Topic: '73 500 - Subframe Fabrication

[calj737]

When I get closer, I'll find real ones for the build. They offer them in many colors, so it will be blue for the Beemer. Not sure yet about the 500

[Tews19]

Cal any updates on this build? I know I've been taking a lot of your free time which I am sorry for in but you seem to be a genuine selfless person.

[Blackfin5]

+1

Cal, do you have pic updates?

[calj737]

Not really. I've been in Florida for about 2 weeks taking of my Mom after surgery, heading home this weekend to see the kids and wife, then back down again next week.

Really I'm still awaiting the transmission from undercutting to come back, finish building the motor, then, start on the frame mock-ups for a custom subframe. And that is awaiting the boy to make his decisions about the design of the tail section and a mock up of the tank and seat.

I'll probabaly be switching most of my efforts to the 572 build since I don't have to wait on my college boy for that one. That trans is out getting undercut too, motor cases are still at powder coat, then head goes to machine shop.

That's why I've got so much free time right now- all my builds are stalled 

[Tews19]

What does undercutting do?

[70CB750]

http://www.aperaceparts.com/transmissions.html

[calj737]

As 70CB linked. The 500 trans is notoriously weak and with the significant gains in power on that motor, felt it best to spend the $ now and insure it holds up.

Sending the 550 out is more of a "condom" since its an unknown motor to me, and Im building it for a buddy. Don't want him to have any trans issues or shifting issues later. I'm only doing gears 2-5 on the upshift side per recommendations from Brent. But its still $500 per trans.

[SOHC4 Cafe Racer Fan]

Not really. I've been in Florida for about 2 weeks taking of my Mom after surgery, heading home this weekend to see the kids and wife, then back down again next week.

Really I'm still awaiting the transmission from undercutting to come back, finish building the motor, then, start on the frame mock-ups for a custom subframe. And that is awaiting the boy to make his decisions about the design of the tail section and a mock up of the tank and seat.

I'll probabaly be switching most of my efforts to the 572 build since I don't have to wait on my college boy for that one. That trans is out getting undercut too, motor cases are still at powder coat, then head goes to machine shop.

That's why I've got so much free time right now- all my builds are stalled 

Sometimes, life gets in the way. I hope your mother recovers well and quickly, Cal.

Don

[Stev-o]

Any update, Cal?   Or more like micro baby steps?!

[calj737]

Well, actually, the motor is waiting on me to pick up from the machine shop. The frame is waiting on my son to finalize his design of the tank, seat and subframe. I pick him up in Detroit next Friday, then he's home for 30 days. I've given him the ultimatum to finalize those aspects so the fabrication can occur while he finishes next semester. I either want this bike done and on the road by VERY early summer, or the motor, carbs and front end (about $10k worth of my money) are going into the 550 and then those components into the 572. I want these nikes done so I can turn my full attention to my BMW.

For the record, I build bikes so I can ride the damn things, not stand about and admire them  Or admire their (lack) progress more accurately.

[SOHC4 Cafe Racer Fan]

With all the time invested up to now, 30 days is plenty for him to finalize his design.  I think it's completely fair to harvest the powertrain and front suspension for the other project if he can't decide.

[SOHC4 Cafe Racer Fan]

Well, Cal, hopefully the college kid made it home okay, and his design will cement in the next month! 

[calj737]

Is in the passenger seat with me as a type on our way home. Fingers crossed!

[SOHC4 Cafe Racer Fan]

Is in the passenger seat with me as a type on our way home. Fingers crossed!

Travel safely.

[Restoration Fan]

Well since I'm new to the game, I had missed this build thread up to now.  Subscribed and caught up.

Cal, you're a heck of a father and an awesome guy to help out on all the threads that you do, while also doing all this work on these bikes. 

[calj737]

We had lots of time last evening on our 10 hour journey to discuss style and method of fabricating the subframe. So, in a few days we will get to work on some mock-ups and see what's "what".

[calj737]

Well got the college boy off his butt (actually separated from his pillow) and out in the garage to mock up his frame and bodywork. He spent several hours creating some templates and then sketching his intentions. His major at college, Transportation Design (the design part of cars/bikes not the engineering side) is beneficial in aiding him in drawing his ideas rather than gesticulating them to me. He's also made some cardboard templates and such to help him decide.

Anyway, I think we've decided to use a Panigale seat pad on top of a custom carbon fiber cowl (he will make at school) mated to a custom aluminum tank (he will carve the mold for from foam while at school. Then, over Spring Break while he's home, we will verify fitment and he will return to make vacuum formed plastic molds. These will be used as guides for the alloy tank and seat cowl.

Meanwhile, he's authorized me to get started on his swing arm (gee, thanks, son!) so that is ready for his return. And we have decided on where his frame and new subframe will connect so I can start on that too. I'm going to use a mortise/tenon joint to connect the subra frame ala modern bikes (think bolt-on connection of subframe to mainframe). I'll be using the truss on this frame since it's not a welded connection, but the subframe and swing arm will be from 6061 tubing.

I will also be adding at least 1 new welded brace across the rear of the main frame above the swing arm pivot. We are thinking about whether a front brace is even needed between the stock motor mounts. Undecided on that.

The only picture of progress was the quick and dirty setup the other day with front end and wheels attached to make the patterns. He is supposed to send me back some color ideations (that's a fancy designers word for sketches I am told) about his tank and seat. And we've decided on a color scheme (again).

