Author Topic: Dorothy III - CB750 (Read 104458 times)

grcamna2 · « **Reply #400 on:** September 22, 2016, 04:46:14 PM »

That swingarm looks like the same one from my 1982' Suzuki GS1100E,I have a full set NOS 'in pckge.' oem swingarm bearings,sleeves and seals for that.

calj737 · « **Reply #401 on:** September 22, 2016, 04:49:03 PM »

Are you planning to shorten at the throat or along the legs?

Retro Rocket · « **Reply #402 on:** September 22, 2016, 05:34:48 PM »

Quote from: calj737 on September 22, 2016, 04:49:03 PM

Are you planning to shorten at the throat or along the legs?

Best done at the pivot end Cal, it won't restrict the wheel diameter you use then...

I had a GSXR1100 arm shortened, I couldn't get it to the required length at the axle end, run out of room, I should have had it shortened at the pivot end for the same reason...

calj737 · « **Reply #403 on:** September 22, 2016, 07:54:51 PM »

Dunno. I'd look at shortening the leg after the bracing and before the bend to the axle. That way the leg angle remains consistent. Cutting at the pivot requires a lot more cutting, fitting and welding to my eye.

Retro Rocket · « **Reply #404 on:** September 22, 2016, 08:19:52 PM »

Quote from: calj737 on September 22, 2016, 07:54:51 PM

Dunno. I'd look at shortening the leg after the bracing and before the bend to the axle. That way the leg angle remains consistent. Cutting at the pivot requires a lot more cutting, fitting and welding to my eye.

Possibly, but the arm isn't the same height front to back, it gets higher all the way from the pivot to the chain adjusters, so there would be a step where its welded, also, the pivot tube is square or flat at the back where its welded to the arm, which makes it relatively easy to reweld if the cuts are nice and square...

70CB750 · « **Reply #405 on:** September 23, 2016, 09:57:28 AM »

I want to make new pivot tube - fitted with bronze bushings - and weld it to the arm; shortening at the throat for sure.

Along the legs would be easier for jigs and alignment, but as RR says, the profile is not constant.

If I oversize the pivot to say 2", I may not need to fish mouth those arms, just two positioning slots on the pivot will be enough.

calj737 · « **Reply #406 on:** September 23, 2016, 10:26:44 AM »

Quote from: 70CB750 on September 23, 2016, 09:57:28 AM

I want to make new pivot tube - fitted with bronze bushings - and weld it to the arm; shortening at the throat for sure.

Along the legs would be easier for jigs and alignment, but as RR says, the profile is not constant.

If I oversize the pivot to say 2", I may not need to fish mouth those arms, just two positioning slots on the pivot will be enough.

Dang, by that time, you're almost making a whole new swing arm... You could buy pivot tubing, box tubing, miter cut it, and transplant the axle clips over. Weld it up, brace with new plate, done.

70CB750 · « **Reply #407 on:** September 23, 2016, 11:06:09 AM »

You got a point

If I take it all apart, I could position legs closer together to make it fit CB750 drum wheel. Decisions, decisions.

calj737 · « **Reply #408 on:** September 23, 2016, 12:35:15 PM »

Its the very reason I decided to make my own instead of modify a stop or donor arm... A wee bit of machine time, some birds mouth cuts, and fire up the welder.

Retro Rocket · « **Reply #409 on:** September 23, 2016, 03:55:59 PM »

Quote from: 70CB750 on September 23, 2016, 11:06:09 AM

You got a point

If I take it all apart, I could position legs closer together to make it fit CB750 drum wheel. Decisions, decisions.

If you are only using stock wheels that could work, make sure you measure at the shock mounts though , they have to line up with the frameto prevent stiction, if my memory serves me well, the GS shock mounts are 5mm a side wider than the 750 arm, I think you'd still have to make custom spacers for the wheel.

70CB750 · « **Reply #410 on:** September 23, 2016, 04:09:35 PM »

You are right, I think I will make new top shock mounts, just like I made one for Red - weld them in the frame.

Retro Rocket · « **Reply #411 on:** September 23, 2016, 04:11:02 PM »

Quote from: 70CB750 on September 23, 2016, 04:09:35 PM

You are right, I think I will make new top shock mounts, just like I made one for Red - weld them in the frame.

Thats what I'm doing...

Interested to see what you end up with here, I never considered a new pivot but now you have me thinking....
I would use the roller bearings though, there is a kit for the Honda sized pivot bolt...

https://www.z1enterprises.com/product/KL31-6923

70CB750 · « **Reply #412 on:** December 21, 2018, 03:35:41 AM »

Yesterday I put the bottom half of Dorothy's engine on the stand and dug out the box with transmission gears.

It is time to bring Dorothy back to life

70CB750 · « **Reply #413 on:** December 21, 2018, 04:11:14 AM »

I guess this will come handy

seanbarney41 · « **Reply #414 on:** December 21, 2018, 06:11:57 AM »

Hell yeah

RAFster122s · « **Reply #415 on:** December 21, 2018, 11:40:15 AM »

Glad to hear Dorothy will fly again

David

70CB750 · « **Reply #416 on:** December 31, 2018, 04:06:27 AM »

With my oldest daughter we played a bit with transmission gears. I think i will keep all original bearings, replace gears and use the old output shaft. Keeping it simple.

Chrysler Fiat put Magdalena through mechanic's training and they assembled 6 speed jeep transmission - I had to show her what a real transmission looks like

Gurp · « **Reply #417 on:** February 23, 2019, 08:09:02 AM »

Just re-read your thread this was one of my Favs too keep up with the first time I was on the forum in 2012.
Took a screenshot of your airbox setup as well.

70CB750 · « **Reply #418 on:** February 23, 2019, 12:05:53 PM »

Quote from: Gurp on February 23, 2019, 08:09:02 AM

Just re-read your thread this was one of my Favs too keep up with the first time I was on the forum in 2012.
Took a screenshot of your airbox setup as well.

Thank you

70CB750 · « **Reply #419 on:** January 09, 2022, 09:09:58 AM »

It took me few years, but I found Don Vesco fairing. Originally meant for Red, but becaue of the sidebox and because the fairing is frame mounted, I guess I will save it for Dorothy.

BenelliSEI · « **Reply #420 on:** January 09, 2022, 01:23:59 PM »

That is a neat piece of “aero”!

RAFster122s · « **Reply #421 on:** January 09, 2022, 01:27:20 PM »

Love the Vesco Rabid Transit fairings...

grcamna2 · « **Reply #422 on:** January 09, 2022, 02:18:43 PM »

Quote from: BenelliSEI on January 09, 2022, 01:23:59 PM

That is a neat piece of “aero”!

+1

Gurp · « **Reply #423 on:** May 05, 2022, 09:40:38 AM »

Gotta love some Dorothy. Hopefully some updates are coming soon!

Alan F. · « **Reply #424 on:** May 05, 2022, 10:55:21 AM »

Good score! I missed one around here a few years back for $100, they do come up now & then.

News:

Author Topic: Dorothy III - CB750 (Read 104458 times)