Topic: An Incredible 1972 CB750 Cafe Project

[MCRider]

This whole weekend has been dedicated to tearing down the forks... and i've failed. I'm stuck on the hex bolt on the bottom of each, that just don't want to budge. I've nearly stripped one of them so I'll have to replace that for sure. Anyone have a spare? haha.

I'm in need of ideas, or else I'll end up taking it to a shop tomorrow to get some help.

Generally, those are not expected to come out. But from personal experience I can say its good to get them out and clean the smegma in the tube and damper thoroughly.

Generally its done this way: With the spring and cap nut still installed, go after it with an impact wrench of the air or electric variety. A hammer impact may work.  YOu need the pressure of the spring to hold everything tight so the impact gets full force.

IS yours spining now?

If the spring is out, stick a broomhandle, shortened for convenience in the lower leg to rest on the damper dealie. Turn it up, broom handle on floor, and go after it with the impact.

Very few shops have experience getting these out as I say, they were not intended to be removed and its not in the manual.  In fact in the early parts books, they don't even show them.

Others?

If you've ruined it, you may resort to drilling the head off and easy out the remainder.

I got mine out no sweat, na na.   

[Tews19]

I have a few extra fork lowers..If stripped you may want to replace now

[Tews19]

I have a few extra fork lowers..If stripped you may want to replace now

Also, if you go with the older style fork lowers you don't have to remove the bolt on bottom

[Itwillbefun]

This whole weekend has been dedicated to tearing down the forks... and i've failed. I'm stuck on the hex bolt on the bottom of each, that just don't want to budge. I've nearly stripped one of them so I'll have to replace that for sure. Anyone have a spare? haha.

I'm in need of ideas, or else I'll end up taking it to a shop tomorrow to get some help.

Generally, those are not expected to come out. But from personal experience I can say its good to get them out and clean the smegma in the tube and damper thoroughly.

Generally its done this way: With the spring and cap nut still installed, go after it with an impact wrench of the air or electric variety. A hammer impact may work.  YOu need the pressure of the spring to hold everything tight so the impact gets full force.

IS yours spining now?

If the spring is out, stick a broomhandle, shortened for convenience in the lower leg to rest on the damper dealie. Turn it up, broom handle on floor, and go after it with the impact.

Very few shops have experience getting these out as I say, they were not intended to be removed and its not in the manual.  In fact in the early parts books, they don't even show them.

Others?

If you've ruined it, you may resort to drilling the head off and easy out the remainder.

I got mine out no sweat, na na.   

All I'm replacing is the spring and seals, but like you said I thought I would go ahead and take it apart to give it a good cleaning while I was at it.

Plus I wanted to paint the lowers.

I have a hammer impact, which I tried but it's spinning. Spring was out already so I think after dinner I'm going to go throw it back in and give it another shot. Kinda lacking broom handles around here!
I don't believe they are ruined, I "accidentally" started with the Wong size hex and distorted it a tad, but the right hex still fits In there strong.

[MCRider]

Good. Put the spring back in. My money is on success.  The spring pushes on the part that is spinning, usually holding it in place enough to get the screw out.

[Itwillbefun]

Okay, what are you guys talking about that's spinning? I meant the upper fork tube, the hex bolt ain't budging. Can you guys clarify?

Another reason I'm trying to get it off is to help get the seal off, is there a simple way to get the seal off without taking the lower off?

Thanks!

[Tews19]

What mc said. I had to do the same with my 550k. Even put fluid back in and had someone put all their weight on it to break it free

[MCRider]

Okay, what are you guys talking about that's spinning? I meant the upper fork tube, the hex bolt ain't budging. Can you guys clarify?

Another reason I'm trying to get it off is to help get the seal off, is there a simple way to get the seal off without taking the lower off?

Thanks!

Huh? You said you were working on the hex bolt in the lower leg. It is threaded into a damper that's about 6-8 inches long, residing in the lower leg. That's what we are talking about spinning when you turn the lower Allen screw.

As far as getting the top cap nut off, that should be loosened before puling the legs out of the triples. Use the triples as clamps.

