since then. The steering stops on the frame were smashed, so I ended up cutting them back a bit and tapping holes in the stops to insert bolts and locknuts -- basically making adjustable steering stops.

 

[chuck hahn]

Well Dan all thats left of the tweeking stage is the broke timber. Sorry.

 

[salty_monk]

You need a camera man Chuck

 

[chuck hahn]

He wasnt home at the time. I can tell you it took all my weight bouncing on that timber to get it twisted back. Set the front tire and fender tonight and it look pretty darn good so far.

 

[uk gs nut]

You done good there chuck !. I tweak frames to pay the bills, very ingenious using the tractor !. Top job use whatever you have handy .

 

[chuck hahn]

UK...yes when you dont have any resources to have it farmed out you anallize, make a plan, and the go MacGyver on it.

 

[chuck hahn]

Well the test ride is in the books.. 40 MPH and let go of the bars and she still goes straight. Im calling this one a success.