Built Thread: Hardtail '78 750 with floating seat

[verde]

For reference: Started as a ragged version of this:

Closest to a before pic I have:

And a bit more tear down:

Engine out, go to pull the head off and this guy had some how survived the engine bright and garden hose.

Head comes off and this piece of nest is sitting on the top of the jugs:

Got the jugs off and found the culprits all the way down against the block:

40K miles of build up, assuming the odo is true.

An exhaust valve after scraping the big stuff off of it. Still a lot of scraping to do on the chambers. Exhaust valves took at lot of lapping.

Pretty standard stuff:

Various stages of clean:

 

[bonanzadave]

more to come...

Looking fwd to your build. Nice photos !

 

[verde]

Setting the axle height and making the initial cuts.

Top tubes hit the frame at the upper engine mounts and here.

And enclose most of the factory axle plate to swing arm welds.

Top tubes tacked in place:

I wanted to retain the stock foot controls rather than make forward controls -- Keep it skinny for lane splitting and be able to stand up for speed bumps and such. Took some aggressive and careful notching. Don't worry, it received a gusset latter.(frame is upside down in this pic)

Swing arm not welcome here anymore.

Made the cross brace to transfer some of the force off of the middle of the vertical section of stock frame, but still leave my seat floating out by itself.

Seat post

I like to service my seat post, if you know what I mean.

Some see the leg off a sit-up bench. I see a seat pan bender. (others may see a brown jack russel puppy)

 

[verde]

Auto parts store was out of black edge trim, so the only 'chrome' I added is gonna be hidden by leather.

Some odds and ends, coil relocation bracket to hollow out the frame. Caliper brace extended using 3/4 square tube and drilled/notched to hook up to the center stand tab left available on the frame.

(her cleavage is showing)

Screw you and your half-assed work ethic, PO. I think they're called bullett connectors.

Put the fender on a diet.

Made this out of rebar:

Painting will have to wait today. Damn coastal fog.

Spent more on brazing rod for modifying the tank than I did on the tank. It's off a 60's john deer riding mower.
One of the only three pieces to receive more than just self etching primer. Fan on and a space heater makes the bathroom a great curing room.

 

[verde]

My 'spoke' for my speedo.

Temporary 'baffles.' More civil pipes are in the plans(currently my neighbors like the novelty of the crazy guy next door building bikes, and I'd like to keep it that way)

Test ride time:

Still to come:

 

[GabrielGoes]

thats nuts i enjoyed looking at all the pics! thanks for sharing... i had a question about your dirty valves... does running the bike clean all that crud off or does it just build it non-stop where it requires scraping?

 

[verde]

Looking fwd to your build. Nice photos !

Thanks. Got lazy and missed some good photos, but had plenty to sift through and choose from anyway.

 

[verde]

i had a question about your dirty valves... does running the bike clean all that crud off or does it just build it non-stop where it requires scraping?

No clue(as to on the face of the valve itself... I know the rest the crud will build up and the engine will need decarb regardless). First time doing valve work. That carbon build up is pretty tough and it was on the face of the ex valves in my case. The little black spots are microscopic pits you can only see by the color change. Took a lot of valve lapping to get them all out(missing some good pics here, maybe on another camera). If your valves are out of spec to the point of bad compression like mine were, I'd recommend lapping them after this experience.

 

[Flaming Chainsaws]

Wow! Genius design for the seat! Cool bike!

 

[midnightcafe]

hot diggity~!

hot diggity~!

damn that's some smart work! If only you applied it in a more functional way than a chopper just busting balls, I like it regardless!

what did you use for the seat foam? Neoprene? And did you carve it to fit the curve in the seat pan or is it a flat piece that's adhered in that manner?

 

[verde]

Bah! It's not really a chopper... sorta a bobber, but I even kept the front fender for now since this will see some puddles. I'm tired of eating my own rooster tail on my triumph. Let's not open the definition can of worms though...

Thanks for the comments

Wow! Genius design for the seat! Cool bike!

Thanks, I'm pretty stoked I pulled it off. Few other mounting options I played with, but that one was my favorite.


