Random questions

[kirrbby]

More random info...
Had a pair of bent CT70 K0 fork legs. They were pretty equally bent, but otherwise they were good parts.

I've had good luck re-straightening them using a bigass vice.
Bigass vice has a 8" jaw...which works. The ¾" plywood is cut 1¾" wide...which works.

I mark the legs down the center...90° off of the bend...this makes the bend easier to see. I also mark around the circumference...at the 2 points where the straight section of pipe ENDS.

The plywood is AC grade, which means it's a good grade with NO voids. The plywood crushes, so the pipe DOESN'T...it takes a LOT of pressure to get these straight. If it was metal on metal, I'm pretty sure you would make a flat spot(s) in the pipe, or marks at the least.
I have multiple hydraulic presses available here at work, but I prefer the vice because I feel I have more/better control...and less fear

I tighten until I have it OVER straight...just a little...knowing that it will spring back some when I release the vice. Remove the pipe and eyeball it for straightness.

I've done about 6 or 8 fork legs this way, with good success.

Be sure to cut your plywood so the grain runs lengthwise...so the grain runs perpendicular to the pipe in use. Otherwise I don't think it will hold up at all...the pipe would just cut/split thru the wood like a VERY dull axe. Strips of solid wood...pine or some other softwood...might work too...can't remember if I might have used it before. Solid wood would need to be knot free.

A smaller vice might work...if it's tough enough. A 6" jaw..?maybe cut the wood narrower... 1¼-1½" maybe..? AND keep about 1¼-1½" of GAP between the strips of wood in the vice.

 

[cjpayne]

Thats so cool you found a way to save those and show how to do it. YOU DA MAN, KIRRBBY!!!

 

[Clayton]

I so need a good vise!!!

 

[kirrbby]

Thats so cool you found a way to save those and show how to do it. YOU DA MAN, KIRRBBY!!!

Thanks CJ.

I spent some time thinking of how to go after this one...
I took this triple tree off of my old green H and replaced it with a good part.
This triple LOOKS pretty good...good paint, but one leg was bent pretty badly. I was prepared to attempt a repair, OR scrap it if I just couldn't fix it well enough.

I found a pipe that fit over the leg with just a little slop. I deburred the end of the pipe. Then 8 neat wraps of masking tape made the pipe fit snug(er) and gave a little protection. I used tape to protect the paint here and there.

I put a piece of tubing into my hitch receiver and duct taped the triple just so it would hang there while I rigged and jigged everything up.

I cut wood supports to give me something to pry against...and more wood to shim them...since I had to jack up the rear of my truck to take the trucks suspension out of the equation.
Pushing down with my pipe...I tried to bend it...just enough...back to straight.

Hopefully my pics will explain the rest...basically...the wood is the fulcrum...pushing down with the pipe supplies the force...pushing against the weight of my truck...
Anyway...it worked..! Lol

 

[kirrbby]

The tube was a little rippled where it had been bent. Putting a pipe and spring inside with a NEW piston slide on it, I could feel it drag a bit as it passed thru the ripples. I ran a stone and then a flap wheel in there to smooth it out just a little.
Still drags...just barely...but it's below the travel area of the pipe piston.
I think I've saved this part.



Forgot to say...my last pic shows a socket inside...it fits pretty well...I put it in there, right at the end while I was straightening...a little insurance so I didn't bend the threaded portion out of round.

 

[kirrbby]

Logging some info...
This is in regards to how the swingarm mounts to the frame on a softail Z50. It's similar for a CT70, except that the bushings are pressed into the FRAME, instead of the swingarm.

This is the answer I offered to a member over on PM. I just copied it to paste up here on LH...
...I have to add...this is information that I first learned from racerx...I only take credit for repeating it. lol



With the stock swingarm setup...nothing spins, at that swingarm-to-frame joint.