[Itwillbefun]

The hex bolt is not spinning, it's not moving... So it should be spinning?

[MCRider]

The hex bolt is not spinning, it's not moving... So it should be spinning?

The bottom bolt screwed into the forkleg from below right?

No it should not be spinning, but often it will when someone tries to remove it, loosens it a skosh, then the damper it is screwed into starts to turn (spin) and no more progress.

So you just can't get it to budge to begin with? I would shy away from a hammer impact driver, though it could work.  Its just so brutal. I mean you're going to have to hit it REALLY hard with at least a 2.5lb hammer.  If you did get it loose, you still have to hold the damper still, either with the spring or broomhandle. Wear a glove on the holding hand as when you missthe impact and smack your hand with that hammer it will hurt. (first hand experience talking)

Spring in, Air (or electric) impact. That's my story and I'm sticking to it. Good luck.

[Itwillbefun]

Haha okay, I've given the impact driver some really good smacks with no luck. I'll probably invest in an electric tomorrow instead of taking it to a shop. I'm sure I'll find more uses for one eventually!

[MCRider]

Haha okay, I've given the impact driver some really good smacks with no luck. I'll probably invest in an electric tomorrow instead of taking it to a shop. I'm sure I'll find more uses for one eventually!

Might be able to rent/borrow one from an autoparts store.

[Dyrden]

Once you have a good impact driver youll wonder what you ever did without it.

[Itwillbefun]

Once you have a good impact driver youll wonder what you ever did without it.

Bought a Milwaukee, forks are now apart and cleaned! Simple as that... I'm kicking myself for not having one of these bad boys already.

[MCRider]

Once you have a good impact driver youll wonder what you ever did without it.

Bought a Milwaukee, forks are now apart and cleaned! Simple as that... I'm kicking myself for not having one of these bad boys already.

Ta Da!  Would have been hard to do with a hammer impact driver, eh?   

[Itwillbefun]

It was impossible to do with a hammer impact! I was wailing away on mine. I better build more than one bike with all these tools I'm gathering

[fastbroshi]

You sure you were using it correctly?  You can't just hold it on the screw and hit it with the hammer.  Some models you have to apply a bit of twisting force in the direction you want it to pop the screw.

[MCRider]

You sure you were using it correctly?  You can't just hold it on the screw and hit it with the hammer.  Some models you have to apply a bit of twisting force in the direction you want it to pop the screw.

Have you ever succeeded in using it on the screw in question? Pretty tough, and I'm an old hand with hammer impacts.

[fastbroshi]

Nope, I used a 3 foot breaker bar first.

[MCRider]

Nope, I used a 3 foot breaker bar first.

I wouldn't have guessed that would work either, but good on you.

[Itwillbefun]

Shhhiiii... I tried everything with the hammer impact driver.

[Itwillbefun]

I promise there will be a real update soon... But I doodled what I hope it looks like while in class today! Ha...

[Stev-o]

Cool, you plan on stretching the frame?!

[Itwillbefun]

Heck yeah man, it's gonna be a first. 

[Itwillbefun]

Wow! School is in full swing now so I've been crunched for time, but things are still rolling!

Finished up the forks last week, and just put the new gator boots on today. I'm really happy with how they look and can't wait to start getting things on the bike.


Besides that, I'm gathering all the bits and pieces together.


In the picture are new break shoes, dime city 6.5 headlight with headlight ears, loaded gun universal rear sets with linkage kit,  two out of the three components needed for the RFID ignition setup I'm going to run, wire harness, kick start rubber and kick stand rubber, all balls bearing kit, and then a few of the pieces I've painted.

I still need a battery, I just haven't decided on which one to go with.

I still need to decide on what sort of turn signals I'm going to go with.

I still need to figure out how the eff I'm going to mount the rear sets.

I need a new break lever because the one I have doesn't match the MC.

The 81 cb750 swing arm is here, I may start working on getting that to fit this weekend. I visited a local shop that deals mostly in Harley's the other day, I thought it might be a good idea to have someone to go to for help fabricating some things, like spacers to help get the swing arm right! Plus they do welding so I can get the rear loop welded on when it gets here.

Exciting things to come!


Justin