Couple of weeks, and I should have some decent progress on my end. It will be about 3 weeks and then I will have the swing arm done. (Shhhh! I'm making 2, one for this bike, and one for my 550). I promised a friend my Dresda-esque swing arm from that bike months and months ago so I'd better get off my lazy butt and deliver before he calls me out on it.

[calj737]

...And, I've spent a great deal of time trying to work out a much cooler wire harness for this bike (and my others) with the MotoGadget products. I'm looking to use maybe Deutsch connectors to create quick disconnect sections of the loom and components for replacement or service. Had to find anyone locally who sells these, so I am on the hunt....

If anyone has some ideas or better options, I'm all ears? Goal is small frame, non-vintage bullet connectors. The main harness will need to detach from the electronics tray outside the tray, and from the handle bars/steering neck area. All front end electrics will be MotoG, so wiring there is very simple and small diameter stuff (LED and micro switched). So vintage bullets aren't the right solution.

Deutsch offers a 2, 4, 6, 8 or 12 cavity connector that would allow me to bring all the bar controls into a single mutation connector, and disconnect separate switches individually without disrupting the others. I like that-

Another option might be terminal blocks, but gotta research those too. Anyone got unique ideas I'm overlooking?

[SOHC4 Cafe Racer Fan]

Well got the college boy off his butt (actually separated from his pillow) and out in the garage to mock up his frame and bodywork. He spent several hours creating some templates and then sketching his intentions. His major at college, Transportation Design (the design part of cars/bikes not the engineering side) is beneficial in aiding him in drawing his ideas rather than gesticulating them to me. He's also made some cardboard templates and such to help him decide.

Anyway, I think we've decided to use a Panigale seat pad on top of a custom carbon fiber cowl (he will make at school) mated to a custom aluminum tank (he will carve the mold for from foam while at school. Then, over Spring Break while he's home, we will verify fitment and he will return to make vacuum formed plastic molds. These will be used as guides for the alloy tank and seat cowl.

Meanwhile, he's authorized me to get started on his swing arm (gee, thanks, son!) so that is ready for his return. And we have decided on where his frame and new subframe will connect so I can start on that too. I'm going to use a mortise/tenon joint to connect the subra frame ala modern bikes (think bolt-on connection of subframe to mainframe). I'll be using the truss on this frame since it's not a welded connection, but the subframe and swing arm will be from 6061 tubing.

I will also be adding at least 1 new welded brace across the rear of the main frame above the swing arm pivot. We are thinking about whether a front brace is even needed between the stock motor mounts. Undecided on that.

The only picture of progress was the quick and dirty setup the other day with front end and wheels attached to make the patterns. He is supposed to send me back some color ideations (that's a fancy designers word for sketches I am told) about his tank and seat. And we've decided on a color scheme (again).

Couple of weeks, and I should have some decent progress on my end. It will be about 3 weeks and then I will have the swing arm done. (Shhhh! I'm making 2, one for this bike, and one for my 550). I promised a friend my Dresda-esque swing arm from that bike months and months ago so I'd better get off my lazy butt and deliver before he calls me out on it.

I would never dream of it!

I'm glad Joe College is getting his ideations and renderings together.  A custom autoclaved CF seat!!  That sounds pretty slick.  The aluminum tank sounds great, in addition to all of the custom subframe work. 

I think the rear frame brace is a good idea.  Adding a cross-brace to the front may be overkill, but the stock frame may benefit from some additional rigidity.  I've seen frames with a front cross-bar and an X bar in the rear.  That said, I've heard that reinforcing these frame too much exacerbates the weaknesses of the stock welds (making them the weak points), so you may want to consider reinforcing those, too.

I always enjoy your build strings, humor and advice, Cal. 

[calj737]

I will be re-welding the entire frame anyway for the reason you mention about over-stressing the frame with new bracing. Figure at 40, who wouldn't want a little "structural tune-up" if we could get one? 

[Retro Rocket]

I will be re-welding the entire frame anyway for the reason you mention about over-stressing the frame with new bracing. Figure at 40, who wouldn't want a little "structural tune-up" if we could get one? 

I have the sleeved  sections on the front down tubes that are spot welded, welded in now for added strength {750} but really, Many people including myself have been bracing these frames for over 35 years on the street and track and i'm yet to see or hear of one failure...

[calj737]

It's more of a "restore" the welds than "improve" the welds. I harbor no illusions that when done this motor is too much for the stock frame, but given how much corrosion ate on this thing (see page 1) I think it's prudent to re-rum the welds.

[Retro Rocket]

It's more of a "restore" the welds than "improve" the welds. I harbor no illusions that when done this motor is too much for the stock frame, but given how much corrosion ate on this thing (see page 1) I think it's prudent to re-rum the welds.

These are the sections i was talking about, they have 3 spot welds, welding them up is a good idea when using modern brakes i think......

[calj737]

Yep. Those, plus many other areas will get welded. The brackets at the lower rear of the frame need some attention. I'll grind a bit and weld up the lower frint engine brackets, plus the backbone area to hoops is going to need some work after the changes to the seat hoop. Now worries, plenty of TIG rod on the shelf.

[Retro Rocket]

I always wanted a 750 frame made from Reynolds531 tubing with all the mods added from the start, I wonder how much lighter and stronger it would be...?  Dreaming again...