Yes, that's neoprene. Left over from my seat build on my triumph. 2 in thick and forced to conform as one piece. Gorilla glue is awesome for foam-to-pan bonding. Just got to use scrap pieces or other means to spread the load out from the clamps while you wait the 2 or so hours it needs. The savvy amongst us might recognize this tool from earlier.

Tapped thin piece of foam to the fender for the test ride as the fender is my 'bump stop.' Have since glued the bump stop foam on the underside of the seat and it will be under leather when all is said and done.

 

[verde]

Ah crap!

Ah crap!

Was cleaning up some stuff and found a copy of 'Zen and the Art of Motorcycle Maintenance.' Flipped to one of two bookmarks in the whole thing and this is what it said.

 

[Guest]

Im interested in the test ride?
How does the bike run?

 

[Tim Tom]

cool bike. It's very unique and well done. I love the seat and there is something really cool about your rear frame cross bracing. Can we get more pics of it? Particularly the front end? Are you running a headlight?? It almost looks like 2 turn signals where a light should be

 

[verde]

Im interested in the test ride?
How does the bike run?

It's running amazing. Absolute blast to ride. Initial test run was cold blooded - 15 pilots, 125 mains, too low a needle setting. At 130 mains right now, and after a needle adjustment I believe I overshot on the pilots and need to bump down from the 20's I put in to 17.5's. That whole saga is over in the carb forum. Odd note though: Due to the airflow around the engine, it looks like the outer cylinders(1 & 4) are getting less air at speed than the inside ones are.

cool bike. It's very unique and well done. I love the seat and there is something really cool about your rear frame cross bracing. Can we get more pics of it? Particularly the front end? Are you running a headlight?? It almost looks like 2 turn signals where a light should be

The ass-end got all the attention -- I just pulled stuff off the front end and left it all ugly I loved how much just FRAME there was as I stripped the bike down, so that influenced putting the tank on top. Had to match it in the back and have spent way to much time looking at tube buggy stuff in the past, so those factors influenced the back.

Lights are just a pair of fog lights and I reused the gauge cluster mounting holes in the top tree. Wanted to mount them from the underside but couldn't get them pointed down far enough. Also couldn't be bothered with making yet another bracket at that point. When I couldn't paint on that really foggy day I made them into angry eyes.

 

[Tim Tom]

Haha your right the ass end is way cooler :-&
Although I do like the angry eyes
What is the master cylinder from?

 

[verde]

What is the master cylinder from?

Not sure what the POs had swapped around, but a very safe guess in this case is a '78 GS750

 

[verde]

Carpet Matches the Drapes

Carpet Matches the Drapes

Sanded down the rusty chrome and painted the front fender to match. Added some more unsprung weight while I was at it:dancing:

 

[verde]

Update

Update

This bike has recently gone from random fun short blast ride on the weekend to my daily commuter thanks to some pipes from another member here(and my nice short commute since I moved). Wasn't a big fan of the headers only but couldn't find the time to build something and couldn't justify the cost or condition of what else I was seeing available. These old aftermarket silencers work with stock headers and just so happen to match the hard tail perfectly!

I also raised the seat a few inches for my knee's sake, moved the gas cap forward and bought about another 1/4 gallon of gas, and added one of "those" gauges.

For anyone considering that style of fuel gauge, I think the weld in bungs with threaded fittings are too clunky and over priced. I picked up two 90 degree brass fittings in the plumbing section and some clear fuel line in the lawn mower section of OSH for about $13 total. Now, the silver brazing is where it could get tricky/pricey when going this route. I happened to have some Safety-Silv 45 on hand and know enough to make it flow OK-ish. If you can't, find a cool jeweler/metal smith who can After the first day the tubing had swollen a bit from the fuel, and I found I had to trim about 1/8" off the length to get it to match the curve of the tank again. Not as on top of it with the in-progress pics these days, but here's a close up of the finished thing after I cleaned it up and masked off just the barb part for painting.

 

[Redneck]

Must say I really like your imagination with this bike. It really does look good if you would have described your intentions I would have thought you were building a rat bike. Looks awesome.

BUT... What is up with this seat lately.... it is everywhere now.... argghhhh are you guys sharing it around from member to member, you must really stop because that is truly one ugly seat.

Paul