The bushings press into the swingarm...tight. The inner sleeves are set in rubber. The frame has a mount that is solid, thru the frame, left to right, and it's the same diameter as the INNER sleeves of the bushings.
When installed, the bolt is tightened against the inner sleeves of the bushings only, tight. which press tight against the frame mount...creating a solid "tube" all thru the swingarm and frame. So when the swingarm flexes, up and down, the bolt and inner sleeves of the bushings stay fixed to the frame, and the outer sleeves that are pressed into the swingarm move with the swingarm, and the rubber flexes to allow that small bit of movement of the shocks.
Soo...nothing spins.

When you put it all together, don't snug the swingarm bolt until the shocks are installed, and then, torque it to spec.

 

[kirrbby]

Had to post this Takegawa engine work bench.
Great description too.
https://japan.webike.net/products/9699797.html#specification

 

[farm dog]

Had to post this Takegawa engine work bench.
Great description too.
https://japan.webike.net/products/9699797.html#specification

WOW Japan pine

 

[Clayton]

That’s AWESOME!! I think they are infringing on my patent lol

 

[kirrbby]

Early Z50 triple tree washers info.
I have some new washers that are just zinc coated 16mm washers. The O.D. seems to be correct...and the thickness.
Plan is to ream them out to ¾" using a step drill. Think it'll be the ticket...better than a ¾" drill bit.
Then I'll probably just file out the notches with a round file...close enough. I'll draw or trace the notches so I have something to reference. But I don't think I need perfection.

 

[kirrbby]

 

[kirrbby]

More random info...

I have a set of 90s bars that I think are straight. And another set that need to be straightened. Good time to log some info.
These bars lay FLAT on a flat table, no rock.
The bottom bar is straight, and lays flat against my saw fence.
There is ONE hole in the right side...for the switch/throttle controls.

 

[kirrbby]

The little brass set screw that holds the speedo gear in...
If a person needed to make one...
m4 and standard thread, is .7
About 4.5mm long and ground to a blunt point.
These in my pic both have maybe 3 threads on them...and slightly convex on the screwdriver/exposed side.
They actually LOOK homemade.

 

[kirrbby]

90s CT70 wire harness routing...

I'm swapping my 90s beater onto a better frame. I also have a 91 here that was mostly unmolested when I got it. I'm referencing that bike for the wire routing, and I got some pics...that I'm gonna post...right now




Sorry, but I was/am WAY too lazy to pull the tank. But the main bundle lays right into the bottom seam...under the tank. Like this...

 

[kirrbby]

From the Seized Honda ST90 thread.
Putting it here so I can find it later...


Look at the KEYWAY on the crankshaft...that keys to the flywheel.
If it's "pointed" toward the piston...then the crank is at the very top of the stroke. If you try driving the piston toward the KEYWAY, you'll be driving the piston/rod STRAIGHT into the big end bearing...the crankshaft cant SPIN, so the piston can't move.



Also, if you spin the crank 180° from there, and the KEYWAY is directly opposite of the piston...same thing.



You need the keyway to be pointing reasonably UP, or DOWN. Then, when you drive the piston toward the crank...the crankshaft CAN spin, so the piston CAN move.

 

[kirrbby]

I have this CT70 triple tree that has nice HL ears, but is badly bent. Not only bent, but one leg is dented, bad enough that I can't remove the inner leg and spring. If I could get the inners out, I'd have a chance of getting the triple tree straightened out well enough to save it.

My other option is to just call it junk. Cut off and save the HL ears and maybe reflector mounts. Then just recycle the bent triple tree.

I didn't get crazy trying to pull the inner out yet. I don't want to cause any damage to anything that's good.
I considered cutting a flap on the triple where I've marked it, then bend it out enough to pull the inner leg and spring...those parts are salvageable. Then I could consider trying to save the triple tree.

Does anyone know if it might be possible to pull the dents in such heavy metal?? Like with a slide hammer. Or is that unrealistic. Anyone have any ideas??

I'm really thinking that it's not worth the work it would take to try to save everything, and I should just plan to scrap the tree, and save what's EASY to save.

 

[JHminitrails]

Does anyone know if it might be possible to pull the dents in such heavy metal?? Like with a slide hammer. Or is that unrealistic. Anyone have any ideas?

