Topic: 1972 CB350 For the Daughter

[Harsh]

And a fourth option.  This one follows the angle of the frame tube.

Nice automobiles Harsh 
I think the supports underneath the center/middle portion of the seat needs to be solid so the seat pan will stay centered w/ the weight of the rider to keep it in a neutral position,fully supported underneath in a few places w/ rubber bumpers attached in at least 4 places against your frame/braces.Then the seat latch assm. won't have any stress on it to cause problems later. imo
Nice Miller mig welder also !  I will need to learn how to weld soon myself;did you take any courses ?

The center part of the seat will be supported.  I just haven't got to that point yet.  No courses yet, but I have looked into some.  The last time I welded was 30 years ago and that was stick welding.

[Restoration Fan]

Wow, nice Miller welder.  You don't play around when you buy a welder!

(Also, nice choice on vehicles.  Both of those tend to be cars that have good longevity.)

[RAFster122s]

Good looking progress and nice cars too. 
It looks like it is coming together.  Just have to tote some stuff up to Calj's to bribe him to come down, he can really handle welding a pretty bead and teach you some stuff too as well.  He has a few welding porn pics of his stuff around the forum.

[calj737]

That is a nice little welder. Grab their SpoolMate so you can MIG aluminum then you're all set!

[grcamna2]

Steven,
I would install the rubber support bumpers before you weld-in the latch mech.

[Harsh]

Why?  Once I get the brackets fully welded in I can/will adjust the supports bumpers to the height necessary.  I want the seat to sit flush against the welded in bracket that the pins slide into.  As the seat goes towards the tank the distance from the frame rails to the seat gets thinner/shorter.  I was planning on making a solid plate that goes across the battery area across the frame rails to support the seat.  The rear will have bumpers that are bolted into the stock curved frame support that goes across the frame just forward of the piece I tacked in.

[grcamna2]

Why?  Once I get the brackets fully welded in I can/will adjust the supports bumpers to the height necessary.  I want the seat to sit flush against the welded in bracket that the pins slide into.  As the seat goes towards the tank the distance from the frame rails to the seat gets thinner/shorter.  I was planning on making a solid plate that goes across the battery area across the frame rails to support the seat.  The rear will have bumpers that are bolted into the stock curved frame support that goes across the frame just forward of the piece I tacked in.

oh,ok.

[Harsh]

I did some crappy photchopping and I am down to these.  I wish I had taken the pics from the same distance as it would make it a tiny bit easier to compare the two.

[calj737]

Why not create a "hoop" that carries along the same line, up under the seat flare and around to the other side? Then you won't have an unfinished look.

Personally, I have never liked the look of these rails once they're cut off and left abandoned. 

[Harsh]

I was going to block off the open end after I cut it.  Which way are you suggesting I run a hoop?  Either way would cause some issues.  The red version would interfere with the tail light at the rear of the seat.  I was planning on insetting a cat eye tail light.  The black version might interfere with the remaining part of the fender and maybe wheel clearance.

[SOHC4 Cafe Racer Fan]

The hoop could kick upwards into the recess of the seat -- perhaps follow the rearward seam line of the seat. 

How are you attaching the taillight? 

[grcamna2]

The hoop could kick upwards into the recess of the seat -- perhaps follow the rearward seam line of the seat. 

How are you attaching the taillight?

That hoop would add lot's of strength to that area too.

[Harsh]

The hoop could kick upwards into the recess of the seat -- perhaps follow the rearward seam line of the seat. 

How are you attaching the taillight? 

That is what I had initially thought, but then I started to over think it.

I will be making a small bracket that will secure the tail light to the fender.  I am trimming the fender so that it isn't really visible when you look at the bike, but it will still provide protection.  You can see a couple of pencil lines where I traced around the bottom of the seat in one of the earlier pictures.

That hoop would add lot's of strength to that area too.

I was thinking the same exact thing.  I think it will especially help keeping the frame from twisting behind he shock mounts.


Thanks for the suggestions fellas.  Ahh, I just love more work.

[Harsh]

So I am stuck.  I have a hoop I cut out of a CL350 that should work for my purposes.  The thickness of the frame 3/4" and the diameter of the hoop is also 3/4" which should make for a nice looking end of the frame once everything is welded together.  The hoop is a fair bit wider than the seat and frame though.  So I cut it in half and will weld it back together once I get the angles and width correct.  However, the underside of the seat has these humps that jut out just above the frame preventing the hoops from being able to go up without bending or pinching them to go around the hump.  Either of which might defeat the purpose of the hoop.  I would probably end up having to make some sort of an "S" bend.  Where I am really stuck is that I need to cut the frame to figure out where I need to place the hoop and make the bends.  Mocking up the hoop on either the inside or the outside of the frame won't provide a true representation of where I need bends/cuts. So I feel I am basically going to have to say the hell with it and take a chance at cutting the frame and hopefully it will work out.

[calj737]

Use some cardboard as a template against the seat and frame. Use it as a welding/cutting guide for your hoop.

[grcamna2]

You might also use a piece of similar dia. copper tubing(it bends easy w/ a plumber's pipe bender)to mock-it-up.

[Harsh]

You might also use a piece of similar dia. copper tubing(it bends easy w/ a plumber's pipe bender)to mock-it-up.

Bill, that is a fantastic idea and I think I have the stuff in the garage already.

[grcamna2]

You might also use a piece of similar dia. copper tubing(it bends easy w/ a plumber's pipe bender)to mock-it-up.

Bill, that is a fantastic idea and I think I have the stuff in the garage already.

The last part would be if you could also bend the steel hoop in a similar way to match the mock-up..

[Harsh]

The copper didn't end up working.  I couldn't get the bend tight enough before it would snap.  So I used a piece of very thing all thread I had laying around.  Bent it to the outside shape I needed and fit the two loop halves together on the inside radius.  Cut the angle I needed on one piece of the hoop and tacked them together.  It seems to fit, but the only way to truly tell is to cut the frame and slide it into place.  I think I am going to cut on line that followed the seat seam and tack in the hoop.

[Restoration Fan]

Looks pretty good.  Next time, if you're trying to bend it, fill the pipe with sand and apply heat.  When it's cherry red, do a slight bend over something with a similar radius.  If you do the bends in a couple of gradual bends and have the pipe hot enough, the sand should keep it from splitting.

[Harsh]

Struggled all weekend with the hoop.  So the hoop is gone.  No matter what I do I just can't get it to fit under the seat.  I decided to try the stock piece I cut off and it fits pretty darn good and the seat fits over it.  Not exactly what I wanted to do to the end of the frame, but it will work.  I braced the stock hoop to the frame with some 3/16" flat stock.

Finished tack welding everything thing in place this evening and a buddy of mine is going to do the finish welding for me tomorrow.  The bit of fender that sticks out under the seat will be cut off to match the shape of the seat.

[grcamna2]

That orig. top/rear frame 'bridge' will work for many different functions 

[RAFster122s]

With a bit of work could you reshape the curve below the shock mount by reducing the radius to sweep it up from the diagonal tube towards the seat's line.
Maybe round the area around the shock mount in a curved bulge.
it doesn't need it but it would be an asthetic change.
Just a spitball idea.

[Harsh]

Re-shaping that was already in the plans.  It just wasn't necessary to do right now in order to get everything ready to be welded.

[Harsh]

Got everything welded up yesterday and spent the morning cleaning up the welds.






Filled in the holes left from some spot welded pieces that I cut off.


Still need to go back and fill in the dimples from drilling out some spot welds.



With the fender installed.  You can see a tiny bit of it under the seat, but that is because the picture was taken at a lower angle and kind of looking up under the seat.