If you could find a small diameter pipe expander to reach up inside the tube, that might work. I'm certain you can buy small diameter expanders. I think that would be the best way rather than welding to it. I just repaired a big dent in an original muffler by pressurizing the inside with 50psi of air and heating the dents up red hot. It's an old 2 stroke pipe repair trick that worked incredibly well. I don't think that kind of method would work on that heavy gauge steel fork tube though. But then again, it's already destined for the scrap pile anyway, so what do you got to lose. Might be worth a shot.

I have came up with a design in my head to make a tapered expanding tool for pushing dents out of the K1 and up headlight ears, I just need to build it. The idea I have in my head could be made with straight metal expanding mandrels and a tapered style as well. I just need to have someone turn down a chunk of aluminum with the matching taper for the ears. The idea is based on a typical tail pipe expander design, but only 2 halves, rather that multiple pieces. If I can get it done, I think it would work great and make for fairly quick dent repairs.

 

[kirrbby]

If you could find a small diameter pipe expander to reach up inside the tube, that might work. I'm certain you can buy small diameter expanders. I think that would be the best way rather than welding to it. I just repaired a big dent in an original muffler by pressurizing the inside with 50psi of air and heating the dents up red hot. It's an old 2 stroke pipe repair trick that worked incredibly well. I don't think that kind of method would work on that heavy gauge steel fork tube though. But then again, it's already destined for the scrap pile anyway, so what do you got to lose. Might be worth a shot.

I have came up with a design in my head to make a tapered expanding tool for pushing dents out of the K1 and up headlight ears, I just need to build it. The idea I have in my head could be made with straight metal expanding mandrels and a tapered style as well. I just need to have someone turn down a chunk of aluminum with the matching taper for the ears. The idea is based on a typical tail pipe expander design, but only 2 halves, rather that multiple pieces. If I can get it done, I think it would work great and make for fairly quick dent repairs.

The very first job is to get the inner leg out of the triple tree. I can't get anything inside of there until I can get that inner leg out. It's stuck hard, by the dent...INTO the white plastic fork slider.

I've spent a lot of time thinking about how to restore bent K3up fork ears...
Do you have a plan to straighten the ear itself? Or just the tube? It would be awesome if someone could come up with a good, repeatable, process.

I've considered making a gadget to allow me to pressurize Z50 fuel tanks for pushing out dents. Sounds like it could be worth pursuing.
I don't have a oxy/acetylene setup at home...that needs to be pursued also

 

[JHminitrails]

The very first job is to get the inner leg out of the triple tree. I can't get anything inside of there until I can get that inner leg out. It's stuck hard, by the dent...INTO the white plastic fork slider.

I've spent a lot of time thinking about how to restore bent K3up fork ears...
Do you have a plan to straighten the ear itself? Or just the tube? It would be awesome if someone could come up with a good, repeatable, process.

I've considered making a gadget to allow me to pressurize Z50 fuel tanks for pushing out dents. Sounds like it could be worth pursuing.
I don't have a oxy/acetylene setup at home...that needs to be pursued also

I suppose that is a slight problem for you. Lol. I wonder if you heat up the tube and try to get it to soften up the plastic bushings, which would allow it to deform around the dent as you pull the inners out. Maybe put a bar through the axle hole and have a helper pound on the bar as you keep some heat on the tube.

I was only trying to make a tool for the dents in the tubes themselves. The dual layer ears on the K3's are a whole new level of difficult to repair without serious surgery from my observations! I have one here that I've been staring at trying to figure out a method, but nothing has hit me yet.

 

[gpzkat]

Out for a ride on a beautiful day, I ran the tank down to reserve, then stopped to refill the tank. I usually fill the tank from a gas can at home. Always run premium pump gas. Filling at the gas station, I hit the premium button and then it took $1.09 to fill. My question is that the pump has one hose supplying all 3 grades of fuel. How much 87 octane was in the hose before I started getting premium from the nozzle?

There's no more 'bang' from premium vs regular, from what I have learned. Same energy quotient but different combustion speed characteristics to benefit high compression motors. If it isn't pinging then run the lowest/cheapest. I wonder how much $$$ has been pitched down this hole over the years. Can't hurt but probably won't help.